LibreOffice BASIC Programming Guide

This guide provides an introduction to programming with LibreOffice Basic. To get the most out of this book, you should be familiar with other programming languages. Extensive examples are provided to help you quickly develop your own LibreOffice Basic programs.

Note: Throughout this document, the LibreOffice installation directory is represented in syntax as install-dir.

LibreOffice BASIC Programming Guide

This guide provides an introduction to programming with LibreOffice Basic. To get the most out of this book, you should be familiar with other programming languages. Extensive examples are provided to help you quickly develop your own LibreOffice Basic programs.

This guide divides information about LibreOffice administration into several chapters. The first three chapters introduce you to LibreOffice Basic:

• #The Language of LibreOffice BASIC
• #Runtime Library
• #Introduction to the API

These chapters provide an overview of LibreOffice Basic and should be read by anyone who intends to write LibreOffice Basic programs. The remaining chapters describe the individual components of the LibreOffice API in more detail and can be read selectively as required:

• #Working with Documents
• #Text Documents
• #Spreadsheet Documents
• #Drawings and Presentations
• #Charts (Diagrams)
• #Databases
• #Dialogs
• #Forms

About LibreOffice Basic

The LibreOffice Basic programming language has been developed especially for LibreOffice and is firmly integrated in the Office package.

As the name suggests, LibreOffice Basic is a programming language from the Basic family. Anyone who has previously worked with other Basic languages — in particular with Visual Basic or Visual Basic for Applications (VBA) from Microsoft — will quickly become accustomed to LibreOffice Basic. Large sections of the basic constructs of LibreOffice Basic are compatible with Visual Basic.

The LibreOffice Basic programming language can be divided into four components:

• The language of LibreOffice Basic: Defines the elementary linguistic constructs, for example, for variable declarations, loops, and functions.
• The runtime library: Provides standard functions which have no direct reference to LibreOffice, for example, functions for editing numbers, strings, date values, and files.
• The LibreOffice API (Application Programming Interface): Permits access to LibreOffice documents and allows these to be created, saved, modified, and printed.
• The Dialog Editor: Creates personal dialog windows and provides scope for the adding of control elements and event handlers.

Note: VBA : Compatibility between LibreOffice Basic and VBA relates to the LibreOffice Basic language as well as the runtime library. The LibreOffice API and the Dialog Editor are not compatible with VBA (standardizing these interfaces would have made many of the concepts provided in LibreOffice impossible).

Intended Users of LibreOffice Basic

The scope of application for LibreOffice Basic begins where the standard functions of LibreOffice end. Routine tasks can therefore be automated in LibreOffice Basic, links can be made to other programs — for example to a database server — and complex activities can be performed at the press of a button by using predefined scripts.

LibreOffice Basic offers complete access to all LibreOffice functions, supports all functions, modifies document types, and provides options for creating personal dialog windows.

Use of LibreOffice Basic

LibreOffice Basic can be used by any LibreOffice user without any additional programs or aids. Even in the standard installation, LibreOffice Basic has all the components needed to create its own Basic macros, including:

• The integrated development environment (IDE) which provides an editor for creating and testing macros.
• The interpreter, which is needed to run LibreOffice Basic macros.
• The interfaces to various LibreOffice applications, which allow for direct access to Office documents.

More Information

The components of the LibreOffice API that are discussed in this guide were selected based on their practical benefits for the LibreOffice Basic programmer. In general, only parts of the interfaces are discussed. For a more detailed picture, see the API reference.

The LibreOffice Developer's Guide describes the LibreOffice API in more detail than this guide, but is primarily intended for Java and C++ programmers. Anyone who is already familiar with LibreOffice Basic programming can find additional information in the Developer's Guide on LibreOffice Basic and LibreOffice programming.

Programmers who want to work directly with Java or C++ rather than LibreOffice Basic should consult the LibreOffice Developer's Guide instead of this guide. LibreOffice programming with Java or C++ is a considerably more complex process than programming with LibreOffice Basic.

The Language of LibreOffice BASIC

LibreOffice Basic belongs to the family of Basic languages. Many parts of LibreOffice Basic are identical to Microsoft Visual Basic for Applications and Microsoft Visual Basic. Anyone who has already worked with these languages can quickly become accustomed to LibreOffice Basic.

Programmers of other languages – such as Java, C++, or Delphi – should also find it easy to familiarize themselves with LibreOffice Basic. LibreOffice Basic is a fully-developed procedural programming language and no longer requires rudimentary control structures, such as GoTo and GoSub.

You can also benefit from the advantages of object-oriented programming since an interface in LibreOffice Basic enables you to use external object libraries. The entire LibreOffice API is based on these interfaces, which are described in more detail in the following chapters of this document.

This chapter provides an overview of the key elements and constructs of the LibreOffice Basic language, as well as the framework in which applications and libraries are oriented to LibreOffice Basic.

Overview of a Basic Program

LibreOffice Basic is an interpreter language. Unlike C++ or Delphi, the LibreOffice Basic compiler does not create executable or self-extracting files that are capable of running automatically. Instead, you execute an LibreOffice Basic program inside LibreOffice. The code is first checked for obvious errors and then executed line by line.

Program Lines

The Basic interpreter's line-oriented execution produces one of the key differences between Basic and other programming languages. Whereas the position of hard line breaks in the source code of Java, C++, or Delphi programs is irrelevant, each line in a Basic program forms a self-contained unit. Function calls, mathematical expressions, and other linguistic elements, such as function and loop headers, must be completed on the same line that they begin on.

If there is not enough space, or if this results in long lines, then several lines can be linked together by adding underscores _. The following example shows how four lines of a mathematical expression can be linked:

LongExpression = (Expression1 * Expression2) + _
(Expression3 * Expression4) + _ 
(Expression5 * Expression6) + _
(Expression7 * Expression8)

Note: The underscore must always be the last character in a linked line and cannot be followed by a space or a tab or a comment, otherwise the code generates an error.

In addition to linking individual lines, in LibreOffice Basic you can use colons to divide one line into several sections, so that there is enough space for several expressions. The assignments

a = 1 
a = a + 1 
a = a + 1

can be written as follows:

a = 1 : a = a + 1 : a = a + 1

Comments

In addition to the program code to be executed, an LibreOffice Basic program can also contain comments that explain the individual parts of the program and provide important information that can be helpful at a later point.

LibreOffice Basic provides two methods for inserting comments in the program code:

• All characters that follow an apostrophe are treated as comments:

  Dim A    ' This is a comment for variable A

• The keyword Rem, followed by the comment:

  Rem This comment is introduced by the keyword Rem.

A comment usually includes all characters up to the end of the line. LibreOffice Basic then interprets the following line as a regular instruction again. If comments cover several lines, each line must be identified as a comment:

Dim B   ' This comment for variable B is relatively long
        ' and stretches over several lines. The
        ' comment character must therefore be repeated
        ' in each line.

Markers

A LibreOffice Basic program can contain dozens, hundreds, or even thousands of markers, which are names for variables, constants, functions, and so on. When you select a name for a marker, the following rules apply:

• Markers can only contain Latin letters, numbers, and underscores (_).
• The first character of a marker must be a letter or an underscore.
• Markers cannot contain special characters, such as ä â î ß.
• The maximum length of a marker is 255 characters.
• No distinction is made between uppercase and lowercase characters. The OneTestVariable marker, for example, defines the same variable as onetestVariable and ONETESTVARIABLE.

There is, however, one exception to this rule: a distinction is made between uppercase and lowercase characters for UNO-API constants. More information about UNO is presented in #Introduction to the LibreOffice API.

Warning: The names of the Basic modules (by default Module1, Module2, etc) are known by Basic on a public scope. You must avoid having a marker of public scope with the same name as one of the modules of the library. Example : Suppose that in your Basic library you have a module named PrintDoc. You must not declare, in any module of your library, a Public variable or a Public constant, or a Sub, or a Function, named PrintDoc. If you do have such collision, Basic may produce strange runtime error messages, or your Sub may not work.

Note: VBA : The rules for constructing markers are different in LibreOffice Basic than in VBA. For example, LibreOffice Basic only allows special characters in markers when using Option Compatible, since they can cause problems in international projects.

Here are a few examples of correct and incorrect markers:

Surname     ' Correct
Surname5    ' Correct (number 5 is not the first digit)
First Name  ' Incorrect (spaces are not permitted)
DéjàVu      ' Incorrect (letters such as é, à are not permitted)
5Surnames   ' Incorrect (the first character must not be a number)
First,Name  ' Incorrect (commas and full stops are not permitted)

Enclosing a variable name in square brackets allows names that might otherwise be disallowed; for example, spaces.

Dim [First Name] As String 'Space accepted in square brackets
Dim [DéjàVu] As Integer    'Special characters in square brackets
[First Name] = "Andrew"
[DéjàVu] = 2

Working With Variables

Implicit Variable Declaration

Basic languages are designed to be easy to use. As a result, LibreOffice Basic enables the creation of a variable through simple usage and without an explicit declaration. In other words, a variable exists from the moment that you include it in your code. Depending on the variables that are already present, the following example declares up to three new variables:

a = b + c

Declaring variables implicitly is not good programming practice because it can result in the inadvertent introduction of a new variable through, for example, a typing error. Instead of producing an error message, the interpreter initializes the typing error as a new variable with a value of 0. It can be very difficult to locate errors of this kind in your code.

Explicit Variable Declaration

To prevent errors caused by an implicit declaration of variables, LibreOffice Basic provides a switch called:

Option Explicit

This must be listed in the first program line of each module and ensures that an error message is issued at run-time if one of the variables used is not declared. The Option Explicit switch should be included in all Basic modules.

In its simplest form, the command for an explicit declaration of a variable is as follows:

Dim MyVar

This example declares a variable with the name MyVar and the type variant. A variant is a universal variable that can record all conceivable values, including strings, whole numbers, floating point figures, and Boolean values. Here are a few examples of Variant variables:

MyVar = "Hello World"     ' Assignment of a string
MyVar = 1                 ' Assignment of a whole number
MyVar = 1.0               ' Assignment of a floating point number
MyVar = True              ' Assignment of a Boolean value

The variables declared in the previous example can even be used for different variable types in the same program. Although this provides considerable flexibility, it is best to restrict a variable to one variable type. When LibreOffice Basic encounters an incorrectly defined variable type in a particular context, an error message is generated.

Use the following style when you make a type-bound variable declaration:

Dim MyVar As Integer  ' Declaration of a variable of the integer type

The variable is declared as an integer type and can record whole number values. You can also use the following style to declare an integer type variable:

Dim MyVar%         ' Declaration of a variable of the integer type

The Dim instruction can record several variable declarations:

Dim MyVar1, MyVar2

If you want to assign the variables to a permanent type, you must make separate assignments for each variable:

Dim MyVar1 As Integer, MyVar2 As Integer

If you do not declare the type for a variable, LibreOffice Basic assigns the variable a variant type. For example, in the following variable declaration, MyVar1 becomes a variant and MyVar2 becomes an integer:

Dim MyVar1, MyVar2 As Integer

The following sections list the variable types that are available in LibreOffice Basic and describe how they can be used and declared.

Strings

Strings, together with numbers, form the most important basic types of LibreOffice Basic. A string consists of a sequence of consecutive individual characters. The computer saves the strings internally as a sequence of numbers where each number represents one specific character.

From a Set of ASCII Characters to Unicode

Character sets match characters in a string with a corresponding code (numbers and characters) in a table that describes how the computer is to display the string.

The ASCII Character Set

The ASCII character set is a set of codes that represent numbers, characters, and special symbols by one byte. The 0 to 127 ASCII codes correspond to the alphabet and to common symbols (such as periods, parentheses, and commas), as well as some special screen and printer control codes. The ASCII character set is commonly used as a standard format for transferring text data between computers.

However, this character set does not include a range of special characters used in Europe, such as â, ä, and î, as well as other character formats, such as the Cyrillic alphabet.

The ANSI Character Set

Microsoft based its Windows product on the American National Standards Institute (ANSI) character set, which was gradually extended to include characters that are missing from the ASCII character set.

Code Pages

The ISO 8859 character sets provide an international standard. The first 128 characters of the ISO character set correspond to the ASCII character set. The ISO standard introduces new character sets (code pages) so that more languages can be correctly displayed. However, as a result, the same character value can represent different characters in different languages.

Unicode

Unicode increases the length of a character to four bytes and combines different character sets to create a standard to depict as many of the world's languages as possible. Version 2.0 of Unicode is now supported by many programs — including LibreOffice and LibreOffice Basic.

String Variables

LibreOffice Basic saves strings as string variables in Unicode. A string variable can store up to 65535 characters. Internally, LibreOffice Basic saves the associated Unicode value for every character. The working memory needed for a string variable depends on the length of the string.

Example declaration of a string variable:

Dim Variable As String

You can also write this declaration as:

Dim Variable$

Note: VBA : When porting VBA applications, ensure that the maximum allowed string length in LibreOffice Basic is observed (65535 characters).

Specification of Explicit Strings

To assign an explicit string to a string variable, enclose the string in quotation marks (").

Dim MyString As String
MyString = " This is a test"

To split a string across two lines of code, add an ampersand sign (the concatenation operator) and the underscore continuation character at the end of the first line:

Dim MyString As String
MyString =  "This string is so long that it " & _
            "has been split over two lines."

To include a quotation mark (") in a string, enter it twice at the relevant point:

Dim MyString As String
MyString = "a ""-quotation mark."   ' produces a "-quotation mark

Numbers

LibreOffice Basic supports five basic types for processing numbers:

• Integer
• Long Integer
• Single
• Double
• Currency

Integer Variables

Integer variables can store any whole number between -32768 and 32767. An integer variable can take up to two bytes of memory. The type declaration symbol for an integer variable is %. Calculations that use integer variables are very fast and are particularly useful for loop counters. If you assign a floating point number to an integer variable, the number is rounded up or down to the next whole number.

Example declarations for integer variables:

Dim Variable As Integer
Dim Variable%

Long Integer Variables

Long integer variables can store any whole number between –2147483648 and 2147483647. A long integer variable can take up to four bytes of memory. The type declaration symbol for a long integer is &. Calculations with long integer variables are very fast and are particularly useful for loop counters. If you assign a floating point number to a long integer variable, the number is rounded up or down to the next whole number.

Example declarations for long integer variables:

Dim Variable as Long
Dim Variable&

Single Variables

Single variables can store any positive or negative floating point number between 3.402823 x 10³⁸ and 1.401298 x 10^-45. A single variable can take up to four bytes of memory. The type declaration symbol for a single variable is !.

Originally, single variables were used to reduce the computing time required for the more precise double variables. However, these speed considerations no longer apply, reducing the need for single variables.

Example declarations for single variables:

Dim Variable as Single
Dim Variable!

Double Variables

Double variables can store any positive or negative floating point numbers between 1.79769313486232 x 10³⁰⁸ and 4.94065645841247 x 10^-324. A double variable can take up to eight bytes of memory. Double variables are suitable for precise calculations. The type declaration symbol is #.

Example declarations of double variables:

Dim Variable As Double
Dim Variable#

Currency Variables

Currency variables differ from the other variable types by the way they handle values. The decimal point is fixed and is followed by four decimal places. The variable can contain up to 15 numbers before the decimal point. A currency variable can store any value between -922337203685477.5808 and +922337203685477.5807 and takes up to eight bytes of memory. The type declaration symbol for a currency variable is @.

Currency variables are mostly intended for business calculations that yield unforeseeable rounding errors due to the use of floating point numbers.

Example declarations of currency variables:

Dim Variable As Currency
Dim Variable@

The handling of Basic Currency type is not reliable. Issue 31001 Issue 54049 Issue 91121 Issue 107277 are still not corrected.

Specification of Explicit Numbers

Numbers can be presented in several ways, for example, in decimal format or in scientific notation, or even with a different base than the decimal system. The following rules apply to numerical characters in LibreOffice Basic:

Whole Numbers

The simplest method is to work with whole numbers. They are listed in the source text without a comma separating the thousand figure:

Dim A As Integer
Dim B As Single
A = 1210
B = 2438

The numbers can be preceded by both a plus (+) or minus (-) sign (with or without a space in between):

Dim A As Integer
Dim B As Double

A = + 121
B = - 243

Decimal Numbers

When you type a decimal number, use a period (.) as the decimal point. This rule ensures that source texts can be transferred from one country to another without conversion.

Dim A As Integer
Dim B As Integer
Dim C As Single ' floating number

A = 1223.53     ' is rounded
B = - 23446.46  ' is rounded
C = + 3532.76323

You can also use plus (+) or minus (-) signs as prefixes for decimal numbers (again with or without spaces).

If a decimal number is assigned to an integer variable, LibreOffice Basic rounds the figure up or down.

Exponential Writing Style

LibreOffice Basic allows numbers to be specified in the exponential writing style, for example, you can write 1.5e-10 for the number 1.5 x 10^-10 (0.00000000015). The letter "e" can be lowercase or uppercase with or without a plus sign (+) as a prefix.

Here are a few correct and incorrect examples of numbers in exponential format:

Dim A As Double

A = 1.43E2   ' Correct
A = + 1.43E2 ' Correct (space between plus and basic number)
A = - 1.43E2 ' Correct (space between minus and basic number)
A = 1.43E-2  ' Correct (negative exponent)
A = 1.43E -2 ' Incorrect (spaces not permitted within the number)
A = 1,43E-2  ' Incorrect (commas not permitted as decimal points)
A = 1.43E2.2 ' Incorrect (exponent must be a whole number)

Note, that in the first and third incorrect examples that no error message is generated even though the variables return incorrect values. The expression

A = 1.43E -2

is interpreted as 1.43 minus 2, which corresponds to the value -0.57. However, the value 1.43 x 10^-2 (corresponding to 0.0143) was the intended value. With the value

A = 1.43E2.2

LibreOffice Basic ignores the part of the exponent after the decimal point and interprets the expression as

A = 1.43E2

Hexadecimal Values

In the hexadecimal system (base 16 system), a 2-digit number corresponds to precisely one byte. This allows numbers to be handled in a manner which more closely reflects machine architecture. In the hexadecimal system, the numbers 0 to 9 and the letters A to F are used as numbers. An A stands for the decimal number 10, while the letter F represents the decimal number 15. LibreOffice Basic lets you use whole numbered hexadecimal values, so long as they are preceded by &H.

Dim A As Long
A = &HFF ' Hexadecimal value FF, corresponds to the decimal value 255
A = &H10 ' Hexadecimal value 10, corresponds to the decimal value 16

Octal Values

LibreOffice Basic also understands the octal system (base 8 system), which uses the numbers 0 to 7. You must use whole numbers that are preceded by &O.

Dim A As Long
A = &O77 ' Octal value 77, corresponds to the decimal value 63
A = &O10 ' Octal value 10, corresponds to the decimal value 8

Boolean Values

Boolean variables can only contain one of two values: True or False. They are suitable for binary specifications that can only adopt one of two statuses. A Boolean value is saved internally as a two-byte integer value, where 0 corresponds to the False and any other value to True. There is no type declaration symbol for Boolean variables. The declaration can only be made using the supplement As Boolean.

Example declaration of a Boolean variable:

Dim Variable As Boolean

Date and Time

Date variables can contain date and time values. When saving date values, LibreOffice Basic uses an internal format that permits comparisons and mathematical operations on date and time values. There is no type declaration symbol for date variables. The declaration can only be made using the supplement As Date.

Example declaration of a date variable:

Dim Variable As Date

Arrays

In addition to simple variables (scalars), LibreOffice Basic also supports arrays (data fields). A data field contains several variables, which are addressed through an index.

Defining Arrays

Arrays can be defined as follows:

Simple Arrays

An array declaration is similar to that of a simple variable declaration. However, unlike the variable declaration, the array name is followed by parentheses which contain the specifications for the number of elements. The expression Dim MyArray(3) declares an array that has four variables of the variant data type, namely MyArray(0), MyArray(1), MyArray(2), and MyArray(3).

You can also declare type-specific variables in an array. For example, the following line declares an array with four integer variables:

Dim MyInteger(3) As Integer

In the previous examples, the index for the array always begins with the standard start value of zero. As an alternative, a validity range with start and end values can be specified for the data field declaration. The following example declares a data field that has six integer values and which can be addressed using the indexes 5 to 10:

Dim MyInteger(5 To 10) As Integer

The indexes do not need to be positive values. The following example also shows a correct declaration, but with negative data field limits:

Dim MyInteger(-10 To -5) As Integer

It declares an integer data field with 6 values that can be addressed using the indexes -10 to -5.

There are no practical limits on the indexes or on the number of elements in an array, so long as there is enough memory:

Dim s(-53000 to 89000) As String
s(-52000) = &aa&
s(79999) = &bb&
print s(-52000), s(79999)

Note: VBA : Other limit values sometimes apply for data field indexes in VBA. The same also applies to the maximum number of elements possible per dimension. The values valid there can be found in the relevant VBA documentation.

Specified Value for Start Index

The start index of a data field usually begins with the value 0. Alternatively, you can change the start index for all data field declarations to the value 1 by using the call:

Option Base 1

The call must be included in the header of a module if you want it to apply to all array declarations in the module. However, this call does not affect the UNO sequences that are defined through the LibreOffice API whose index always begins with 0. To improve clarity, you should avoid using Option Base 1.

The number of elements in an array is not affected if you use Option Base 1, only the start index changes. The declaration

Option Base 1
' ...
Dim MyInteger(3)

creates 4 integer variables which can be described with the expressions MyInteger(1), MyInteger(2), MyInteger(3), and MyInteger(4).

Note: VBA : In LibreOffice Basic, the expression Option Base 1 does not affect the number of elements in an array as it does in VBA. It is, rather, the start index which moves in LibreOffice Basic. While the declaration MyInteger(3) creates three integer values in VBA with the indexes 1 to 3, the same declaration in LibreOffice Basic creates four integer values with the indexes 1 to 4. By using Option Compatible, LibreOffice Basic behaves like VBA.

Multi-Dimensional Data Fields

In addition to single dimensional data fields, LibreOffice Basic also supports work with multi-dimensional data fields. The corresponding dimensions are separated from one another by commas. The example Dim MyIntArray(5, 5) As Integer defines an integer array with two dimensions, each with 6 indexes (can be addressed through the indexes 0 to 5). The entire array can record a total of 6 x 6 = 36 integer values.

You can define hundreds of dimensions in LibreOffice Basic Arrays; however, the amount of available memory limits the number of dimensions you can have.

Dynamic Changes in the Dimensions of Data Fields

The previous examples are based on data fields of a specified dimension. You can also define arrays in which the dimension of the data fields dynamically changes. For example, you can define an array to contain all the words in a text that begin with the letter A. As the number of these words is initially unknown, you need to be able to subsequently change the field limits. To do this in LibreOffice Basic, use the following call:

ReDim MyArray(10)

Note: VBA : Unlike VBA, where you can only dimension dynamic arrays by using Dim MyArray(), LibreOffice Basic lets you change both static and dynamic arrays using ReDim.

The following example changes the dimension of the initial array so that it can record 11 or 21 values:

Dim MyArray(4) As Integer ' Declaration with five elements
' ...
ReDim MyArray(10) As Integer ' Increase to 11 elements
' ...
ReDim MyArray(20) As Integer ' Increase to 21 elements

When you reset the dimensions of an array, you can use any of the options outlined in the previous sections. This includes declaring multi-dimensional data fields and specifying explicit start and end values. When the dimensions of the data field are changed, all contents are lost. If you want to keep the original values, use the Preserve command:

Dim MyArray(10) As Integer ' Defining the initial
' dimensions
' ...
ReDim Preserve MyArray(20) As Integer ' Increase in
' data field, while
' retaining content

When you use Preserve, ensure that the number of dimensions and the type of variables remain the same.

Note: VBA : Unlike VBA, where only the upper limit of the last dimension of a data field can be changed through Preserve, LibreOffice Basic lets you change other dimensions as well.

If you use ReDim with Preserve, you must use the same data type as specified in the original data field declaration.

Determining the Dimensions of Data Fields

Functions LBound() and UBound() return respectively the lowest permitted index value and the highest permitted index value of an array. This is useful when an array has changed its dimensions.

Dim MyArray(10) As Integer
' ... some instructions
Dim n As Integer
n = 47 ' could be the result of a computation
Redim MyArray(n) As Integer
MsgBox(LBound(MyArray)) ' displays : 0
MsgBox(UBound(MyArray)) ' displays : 47

For a multi-dimensional array you need to specify the position (1 to n) of the index you want to know the permitted lower and upper values:

Dim MyArray(10, 13 to 28) As Integer
MsgBox(LBound(MyArray, 2)) ' displays : 13
MsgBox(UBound(MyArray, 2)) ' displays : 28

Empty arrays

In some cases, especially when dealing with the API, you need to declare an empty array. Such array is declared without dimension, but may later be filled by an API function or with a Redim statement:

Dim s() As String ' declare an empty array
' --- later in the program ...
Redim s(13) As String

You cannot assign a value to an empty array, since it does not contain any elements.

The "signature" of an empty array is that UBound() returns -1 and LBound() returns 0:

Dim MyArray() As Integer
MsgBox(LBound(MyArray)) ' displays : 0
MsgBox(UBound(MyArray)) ' displays : -1

Some API functions return an array containing elements (indexed from zero) or return an empty array. Use UBound() to check if the returned array is empty.

Defining values for arrays

Values for the Array fields can be stored like this:

MyArray(0) = "somevalue"

Accessing Arrays

Accessing values in an array works like this:

MsgBox("Value:" & MyArray(0))

Array Creation, value assignment and access example

And example containing all steps that show real array usage:

Sub TestArrayAxess
    Dim MyArray(3)
    MyArray(0) = "lala"
    MsgBox("Value:" & MyArray(0))
End Sub

Scope and Life Span of Variables

A variable in LibreOffice Basic has a limited life span and a limited scope from which it can be read and used in other program fragments. The amount of time that a variable is retained, as well as where it can be accessed from, depends on its specified location and type.

Local Variables

Variables that are declared in a function or a procedure are called local variables:

Sub Test
  Dim MyInteger As Integer
  ' ...
End Sub

Local variables only remain valid as long as the function or the procedure is executing, and then are reset to zero. Each time the function is called, the values generated previously are not available.

To keep the previous values, you must define the variable as Static:

Sub Test
  Static MyInteger As Integer
  ' ...
End Sub

Note: VBA : Unlike VBA, LibreOffice Basic ensures that the name of a local variable is not used simultaneously as a global and a private variable in the module header. When you port a VBA application to LibreOffice Basic, you must change any duplicate variable names.

Public Domain Variables

Public domain variables are defined in the header section of a module by the keyword Dim. These variables are available to all the modules in their library:

Module A:

Dim A As Integer
Sub Test
  Flip
  Flop
End Sub

Sub Flip
  A = A + 1
End Sub

Module B:

Sub Flop
  A = A - 1
End Sub

The value of variable A is not changed by the Test function, but is increased by one in the Flip function and decreased by one in the Flop function. Both of these changes to the variable are global.

You can also use the keyword Public instead of Dim to declare a public domain variable:

Public A As Integer

A public domain variable is only available so long as the associated macro is executing and then the variable is reset.

Global Variables

In terms of their function, global variables are similar to public domain variables, except that their values are retained even after the associated macro has executed. Global variables are declared in the header section of a module using the keyword Global:

Global A As Integer

Private Variables

Private variables are only available in the module in which they are defined. Use the keyword Private to define the variable:

Private MyInteger As Integer

If several modules contain a Private variable with the same name, LibreOffice Basic creates a different variable for each occurrence of the name. In the following example, both module A and B have a Private variable called C. The Test function first sets the Private variable in module A and then the Private variable in module B.

Module A:

Private C As Integer

Sub Test
  SetModuleA     ' Sets the variable C from module A
  SetModuleB     ' Sets the variable C from module B
  ShowVarA       ' Shows the variable C from module A (= 10)
  ShowVarB       ' Shows the variable C from module B (= 20)
End Sub

Sub SetModuleA
  C = 10
End Sub

Sub ShowVarA
  MsgBox C       ' Shows the variable C from module A.
End Sub

Module B:

Private C As Integer

Sub SetModuleB
  C = 20
End Sub

Sub ShowVarB
  MsgBox C       ' Shows the variable C from module B.
End Sub

Keep in mind that ShowVarB only shows the expected value of C (20) because Sub Test is keeping it in scope. If the calls to SetModuleB and ShowVarB are independent, e.g. SetModuleB is triggered from one toolbar button and ShowVarB is triggered from another toolbar button, then ShowVarB will display a C value of 0 since module variables are reset after each macro completion.

Note: Using Library.Module variable qualification grants explicit access to module-scoped variables: Module Z: Sub Test ModuleA.C = 44 ' Sets the variable C from module A ModuleB.C = 55 ' Sets the variable C from module B ShowVarA ' Shows the variable C from module A (= 44) ShowVarB ' Shows the variable C from module B (= 55) End Sub

Constants

Constants are values which may be used but not changed by the program.

Defining Constants

In LibreOffice Basic, use the keyword Const to declare a constant.

Const A = 10
Const B = A+5
Const Hi = "Hello World"

Warning: Do not specify the constant type in the declaration : it will be silently ignored. This code shows that you do not get the type that you specify. Const alpha As Long = 1 Const beta As Single = 3.1 Const gamma As Boolean = True Const delta As Currency = 123456.05 Const phi As Long = 32768 MsgBox(TypeName(alpha)) ' displays : Integer MsgBox(TypeName(beta)) ' displays : Double MsgBox(TypeName(gamma)) ' displays : Integer MsgBox(TypeName(delta)) ' displays : Double MsgBox(TypeName(phi)) ' displays : Double As Basic makes automatic type conversions, there is usually no problems using a constant in an expression. If you want to specify the type of a data, use a typed variable, not a constant.

Scope of Constants

Constants have the same scope as variables (see #Scope_of_Variables Scope and Life Span of Variables), but the syntax is slightly different. A Const definition in the module header is available to the code in that module. To make the definition available to other modules, add the Public keyword.

Public Const one = 1

Predefined Constants

LibreOffice Basic predefines several constants. Among the most useful are:

• True and False, for Boolean assignment statements
• PI as a type Double numeric value

Dim bHit as Boolean
bHit = True

Dim dArea as Double, dRadius as Double
' ... (assign a value to dRadius)
dArea = PI * dRadius * dRadius

Operators

LibreOffice Basic understands common mathematical, logical, and comparison operators.

Mathematical Operators

Mathematical operators can be applied to all numbers types, whereas the + operator can also be used to concatenate strings.

+	Addition of numbers and date values, concatenation of strings
&	Concatenation of strings
-	Subtraction of numbers and date values
*	Multiplication of numbers
/	Division of numbers
\	Division of numbers with a whole number result (rounded)
^	Raising the power of numbers
MOD	modulo operation (calculation of the remainder of a division)

Note: Although you can use the + operator to concatenate strings, the Basic interpreter can become confused when concatenating a number to a string. The & operator is safer when dealing with strings because it assumes that all arguments should be strings, and converts the arguments to strings if they are not strings.

Logical Operators

Logical operators allow you to do operations on elements according to the rules of Boolean algebra. If the operators are applied to Boolean values, the operation provides the result required directly. If used in conjunction with integer and long integer values, the operation is done at the bit level.

AND	And operator
OR	Or operator
XOR	Exclusive Or operator
NOT	Negation
EQV	Equivalent test (both parts True or False)
IMP	Implication (if the first expression is true, then the second must also be true)

Comparison Operators

Comparison operators can be applied to all elementary variable types (numbers, date details, strings, and Boolean values).

=	Equality of numbers, date values and strings
<>	Inequality of numbers, date values and strings
>	Greater than check for numbers, date values and strings
>=	Greater than or equal to check for numbers, date values and strings
<	Less than check for numbers, date values and strings
<=	Less than or equal to check for numbers, date values and strings

Note: VBA : LibreOffice Basic does not support the VBA Like comparison operator.

Branching

Use branching statements to restrict the execution of a code block until a particular condition is satisfied.

If...Then...Else

The most common branching statement is the If statement as shown in the following example:

If A > 3 Then
  B = 2
End If

The B = 2 assignment only occurs when value of variable A is greater than three. A variation of the If statement is the If/Else clause:

If A > 3 Then
  B = 2
Else
  B = 0
End If

In this example, the variable B is assigned the value of 2 when A is greater than 3, otherwise B is assigned the value of 0.

For more complex statements, you can cascade the If statement, for example:

If A = 0 Then
  B = 0
ElseIf A < 3 Then
  B = 1
Else
  B = 2
End If

If the value of variable A equals zero, B is assigned the value 0. If A is less than 3 (but not equal to zero), then B is assigned the value 1. In all other instances (that is, if A is greater than or equal to 3), B is assigned the value 2.

A complete If statement may be written on a single line, with a simpler syntax. The first example of this page may be written as:

If A > 3 Then B = 2

The second example of this page may be written as:

If A > 3 Then B = 2 Else B = 0

Select...Case

The Select...Case instruction is an alternative to the cascaded If statement and is used when you need to check a value against various conditions:

Select Case DayOfWeek
  Case 1:
    NameOfWeekday = "Sunday"
  Case 2:
    NameOfWeekday = "Monday"
  Case 3:
    NameOfWeekday = "Tuesday"
  Case 4:
    NameOfWeekday = "Wednesday"
  Case 5:
    NameOfWeekday = "Thursday"
  Case 6:
    NameOfWeekday = "Friday"
  Case 7:
    NameOfWeekday = "Saturday"
End Select

In this example, the name of a weekday corresponds to a number, so that the DayOfWeek variable is assigned the value of 1 for Sunday, 2 for Monday value, and so on.

The Select command is not restricted to simple 1:1 assignments — you can also specify comparison operators or lists of expressions in a Case branch. The following example lists the most important syntax variants:

Select Case Var
  Case 1 To 5
    ' ... Var is between the numbers 1 and 5 (including the values 1 and 5).
  Case > 100
    ' ... Var is greater than 100
  Case 6, 7, 8
    ' ... Var is 6, 7 or 8
  Case 6, 7, 8, > 15, < 0
    ' ... Var is 6, 7, 8, greater than 15, or less than 0
  Case Else
    ' ... all other instances
End Select

Now consider a misleading (advanced) example, and a common error:

Select Case Var
  Case Var = 8
    ' ... Var is 0
  Case Else
    ' ... all other instances
End Select

The statement (Var = 8) evaluates to TRUE if Var is 8, and FALSE otherwise. TRUE is -1 and FALSE is 0. The Select Case statement evaluates the expression, which is TRUE or FALSE, and then compares that value to Var. When Var is 0, there is a match. If you understand the last example, then you also know why this example does not do what it appears

Select Case Var
  Case Var > 8 And Var < 11
    ' ... Var is 0
  Case Else
    ' ... all other instances
End Select

Loops

A loop executes a code block for the number of passes that are specified. You can also have loops with an undefined number of passes.

For...Next

The For...Next loop has a fixed number of passes. The loop counter defines the number of times that the loop is to be executed. In the following example, variable I is the loop counter, with an initial value of 1. The counter is incremented by 1 at the end of each pass. When variable I equals 10, the loop stops.

Dim I
For I = 1 To 10
  ' ... Inner part of loop
Next I

If you want to increment the loop counter by a value other than 1 at the end of each pass, use the Step function:

Dim I
For I = 1 To 10 Step 0.5
  ' ... Inner part of loop
Next I

In the preceding example, the counter is increased by 0.5 at the end of each pass and the loop is executed 19 times.

You can also use negative step values:

Dim I
For I = 10 To 1 Step -1
  ' ... Inner part of loop
Next I

In this example, the counter begins at 10 and is reduced by 1 at the end of each pass until the counter is 1.

The Exit For instruction allows you to exit a For loop prematurely. In the following example, the loop is terminated during the fifth pass:

Dim I
For I = 1 To 10
  If I = 5 Then
    Exit For
  End If
  ' ... Inner part of loop
Next I

For Each

The For Each...Next loop variation in VBA is supported in LibreOffice Basic. For Each loops do not use an explicit counter like a For...Next loop does. A For Each loop says "do this to everything in this set", rather than "do this n times". For example:

Const d1 = 2
Const d2 = 3
Const d3 = 2
Dim i
Dim a(d1, d2, d3)
For Each i In a()
  ' ... Inner part of loop
Next i

The loop will execute 36 times.

Do...Loop

The Do...Loop is not linked to a fixed number of passes. Instead, the Do...Loop is executed until a certain condition is met. There are four versions of the Do...Loop. In the first two examples, the code within the loop may not be executed at all ("do 0 times" logic). In the latter examples, the code will be executed at least once. (In the following examples, A > 10 represents any condition):

1. The Do While...Loop version

   Do While A > 10
      ' ... loop body
   Loop

2. The Do Until...Loop version

   Do Until A > 10
     ' ... loop body
   Loop

3. The Do...Loop While version

   Do
     ' ... loop body
   Loop While A > 10

4. The Do...Loop Until version

   Do
     ' ... loop body
   Loop Until A > 10

As in the For...Next loop, the Do...Loop also provides a terminate command. The Exit Do command can exit at loop at any point within the loop.

Do
  If A = 4 Then
    Exit Do
  End If
  ' ... loop body
Loop While A > 10

In some cases the loop may only terminate when a condition is met within the loop. Then you can use the "perpetual" Do Loop:

Do
  ' ... some internal calculations
  If A = 4 Then   Exit Do
  ' ... other instructions
Loop

While...Wend

The While...Wend loop construct works exactly the same as the Do While...Loop, but with the disadvantage that there is no Exit command available. The following two loops produce identical results:

Do While A > 10
  ' ... loop body
Loop

While A > 10
  ' ... loop body
Wend

Programming Example: Sorting With Embedded Loops

There are many ways to use loops, for example, to search lists, return values, or execute complex mathematical tasks. The following example is an algorithm that uses two loops to sort a list by names.

Sub Sort
  Dim Entry(1 To 10) As String
  Dim Count As Integer
  Dim Count2 As Integer
  Dim Temp As String

  Entry(1) = "Patty"
  Entry(2) = "Kurt"
  Entry(3) = "Thomas"
  Entry(4) = "Michael"
  Entry(5) = "David"
  Entry(6) = "Cathy"
  Entry(7) = "Susie"
  Entry(8) = "Edward"
  Entry(9) = "Christine"
  Entry(10) = "Jerry"

  For Count = 1 To 9
    For Count2 = Count + 1 To 10
      If Entry(Count) > Entry(Count2) Then
        Temp = Entry(Count)
        Entry(Count) = Entry(Count2)
        Entry(Count2) = Temp
      End If
    Next Count2
  Next Count

  For Count = 1 To 10
    Print Entry(Count)
  Next Count

End Sub

The values are interchanged as pairs several times until they are finally sorted in ascending order. Like bubbles, the variables gradually migrate to the right position. For this reason, this algorithm is also known as a Bubble sort⁠.

Procedures and Functions

Procedures and functions form pivotal points in the structure of a program. They provide the framework for dividing a complex problem into various sub-tasks.

Procedures

A procedure executes an action without providing an explicit value. Its syntax is

Sub Test
  ' ... here is the actual code of the procedure
End Sub

The example defines a procedure called Test that contains code that can be accessed from any point in the program. The call is made by entering the procedure name at the relevant point of the program.

Functions

A function, just like a procedure, combines a block of programs to be executed into one logical unit. However, unlike a procedure, a function provides a return value.

Function Test
  ' ... here is the actual code of the function
  Test = 123
End Function

The return value is assigned using simple assignment. The assignment does not need to be placed at the end of the function, but can be made anywhere in the function.

The preceding function can be called within a program as follows:

Dim A
A = Test

The code defines a variable A and assigns the result of the Test function to it.

The return value can be overwritten several times within the function. As with classic variable assignment, the function in this example returns the value that was last assigned to it.

Function Test
  Test = 12
  ' ...
  Test = 123
End Function

In this example, the return value of the function is 123.

If nothing is assigned, the function returns a zero value (number 0 for numerical values and a blank for strings).

The return value of a function can be any type. The type is declared in the same way as a variable declaration:

Function Test As Integer
  ' ... here is the actual code of the function
End Function

If the return type is not specified (see first example of this page), the function returns a variant.

Terminating Procedures and Functions Prematurely

In LibreOffice Basic, you can use the Exit Sub and Exit Function commands to terminate a procedure or function prematurely, for example, for error handling. These commands stop the procedure or function and return the program to the point at which the procedure or function was called up.

The following example shows a procedure which terminates implementation when the ErrorOccured variable has the value True.

Sub Test
  Dim ErrorOccured As Boolean
  ' ...
  If ErrorOccured Then
    Exit Sub
  End If
  ' ...
End Sub

Passing Parameters

Functions and procedures can receive one or more parameters. Essential parameters must be enclosed in parentheses after the function or procedure names. The following example defines a procedure that expects an integer value A and a string B as parameters.

Sub Test (A As Integer, B As String)
  ' ...
End Sub

Parameters are normally passed by Reference⁠ in LibreOffice Basic. Changes made to the variables are retained when the procedure or function is exited:

Sub Test
  Dim A As Integer
  A = 10
  ChangeValue(A)
  ' The parameter A now has the value 20
End Sub

Sub ChangeValue(TheValue As Integer)
  TheValue = 20
End Sub

In this example, the value A that is defined in the Test function is passed as a parameter to the ChangeValue function. The value is then changed to 20 and passed to TheValue, which is retained when the function is exited.

You can also pass a parameter as a value if you do not want subsequent changes to the parameter to affect the value that is originally passed. To specify that a parameter is to be passed as a value, ensure that the ByVal keyword precedes the variable declaration in the function header.

In the preceding example, if we replace the ChangeValue function then the superordinate variable A remains unaffected by this change. After the call for the ChangeValue function, variable A retains the value 10.

Sub ChangeValue(ByVal TheValue As Integer)
  TheValue = 20
End Sub

Note: VBA : The method for passing parameters to procedures and functions in LibreOffice Basic is virtually identical to that in VBA. By default, the parameters are passed by reference. To pass parameters as values, use the ByVal keyword. In VBA, you can also use the keyword ByRef to force a parameter to be passed by reference. LibreOffice Basic recognizes but ignores this keyword, because this is already the default procedure in LibreOffice Basic.

Optional Parameters

Functions and procedures can only be called up if all the necessary parameters are passed during the call.

LibreOffice Basic lets you define parameters as optional, that is, if the corresponding values are not included in a call, LibreOffice Basic passes an empty parameter. In the following example the A parameter is obligatory, whereas the B parameter is optional.

Sub Test(A As Integer, Optional B As Integer)
  ' ...
End Sub

The IsMissing function checks whether a parameter has been passed or is left out.

Sub Test(A As Integer, Optional B As Integer)
  Dim B_Local As Integer
  ' Check whether B parameter is actually present
  If Not IsMissing (B) Then
    B_Local = B     ' B parameter present
  Else
    B_Local = 0     ' B parameter missing -> default value 0
  End If
  ' ... Start the actual function
End Sub

The example first tests whether the B parameter has been passed and, if necessary, passes the same parameter to the internal B_Local variable. If the corresponding parameter is not present, then a default value (in this instance, the value 0) is passed to B_Local rather than the passed parameter.

Note: VBA : The ParamArray keyword present in VBA is not supported in LibreOffice Basic.

Recursion

A recursive procedure or function is one that has the ability to call itself until it detects that some base condition has been satisfied. When the function is called with the base condition, a result is returned.

The following example uses a recursive function to calculate the factorial of the numbers 42, -42, and 3.14:

Sub Main
  Msgbox CalculateFactorial( 42 )   ' Displays 1,40500611775288E+51
  Msgbox CalculateFactorial( -42 )   ' Displays "Invalid number for factorial!"
  Msgbox CalculateFactorial( 3.14 )  ' Displays "Invalid number for factorial!"
End Sub

Function CalculateFactorial( Number )
  If Number < 0 Or Number <> Int( Number ) Then
    CalculateFactorial = "Invalid number for factorial!"
  ElseIf Number = 0 Then
    CalculateFactorial = 1
  Else
    ' This is the recursive call:
    CalculateFactorial = Number * CalculateFactorial( Number - 1 )
  Endif
End Function

The example returns the factorial of the number 42 by recursively calling the CalculateFactorial function until it reaches the base condition of 0! = 1.

Note: The recursion levels are set at different levels based on the software platform. For Windows the recursion level is 5800. For Solaris and Linux, an evaluation of the stacksize is performed and the recursion level is calculated.

Error Handling

Correct handling of error situations is one of the most time-consuming tasks of programming. LibreOffice Basic provides a range of tools for simplifying error handling.

The On Error Instruction

The On Error instruction is the key to any error handling:

Sub Test
  On Error Goto ErrorHandler
  ' ... undertake task during which an error may occur
  Exit Sub
  ErrorHandler:
    ' ... individual code for error handling
End Sub

The On Error Goto ErrorHandler line defines how LibreOffice Basic proceeds in the event of an error. The Goto ErrorHandler ensures that LibreOffice Basic exits the current program line and then executes the ErrorHandler: code.

The Resume Command

The Resume Next command continues the program from the line that follows where the error occurred in the program after the code in the error handler has been executed:

ErrorHandler:
  ' ... individual code for error handling
  Resume Next

Use the Resume Proceed command to specify a jump point for continuing the program after error handling:

ErrorHandler:
  ' ... individual code for error handling
  Resume Proceed
Proceed:
  ' ... the program continues here after the error

The term Proceed is a label. It could be for example, A247. The syntax for label names is the same as for variable names.

To continue a program without an error message when an error occurs, use the following format:

Sub Test
  On Error Resume Next
  ' ... perform task during which an error may occur
End Sub

Use the On Error Resume Next command with caution as its effect is global.

Queries Regarding Error Information

In error handling, it is useful to have a description of the error and to know where and why the error occurred:

• The Err variable contains a number identifying the type of error that has occurred.
• The Error$ variable contains a description of the error.
• The Erl variable contains the line number where the error occurred.

The call

MsgBox "Error " & Err & ": " & Error$ & " (line : " & Erl & ")"

shows how the error information can be displayed in a message window.

Note: VBA : Whereas VBA summarizes the error messages in a statistical object called Err, LibreOffice Basic provides the Err, Error$, and Erl variables.

The status information remains valid until the program encounters a Resume or On Error command, whereupon the information is reset.

Note: VBA : In VBA, the Err.Clear method of the Err object resets the error status after an error occurs. In LibreOffice Basic, this is accomplished with the On Error or Resume commands.

Tips for Structured Error Handling

Both the definition command, On Error, and the return command, Resume, are variants of the Goto construct.

If you want to cleanly structure your code to prevent generating errors when you use this construct, you should not use jump commands without monitoring them.

Care should be taken when you use the On Error Resume Next command as this dismisses all open error messages.

The best solution is to use only one approach for error handling within a program - keep error handling separate from the actual program code and do not jump back to the original code after the error occurs.

The following code is an example of an error handling procedure:

Sub Example
  ' Define error handler at the start of the function
  On Error Goto ErrorHandler
    ' ... Here is the actual program code
  On Error Goto 0          ' Deactivate error handling
    ' End of regular program implementation
  Exit Sub

  ' Start point of error handling
  ErrorHandler:
    ' Check whether error was expected
    If Err = ExpectedErrorNo Then
      ' ... Process error
    Else
      ' ... Warning of unexpected error
    End If
  On Error Goto 0           ' Deactivate error handling
End Sub

This procedure begins with the definition of an error handler, followed by the actual program code. At the end of the program code, the error handling is deactivated by the On Error Goto 0 call and the procedure implementation is ended by the Exit Sub command (not to be confused with End Sub).

The example first checks if the error number corresponds to the expected number (as stored in the imaginary ExpectedErrorNo constant) and then handles the error accordingly. If another error occurs, the system outputs a warning. It is important to check the error number so that unanticipated errors can be detected.

The On Error Goto 0 call at the end of the code resets the status information of the error (the error code in the Err system variables) so that an error occurring at a later date can be clearly recognized.

Other Instructions

Type...End Type

Struct

A struct is an ordered collection of data fields, that can be manipulated as a single item. In other terms, you may think of a struct as a record, or part of a record.

The #API often uses pre-defined structs, but these are UNO structs, a highly-specialized kind of struct.

Definition

With the Type...End Type statements, you can define your own (non-UNO) structs:

Type aMenuItem                       'assign the name of the type
  'Define the data fields within the struct. Each
  ' definition looks like a Dim statement, without the "Dim".
  aCommand as String
  aText as String
End Type                       'close the definition

Instance

The Type definition is only a pattern or template, not a set of actual variables. To make an instance of the type — actual variables that can be read and stored — use the Dim as New statement:

Dim maItem as New aMenuItem

Scope

As shown in the example below, the Type definition may be written at the start of a module (before the first Sub or Function). The definition will then be available to all routines in the module.

As of LibreOffice Version 3.0, unlike variables, there is no way to make the definition accessible outside of the module.

An instance of the new type is a variable, and follows the usual rules for variable scope (see #Scope and Life Span of Variables).

An example of how to use the definition, and how to reference the fields within an instance, appears in the section on With...End With.

With...End With

Qualifiers

In general, Basic does not look inside a container, such as an Object, to see what names might be defined there. If you want to use such a name, you must tell Basic where to look. You do that by using the name of the object as a qualifier. Write it before the inner name, and separate it by a period:

MyObject.SomeName

Since containers may hold other containers, you may need more than one qualifier. Write the qualifiers in order, from outer to inner:

OuterObject.InnerObject.FarInsideObject.SomeName

These names may also be described as, "concatenated with the dot-operator ('.')".

The With Alternative

The With...End With bracketing statements provide an alternative to writing out all the qualifiers, every time – and some of the qualifiers in the API can be quite long. You specify the qualifiers in the With statement. Until Basic encounters the End With statement, it looks for partly-qualified names: names that begin with a period (unary dot-operator). The compiler uses the qualifiers from the With as though they were written in front of the partly-qualified name.

Example 1: A User-defined Struct

This example shows how you may define and use a struct, and how to reference the items within it, both with and without With. Either way, the names of the data fields (from the Type definition) must be qualified by the name of the instance (from the Dim statement).

Type aMenuItem
  aCommand as String
  aText as String
End Type

Sub Main
  'Create an instance of the user-defined struct.
  ' Note the keyword, "New".
  Dim maItem as New aMenuItem
  With maItem
      .aCommand = ".uno:Copy"
      .aText = "~Copy"
  End With

  MsgBox "Command: " & maItem.aCommand & Chr(13) _
          & "Text: " & maItem.aText
End Sub

Example 2: Case statement

In #Cells and Ranges, the following example has the qualifiers in the Case statements written out completely, for clarity. You can write it more easily, this way:

Dim Doc As Object
Dim Sheet As Object
Dim Cell As Object

Doc = ThisComponent
Sheet = Doc.Sheets(0)
Cell = Sheet.getCellByPosition(1,1)       'Cell "B2" (0-based!)

Cell.Value = 1000

With com.sun.star.table.CellContentType
  Select Case Cell.Type
    Case .EMPTY
      MsgBox "Content: Empty"
    Case .VALUE
      MsgBox "Content: Value"
    Case .TEXT
      MsgBox "Content: Text"
    Case .FORMULA
      MsgBox "Content: Formula"
  End Select
End With

Notice that the With construct must be entirely outside of the Select construct.

Runtime Library

The following sections present the central functions of the runtime library:

• #Conversion Functions
• #Strings
• #Date and Time
• #Files and Directories
• #Message and Input Boxes
• #Other Functions

Conversion Functions

In many situations, circumstances arise in which a variable of one type has to be changed into a variable of another type.

Implicit and Explicit Type Conversions

The easiest way to change a variable from one type to another is to use an assignment.

Dim A As String
Dim B As Integer

B = 101
A = B

In this example, variable A is a string, and variable B is an integer. LibreOffice Basic ensures that variable B is converted to a string during assignment to variable A. This conversion is much more elaborate than it appears: the integer B remains in the working memory in the form of a two-byte long number. A, on the other hand, is a string, and the computer saves a one- or two-byte long value for each character (each number). Therefore, before copying the content from B to A, B has to be converted into A's internal format.

Unlike most other programming languages, Basic performs type conversion automatically. However, this may have fatal consequences. Upon closer inspection, the following code sequence

Dim A As String
Dim B As Integer
Dim C As Integer

B = 1
C = 1
A = B + C

which at first glance seems straightforward, ultimately proves to be something of a trap. The Basic interpreter first calculates the result of the addition process and then converts this into a string, which, as its result, produces the string 2.

If, on the other hand, the Basic interpreter first converts the start values B and C into a string and applies the plus operator to the result, it produces the string 11.

The same applies when using variant variables:

Dim A
Dim B
Dim C

B = 1
C = "1"
A = B + C

Since variant variables may contain both numbers and strings, it is unclear whether variable A is assigned the number 2 or the string 11.

The error sources noted for implicit type conversions can only be avoided by careful programming; for example, by not using the variant data type.

To avoid other errors resulting from implicit type conversions, LibreOffice Basic offers a range of conversion functions, which you can use to define when the data type of an operation should be converted:

CStr(Var)

converts any data type into a string.

CInt(Var)

converts any data types into an integer value.

CLng(Var)

converts any data types into a long value.

CSng(Var)

converts any data types into a single value.

CDbl(Var)

converts any data types into a double value.

CBool(Var)

converts any data types into a Boolean value.

CDate(Var)

converts any data types into a date value.

You can use these conversion functions to define how LibreOffice Basic should perform these type conversion operations:

Dim A As String
Dim B As Integer
Dim C As Integer

B = 1
C = 1
A = CStr(B + C)        ' B and C are added together first, then
                      ' converted to the string "2"
A = CStr(B) + CStr(C)  ' B and C are converted into a string,then
                      ' combined to produce the string "11"

During the first addition in the example, LibreOffice Basic first adds the integer variables and then converts the result into a chain of characters. A is assigned the string 2. In the second instance, the integer variables are first converted into two strings and then linked with one another by means of the assignment. A is therefore assigned the string 11.

The numerical CSng and CDbl conversion functions also accept decimal numbers. The symbol defined in the corresponding country-specific settings must be used as the decimal point symbol. Conversely, the CStr methods use the currently selected country-specific settings when formatting numbers, dates and time details.

The Val function is different from the Csng, Cdbl and Cstr methods. It converts a string into a number; however it always expects a period to be used as the decimal point symbol.

Dim A As String
Dim B As Double

A = "2.22"
B = Val(A)     ' Is converted correctly regardless of the
              ' country-specific settings

Checking the Content of Variables

In some instances, the date cannot be converted:

Dim A As String
Dim B As Date

A = "test"
B = A           ' Creates error message

In the example shown, the assignment of the test string to a date variable makes no sense, so the Basic interpreter reports an error. The same applies when attempting to assign a string to a Boolean variable:

Dim A As String
Dim B As Boolean

A = "test"
B = A           ' Creates error message

Again, the basic interpreter reports an error.

These error messages can be avoided by checking the program before an assignment, in order to establish whether the content of the variable to be assigned matches the type of the target variable. LibreOffice Basic provides the following test functions for this purpose:

IsNumeric(Value)

checks whether a value is a number.

IsDate(Value)

checks whether a value is a date.

IsArray(Value)

checks whether a value is an array.

These functions are especially useful when querying user input. For example, you can check whether a user has typed a valid number or date.

If IsNumeric(UserInput) Then
  ValidInput = UserInput
Else
  ValidInput = 0
  MsgBox "Error message."
End If

In the previous example, if the UserInput variable contains a valid numerical value, then this is assigned to the ValidInput variable. If UserInput does not contain a valid number, ValidInput is assigned the value 0 and an error message is returned.

While test functions exist for checking numbers, date details and arrays in LibreOffice Basic, a corresponding function for checking Boolean values does not exist. The functionality can, however, be imitated by using the IsBoolean function:

Function IsBoolean(Value As Variant) As Boolean
  On Error Goto ErrorIsBoolean:
  Dim Dummy As Boolean
  Dummy = Value
  IsBoolean = True
  On Error Goto 0
  Exit Sub

  ErrorIsBoolean:
  IsBoolean = False
  On Error Goto 0
End Function

The IsBoolean function defines an internal Dummy help variable of the Boolean type and tries to assign this to the transferred value. If assignment is successful, the function returns True. If it fails, a runtime error is produced, the error handler intercepts the error, and the function returns False.

Note: VBA : If a string in LibreOffice Basic contains a non-numerical value and if this is assigned to a number, LibreOffice Basic does not produce an error message, but stops converting the string at the first invalid character. This procedure differs from VBA. There, an error is triggered and program implementation terminated if a corresponding assignment is executed.

Strings

Working with Sets of Characters

When administering strings, LibreOffice Basic uses the set of Unicode characters. The Asc and Chr functions allow the Unicode value belonging to a character to be established and/or the corresponding character to be found for a Unicode value. The following expressions assign the various Unicode values to the code variable:

Code = Asc("A")        ' Latin letter A (Unicode-value 65)
Code = Asc("€")        ' Euro character (Unicode-value 8364)
Code = Asc("Л")        ' Cyrillic letter Л (Unicode-value 1083)

Conversely, the expression

MyString = Chr(13)

ensures that the MyString string is initialized with the value of the number 13, which stands for a hard line break.

The Chr command is often used in Basic languages to insert control characters in a string. The assignment

MyString = Chr(9) + "This is a test" + Chr(13)

therefore ensures that the text is preceded by a tab character (Unicode-value 9) and that a hard line break (Unicode-value 13) is added after the text.

Case conversion

LibreOffice Basic provides two functions to convert lowercase characters in a string to uppercase and vice-versa.

LCase(MyString)

converts all letters in MyString to lowercase. Only uppercase letters within the string are converted. All lowercase letters and nonletter characters remain unchanged.

UCase(MyString)

converts all letters in MyString to uppercase. Only lowercase letters within the string are converted. All uppercase letters and nonletter characters remain unchanged.

Accessing Parts of a String

LibreOffice Basic provides four functions that return partial strings, plus a length function:

Left(MyString, Length)

returns the first Length characters of MyString.

Right(MyString, Length)

returns the last Length characters of MyString.

Mid(MyString, Start, Length)

returns first Length characters of MyString as of the Start position.

Trim(MyString)

removes all leading and trailing spaces from MyString.

Len(MyString)

returns the number of characters in MyString.

Unlike array subscripts, character positions in a string start with 1. Here are a few example calls for the named functions:

Dim MyString As String
Dim MyResult As String
Dim MyLen As Integer

MyString = "This is a small test"
MyResult = Left(MyString,5)     ' Provides the string "This "
MyResult = Right(MyString, 5)   ' Provides the string " test"
MyResult = Mid(MyString, 8, 5)  ' Provides the string " a sm"
MyResult = Trim("   String with spaces   ") ' Provides the string "String with spaces"
MyLen = Len(MyString)           ' Provides the value 20

Search and Replace

LibreOffice Basic provides the InStr function for searching for a partial string within another string:

PositionOfMatch = InStr(MyString, StringToFind)

The StringToFind parameter specifies the string to be searched for within MyString. The function returns a number that contains the position at which the StringToFind first appears within MyString; a return value of zero indicates no match. If you want to find other matches for the string, the function also provides the opportunity to specify an optional start position from which LibreOffice Basic begins the search. In this case, the syntax of the function is:

PositionOfMatch = InStr(StartPosition, MyString, StringToFind)

In the previous examples, InStr ignores uppercase and lowercase characters. To change the search so that InStr is case sensitive, add the parameter 0, as shown in the following example:

PositionOfMatch = InStr(MyString, StringToFind, 0)

Using the previous functions for editing strings, programmers can search for and replace one string in another string:

Function Replace(Source As String, Search As String, NewPart As String)
  Dim Result As String
  Dim StartPos As Long
  Dim CurrentPos As Long

  Result = ""
  StartPos = 1
  CurrentPos = 1

  If Search = "" Then
    Result = Source
  Else
    Do While CurrentPos <> 0
      CurrentPos = InStr(StartPos, Source, Search)
      If CurrentPos <> 0 Then
        Result = Result + Mid(Source, StartPos, _
        CurrentPos - StartPos)
        Result = Result + NewPart
        StartPos = CurrentPos + Len(Search)
      Else
        Result = Result + Mid(Source, StartPos, Len(Source))
      End If               ' Position <> 0
    Loop
  End If

  Replace = Result
End Function

The function searches through the transferred Search string in a loop by means of InStr in the original term Source. If it finds the search term, it takes the part before the expression and writes it to the Result return buffer. It adds the NewPart section at the point of the search term Search. If no more matches are found for the search term, the function establishes the part of the string still remaining and adds this to the return buffer. It returns the string produced in this way as the result of the replacement process.

Since replacing parts of character sequences is one of the most frequently used functions, the Mid function in LibreOffice Basic has been extended so that this task is performed automatically. The following example replaces three characters with the string is from the sixth position of the MyString string.

Dim MyString As String

MyString = "This was my text"
Mid(MyString, 6, 3, "is")

Or this much simpler function can be used. First it splits "Source" dividing it at all "Search", and joins the parts back with "NewPart". So Replace("This is a test", " ", "_") yields "This_is_a_test" :D

Function Replace(Source As String, Search As String, NewPart As String)
  Dim Result As String  
  Result = join(split(Source, Search), NewPart)
  Replace = Result
End Function

Warning: When it is used with 4 arguments, to replace a sub-string in a string, Mid is an instruction, not a function : it does not return any value !

Formatting Strings

The Format function formats numbers as a string. To do this, the function expects a Format expression to be specified, which is then used as the template for formatting the numbers. Each placeholder within the template ensures that this item is formatted correspondingly in the output value. The five most important placeholders within a template are the zero (0), pound sign (#), period (.), comma (,) and dollar sign ($) characters.

The 0 character within the template ensures that a number is always placed at the corresponding point. If a number is not provided, 0 is displayed in its place.

A . stands for the decimal point symbol defined by the operating system in the country-specific settings.

The example below shows how the characters 0 and . can define the digits after the decimal point in an expression:

MyFormat = "0.00"
MyString = Format(-1579.8, MyFormat)    ' Provides "-1579,80"
MyString = Format(1579.8, MyFormat)     ' Provides "1579,80"
MyString = Format(0.4, MyFormat)        ' Provides "0,40"
MyString = Format(0.434, MyFormat)      ' Provides "0,43"

In the same way, zeros can be added in front of a number to achieve the desired length:

MyFormat = "0000.00"
MyString = Format(-1579.8, MyFormat)    ' Provides "-1579,80"
MyString = Format(1579.8, MyFormat)     ' Provides "1579,80"
MyString = Format(0.4, MyFormat)        ' Provides "0000,40"
MyString = Format(0.434, MyFormat)      ' Provides "0000,43"

A , represents the character that the operating system uses for a thousands separator, and the # stands for a digit or place that is only displayed if it is required by the input string.

MyFormat = "#,##0.00"
MyString = Format(-1579.8, MyFormat)    ' Provides "-1.579,80"
MyString = Format(1579.8, MyFormat)     ' Provides "1.579,80"
MyString = Format(0.4, MyFormat)        ' Provides "0,40"
MyString = Format(0.434, MyFormat)      ' Provides "0,43"

In place of the $ placeholder, the Format function displays the relevant currency symbol defined by the system (this example assumes a European locale has been defined):

MyFormat = "#,##0.00 $"
MyString = Format(-1579.8, MyFormat)    ' Provides "-1.579,80 €"
MyString = Format(1579.8, MyFormat)     ' Provides "1.579,80 €"
MyString = Format(0.4, MyFormat)        ' Provides "0,40 €"
MyString = Format(0.434, MyFormat)      ' Provides "0,43 €"

The format instructions used in VBA for formatting date and time details can also be used:

sub main
  dim myDate as date
  myDate = "01/06/98"
  TestStr = Format(myDate, "mm-dd-yyyy") ' 01-06-1998
  MsgBox TestStr
end sub

Date and Time

LibreOffice Basic provides the Date data type, which saves the date and time details in binary format.

Specification of Date and Time Details within the Program Code

You can assign a date to a date variable through the assignment of a simple string:

Dim MyDate As Date
MyDate = "24.1.2002"

This assignment can function properly because LibreOffice Basic automatically converts the date value defined as a string into a date variable. This type of assignment, however, can cause errors, date and time values are defined and displayed differently in different countries.

Since LibreOffice Basic uses the country-specific settings of the operating system when converting a string into a date value, the expression shown previously only functions correctly if the country-specific settings match the string expression.

To avoid this problem, the DateSerial function should be used to assign a fixed value to a date variable:

Dim MyVar As Date
MyDate = DateSerial (2001, 1, 24)

The function parameter must be in the sequence: year, month, day. The function ensures that the variable is actually assigned the correct value regardless of the country-specific settings

The TimeSerial function formats time details in the same way that the DateSerial function formats dates:

Dim MyVar As Date
MyDate = TimeSerial(11, 23, 45)

Their parameters should be specified in the sequence: hours, minutes, seconds.

Literals for Dates

Date literals allow to specify unambiguous date variables that are independent from the current language. Literals are enclosed between hash signs #. Possible formats are:

• #yyyy-mm-dd#
• #mm/dd/yyyy#

start_date = #12/30/1899# ' = 1
date_of_birth = #2010-09-28#

Extracting Date and Time Details

The following functions form the counterpart to the DateSerial and TimeSerial functions:

Day(MyDate)

returns the day of the month from MyDate.

Month(MyDate)

returns the month from MyDate.

Year(MyDate)

returns the year from MyDate.

Weekday(MyDate)

returns the number of the weekday from MyDate.

Hour(MyTime)

returns the hours from MyTime.

Minute(MyTime)

returns the minutes from MyTime.

Second(MyTime)

returns the seconds from MyTime.

These functions extract the date or time sections from a specified Date variable. The following example checks whether the date saved in MyDate is in the year 2003.

Dim MyDate As Date
' ... Initialization of MyDate

If Year(MyDate) = 2003 Then
  ' ... Specified date is in the year 2003
End If

In the same way, the following example checks whether MyTime is between 12 and 14 hours.

Dim MyTime As Date
' ... Initialization of MyTime

If Hour(MyTime) >= 12 And Hour(MyTime) < 14 Then
  ' ... Specified time is between 12 and 14 hours
End If

The Weekday function returns the number of the weekday for the transferred date:

Dim MyDate As Date
Dim MyWeekday As String
' ... initialize MyDate

Select Case WeekDay(MyDate)
  case 1
    MyWeekday = "Sunday"
  case 2
    MyWeekday = "Monday"
  case 3
    MyWeekday = "Tuesday"
  case 4
    MyWeekday = "Wednesday"
  case 5
    MyWeekday = "Thursday"
  case 6
    MyWeekday = "Friday"
  case 7
    MyWeekday = "Saturday"
End Select

Note: Sunday is considered the first day of the week.

Retrieving System Date and Time

The following functions are available in LibreOffice Basic to retrieve the system time and system date:

Date

returns the present date as a string. The format depends on localization settings.

Time

returns the present time as a string.

Now

returns the present point in time (date and time) as a combined value of type Date.

Files and Directories

Working with files is one of the basic tasks of an application. The LibreOffice API provides you with a whole range of objects with which you can create, open and modify Office documents. These are presented in detail in the #Introduction to the LibreOffice API. Regardless of this, in some instances you will have to directly access the file system, search through directories or edit text files. The runtime library from LibreOffice Basic provides several fundamental functions for these tasks.

Note: Some DOS-specific file and directory functions are no longer provided in LibreOffice, or their function is only limited. For example, support for the ChDir, ChDrive and CurDir functions is not provided. Some DOS-specific properties are no longer used in functions that expect file properties as parameters (for example, to differentiate from concealed files and system files). This change became necessary to ensure the greatest possible level of platform independence for LibreOffice.

Administering Files

Compatibility Mode

The CompatibilityMode statement and function provide greater compatibility with VBA, by changing the operation of certain functions. The effect on any particular function is described with that function, below.

As a statement, CompatibilityMode( value ) takes a Boolean value to set or clear the mode. As a function, CompatibilityMode() returns the Boolean value of the mode.

CompatibilityMode( True ) 'set mode
CompatibilityMode( False) 'clear mode

Dim bMode as Boolean
bMode = CompatibilityMode()

Searching Through Directories

The Dir function in LibreOffice Basic is responsible for searching through directories for files and sub-directories. When first requested, a string containing the path of the directories to be searched must be assigned to Dir as its first parameter. The second parameter of Dir specifies whether files or directories are to be searched for. LibreOffice Basic returns the name of the first directory entry found. To retrieve the next entry, the Dir function should be requested without parameters. If the Dir function finds no more entries, it returns an empty string.

The following example shows how the Dir function can be used to request all files located in one directory. The procedure saves the individual file names in the AllFiles variable and then displays this in a message box.

Sub ShowFiles
  Dim NextFile As String
  Dim AllFiles As String

  AllFiles = ""
  NextFile = Dir("C:\", 0)

  While NextFile <> ""
    AllFiles = AllFiles & Chr(13) & NextFile
    NextFile = Dir
  Wend

  MsgBox AllFiles
End Sub

The 0 (zero) used as the second parameter in the Dir function ensures that Dir only returns the names of files; directories are ignored. The following parameters can be specified here:

• 0 : returns normal files
• 16 : sub-directories

The following example is virtually the same as the preceding example, but the Dir function transfers the value 16 as a parameter, which returns the sub-directories of a folder rather than the file names.

Sub ShowDirs
  Dim NextDir As String
  Dim AllDirs As String

  AllDirs = ""
  NextDir = Dir("C:\", 16)

  While NextDir <> ""
    AllDirs = AllDirs & Chr(13) & NextDir
    NextDir = Dir
  Wend

  MsgBox AllDirs
End Sub

Note: VBA : When requested in LibreOffice Basic, the Dir function, using the parameter 16, only returns the sub-directories of a folder. In VBA, the function also returns the names of the standard files so that further checking is needed to retrieve the directories only. When using the CompatibilityMode ( true ) function, LibreOffice Basic behaves like VBA and the Dir function, using parameter 16, returns sub-directories and standard files.

Note: VBA : The options provided in VBA for searching through directories specifically for files with the concealed, system file, archived, and volume name properties does not exist in LibreOffice Basic because the corresponding file system functions are not available on all operating systems.

Note: VBA : The path specifications listed in Dir may use the * and ? placeholders in both VBA and LibreOffice Basic. In LibreOffice Basic, the * placeholder may however only be the last character of a file name and/or file extension, which is not the case in VBA.

Creating and Deleting Directories

LibreOffice Basic provides the MkDir function for creating directories.

MkDir ("C:\SubDir1")

This function creates directories and sub-directories. All directories needed within a hierarchy are also created, if required. For example, if only the C:\SubDir1 directory exists, then a call

MkDir ("C:\SubDir1\SubDir2\SubDir3\")

creates both the C:\SubDir1\SubDir2 directory and the C:\SubDir1\SubDir2\SubDir3 directory.

The RmDir function deletes directories.

RmDir ("C:\SubDir1\SubDir2\SubDir3\")

If the directory contains sub-directories or files, these are also deleted. You should therefore be careful when using RmDir.

Note: VBA : In VBA, the MkDir and RmDir functions only relate to the current directory. In LibreOffice Basic on the other hand, MkDir and RmDir can be used to create or delete levels of directories.

Note: VBA : In VBA, RmDir produces an error message if a directory contains a file. In LibreOffice Basic, the directory and all its files are deleted. If you use the CompatibilityMode ( true ) function, LibreOffice Basic will behave like VBA.

Copying, Renaming, Deleting and Checking the Existence of Files

The following call creates a copy of the Source file under the name of Destination:

FileCopy(Source, Destination)

With the help of the following function you can rename the OldName file with NewName. The As keyword syntax, and the fact that a comma is not used, goes back to the roots of the Basic language.

Name OldName As NewName

The following call deletes the Filename file. If you want to delete directory (including its files) use the RmDir function.

Kill(Filename)

The FileExists function can be used to check whether a file exists:

If FileExists(Filename) Then
  MsgBox "file exists."
End If

Reading and Changing File Properties

When working with files, it is sometimes important to be able to establish the file properties, the time the file was last changed and the length of the file.

The following call returns some properties about a file.

Dim Attr As Integer
Attr = GetAttr(Filename)

The return value is provided as a bit mask in which the following values are possible:

• 1 : read-only file
• 16 : name of a directory

The following example determines the bit mask of the test.txt file and checks whether this is read-only whether it is a directory. If neither of these apply, FileDescription is assigned the "normal" string.

Dim FileMask As Integer
Dim FileDescription As String

FileMask = GetAttr("test.txt")

If (FileMask AND 1) > 0 Then
  FileDescription = FileDescription & " read-only "
End IF

If (FileMask AND 16) > 0 Then
  FileDescription = FileDescription & " directory "
End IF

If FileDescription = "" Then
  FileDescription = " normal "
End IF

MsgBox FileDescription

Note: VBA : The flags used in VBA for querying the concealed, system file,archived and volume name file properties are not supported in LibreOffice Basic because these are Windows-specific and are not or are only partially available on other operating systems.

The SetAttr function permits the properties of a file to be changed. The following call can therefore be used to provide a file with read-only status:

SetAttr("test.txt", 1)

An existing read-only status can be deleted with the following call:

SetAttr("test.txt", 0)

The date and time of the last amendment to a file are provided by the FileDateTime function. The date is formatted here in accordance with the country-specific settings used on the system.

FileDateTime("test.txt")  ' Provides date and time of the last file amendment.

The FileLen function determines the length of a file in bytes (as long integer value).

FileLen("test.txt")     ' Provides the length of the file in bytes

Writing and Reading Text Files

LibreOffice Basic provides a whole range of methods for reading and writing files. The following explanations relate to working with text files (not text documents).

Writing Text Files

Before a text file is accessed, it must first be opened. To do this, a free file handle is needed, which clearly identifies the file for subsequent file access.

The FreeFile function is used to create a free file handle:

FileNo = FreeFile

FileNo is an integer variable that receives the file handle. The handle is then used as a parameter for the Open instruction, which opens the file.

To open a file so that it can be written as a text file, the Open call is:

Open Filename For Output As #FileNo

Filename is a string containing the name of the file. FileNo is the handle created by the FreeFile function.

Once the file is opened, the Print instruction can create the file contents, line by line:

Print #FileNo, "This is a test line."

FileNo also stands for the file handle here. The second parameter specifies the text that is to be saved as a line of the text file.

Once the writing process has been completed, the file must be closed using a Close call:

Close #FileNo

Again here, the file handle should be specified.

The following example shows how a text file is opened, written, and closed:

Dim FileNo As Integer
Dim CurrentLine As String
Dim Filename As String

Filename = "c:\data.txt"           ' Define file name
FileNo = FreeFile              ' Establish free file handle

Open Filename For Output As #FileNo        ' Open file (writing mode)
Print #FileNo, "This is a line of text"     ' Save line
Print #FileNo, "This is another line of text"  ' Save line
Close #FileNo                 ' Close file

Reading Text Files

Text files are read in the same way that they are written. The Open instruction used to open the file contains the For Input expression in place of the For Output expression and, rather than the Print command for writing data, the Line Input instruction should be used to read the data.

Finally, when calling up a text file, the eof instruction is used to check whether the end of the file has been reached:

eof(FileNo)

The following example shows how a text file can be read:

Dim FileNo As Integer
Dim CurrentLine As String
Dim File As String
Dim Msg as String

' Define filename
Filename = "c:\data.txt"

' Establish free file handle
FileNo = Freefile

' Open file (reading mode)
Open Filename For Input As FileNo

' Check whether file end has been reached
Do While not eof(FileNo)
  ' Read line
  Line Input #FileNo, CurrentLine
  If CurrentLine <>"" then
    Msg = Msg & CurrentLine & Chr(13)
  end if
Loop

' Close file

Close #FileNo
Msgbox Msg

The individual lines are retrieved in a Do While loop, saved in the Msg variable, and displayed at the end in a message box.

Message and Input Boxes

LibreOffice Basic provides the MsgBox and InputBox functions for basic user communication.

Displaying Messages

MsgBox displays a basic information box, which can have one or more buttons. In its simplest variant the MsgBox only contains text and an OK button:

MsgBox "This is a piece of information!"

The appearance of the information box can be changed using a parameter. The parameter provides the option of adding additional buttons, defining the pre-assigned button, and adding an information symbol.

Note: By convention, the symbolic names given below are written in UPPERCASE, to mark them as predefined, rather than user-defined. However, the names are not case-sensitive.

The values for selecting the buttons are:

• 0, MB_OK - OK button
• 1, MB_OKCANCEL - OK and Cancel button
• 2, MB_ABORTRETRYIGNORE - Abort, Retry, and Ignore buttons
• 3, MB_YESNOCANCEL - Yes, No, and Cancel buttons
• 4, MB_YESNO - Yes and No buttons
• 5, MB_RETRYCANCEL - Retry and Cancel buttons

To set a button as the default button, add one of the following values to the parameter value from the list of button selections. For example, to create Yes, No and Cancel buttons (value 3) where Cancel is the default (value 512), the parameter value is 3 + 512 = 515. The expression MB_YESNOCANCEL + MB_DEFBUTTON3 is harder to write, but easier to understand.

• 0, MB_DEFBUTTON1 - First button is default value
• 256, MB_DEFBUTTON2 - Second button is default value
• 512, MB_DEFBUTTON3 - Third button is default value

Finally, the following information symbols are available and can also be displayed by adding the relevant parameter values:

• 16, MB_ICONSTOP - Stop sign
• 32, MB_ICONQUESTION - Question mark
• 48, MB_ICONEXCLAMATION - Exclamation point
• 64, MB_ICONINFORMATION - Tip icon

The following call displays an information box with the Yes and No buttons (value 4), of which the second button (No) is set as the default value (value 256) and which also receives a question mark (value 32), 4+256+32=292.

MsgBox "Do you want to continue?", 292
' or,
MsgBox "Do you want to continue?", MB_YESNO + MB_DEFBUTTON2 + MB_ICONQUESTION

File:Pictures/10000201000000C50000006978F16295.png Display of the Message Box

If an information box contains several buttons, then a return value should be queried to determine which button has been pressed. The following return values are available in this instance:

• 1, IDOK - Ok
• 2, IDCANCEL - Cancel
• 3, IDABORT - Abort
• 4, IDRETRY - Retry
• 5 - Ignore
• 6, IDYES - Yes
• 7, IDNO - No

In the previous example, checking the return values could be as follows:

Dim iBox as Integer
iBox = MB_YESNO + MB_DEFBUTTON2 + MB_ICONQUESTION
If MsgBox ("Do you want to continue?", iBox) = IDYES Then
' or,
If MsgBox ("Do you want to continue?", 292) = 6 Then
  ' Yes button pressed
Else
  ' No button pressed
End IF

In addition to the information text and the parameter for arranging the information box, MsgBox also permits a third parameter, which defines the text for the box title:

MsgBox "Do you want to continue?", 292, "Box Title"

If no box title is specified, the default is “soffice”.

Input Box For Querying Simple Strings

The InputBox function queries simple strings from the user. It is therefore a simple alternative to configuring dialogs. InputBox receives three standard parameters:

• An information text.
• A box title.
• A default value which can be added within the input area.

InputVal = InputBox("Please enter value:", "Test", "default value")

File:Pictures/1000020100000244000000AFAF261E64.png Display of the Input Box

• The dimensions of the InputBox window cannot be changed.
• If the user clicks the OK button, the InputBox returns the string typed by the user (or the default string if it was not changed).
• If the user clicks the Cancel button or closes the window, the InputBox returns an empty string.

Other Functions

Beep

The Beep function causes the system to play a sound that can be used to warn the user of an incorrect action. Beep does not have any parameters:

Beep    ' creates an informative tone

Shell

External programs can be started using the Shell function.

Shell(Pathname, Windowstyle, Param, bSync)

Pathname

the path of the program to be executed.

In MS-Windows, use ConvertToURL(Pathname) otherwise the command will not work if Pathname contains spaces or national characters.

Windowstyle

the window in which the program is started.

The following values are possible:

• 0 - The program receives the focus and is started in a concealed window.
• 1 - The program receives the focus and is started in a normal-sized window.
• 2 - The program receives the focus and is started in a minimized window.
• 3 - The program receives the focus and is started in a maximized window.
• 4 - The program is started in a normal-sized window, without receiving the focus.
• 6 - The program is started in a minimized window, the focus remains in the current window.
• 10 - The program is started in full screen mode.

Param

command line parameters to be transferred to the program to be started.

bSync

wait for shell command to finish flag

• true - wait for shell command to finish
• false - don't wait for shell command to finish

Wait and WaitUntil

The Wait statement suspends program execution for a specified time. The waiting period is specified in milliseconds. The command:

Wait 2000

specifies a delay of 2 seconds (2000 milliseconds).

The WaitUntil statement provides a greater degree of compatibility with VBA parameter usage. WaitUntil takes a parameter of type Date, with a combined date and time value. The command:

WaitUntil Now + TimeValue("00:00:02")

specifies the same delay, 2 seconds, as the previous example.

Environ

The Environ function returns the environmental variables of the operating system. Depending on the system and configuration, various types of data are saved here. The following call determines the environment variables of the temporary directory of the operating system:

Dim TempDir
TempDir=Environ ("TEMP")

Introduction to the API

LibreOffice objects and methods, such as paragraphs, spreadsheets, and fonts, are accessible to LibreOffice Basic through the LibreOffice application programming interface, or API. Through the API, for example, documents can be created, opened, modified and printed. The API can be used not only by LibreOffice Basic, but also by other programming languages, such as Java and C++. The interface between the API and various programming languages is provided by something called Universal Network Objects (UNO).

This chapter provides a background on the API. Building on this background, the following chapters will show how the API can be used to make LibreOffice do what you want it to do.

Universal Network Objects (UNO)

LibreOffice provides a programming interface in the form of the Universal Network Objects (UNO). This is an object-oriented programming interface which LibreOffice sub-divides into various objects which for their part ensure program-controlled access to the Office package.

Since LibreOffice Basic is a procedural programming language, several linguistic constructs have had to be added to it which enable the use of UNO.

To use a Universal Network Object in LibreOffice Basic, you will need a variable declaration for the associated object. The declaration is made using the Dim instruction (see #The Language of LibreOffice Basic). The Object type designation should be used to declare an object variable:

Dim Obj As Object

The call declares an object variable named Obj.

The object variable created must then be initialized so that it can be used. This can be done using the createUnoService function:

Obj = createUnoService("com.sun.star.frame.Desktop")

This call assigns to the Obj variable a reference to the newly created object. com.sun.star.frame.Desktop resembles an object type; however in UNO terminology it is called a service rather than a type. In accordance with UNO philosophy, an Obj is described as a reference to an object which supports the com.sun.star.frame.Desktop service. The service term used in LibreOffice Basic therefore corresponds to the type and class terms used in other programming languages.

There is, however, one main difference: a Universal Network Object may support several services at the same time. Some UNO services in turn support other services so that, through one object, you are provided with a whole range of services. For example, the aforementioned object, which is based on the com.sun.star.frame.Desktop service, can also include other services for loading documents and for ending the program.

Note: VBA : Whereas the structure of an object in VBA is defined by the class to which it belongs, in LibreOffice Basic the structure is defined through the services which it supports. A VBA object is always assigned to precisely one single class. A LibreOffice Basic object can, however, support several services.

Properties and Methods

An object in LibreOffice Basic provides a range of properties and methods which can be called by means of the object.

Properties

Properties are like the properties of an object; for example, Filename and Title for a Document object.

The properties are set by means of a simple assignment:

Document.Title = "LibreOffice Basic Programmer's Guide"
Document.Filename = "basguide.odt"

A property, just like a normal variable, has a type that defines which values it can record. The preceding Filename and Title properties are of the string type.

Real Properties and Imitated Properties

Most of the properties of an object in LibreOffice Basic are defined as such in the UNO description of the service. In addition to these "real" properties, there are also properties in LibreOffice Basic which consist of two methods at the UNO level. One of these is used to query the value of the property and the other is issued to set it (get and set methods). The property has been virtually imitated from two methods. Character objects in UNO, for example, provide the getPosition and setPosition methods through which the associated key point can be called up and changed. The LibreOffice Basic programmer can access the values through the Position property. Regardless of this, the original methods are also available (in our example, getPosition and setPosition).

Methods

Methods can be understood as functions that relate directly to an object and through which this object is called. The preceding Document object could, for example, provide a Save method, which can be called as follows:

Document.Save()

Methods, just like functions, may contain parameters and return values. The syntax of such method calls is oriented towards classic functions. The following call also specifies the True parameter for the document object when requesting the Save method.

Ok = Document.Save(True)

Once the method has been completed, Save saves a return value in the Ok variable.

Modules, Services and Interfaces

LibreOffice provides hundreds of services. To provide an overview of these services, they have been combined into modules. The modules are of no other functional importance for LibreOffice Basic programmers. When specifying a service name, it is only the module name which is of any importance because this must be also listed in the name. The complete name of a service consists of the com.sun.star expression, which specifies that it is a LibreOffice service, followed by the module name, such as frame, and finally the actual service name, such as Desktop. The complete name in the named example would be:

com.sun.star.frame.Desktop

In addition to the module and service terms, UNO introduces the term 'interface'. While this term may be familiar to Java programmers, it is not used in Basic.

An interface combines several methods. In the strictest sense of the word, a service in UNO does not support methods, but rather interfaces, which in turn provide different methods. In other words, the methods are assigned (as combinations) to the service in interfaces. This detail may be of interest in particular to Java- or C++ programmers, since in these languages, the interface is needed to request a method. In LibreOffice Basic, this is irrelevant. Here, the methods are called directly by means of the relevant object.

For an understanding of the API, it is, however, useful to have the assignment of methods to various interfaces handy, since many interfaces are used in the different services. If you are familiar with an interface, then you can transfer your knowledge from one service to another.

Some central interfaces are used so frequently, triggered by different services, that they are shown again at the end of this chapter.

Tools for Working with UNO

The question remains as to which objects — or services if we are going to remain with UNO terminology — support which properties, methods and interfaces and how these can be determined. In addition to this guide, you can get more information about objects from the following sources: the supportsService method, the debug methods as well as the Developer's Guide, and the API reference.

The supportsService Method

A number of UNO objects support the supportsService method, with which you can establish whether an object supports a particular service. The following call, for example, determines whether the TextElement object supports the com.sun.star.text.Paragraph service.

Ok = TextElement.supportsService("com.sun.star.text.Paragraph")

Debug Properties

Every UNO object knows what properties, methods and interfaces it already contains. LibreOffice Basic provides properties that return these in the form of a string containing a list. The corresponding properties are:

DBG_properties

returns a string containing all properties of an object

DBG_methods

returns a string containing all methods of an object

DBG_supportedInterfaces

returns a string containing all interfaces which support an object.

The following program code shows how DBG_properties and DBG_methods can be used in real-life applications. It first creates the com.sun.star.frame.Desktop service and then displays the supported properties and methods in message boxes.

Dim Obj As Object
Obj = createUnoService("com.sun.star.frame.Desktop")

MsgBox Obj.DBG_Properties
MsgBox Obj.DBG_methods

When using DBG_properties, note that the function returns all properties that the services offered by the object can theoretically support. No assurances are, however, provided for whether these can also be used by the object in question. In very rare cases, before calling up some property, use the IsEmpty function to check whether it is actually available.

Debugging tools

Using the DBG_ properties is a very crude method to discover the contents of an API objects.

The watch window of the Basic IDE can display the properties of a Uno object (but not the methods, not the interfaces).

To display all information available from an object and link to the corresponding API documentation, use instead the Development Tools built into LibreOffice or MRI extension.

Note: VBA : LibreOffice Basic does not provide code completion. Only at run-time can you find out which properties or methods are available for an object. All the above debug tools work on a running program.

API Reference

More information about the available services, and their interfaces, methods and properties can be found in the reference for the LibreOffice API.

Overview of Central Interfaces

Some interfaces of LibreOffice can be found in many parts of the LibreOffice API. They define sets of methods for abstract tasks which can be applied to various problems. Here, you will find an overview of the most common of these interfaces.

The origin of the objects is explained at a later point in this guide. At this point, only some of the abstract aspects of objects, for which the LibreOffice API provides some central interfaces, are discussed.

Creating Context-Dependent Objects

The LibreOffice API provides two options for creating objects. One can be found in the createUnoService function mentioned at the start of this chapter. createUnoService creates an object which can be used universally. Such objects and services are also known as context-independent services.

In addition to context-independent services, there are also context-dependent services whose objects are only useful when used in conjunction with another object. A drawing object for a spreadsheet document, for example, can therefore only exist in conjunction with this one document.

com.sun.star.lang.XMultiServiceFactory Interface

Context-dependent objects are usually created by means of an object method, on which the object depends. The createInstance method, which is defined in the XMultiServiceFactory interface, is used in particular in the document objects.

The drawing object can, for example, be created as follows using a spreadsheet object:

Dim RectangleShape As Object
RectangleShape = _
  Spreadsheet.createInstance("com.sun.star.drawing.RectangleShape")

A paragraph template in a text document is created in the same way:

Dim Style as Object
Style = Textdocument.createInstance("com.sun.star.style.ParagraphStyle")

Named Access to Subordinate Objects

The XNameAccess and XNameContainer interfaces are used in objects that contain subordinate objects, which can be addressed using a natural language name.

While XNameAccess permits access to the individual objects, XNameContainer takes on the insertion, modification and deletion of elements.

com.sun.star.container.XNameAccess Interface

An example of the use of XNameAccess is provided by the sheets object of a spreadsheet. It combines all the pages within the spreadsheet. The individual pages are accessed from the sheets object, by using the getByName method from XNameAccess:

Dim Sheets As Object
Dim Sheet As Object

Sheets = Spreadsheet.Sheets
Sheet = Sheets.getByName("Sheet1")

The getElementNames method provides an overview of the names of all elements. As a result, it returns a data field containing the names. The following example shows how all element names of a spreadsheet can thereby be determined and displayed in a loop:

Dim Sheets As Object
Dim SheetNames
Dim I As Integer

Sheets = Spreadsheet.Sheets
SheetNames = Sheets.getElementNames

For I=LBound(SheetNames) To UBound(SheetNames)
  MsgBox SheetNames(I)
Next I

The hasByName method of the XNameAccess interface reveals whether a subordinate object with a particular name exists within the basic object. The following example therefore displays a message that informs the user whether the Spreadsheet object contains a page of the name Sheet1.

Dim Sheets As Object

Sheets = Spreadsheet.Sheets
If Sheets.HasByName("Sheet1") Then
  MsgBox " Sheet1 available"
Else
  MsgBox "Sheet1 not available"
End If

com.sun.star.container.XNameContainer Interface

The XNameContainer interface takes on the insertion, deletion and modification of subordinate elements in a basic object. The functions responsible are insertByName, removeByName and replaceByName.

The following is a practical example of this. It calls a text document, which contains a StyleFamilies object and uses this to in turn make the paragraph templates (ParagraphStyles) of the document available.

Dim StyleFamilies As Object
Dim ParagraphStyles As Object
Dim NewStyle As Object

StyleFamilies = Textdoc.StyleFamilies
ParagraphStyles = StyleFamilies.getByName("ParagraphStyles")
ParagraphStyles.insertByName("NewStyle", NewStyle)
ParagraphStyles.replaceByName("ChangingStyle", NewStyle)
ParagraphStyles.removeByName("OldStyle")

The insertByName line inserts the NewStyle style under the name of the same name in the ParagraphStyles object. The replaceByName line changes the object behind ChangingStyle into NewStyle. Finally, the removeByName call removes the object behind OldStyle from ParagraphStyles.

Index-Based Access to Subordinate Objects

The XIndexAccess and XIndexContainer interfaces are used in objects which contain subordinate objects and which can be addressed using an index.

XIndexAccess provides the methods for accessing individual objects. XIndexContainer provides methods for inserting and removing elements.

com.sun.star.container.XIndexAccess Interface

XIndexAccess provides the getByIndex and getCount methods for calling the subordinate objects. getByIndex provides an object with a particular index. getCount returns how many objects are available.

Dim Sheets As Object
Dim Sheet As Object
Dim I As Integer

Sheets = Spreadsheet.Sheets

For I = 0 to Sheets.getCount() - 1
  Sheet = Sheets.getByIndex(I)
  ' Editing sheet
Next I

The example shows a loop that runs through all sheet elements one after another and saves a reference to each in the Sheet object variable. When working with the indexes, note that getCount returns the number of elements. The elements in getByIndex however are numbered beginning with 0. The counting variable of the loop therefore runs from 0 to getCount()-1.

com.sun.star.container.XIndexContainer Interface

The XIndexContainer interface provides the insertByIndex and removeByIndex functions. The parameters are structured in the same way as the corresponding functions in XNameContainer.

Iterative Access to Subordinate Objects

In some instances, an object may contain a list of subordinate objects that cannot be addressed by either a name or an index. In these situations, the XEnumeration and XenumerationAccess interfaces are appropriate. They provide a mechanism through which all subordinate elements of an objects can be passed, step by step, without having to use direct addressing.

com.sun.star.container.XEnumeration and XenumerationAccess Interfaces

The basic object must provide the XEnumerationAccess interface, which contains only a createEnumeration method. This returns an auxiliary object, which in turn provides the XEnumeration interface with the hasMoreElements and nextElement methods. Through these, you then have access to the subordinate objects.

The following example steps through all the paragraphs of a text:

Dim ParagraphEnumeration As Object
Dim Paragraph As Object

ParagraphEnumeration = Textdoc.Text.createEnumeration

While ParagraphEnumeration.hasMoreElements()
Paragraph = ParagraphEnumeration.nextElement()
Wend

The example first creates a ParagraphEnumeration auxiliary object. This gradually returns the individual paragraphs of the text in a loop. The loop is terminated as soon as the hasMoreElements method returns the False value, signaling that the end of the text has been reached.

Working with Documents

The LibreOffice API has been structured so that as many of its parts as possible can be used universally for different tasks. This includes the interfaces and services for creating, opening, saving, converting, and printing documents and for template administration. Since these function areas are available in all types of documents, they are explained first in this chapter.

• #The StarDesktop
• #Styles and Templates

The current document

In previous versions of the Basic Programming Guide these instructions were used to obtain the current document :

Dim Doc As Object

Doc = StarDesktop.CurrentComponent

This correct code has a drawback : it does not work if the macro is started from the IDE because it then refers to the IDE, not the document. This code works only if the macro is started from the document itself!

You should instead use Basic object ThisComponent. It returns the document object on which the macro is run. If you start the macro from the IDE, ThisComponent will still find and return your document.

Dim Doc As Object

Doc = ThisComponent ' recommended coding for Basic

The StarDesktop

When working with documents, two services are used most frequently:

• The com.sun.star.frame.Desktop service, which is similar to the core service of LibreOffice. It provides the functions for the frame object of LibreOffice, under which all document windows are classified. Documents can also be created, opened and imported using this service.
• The basic functionality for the individual document objects is provided by the com.sun.star.document.OfficeDocument service. This provides the methods for saving, exporting and printing documents.

The com.sun.star.frame.Desktop service is created automatically when LibreOffice is started. This service can be addressed in LibreOffice Basic using the global name StarDesktop.

The most important interface of the StarDesktop is com.sun.star.frame.XComponentLoader. This basically covers the loadComponentFromURL method, which is responsible for creating, importing, and opening documents.

Note: StarOffice 5 : The name of the StarDesktop object dates back to StarOffice 5, in which all document windows were embedded in one common application called StarDesktop. In the present version of LibreOffice, a visible StarDesktop is no longer used. The name StarDesktop was, however, retained for the frame object of LibreOffice because it clearly indicates that this is a basic object for the entire application. The StarDesktop object replaces the Application object of StarOffice 5 which previously applied as a root object. However, unlike the old Application object, StarDesktop is primarily responsible for opening new documents. The functions resident in the old Application object for controlling the on-screen depiction of LibreOffice (for example, FullScreen, FunctionBarVisible, Height, Width, Top, Visible) are no longer used.

Note: VBA : Whereas the active document in Word is accessed through Application.ActiveDocument and in Excel through Application.ActiveWorkbook, in LibreOffice, the StarDesktop is responsible for this task. The active document object is accessed in LibreOffice through the StarDesktop.CurrentComponent property, or through ThisComponent.

ThisComponent

The global name ThisComponent generally returns the same object as StarDesktop.CurrentComponent, with one significant advantage. If you are running from within the Basic IDE, debugging or exploring, then StarDesktop returns the Basic IDE itself. This is probably not what you want. ThisComponent returns the last previously active document.

Basic Information about Documents in LibreOffice

When working with LibreOffice documents, it is useful to deal with some of the basic issues of document administration in LibreOffice. This includes the way in which file names are structured for LibreOffice documents, as well as the format in which files are saved.

File Names in URL Notation

Since LibreOffice is a platform-independent application, it uses URL notation (which is independent of any operating system), as defined in the Internet Standard RFC 1738 for file names. Standard file names using this system begin with the prefix file:/// followed by the local path. If the file name contains sub-directories, then these are separated by a single forward slash, not with a backslash usually used under Windows. The following path references the test.odt file in the doc directory on the C: drive: file:///C:/doc/test.odt </syntaxhighlight>

To convert local file names into a URL, LibreOffice provides the ConvertToUrl function. To convert a URL into a local file name, LibreOffice provides the ConvertFromUrl function:

MsgBox ConvertToUrl("C:\doc\test.odt")
  ' supplies file:///C:/doc/test.odt
MsgBox ConvertFromUrl("file:///C:/doc/test.odt")
  ' supplies (under Windows) c:\doc\test.odt

The example converts a local file name into a URL and displays it in a message box. It then converts a URL into a local file name and also displays this.

The Internet Standard RFC 1738, upon which this is based, permits use of the 0-9, a-z, and A-Z characters. All other characters are inserted as escape coding in the URLs. To do this, they are converted into their hexadecimal value in the UTF-8 set of characters and are preceded by a percent sign. A space in a local file name therefore, for example, becomes a %20 in the URL.

XML File Format

LibreOffice documents are based on the XML file format. XML-based files can be opened and edited with other programs.

Compression of Files

Since XML is based on standard text files, the resultant files are usually very large. LibreOffice therefore compresses the files and saves them as a ZIP file. By means of a storeAsURL method option, the user can save the original XML files directly. See #storeAsURL Method Options, below.

Creating, Opening and Importing Documents

Documents are opened, imported and created using the method StarDesktop.loadComponentFromURL(URL, Frame, SearchFlags, FileProperties) The first parameter of loadComponentFromURL specifies the URL of the associated file.

As the second parameter, loadComponentFromURL expects a name for the frame object of the window that LibreOffice creates internally for its administration. The predefined _blank name is usually specified here, and this ensures that LibreOffice creates a new window.

Using these parameters, the user can open a LibreOffice document, since placeholders (dummy values) can be assigned to the last two parameters:

Dim Doc As Object
Dim Url As String
Dim Dummy() 'An (empty) array of PropertyValues

Url = "file:///C:/test.odt"

Doc = StarDesktop.loadComponentFromURL(Url, "_blank", 0, Dummy)

The preceding call opens the test.odt file and displays this in a new window.

Any number of documents can be opened in this way in LibreOffice Basic and then edited using the returned document objects.

Note: StarOffice 5 : StarDesktop.loadComponentFromURL supersedes the Documents.Add and Documents.Open methods from the old LibreOffice API.

Replacing the Content of the Document Window

The named _blank value for the Frame parameter ensures that LibreOffice creates a new window for every call from loadComponentFromURL. In some situations, it is useful to replace the content of an existing window. In this case, the frame object of the window should contain an explicit name. Note that this name must not begin with an underscore. Furthermore, the SearchFlags parameter must be set so that the corresponding framework is created, if it does not already exist. The corresponding constant for SearchFlags is:

SearchFlags = com.sun.star.frame.FrameSearchFlag.CREATE + _
              com.sun.star.frame.FrameSearchFlag.ALL

The following example shows how the content of an opened window can be replaced with the help of the frame parameter and SearchFlags:

Dim Doc As Object
Dim Dummy()
Dim Url As String
Dim SearchFlags As Long

SearchFlags = com.sun.star.frame.FrameSearchFlag.CREATE + _
              com.sun.star.frame.FrameSearchFlag.ALL
Url = "file:///C:/test.odt"
Doc = StarDesktop.loadComponentFromURL(Url, "MyFrame", SearchFlags, Dummy)
MsgBox "Press OK to display the second document."

Url = "file:///C:/test2.odt"
Doc = StarDesktop.loadComponentFromURL(Url, "MyFrame", _
      SearchFlags, Dummy)

The example first opens the test.odt file in a new window with the frame name of MyFrame. Once the message box has been confirmed, it replaces the content of the window with the test2.odt file.

loadComponentFromURL Method Options

The fourth parameter of the loadComponentFromURL function is a PropertyValue data field. which provides LibreOffice with various options for opening and creating documents. The data field must provide a PropertyValue structure for each option in which the name of the option is saved as a string as well as the associated value.

loadComponentFromURL supports the following options:

AsTemplate (Boolean)

if true, loads a new, untitled document from the given URL. If is false, template files are loaded for editing.

CharacterSet (String)

defines which set of characters a document is based on.

FilterName (String)

specifies a special filter for the loadComponentFromURL function. The filter names available are defined in the \share\config\registry\instance\org\openoffice\office\TypeDetection.xml file.

FilterData (String)

defines additional options for filters.

FilterOptions (String)

defines additional options (used by old filters).

Hidden (Boolean)

value true loads the document in invisible mode.

JumpMark (String)

once a document has been opened, jumps to the position defined in JumpMark.

MacroExecutionMode (Integer)

indicates if document macros may be executed. Values : see com.sun.star.document.MacroExecMode

Password (String)

transfers a password for a protected file.

ReadOnly (Boolean)

value true loads a document in read-only mode.

UpdateDocMode (Integer)

indicates how/if links will be updated. Values : see com.sun.star.document.UpdateDocMode

The following example shows how a text file separated by a comma in LibreOffice Calc can be opened using the FilterName option.

Dim Doc As Object
Dim FileProperties(1) As New com.sun.star.beans.PropertyValue
Dim Url As String

Url = "file:///C:/doc.csv"
FileProperties(0).Name = "FilterName"
FileProperties(0).Value ="Text - txt - csv (StarCalc)"
FileProperties(1).Name = "FilterOptions"
FileProperties(1).value = "44,34,0,1"

Doc = StarDesktop.loadComponentFromURL(Url, "_blank", 0, FileProperties())

The FileProperties array has two elements, one for each option used. The Filtername property defines whether LibreOffice uses a LibreOffice Calc text filter to open files. The FilterOptions property contains the description of the syntax of the csv file.

Creating New Documents

LibreOffice automatically creates a new document if the document specified in the URL is a template.

Alternatively, if only an empty document without any adaptation is needed, a private:factory URL can be specified:

Dim Dummy()
Dim Url As String
Dim Doc As Object

Url = "private:factory/swriter"
Doc = StarDesktop.loadComponentFromURL(Url, "_blank", 0, Dummy())

The call creates an empty LibreOffice writer document.

Document Objects

The loadComponentFromURL function introduced in the previous section returns a document object. This supports the com.sun.star.document.OfficeDocument service, which in turn provides two central interfaces:

• The com.sun.star.frame.XStorable interface, which is responsible for saving documents.
• The com.sun.star.view.XPrintable interface, which contains the methods for printing documents.

Saving and Exporting Documents

LibreOffice documents are saved directly through the document object. The store method of the com.sun.star.frame.XStorable interface is available for this purpose:

Doc.store()

This call functions provided that the document has already been assigned a memory space. This is not the case for new documents. In this instance, the storeAsURL method is used. This method is also defined in com.sun.star.frame.XStorable and can be used to define the location of the document:

Dim URL As String
Dim Dummy()

Url = "file:///C:/test3.odt"
Doc.storeAsURL(URL, Dummy())

In addition to the preceding methods, com.sun.star.frame.XStorable also provides some help methods which are useful when saving documents. These are:

hasLocation()

specifies whether the document has already been assigned a URL.

isReadonly()

specifies whether a document has read-only protection.

isModified()

specifies whether a document has been modified since it was last saved.

The code for saving a document can be extended by these options so that the document is only saved if the object has actually been modified and the file name is only queried if it is actually needed:

If (Doc.isModified) Then
  If (Doc.hasLocation And (Not Doc.isReadOnly)) Then
    Doc.store()
  Else
    Doc.storeAsURL(URL, Dummy())
  End If
End If

The example first checks whether the relevant document has been modified since it was last saved. It only continues with the saving process if this is the case. If the document has already been assigned a URL and is not a read-only document, it is saved under the existing URL. If it does not have a URL or was opened in its read-only status, it is saved under a new URL.

storeAsURL Method Options

As with the loadComponentFromURL method, some options can also be specified in the form of a PropertyValue data field using the storeAsURL method. These determine the procedure LibreOffice uses when saving a document. storeAsURL provides the following options:

CharacterSet (String)

defines which set of characters a document is based on.

FilterName (String)

specifies a special filter for the loadComponentFromURL function. The filter names available are defined in the \share\config\registry\instance\org\openoffice\office\TypeDetection.xml file.

FilterData (String)

defines additional options for filters.

FilterOptions (String)

defines additional options (used by old filters).

Overwrite (Boolean)

allows a file which already exists to be overwritten without a query.

Password (String)

transfers the password for a protected file.

Unpacked (Boolean)

saves the document (not compressed) in sub-directories.

The possibility to store documents in unpacked way is not currently supported, the "Unpacked" property is just ignored, see Issue 64364.

The following example shows how the Overwrite option can be used in conjunction with storeAsURL:

Dim Doc As Object
Dim FileProperties(0) As New com.sun.star.beans.PropertyValue
Dim Url As String
' ... Initialize Doc

Url = "file:///c:/test3.odt"
FileProperties(0).Name = "Overwrite"
FileProperties(0).Value = True
Doc.storeAsURL(Url, FileProperties())

The example then saves Doc under the specified file name if a file already exists under the name.

Printing Documents

Similar to saving, documents are printed out directly by means of the document object. The Print method of the com.sun.star.view.Xprintable interface is provided for this purpose. In its simplest form, the print call is:

Dim Dummy()

Doc.print(Dummy())

As in the case of the loadComponentFromURL method, the Dummy parameter is a PropertyValue data field through which LibreOffice can specify several options for printing.

The options of the print method

The print method expects a PropertyValue data field as a parameter, which reflects the settings of the print dialog of LibreOffice:

CopyCount (Integer)

specifies the number of copies to be printed.

FileName (String)

prints the document in the specified file.

Collate (Boolean)

advises the printer to collate the pages of the copies.

Sort (Boolean)

sorts the pages when printing out several copies (CopyCount > 1).

Pages (String)

contains the list of the pages to be printed (syntax as specified in print dialog).

Wait (Boolean)

if set to True the print method will return after the job is stored on the waiting list for the printer. Use this option if you want to close the document after print.

The following example shows how several pages of a document can be printed out using the Pages option:

Dim Doc As Object
Dim PrintProperties(1) As New com.sun.star.beans.PropertyValue

PrintProperties(0).Name="Pages"
PrintProperties(0).Value="1-3; 7; 9"
PrintProperties(1).Name="Wait"
PrintProperties(1).Value=True
Doc.print(PrintProperties())

Printer selection and settings

The com.sun.star.view.XPrintable interface provides the Printer property, which selects the printer. This property receives a PropertyValue data field with the following settings:

Name (String)

specifies the name of printer.

PaperOrientation (Enum)

specifies the paper orientation (com.sun.star.view.PaperOrientation.PORTRAIT value for portrait format, com.sun.star.view.PaperOrientation.LANDSCAPE for landscape format).

PaperFormat (Enum)

specifies the paper format (for example, com.sun.star.view.PaperFormat.A4 for DIN A4 or com.sun.star.view.PaperFormat.Letter for US letters).

PaperSize (Size)

specifies the paper size in hundredths of a millimeter.

The following example shows how a printer can be changed and the paper size set with the help of the Printer property.

Dim Doc As Object
Dim PrinterProperties(1) As New com.sun.star.beans.PropertyValue
Dim PaperSize As New com.sun.star.awt.Size

PaperSize.Width = 20000  ' corresponds to 20 cm
PaperSize.Height = 20000  ' corresponds to 20 cm
PrinterProperties (0).Name="Name"
PrinterProperties (0).Value="My HP Laserjet"
PrinterProperties (1).Name="PaperSize"
PrinterProperties (1).Value=PaperSize
Doc.Printer = PrinterProperties()

The example defines an object named PaperSize with the com.sun.star.awt.Size type. This is needed to specify the paper size. Furthermore, it creates a data field for two PropertyValue entries named PrinterProperties. This data field is then initialized with the values to be set and assigned the Printer property. From the standpoint of UNO, the printer is not a real property but an imitated one.

Styles and Templates

Styles

Styles are named lists containing formatting attributes. They work in all applications of LibreOffice and help to significantly simplify formatting. If the user changes one of the attributes of a style, then LibreOffice automatically adjusts all document sections depending on the attribute. The user can therefore, for example, change the font type of all level one headers by means of a central modification in the document.

Style Types

Depending on the relevant document types, LibreOffice recognizes a whole range of different types of styles.

LibreOffice Writer supports the following types of styles:

• Character styles
• Paragraph styles
• Frame styles
• Page styles
• Numbering styles

LibreOffice Calc supports the following types of styles:

• Cell styles
• Page styles

LibreOffice Impress supports the following types of styles:

• Character element styles
• Presentation styles

In LibreOffice terminology, the different types of styles are called StyleFamilies in accordance with the com.sun.star.style.StyleFamily service on which they are based. The StyleFamilies are accessed by means of the document object:

Dim Doc As Object
Dim Sheet As Object
Dim StyleFamilies As Object
Dim CellStyles As Object

Doc = ThisComponent
StyleFamilies = Doc.StyleFamilies
CellStyles = StyleFamilies.getByName("CellStyles")

The example uses the StyleFamilies property of a spreadsheet document to establish a list containing all available cell styles.

The individual styles can be accessed directly by means of an index:

Dim Doc As Object
Dim Sheet As Object
Dim StyleFamilies As Object
Dim CellStyles As Object
Dim CellStyle As Object
Dim I As Integer

Doc = ThisComponent
StyleFamilies = Doc.StyleFamilies
CellStyles = StyleFamilies.getByName("CellStyles")

For I = 0 To CellStyles.Count - 1
  CellStyle = CellStyles(I)
  MsgBox CellStyle.Name
Next I

The loop added since the previous example displays the names of all cell styles one after another in a message box.

Note: The reference CellStyles(I) corresponds to the method getByIndex(), which is optional for these style container objects. It may not be available in all types of documents. The method getByName() is mandatory, and should always be available.

Details about various formatting options

Each type of style provides a whole range of individual formatting properties. Here is an overview of the most important formatting properties and the points at which they are explained:

• #Character properties, com.sun.star.style.CharacterProperties service
• #Paragraph properties, com.sun.star.text.Paragraph service
• #Cell properties, com.sun.star.table.CellProperties service
• #Page properties, com.sun.star.style.PageProperties service
• #Character element properties, Various services

The format properties are by no means restricted to the applications in which these are explained, but instead can be used universally. For example, most of the page properties described in #Spreadsheets can therefore be used not only in LibreOffice Calc, but also in LibreOffice Writer.

More information about working with styles can be found in the '''#Default values for character and paragraph properties''' section in #Text Documents.

Templates

Templates are auxiliary documents. They provide a very convenient way to store, maintain, and distribute styles, macros, boiler-plate text, and other useful things.

Document and Template Types

Each major type of LibreOffice document has its own associated template type. In general, and for styles in particular, you can access information within a template in the same way you would access the same information in the associated document type. In other words, code (like the above examples) that works in a particular document type should also work for the associated template type.

Automatic Update

Most template types – Draw templates are the exception – have an automatic-update feature. If a style in the template has been changed, and you open a document created with that template, you will see a message asking whether to update the styles in the document. If you click on Yes, the new or changed styles will be copied into the document. Styles deleted from the template are not removed from documents.

A problem may arise if you click on No: the styles will not be updated, and the automatic-update feature will be turned off. As of LibreOffice Version 3.3, this status does not show in the GUI, nor is there any GUI way to re-enable the feature. (For Writer documents only, you can use the Template Changer extension to set this feature again.)

The following subroutine, adapted from the Template Changer extension, will re-enable the update feature for all document types.

Sub FixUpdate
Dim oDocSettings as Object
  oDocSettings = ThisComponent.createInstance( "com.sun.star.document.Settings" )
  oDocSettings.UpdateFromTemplate = True
End Sub 'FixUpdate

Text Documents

In addition to pure strings, text documents also contain formatting information. These may appear at any point in the text. The structure is further complicated by tables. These include not only single-dimensional strings, but also two-dimensional fields. Most word processing programs now finally provide the option of placing drawing objects, text frames and other objects within a text. These may be outside the flow of text and can be positioned anywhere on the page.

This chapter presents the central interfaces and services of text documents.

• #The Structure of Text Documents
• #Editing Text Documents
• #More than Just Text

The first section deals with the anatomy of text documents and concentrates on how a LibreOffice Basic program can be used to take iterative steps through a LibreOffice document. It focuses on paragraphs, paragraph portions and their formatting.

The second section focuses on efficiently working with text documents. For this purpose, LibreOffice provides several help objects, such as the TextCursor object, which extend beyond those specified in the first section.

The third section moves beyond work with texts. It concentrates on tables, text frames, text fields, bookmarks, content directories and more.

Information about how to create, open, save and print documents is described in #Working with Documents, because it can be used not only for text documents, but also for other types of documents.

The Structure of Text Documents

A text document can essentially contain four types of information:

• The actual text
• Templates for formatting characters, paragraphs, and pages
• Non-text elements such as tables, graphics and drawing objects
• Global settings for the text document

This section concentrates on the text and associated formatting options.

Paragraphs and Paragraph Portions

The core of a text document consists of a sequence of paragraphs. These are neither named nor indexed and there is therefore no possible way of directly accessing individual paragraphs. The paragraphs can however be sequentially traversed with the help of the Enumeration object described in #Introduction to the API. This allows the paragraphs to be edited.

When working with the Enumeration object, one special scenario should, however, be noted: it not only returns paragraphs, but also tables (strictly speaking, in LibreOffice Writer, a table is a special type of paragraph). Before accessing a returned object, you should therefore check whether the returned object supports the com.sun.star.text.Paragraph service for paragraphs or the com.sun.star.text.TextTable service for tables.

The following example traverses the contents of a text document in a loop and uses a message in each instance to inform the user whether the object in question is a paragraph or table.

Dim Doc As Object
Dim Enum As Object
Dim TextElement As Object

' Create document object
Doc = ThisComponent
' Create enumeration object
Enum = Doc.Text.createEnumeration
' loop over all text elements

While Enum.hasMoreElements
  TextElement = Enum.nextElement

  If TextElement.supportsService("com.sun.star.text.TextTable") Then
    MsgBox "The current block contains a table."
  End If

  If TextElement.supportsService("com.sun.star.text.Paragraph") Then
    MsgBox "The current block contains a paragraph."
  End If

Wend

The example creates a Doc document object which references the current LibreOffice document. With the aid of Doc, the example then creates an Enumeration object that traverses through the individual parts of the text (paragraphs and tables) and assigns the current element to TextElement object. The example uses the supportsService method to check whether the TextElement is a paragraph or a table.

Paragraphs

The com.sun.star.text.Paragraph service grants access to the content of a paragraph. The text in the paragraph can be retrieved and modified using the String property:

Dim Doc As Object
Dim Enum As Object
Dim TextElement As Object

Doc = ThisComponent
Enum = Doc.Text.createEnumeration

While Enum.hasMoreElements
  TextElement = Enum.nextElement

  If TextElement.supportsService("com.sun.star.text.Paragraph") Then
    TextElement.String = Replace(TextElement.String, "you", "U")
    TextElement.String = Replace(TextElement.String, "too", "2")
    TextElement.String = Replace(TextElement.String, "for", "4")
  End If

Wend

The example opens the current text document and passes through it with the help of the Enumeration object. It uses the TextElement.String property in all paragraphs to access the relevant paragraphs and replaces the you, too and for strings with the U, 2 and 4 characters. The Replace function used for replacing does not fall within the standard linguistic scope of LibreOffice Basic. This is an instance of the example function described in #Search and Replace.

Note: VBA : The content of the procedure described here for accessing the paragraphs of a text is comparable with the Paragraphs listing used in VBA, which is provided in the Range and Document objects available there. Whereas in VBA the paragraphs are accessed by their number (for example, by the Paragraph(1) call), in LibreOffice Basic, the Enumeration object described previously should be used.

There is no direct counterpart in LibreOffice Basic for the Characters, Sentences and Words lists provided in VBA. You do, however, have the option of switching to a TextCursor which allows for navigation at the level of characters, sentences and words.

Paragraph Portions

The previous example may change the text as requested, but it may sometimes also destroy the formatting.

This is because a paragraph in turn consists of individual sub-objects. Each of these sub-objects contains its own formatting information. If the center of a paragraph, for example, contains a word printed in bold, then it will be represented in LibreOffice by three paragraph portions: the portion before the bold type, then the word in bold, and finally the portion after the bold type, which is again depicted as normal.

If the text of the paragraph is now changed using the paragraph's String property, then LibreOffice first deletes the old paragraph portions and inserts a new paragraph portion. The formatting of the previous sections is then lost.

To prevent this effect, the user can access the associated paragraph portions rather than the entire paragraph. Paragraphs provide their own Enumeration object for this purpose. The following example shows a double loop which passes over all paragraphs of a text document and the paragraph portions they contain and applies the replacement processes from the previous example:

Dim Doc As Object
Dim Enum1 As Object
Dim Enum2 As Object
Dim TextElement As Object
Dim TextPortion As Object

Doc = ThisComponent
Enum1 = Doc.Text.createEnumeration

' loop over all paragraphs
While Enum1.hasMoreElements
  TextElement = Enum1.nextElement

  If TextElement.supportsService("com.sun.star.text.Paragraph") Then
    Enum2 = TextElement.createEnumeration
    ' loop over all sub-paragraphs

    While Enum2.hasMoreElements
      TextPortion = Enum2.nextElement
      MsgBox "'" & TextPortion.String & "'"
      TextPortion.String = Replace(TextPortion.String, "you", "U")
      TextPortion.String = Replace(TextPortion.String, "too", "2")
      TextPortion.String = Replace(TextPortion.String, "for", "4")
    Wend

  End If
Wend

The example runs through a text document in a double loop. The outer loop refers to the paragraphs of the text. The inner loop processes the paragraph portions in these paragraphs. The example code modifies the content in each of these paragraph portions using the String property of the string. as is the case in the previous example for paragraphs. Since however, the paragraph portions are edited directly, their formatting information is retained when replacing the string.

Formatting

There are various ways of formatting text. The easiest way is to assign the format properties directly to the text sequence. This is called direct formatting. Direct formatting is used in particular with short documents because the formats can be assigned by the user with the mouse. You can, for example, highlight a certain word within a text using bold type or center a line.

In addition to direct formatting, you can also format text using templates. This is called indirect formatting. With indirect formatting, the user assigns a pre-defined template to the relevant text portion. If the layout of the text is changed at a later date, the user only needs to change the template. LibreOffice then changes the way in which all text portions which use this template are depicted.

Note: VBA : In VBA, the formatting properties of an object are usually spread over a range of sub-objects (for example, Range.Font, Range.Borders, Range.Shading, Range.ParagraphFormat). The properties are accessed by means of cascading expressions (for example, Range.Font.AllCaps). In LibreOffice Basic, the formatting properties on the other hand are available directly, using the relevant objects (TextCursor, Paragraph, and so on). You will find an overview of the character and paragraph properties available in LibreOffice in the following two sections.

Note: The formatting properties can be found in each object (Paragraph, TextCursor, and so on) and can be applied directly.

Character Properties

Those format properties that refer to individual characters are described as character properties. These include bold type and the font type. Objects that allow character properties to be set have to support the com.sun.star.style.CharacterProperties service. LibreOffice recognizes a whole range of services that support this service. These include the previously described com.sun.star.text.Paragraph services for paragraphs as well as the com.sun.star.text.TextPortion services for paragraph portions.

The com.sun.star.style.CharacterProperties service does not provide any interfaces, but instead offers a range of properties through which character properties can be defined and called. A complete list of all character properties can be found in the LibreOffice API reference. The following list describes the most important properties:

CharFontName (String)

name of font type selected.

CharColor (Long)

text color.

CharHeight (Float)

character height in points (pt).

CharUnderline (Constant group)

type of underscore (constants in accordance with com.sun.star.awt.FontUnderline ).

CharWeight (Constant group)

font weight (constants in accordance with com.sun.star.awt.FontWeight).

CharBackColor (Long)

background color.

CharKeepTogether (Boolean)

suppression of automatic line break.

CharStyleName (String)

name of character template.

Paragraph Properties

Formatting information that does not refer to individual characters, but to the entire paragraph is considered to be a paragraph property. This includes the distance of the paragraph from the edge of the page as well as line spacing. The paragraph properties are available through the com.sun.star.style.ParagraphProperties service.

Even the paragraph properties are available in various objects. All objects that support the com.sun.star.text.Paragraph service also provide support for the paragraph properties in com.sun.star.style.ParagraphProperties.

A complete list of the paragraph properties can be found in the LibreOffice API reference. The most common paragraph properties are:

ParaAdjust (enum)

vertical text orientation (constants in accordance with com.sun.star.style.ParagraphAdjust ).

ParaLineSpacing (struct)

line spacing (structure in accordance with com.sun.star.style.LineSpacing).

ParaBackColor (Long)

background color.

ParaLeftMargin (Long)

left margin in 100ths of a millimeter.

ParaRightMargin (Long)

right margin in 100ths of a millimeter.

ParaTopMargin (Long)

top margin in 100ths of a millimeter.

ParaBottomMargin (Long)

bottom margin in 100ths of a millimeter.

ParaTabStops (Array of struct)

type and position of tabs (array with structures of the type com.sun.star.style.TabStop ).

ParaStyleName (String)

name of the paragraph template.

Example: simple HTML export

The following example demonstrates how to work with formatting information. It iterates through a text document and creates a simple HTML file. Each paragraph is recorded in its own HTML element <P> for this purpose. Paragraph portions displayed in bold type are marked using a <B> HTML element when exporting.

Dim FileNo As Integer, Filename As String, CurLine As String
Dim Doc As Object
Dim Enum1 As Object, Enum2 As Object
Dim TextElement As Object, TextPortion As Object

Filename = "c:\text.html"
FileNo = Freefile
Open Filename For Output As #FileNo
Print #FileNo, "<HTML><BODY>"
Doc = ThisComponent
Enum1 = Doc.Text.createEnumeration

' loop over all paragraphs
While Enum1.hasMoreElements
  TextElement = Enum1.nextElement

  If TextElement.supportsService("com.sun.star.text.Paragraph") Then
    Enum2 = TextElement.createEnumeration
    CurLine = "<P>"

    ' loop over all paragraph portions
    While Enum2.hasMoreElements
      TextPortion = Enum2.nextElement

      If TextPortion.CharWeight = com.sun.star.awt.FontWeight.BOLD THEN
        CurLine = CurLine & "<B>" & TextPortion.String & "</B>"
      Else
        CurLine = CurLine & TextPortion.String
      End If

    Wend

    ' output the line
    CurLine = CurLine & "</P>"
    Print #FileNo, CurLine
  End If

Wend

' write HTML footer
Print #FileNo, "</BODY></HTML>"
Close #FileNo

The basic structure of the example is oriented towards the examples for running though the paragraph portions of a text already discussed previously. The functions for writing the HTML file, as well as a test code that checks the font weight of the corresponding text portions and provides paragraph portions in bold type with a corresponding HTML tag, have been added.

Default values for character and paragraph properties

Direct formatting always takes priority over indirect formatting. In other words, formatting using templates is assigned a lower priority than direct formatting in a text.

Establishing whether a section of a document has been directly or indirectly formatted is not easy. The symbol bars provided by LibreOffice show the common text properties such as font type, weight and size. However, whether the corresponding settings are based on template or direct formatting in the text is still unclear.

LibreOffice Basic provides the getPropertyState method, with which programmers can check how a certain property was formatted. As a parameter, this takes the name of the property and returns a constant that provides information about the origin of the formatting. The following responses, which are defined in the com.sun.star.beans.PropertyState enumeration, are possible:

• com.sun.star.beans.PropertyState.DIRECT_VALUE

  the property is defined directly in the text (direct formatting)

• com.sun.star.beans.PropertyState.DEFAULT_VALUE

  the property is defined by a template (indirect formatting)

• com.sun.star.beans.PropertyState.AMBIGUOUS_VALUE

  the property is unclear. This status arises, for example, when querying the bold type property of a paragraph, which includes both words depicted in bold and words depicted in normal font.

The following example shows how format properties can be edited in LibreOffice. It searches through a text for paragraph portions which have been depicted as bold type using direct formatting. If it encounters a corresponding paragraph portion, it deletes the direct formatting using the setPropertyToDefault method and assigns a MyBold character template to the corresponding paragraph portion.

Dim Doc As Object
Dim Enum1 As Object
Dim Enum2 As Object
Dim TextElement As Object
Dim TextPortion As Object

Doc = ThisComponent
Enum1 = Doc.Text.createEnumeration

' loop over all paragraphs
While Enum1.hasMoreElements
  TextElement = Enum1.nextElement

  If TextElement.supportsService("com.sun.star.text.Paragraph") Then
    Enum2 = TextElement.createEnumeration
    ' loop over all paragraph portions

    While Enum2.hasMoreElements
      TextPortion = Enum2.nextElement

      If TextPortion.CharWeight = _
        com.sun.star.awt.FontWeight.BOLD AND _
        TextPortion.getPropertyState("CharWeight") = _
        com.sun.star.beans.PropertyState.DIRECT_VALUE Then
          TextPortion.setPropertyToDefault("CharWeight")
          TextPortion.CharStyleName = "MyBold"
      End If
    Wend
  End If
Wend

Editing Text Documents

The previous section has already discussed a whole range of options for editing text documents, focusing on the com.sun.star.text.TextPortion and com.sun.star.text.Paragraph services, which grant access to paragraph portions as well as paragraphs. These services are appropriate for applications in which the content of a text is to be edited in one pass through a loop. However, this is not sufficient for many problems. LibreOffice provides the com.sun.star.text.TextCursor service for more complicated tasks, including navigating backward within a document or navigating based on sentences and words rather than TextPortions.

The TextCursor

A TextCursor in the LibreOffice API is comparable with the visible cursor used in a LibreOffice document. It marks a certain point within a text document and can be navigated in various directions through the use of commands. The TextCursor objects available in LibreOffice Basic should not, however, be confused with the visible cursor. These are two very different things.

Note: VBA : Terminology differs from that used in VBA: In terms of scope of function, the Range object from VBA can be compared with the TextCursor object in LibreOffice and not — as the name possibly suggests — with the Range object in LibreOffice.

The TextCursor object in LibreOffice, for example, provides methods for navigating and changing text which are included in the Range object in VBA (for example, MoveStart, MoveEnd, InsertBefore, InsertAfter). The corresponding counterparts of the TextCursor object in LibreOffice are described in the following sections.

Navigating within a Text

The TextCursor object in LibreOffice Basic acts independently from the visible cursor in a text document. A program-controlled position change of a TextCursor object has no impact whatsoever on the visible cursor. Several TextCursor objects can even be opened for the same document and used in various positions, which are independent of one another.

A TextCursor object is created using the createTextCursor call:

Dim Doc As Object
Dim Cursor As Object

Doc = ThisComponent
Cursor = Doc.Text.createTextCursor()

The Cursor object created in this way supports the com.sun.star.text.TextCursor service, which in turn provides a whole range of methods for navigating within text documents. The following example first moves the TextCursor ten characters to the left and then three characters to the right:

Cursor.goLeft(10, False)
Cursor.goRight(3, False)

A TextCursor can highlight a complete area. This can be compared with highlighting a point in the text using the mouse. The False parameter in the previous function call specifies whether the area passed over with the cursor movement is highlighted. For example, the TextCursor in the following example

Cursor.goRight(10, False)
Cursor.goLeft(3, True)

first moves ten characters to the right without highlighting, and then moves back three characters and highlights this. The area highlighted by the TextCursor therefore begins after the seventh character in the text and ends after the tenth character.

Here are the central methods that the com.sun.star.text.TextCursor service provides for navigation:

goLeft (Count, Expand)

jumps Count characters to the left.

goRight (Count, Expand)

jumps Count characters to the right.

gotoStart (Expand)

jumps to the start of the text document.

gotoEnd (Expand)

jumps to the end of the text document.

gotoRange (TextRange, Expand)

jumps to the specified TextRange-Object.

gotoStartOfWord (Expand)

jumps to the start of the current word.

gotoEndOfWord (Expand)

jumps to the end of the current word.

gotoNextWord (Expand)

jumps to the start of the next word.

gotoPreviousWord (Expand)

jumps to the start of the previous word.

isStartOfWord ()

returns True if the TextCursor is at the start of a word.

isEndOfWord ()

returns True if the TextCursor is at the end of a word.

gotoStartOfSentence (Expand)

jumps to the start of the current sentence.

gotoEndOfSentence (Expand)

jumps to the end of the current sentence.

gotoNextSentence (Expand)

jumps to the start of the next sentence.

gotoPreviousSentence (Expand)

jumps to the start of the previous sentence.

isStartOfSentence ()

returns True if the TextCursor is at the start of a sentence.

isEndOfSentence ()

returns True if the TextCursor is at the end of a sentence.

gotoStartOfParagraph (Expand)

jumps to the start of the current paragraph.

gotoEndOfParagraph (Expand)

jumps to the end of the current paragraph.

gotoNextParagraph (Expand)

jumps to the start of the next paragraph.

gotoPreviousParagraph (Expand)

jumps to the start of the previous paragraph.

isStartOfParagraph ()

returns True if the TextCursor is at the start of a paragraph.

isEndOfParagraph ()

returns True if the TextCursor is at the end of a paragraph.

The text is divided into sentences on the basis of sentence symbols. Periods are, for example, interpreted as symbols indicating the end of sentences. (In English, at least, they must be followed by a space, tab, or return for this to work.)

The Expand parameter is a Boolean value which specifies whether the area passed over during navigation is to be highlighted. All navigation methods furthermore return a Boolean parameter which specifies whether the navigation was successful or whether the action was terminated for lack of text.

The following is a list of several methods for editing highlighted areas using a TextCursor and which also support the com.sun.star.text.TextCursor service:

collapseToStart ()

resets the highlighting and positions the TextCursor at the start of the previously highlighted area.

collapseToEnd ()

resets the highlighting and positions the TextCursor at the end of the previously highlighted area.

isCollapsed ()

returns True if the TextCursor does not cover any highlighting at present.

Formatting Text with TextCursor

The com.sun.star.text.TextCursor service supports all the character and paragraph properties that were presented at the start of this chapter.

The following example shows how these can be used in conjunction with a TextCursor. It passes through a complete document and formats the first word of every sentence in bold type.

Dim Doc As Object
Dim Cursor As Object
Dim Proceed As Boolean

Doc = ThisComponent
Cursor = Doc.Text.createTextCursor

Do
  Cursor.gotoEndOfWord(True)
  Cursor.CharWeight = com.sun.star.awt.FontWeight.BOLD
  Proceed = Cursor.gotoNextSentence(False)
  Cursor.gotoNextWord(False)
Loop While Proceed

The example first creates a document object for the text that has just been opened. Then it iterates through the entire text, sentence by sentence, and highlights each of the first words and formats this in bold.

Retrieving and Modifying Text Contents

If a TextCursor contains a highlighted area, then this text is available by means of the String property of the TextCursor object. The following example uses the String property to display the first words of a sentence in a message box:

Dim Doc As Object
Dim Cursor As Object
Dim Proceed As Boolean

Doc = ThisComponent
Cursor = Doc.Text.createTextCursor

Do
  Cursor.gotoEndOfWord(True)
  MsgBox Cursor.String
  Proceed = Cursor.gotoNextSentence(False)
  Cursor.gotoNextWord(False)
Loop While Proceed

The first word of each sentence can be modified in the same way using the String property:

Dim Doc As Object
Dim Cursor As Object
Dim Proceed As Boolean

Doc = ThisComponent
Cursor = Doc.Text.createTextCursor

Do
  Cursor.gotoEndOfWord(True)
  Cursor.String = "Ups"
  Proceed = Cursor.gotoNextSentence(False)
  Cursor.gotoNextWord(False)
Loop While Proceed

If the TextCursor contains a highlighted area, an assignment to the String property replaces this with the new text. If there is no highlighted area, the text is inserted at the present TextCursor position.

Inserting Control Codes

In some situations, it is not the actual text of a document, but rather its structure that needs modifying. LibreOffice provides control codes for this purpose. These are inserted in the text and influence its structure. The control codes are defined in the com.sun.star.text.ControlCharacter group of constants. The following control codes are available in LibreOffice:

PARAGRAPH_BREAK

paragraph break.

LINE_BREAK

line break within a paragraph.

SOFT_HYPHEN

possible point for syllabification.

HARD_HYPHEN

obligatory point for syllabification.

HARD_SPACE

protected space that is not spread out or compressed in justified text.

To insert the control codes, you need not only the cursor but also the associated text document objects. The following example inserts a paragraph after the 20th character of a text:

Dim Doc As Object
Dim Cursor As Object
Dim Proceed As Boolean

Doc = ThisComponent
Cursor = Doc.Text.createTextCursor
Cursor.goRight(20, False)
Doc.Text.insertControlCharacter(Cursor, _
    com.sun.star.text.ControlCharacter.PARAGRAPH_BREAK, False)

The False parameter in the call of the insertControlCharacter method ensures that the area currently highlighted by the TextCursor remains after the insert operation. If the True parameter is passed here, then insertControlCharacter replaces the current text.

Searching for Text Portions

In many instances, it is the case that a text is to be searched for a particular term and the corresponding point needs to be edited. All LibreOffice documents provide a special interface for this purpose, and this interface always functions in accordance with the same principle: Before a search process, what is commonly referred to as a SearchDescriptor must first be created. This defines what LibreOffice searches for in a document. A SearchDescriptor is an object which supports the com.sun.star.util. SearchDescriptor service and can be created by means of the createSearchDescriptor method of a document:

Dim SearchDesc As Object
SearchDesc = Doc.createSearchDescriptor

Once the SearchDescriptor has been created, it receives the text to be searched for:

SearchDesc.searchString="any text"

In terms of its function, the SearchDescriptor is best compared with the search dialog from LibreOffice. In a similar way to the search window, the settings needed for a search can be set in the SearchDescriptor object.

The properties are provided by the com.sun.star.util.SearchDescriptor service:

SearchBackwards (Boolean)

searches through the text backward rather than forward.

SearchCaseSensitive (Boolean)

takes uppercase and lowercase characters into consideration during the search.

SearchRegularExpression (Boolean)

treats the search expression like a regular expression.

SearchStyles (Boolean)

searches through the text for the specified paragraph template.

SearchWords (Boolean)

only searches for complete words.

The LibreOffice SearchSimilarity (or “fuzzy match”) function is also available in LibreOffice Basic. With this function, LibreOffice searches for an expression that may be similar to but not exactly the same as the search expression. The number of additional, deleted and modified characters for these expressions can be defined individually. Here are the associated properties of the com.sun.star.util.SearchDescriptor service:

SearchSimilarity (Boolean)

performs a similarity search.

SearchSimilarityAdd (Short)

number of characters which may be added for a similarity search.

SearchSimilarityExchange (Short)

number of characters which may be replaced as part of a similarity search.

SearchSimilarityRemove (Short)

number of characters which may be removed as part of a similarity search.

SearchSimilarityRelax (Boolean)

takes all deviation rules into consideration at the same time for the search expression.

Once the SearchDescriptor has been prepared as requested, it can be applied to the text document. The LibreOffice documents provide the findFirst and findNext methods for this purpose:

Found = Doc.findFirst (SearchDesc)

Do Until IsNull(Found)
  ' Edit search results...
  Found = Doc.findNext( Found.End, SearchDesc)
Loop

The example finds all matches in a loop and returns a TextRange object, which refers to the found text passage.

Example: Similarity Search

This example shows how a text can be searched for the word "turnover" and the results formatted in bold type. A similarity search is used so that not only the word “turnover”, but also the plural form "turnovers" and declinations such as "turnover's" are found. The found expressions differ by up to two letters from the search expression:

Dim SearchDesc As Object
Dim Doc As Object

Doc = ThisComponent
SearchDesc = Doc.createSearchDescriptor
SearchDesc.SearchString="turnover"
SearchDesc.SearchSimilarity = True
SearchDesc.SearchSimilarityAdd = 2
SearchDesc.SearchSimilarityExchange = 2
SearchDesc.SearchSimilarityRemove = 2
SearchDesc.SearchSimilarityRelax = False
Found = Doc.findFirst (SearchDesc)

Do Until IsNull(Found)
  Found.CharWeight = com.sun.star.awt.FontWeight.BOLD
  Found = Doc.findNext( Found.End, SearchDesc)
Loop

Note: VBA : The basic idea of search and replace in LibreOffice is comparable to that used in VBA. Both interfaces provide you with an object, through which the properties for searching and replacing can be defined. This object is then applied to the required text area in order to perform the action. Whereas the responsible auxiliary object in VBA can be reached through the Find property of the Range object, in LibreOffice Basic it is created by the createSearchDescriptor or createReplaceDescriptor call of the document object. Even the search properties and methods available differ.

As in the old API from LibreOffice, searching and replacing text in the new API is also performed using the document object. Whereas previously there was an object called SearchSettings especially for defining the search options, in the new object searches are now performed using a SearchDescriptor or ReplaceDescriptor object for automatically replacing text. These objects cover not only the options, but also the current search text and, if necessary, the associated text replacement. The descriptor objects are created using the document object, completed in accordance with the relevant requests, and then transferred back to the document object as parameters for the search methods.

Replacing Text Portions

Just as with the search function, the replacement function from LibreOffice is also available in LibreOffice Basic. The two functions are handled identically. A special object which records the parameters for the process is also first needed for a replacement process. It is called a ReplaceDescriptor and supports the com.sun.star.util.ReplaceDescriptor service. All the properties of the SearchDescriptor described in the previous paragraph are also supported by ReplaceDescriptor. For example, during a replacement process, case sensitivity can also be activated and deactivated, and similarity searches can be performed.

The following example demonstrates the use of ReplaceDescriptors for a search within a LibreOffice document.

Dim I As Long
Dim Doc As Object
Dim Replace As Object
Dim BritishWords(5) As String
Dim USWords(5) As String

BritishWords() = Array("colour", "neighbour", "centre", "behaviour", _
  "metre", "through")
USWords() = Array("color", "neighbor", "center", "behavior", _
  "meter", "thru")

Doc = ThisComponent
Replace = Doc.createReplaceDescriptor

For I = 0 To 5
  Replace.SearchString = BritishWords(I)
  Replace.ReplaceString = USWords(I)
  Doc.replaceAll(Replace)
Next I

The expressions for searching and replacing are set using the SearchString and ReplaceString properties of the ReplaceDescriptors. The actual replacement process is finally implemented using the replaceAll method of the document object, which replaces all occurrences of the search expression.

Example: searching and replacing text with regular expressions

The replacement function of LibreOffice is particularly effective when used in conjunction with regular expressions. These provide the option of defining a variable search expression with placeholders and special characters rather than a fixed value.

The regular expressions supported by LibreOffice are described in detail in the online help section for LibreOffice. Here are a few examples:

• A period within a search expression stands for any character. The search expression sh.rt therefore can stand for both for shirt and for short.
• The character ^ marks the start of a paragraph. All occurrences of the name Peter that are at the start of a paragraph can therefore be found using the search expression ^Peter.
• The character $ marks a paragraph end. All occurrences of the name Peter that are at the end of a paragraph can therefore be found using the search expression Peter$.
• A * indicates that the preceding character may be repeated any number of times. It can be combined with the period as a placeholder for any character. The temper.*e expression, for example, can stand for the expressions temperance and temperature.

The following example shows how all empty lines in a text document can be removed with the help of the regular expression ^$:

Dim Doc As Object
Dim Replace As Object
Dim I As Long

Doc = ThisComponent
Replace = Doc.createReplaceDescriptor
Replace.SearchRegularExpression = True
Replace.SearchString = "^$"
Replace.ReplaceString = ""

Doc.replaceAll(Replace)

More Than Just Text

So far, this chapter has only dealt with text paragraphs and their portions. But text documents may also contain other objects. These include tables, drawings, text fields and directories. All of these objects can be anchored to any point within a text.

Thanks to these common features, all of these objects in LibreOffice support a common basic service called com.sun.star.text.TextContent. This provides the following properties:

AnchorType (Enum)

determines the anchor type of a TextContent object (default values in accordance with com.sun.star.text.TextContentAnchorType enumeration).

AnchorTypes (sequence of Enum)

enumeration of all AnchorTypes which support a special TextContent object.

TextWrap (Enum)

determines the text wrap type around a TextContent object (default values in accordance with com.sun.star.text.WrapTextMode enumeration).

The TextContent objects also share some methods – in particular, those for creating, inserting and deleting objects.

• A new TextContent object is created using the createInstance method of the document object.
• An object is inserted using the insertTextContent method of the text object.
• TextContent objects are deleted using the removeTextContent method.

You will find a range of examples which use these methods in the following sections.

Tables

The following example creates a table with the help of the createInstance method described previously.

Dim Doc As Object
Dim Table As Object
Dim Cursor As Object

Doc = ThisComponent
Cursor = Doc.Text.createTextCursor()

Table = Doc.createInstance("com.sun.star.text.TextTable")
Table.initialize(5, 4)

Doc.Text.insertTextContent(Cursor, Table, False)

Once created, the table is set to the number of rows and columns requested using an initialize call and then inserted in the text document using insertTextContent.

As can be seen in the example, the insertTextContent method expects not only the Content object to be inserted, but two other parameters:

• a Cursor object which determines the insert position
• a Boolean variable which specifies whether the Content object is to replace the current selection of the cursor (True value) or is to be inserted before the current selection in the text (False)

Note: VBA : When creating and inserting tables in a text document, objects similar to those available in VBA are used in LibreOffice Basic: The document object and a TextCursor object in LibreOffice Basic, or the Range object as the VBA counterpart. Whereas the Document.Tables.Add method takes on the task of creating and setting the table in VBA, this is created in LibreOffice Basic in accordance with the previous example using createInstance, initialized, and inserted in the document through insertTextContent.

The tables inserted in a text document can be determined using a simple loop. The method getTextTables() of the text document object is used for this purpose:

Dim Doc As Object
Dim TextTables As Object
Dim Table As Object
Dim I As Integer
Doc = ThisComponent
TextTables = Doc.getTextTables()
For I = 0 to TextTables.count - 1

  Table = TextTables(I)
  ' Editing table

Next I

Note: Text tables are available in LibreOffice through the TextTables list of the document object. The previous example shows how a text table can be created. The options for accessing text tables are described in the following section.

Editing Tables

A table consists of individual rows. These in turn contain the various cells. Strictly speaking, there are no table columns in LibreOffice. These are produced implicitly by arranging the rows (one under another) next to one another. To simplify access to the tables, LibreOffice, however, provides some methods which operate using columns. These are useful if no cells have been merged in the table.

Let us first take the properties of the table itself. These are defined in the com.sun.star.text.TextTable service. Here is an list of the most important properties of the table object:

BackColor (Long)

background color of table.

BottomMargin (Long)

bottom margin in 100ths of a millimeter.

LeftMargin (Long)

left margin in 100ths of a millimeter.

RightMargin (Long)

right margin in 100ths of a millimeter.

TopMargin (Long)

top margin in 100ths of a millimeter.

RepeatHeadline (Boolean)

table header is repeated on every page.

Width (Long)

absolute width of the table in 100ths of a millimeter.

Rows

A table consists of a list containing rows. The following example shows how the rows of a table can be retrieved and formatted.

Dim Doc As Object
Dim Table As Object
Dim Cursor As Object
Dim Rows As Object
Dim Row As Object
Dim I As Integer

Doc = ThisComponent
Cursor = Doc.Text.createTextCursor()

Table = Doc.createInstance("com.sun.star.text.TextTable")
Table.initialize(5, 4)

Doc.Text.insertTextContent(Cursor, Table, False)
Rows = Table.getRows
For I = 0 To Rows.getCount() - 1
  Row = Rows.getByIndex(I)
  Row.BackColor = &HFF00FF
Next

The example first creates a list containing all rows using a Table.getRows call. The getCount and getByIndex methods allow the list to be further processed and belongs to the com.sun.star.table.XtableRows interface. The getByIndex method returns a row object, which supports the com.sun.star.text.TextTableRow service.

Here are the central methods of the com.sun.star.table.XtableRows interface:

getByIndex(Integer)

returns a row object for the specified index.

getCount()

returns the number of row objects.

insertByIndex(Index, Count)

inserts Count rows in the table as of the Index position.

removeByIndex(Index, Count)

deletes Count rows from the table as of the Index position.

Whereas the getByIndex and getCount methods are available in all tables, the insertByIndex and removeByIndex methods can only be used in tables that do not contain merged cells.

The com.sun.star.text.TextTableRow service provides the following properties:

BackColor (Long)

background color of row.

Height (Long)

height of line in 100ths of a millimeter.

IsAutoHeight (Boolean)

table height is dynamically adapted to the content.

VertOrient (const)

vertical orientation of the text frame — details on vertical orientation of the text within the table (values in accordance with com.sun.star.text.VertOrientation)

Columns

Columns are accessed in the same way as rows, using the getByIndex, getCount, insertByIndex, and removeByIndex methods on the Column object, which is reached through getColumns. They can, however, only be used in tables that do not contain merged table cells. Cells cannot be formatted by column in LibreOffice Basic. To do so, the method of formatting individual table cells must be used.

Cells

Each cell of a LibreOffice document has a unique name. If the cursor of LibreOffice is in a cell, then the name of that cell can be seen in the status bar. The top left cell is usually called A1 and the bottom right row is usually called Xn, where X stands for the letters of the top column and n for the numbers of the last row. The cell objects are available through the getCellByName() method of the table object. The following example shows a loop that passes through all the cells of a table and enters the corresponding row and column numbers into the cells.

Dim Doc As Object
Dim Table As Object
Dim Cursor As Object
Dim Rows As Object
Dim RowIndex As Integer
Dim Cols As Object
Dim ColIndex As Integer
Dim CellName As String
Dim Cell As Object

Doc = ThisComponent
Cursor = Doc.Text.createTextCursor()

Table = Doc.createInstance("com.sun.star.text.TextTable")
Table.initialize(5, 4)

Doc.Text.insertTextContent(Cursor, Table, False)

Rows = Table.getRows
Cols = Table.getColumns

For RowIndex = 1 To Rows.getCount()
  For ColIndex = 1 To Cols.getCount()
    CellName = Chr(Asc("A") - 1 + ColIndex) & RowIndex
    Cell = Table.getCellByName(CellName)
    Cell.String = "row: " & CStr(RowIndex) + ", column: " & CStr(ColIndex)
  Next
Next

A table cell is comparable with a standard text. It supports the createTextCursor interface for creating an associated TextCursor object.

CellCursor = Cell.createTextCursor()

All formatting options for individual characters and paragraphs are therefore automatically available.

The following example searches through all tables of a text document and applies the right-align format to all cells with numerical values by means of the corresponding paragraph property.

Dim Doc As Object
Dim TextTables As Object
Dim Table As Object
Dim CellNames
Dim Cell As Object
Dim CellCursor As Object
Dim I As Integer
Dim J As Integer

Doc = ThisComponent
TextTables = Doc.getTextTables()

For I = 0 to TextTables.count - 1
  Table = TextTables(I)
  CellNames = Table.getCellNames()

  For J = 0 to UBound(CellNames)
    Cell = Table.getCellByName(CellNames(J))
    If IsNumeric(Cell.String) Then
        CellCursor = Cell.createTextCursor()
        CellCursor.paraAdjust = com.sun.star.style.ParagraphAdjust.RIGHT
    End If
  Next
Next

The example creates a TextTables list containing all tables of a text that are traversed in a loop. LibreOffice then creates a list of the associated cell names for each of these tables. There are passed through in turn in a loop. If a cell contains a numerical value, then the example changes the formatting correspondingly. To do this, it first creates a TextCursor object which makes reference to the content of the table cell and then adapts the paragraph properties of the table cell.

Text Frames

Text frames are considered to be TextContent objects, just like tables and graphs. They may essentially consist of standard text, but can be placed at any position on a page and are not included in the text flow.

As with all TextContent objects, a distinction is also made with text frames between the actual creation and insertion in the document.

Dim Doc As Object
Dim TextTables As Object
Dim Cursor As Object
Dim Frame As Object

Doc = ThisComponent
Cursor = Doc.Text.createTextCursor()
Frame = Doc.createInstance("com.sun.star.text.TextFrame")
Doc.Text.insertTextContent(Cursor, Frame, False)

The text frame is created using the createInstance method of the document object. The text frame created in this way can then be inserted in the document using the insertTextContent method of the Text object. In so doing, the name of the proper com.sun.star.text.TextFrame service should be specified.

The text frame's insert position is determined by a Cursor object, which is also executed when inserted.

Note: VBA : Text frames are LibreOffice's counterpart to the position frame used in Word. Whereas VBA uses the Document.Frames.Add method for this purpose, creation in LibreOffice Basic is performed using the previous procedure with the aid of a TextCursor as well as the createInstance method of the document object.

Text frame objects provide a range of properties with which the position and behavior of the frame can be influenced. The majority of these properties are defined in the com.sun.star.text.BaseFrameProperties service, which is also supported by each TextFrame service. The central properties are:

BackColor (Long)

background color of the text frame.

BottomMargin (Long)

bottom margin in 100ths of a millimeter.

LeftMargin (Long)

left margin in 100ths of a millimeter.

RightMargin (Long)

right margin in 100ths of a millimeter.

TopMargin (Long)

top margin in 100ths of a millimeter.

Height (Long)

height of text frame in 100ths of a millimeter.

Width (Long)

width of text frame in 100ths of a millimeter.

HoriOrient (const)

horizontal orientation of text frame (in accordance with com.sun.star.text.HoriOrientation).

VertOrient (const)

vertical orientation of text frame (in accordance with com.sun.star.text.VertOrientation).

The following example creates a text frame using the properties described previously:

Dim Doc As Object
Dim TextTables As Object
Dim Cursor As Object
Dim Frame As Object

Doc = ThisComponent
Cursor = Doc.Text.createTextCursor()
Cursor.gotoNextWord(False)
Frame = Doc.createInstance("com.sun.star.text.TextFrame")

Frame.Width = 3000
Frame.Height = 1000
Frame.AnchorType = com.sun.star.text.TextContentAnchorType.AS_CHARACTER
Frame.TopMargin = 0
Frame.BottomMargin = 0
Frame.LeftMargin = 0
Frame.RightMargin = 0
Frame.BorderDistance = 0
Frame.HoriOrient = com.sun.star.text.HoriOrientation.NONE
Frame.VertOrient = com.sun.star.text.VertOrientation.LINE_TOP

Doc.Text.insertTextContent(Cursor, Frame, False)

The example creates a TextCursor as the insertion mark for the text frame. This is positioned between the first and second word of the text. The text frame is created using Doc.createInstance. The properties of the text frame objects are set to the starting values required.

The interaction between the AnchorType (from the TextContent Service) and VertOrient (from the BaseFrameProperties Service) properties should be noted here. AnchorType receives the AS_CHARACTER value. The text frame is therefore inserted directly in the text flow and behaves like a character. It can, for example, be moved into the next line if a line break occurs. The LINE_TOP value of the VertOrient property ensures that the upper edge of the text frame is at the same height as the upper edge of the character.

Once initialization is complete, the text frame is finally inserted in the text document using a call from insertTextContent.

To edit the content of a text frame, the user uses the TextCursor, which has already been mentioned numerous times and is also available for text frames.

Dim Doc As Object
Dim TextTables As Object
Dim Cursor As Object
Dim Frame As Object
Dim FrameCursor As Object

Doc = ThisComponent
Cursor = Doc.Text.createTextCursor()
Frame = Doc.createInstance("com.sun.star.text.TextFrame")

Frame.Width = 3000
Frame.Height = 1000

Doc.Text.insertTextContent(Cursor, Frame, False)

FrameCursor = Frame.createTextCursor()
FrameCursor.charWeight = com.sun.star.awt.FontWeight.BOLD
FrameCursor.paraAdjust = com.sun.star.style.ParagraphAdjust.CENTER
FrameCursor.String = "This is a small Test!"

The example creates a text frame, inserts this in the current document and opens a TextCursor for the text frame. This cursor is used to set the frame font to bold type and to set the paragraph orientation to centered. The text frame is finally assigned the “This is a small test!” string.

Text Fields

Text fields are TextContent objects because they provide additional logic extending beyond pure text. Text fields can be inserted in a text document using the same methods as those used for other TextContent objects:

Dim Doc As Object
Dim DateTimeField As Object
Dim Cursor As Object
Doc = ThisComponent
Cursor = Doc.Text.createTextCursor()

DateTimeField = Doc.createInstance("com.sun.star.text.textfield.DateTime")
DateTimeField.IsFixed = False
DateTimeField.IsDate = True
Doc.Text.insertTextContent(Cursor, DateTimeField, False)

The example inserts a text field with the current date at the start of the current text document. The True value of the IsDate property results in only the date and not time being displayed. The False value for IsFixed ensures that the date is automatically updated when the document is opened.

Note: VBA : While the type of a field in VBA is specified by a parameter of the Document.Fields.Add method, the name of the service that is responsible for the field type in question defines it in LibreOffice Basic.

Note: StarOffice 5 : In the past, text fields were accessed using a whole range of methods that LibreOffice made available in the old Selection object (for example InsertField, DeleteUserField, SetCurField).

In LibreOffice, the fields are administered using an object-oriented concept. To create a text field, a text field of the type required should first be created and initialized using the properties required. The text field is then inserted in the document using the insertTextContent method. A corresponding source text can be seen in the previous example. The most important field types and their properties are described in the following sections.

In addition to inserting text fields, searching a document for the fields can also be an important task. The following example shows how all text fields of a text document can be traversed in a loop and checked for their relevant type.

Dim Doc As Object
Dim TextFieldEnum As Object
Dim TextField As Object
Dim I As Integer

Doc = ThisComponent

TextFieldEnum = Doc.getTextFields.createEnumeration

While TextFieldEnum.hasMoreElements()

  TextField = TextFieldEnum.nextElement()

  If TextField.supportsService("com.sun.star.text.textfield.DateTime") Then
    MsgBox "Date/time"
  ElseIf TextField.supportsService("com.sun.star.text.textfield.Annotation") Then
    MsgBox "Annotation"
  Else
    MsgBox "unknown"
  End If

Wend

The starting point for establishing the text fields present is the TextFields list of the document object. The example creates an Enumeration object on the basis of this list, with which all text fields can be queried in turn in a loop. The text fields found are checked for the service supported using the supportsService method. If the field proves to be a date/time field or an annotation, then the corresponding field type is displayed in an information box. If on the other hand, the example encounters another field, then it displays the information “unknown”.

Below, you will find a list of the most important text fields and their associated properties. A complete list of all text fields is provided in the API reference in the com.sun.star.text.textfield module. (When listing the service name of a text field, uppercase and lowercase characters should be used in LibreOffice Basic, as in the previous example.)

Number of Pages, Words and Characters

The text fields

• com.sun.star.text.textfield.PageCount
• com.sun.star.text.textfield.WordCount
• com.sun.star.text.textfield.CharacterCount

return the number of pages, words, or characters of a text. They support the following property:

NumberingType (const)

numbering format (guidelines in accordance with constants from com.sun.star.style.NumberingType ).

Current Page

The number of the current page can be inserted in a document using the com.sun.star.text.textfield.PageNumber text field. The following properties can be specified:

NumberingType (const)

number format (guidelines in accordance with constants from com.sun.star.style.NumberingType).

Offset (short)

offset added to the number of pages (negative specification also possible).

The following example shows how the number of pages can be inserted into the footer of a document.

Dim Doc As Object
Dim DateTimeField As Object
Dim PageStyles As Object
Dim StdPage As Object
Dim FooterCursor As Object
Dim PageNumber As Object

Doc = ThisComponent

PageNumber = Doc.createInstance("com.sun.star.text.textfield.PageNumber")
PageNumber.NumberingType = com.sun.star.style.NumberingType.ARABIC

PageStyles = Doc.StyleFamilies.getByName("PageStyles")

StdPage = PageStyles("Default")
StdPage.FooterIsOn = True

FooterCursor = StdPage.FooterTextLeft.Text.createTextCursor()
StdPage.FooterTextLeft.Text.insertTextContent(FooterCursor, PageNumber, False)

The example first creates a text field which supports the com.sun.star.text.textfield.PageNumber service. Since the header and footer lines are defined as part of the page templates of LibreOffice, this is initially established using the list of all PageStyles.

To ensure that the footer line is visible, the FooterIsOn property is set to True. The text field is then inserted in the document using the associated text object of the left-hand footer line.

Annotations

Annotation fields (com.sun.star.text.textfield.Annotation) can be seen by means of a small yellow symbol in the text. Clicking on this symbol opens a text field, in which a comment on the current point in the text can be recorded. An annotation field has the following properties.

Author (String)

name of author.

Content (String)

comment text.

Date (Date)

date on which annotation is written.

Date / Time

A date / time field (com.sun.star.text.textfield.DateTime) represents the current date or the current time. It supports the following properties:

IsFixed (Boolean)

if True, the time details of the insertion remain unchanged, if False, these are updated each time the document is opened.

IsDate (Boolean)

if True, the field displays the current date, otherwise the current time.

DateTimeValue (struct)

current content of field (com.sun.star.util.DateTime structure)

NumberFormat (const)

format in which the time or date is depicted.

Chapter Name / Number

The name of the current chapter is available through a text field of the com.sun.star.text.textfield.Chapter type. The form can be defined using two properties.

ChapterFormat (const)

determines whether the chapter name or the chapter number is depicted (in accordance with com.sun.star.text.ChapterFormat)

Level (Integer)

determines the chapter level whose name and/or chapter number is to be displayed. The value 0 stands for highest level available.

Bookmarks

Bookmarks (Service com.sun.star.text.Bookmark) are TextContent objects. Bookmarks are created and inserted using the concept already described previously:

Dim Doc As Object
Dim Bookmark As Object
Dim Cursor As Object

Doc = ThisComponent

Cursor = Doc.Text.createTextCursor()

Bookmark = Doc.createInstance("com.sun.star.text.Bookmark")
Bookmark.Name = "My bookmarks"
Doc.Text.insertTextContent(Cursor, Bookmark, True)

The example creates a Cursor, which marks the insert position of the bookmark and then the actual bookmark object (Bookmark). The bookmark is then assigned a name and is inserted in the document through insertTextContent at the cursor position.

The bookmarks of a text are accessed through a list called Bookmarks. The bookmarks can either be accessed by their number or their name.

The following example shows how a bookmark can be found within a text, and a text inserted at its position.

Dim Doc As Object
Dim Bookmark As Object
Dim Cursor As Object

Doc = ThisComponent

Bookmark = Doc.Bookmarks.getByName("My bookmarks")

Cursor = Doc.Text.createTextCursorByRange(Bookmark.Anchor)
Cursor.String = "Here is the bookmark"

In this example, the getByName method is used to find the bookmark required by means of its name. The createTextCursorByRange call then creates a Cursor, which is positioned at the anchor position of the bookmark. The cursor then inserts the text required at this point.

Spreadsheet Documents

LibreOffice Basic provides an extensive interface for program-controlled creation and editing of spreadsheets. This chapter describes how to control the relevant services, methods and properties of spreadsheet documents:

• #The Structure of Spreadsheets
• #Editing Spreadsheet Documents

The first section addresses the basic structure of spreadsheet documents and shows you how to access and to edit the contents of individual cells.

The second section concentrates on how to edit spreadsheets efficiently by focusing on cell areas and the options for searching and replacing cell contents.

Note: StarOffice 5 : The Range object allows you to address any table area and has been extended in the new API.

The Structure of Spreadsheets

The document object of a spreadsheet is based on the com.sun.star.sheet.SpreadsheetDocument service. Each of these documents may contain several spreadsheets. In this guide, a table-based document or spreadsheet document is the entire document, whereas a spreadsheet (or sheet for short) is a sheet (table) in the document.

Note: VBA : Different terminology for spreadsheets and their content is used in VBA and LibreOffice Basic. Whereas the document object in VBA is called a Workbook and its individual pages Worksheets, they are called SpreadsheetDocument and Sheet in LibreOffice Basic.

Spreadsheets

You can access the individual sheets of a spreadsheet document through the Sheets list.

The following examples show you how to access a sheet either through its number or its name.

Example 1: access by means of the number (numbering begins with 0)

Dim Doc As Object
Dim Sheet As Object

Doc = ThisComponent
Sheet = Doc.Sheets(0)

Note: ThisComponent returns the currently active document. The expression Doc.Sheets(0) is a Basic simplification of the API call : Doc.getSheets.getByIndex(0)

Example 2: access by means of the name

Dim Doc As Object
Dim Sheet As Object

Doc = ThisComponent
Sheet = Doc.Sheets.getByName("Sheet 1")

In the first example, the sheet is accessed by its number (counting begins at 0). In the second example, the sheet is accessed by its name and the getByName method.

The Sheet object that is obtained by the getByName method supports the com.sun.star.sheet.Spreadsheet service. In addition to providing several interfaces for editing the content, this service provides the following properties:

IsVisible (Boolean)

value True if the spreadsheet is visible.

PageStyle (String)

name of the page template for the spreadsheet.

Renaming Sheets

A sheet provides methods getName and setName to read and modify its name. Basic can handle both methods like a property Name. Here we rename the first sheet of the spreadsheet document.

Dim Doc As Object
Dim Sheet As Object

Doc = ThisComponent
Sheet = Doc.Sheets(0)
Sheet.Name = "First"

Creating and Deleting Sheets

The Sheets container of a spreadsheet document is also used to create and delete individual sheets. The following example uses the hasByName method to check if a sheet called MySheet exists. If it does, the method determines a corresponding object reference by using the getByName method and then saves the reference in a variable in Sheet. If the corresponding sheet does not exist, it is created by the createInstance call and inserted in the spreadsheet document by the insertByName method.

Dim Doc As Object
Dim Sheet As Object

Doc = ThisComponent

If Doc.Sheets.hasByName("MySheet") Then
  Sheet = Doc.Sheets.getByName("MySheet")
Else
  Sheet = Doc.createInstance("com.sun.star.sheet.Spreadsheet")
  Doc.Sheets.insertByName("MySheet", Sheet)
End If

The hasByName, getByName and insertByName methods are obtained from the com.sun.star.container.XNameContainer interface as described in #Introduction to the API.

The interface com.sun.star.sheet.Spreadsheets provides a better method to create a new sheet: insertNewByName. It inserts a new sheet with the name specified by the first argument, at the position specified by the second argument.

Dim Doc As Object

Doc = ThisComponent

Doc.Sheets.insertNewByName("OtherSheet", 2)

The same interface provides methods moveByName and copyByName.

The com.sun.star.container.XNameContainer interface provides a method to remove a sheet of a given name:

Dim Doc As Object

Doc = ThisComponent

Doc.Sheets.removeByName("OtherSheet")

Rows and Columns

Each sheet contains a list of its rows and columns. These are available through the Rows and Columns properties of the spreadsheet object and support the com.sun.star.table.TableColumns and/or com.sun.star.table.TableRows services.

The following example creates two objects that reference the first row and the first column of a sheet and stores the references in the FirstCol and FirstRow object variables.

Dim Doc As Object
Dim Sheet As Object
Dim FirstRow As Object
Dim FirstCol As Object

Doc = ThisComponent
Sheet = Doc.Sheets(0)

FirstCol = Sheet.Columns(0)
FirstRow = Sheet.Rows(0)

The column objects support the com.sun.star.table.TableColumn service that has the following properties:

Width (long)

width of a column in hundredths of a millimeter.

OptimalWidth (Boolean)

sets a column to its optimum width.

IsVisible (Boolean)

displays a column.

IsStartOfNewPage (Boolean)

when printing, creates a page break before a column.

The width of a column is only optimized when the OptimalWidth property is set to True. If the width of an individual cell is changed, the width of the column that contains the cell is not changed. In terms of functionality, OptimalWidth is more of a method than a property.

The row objects are based on the com.sun.star.table.TableRow service that has the following properties:

Height (long)

height of the row in 100ths of a millimeter.

OptimalHeight (Boolean)

sets the row to its optimum height.

IsVisible (Boolean)

displays the row.

IsStartOfNewPage (Boolean)

when printing, creates a page break before the row.

If the OptimalHeight property of a row is set to the True, the row height changes automatically when the height of a cell in the row is changed. Automatic optimization continues until the row is assigned an absolute height through the Height property.

The following example activates the automatic height optimization for the first five rows in the sheet and makes the second column invisible.

Dim Doc As Object
Dim Sheet As Object
Dim Row As Object
Dim Col As Object
Dim I As Integer

Doc = ThisComponent
Sheet = Doc.Sheets(0)

For I = 0 To 4
  Row = Sheet.Rows(I)
  Row.OptimalHeight = True
Next I

Col = Sheet.Columns(1)
Col.IsVisible = False

Note: The Rows and Columns lists can be accessed through an index in LibreOffice Basic. The real API call is : Sheet.getColumns.getByIndex(1)

Note: VBA : Unlike in VBA, the first column has the index 0 and not the index 1.

Inserting and Deleting Rows and Columns

The Rows and Columns objects of a sheet can access existing rows and columns as well as insert and delete them.

Dim Doc As Object
Dim Sheet As Object
Dim NewColumn As Object

Doc = ThisComponent
Sheet = Doc.Sheets(0)

Sheet.Columns.insertByIndex(3, 1)
Sheet.Columns.removeByIndex(5, 1)

This example uses the insertByIndex method to insert a new column into the fourth column position in the sheet (index 3 - numbering starts at 0). The second parameter specifies the number of columns to be inserted (in this example: one).

The removeByIndex method deletes the sixth column (index 5). Again, the second parameter specifies the number of columns that you want to delete.

The methods for inserting and deleting rows use the Rows object function in the same way as the methods shown for editing columns using the Columns object.

Cells and Ranges

A spreadsheet consists of a two-dimensional list containing cells. Each cell is defined by its X and Y-position with respect to the top left cell which has the position (0,0).

Addressing and Editing Individual Cells

The following example creates an object that references the top left cell and inserts a text in the cell:

Dim Doc As Object
Dim Sheet As Object
Dim Cell As Object

Doc = ThisComponent
Sheet = Doc.Sheets(0)

Cell = Sheet.getCellByPosition(0, 0)
Cell.String = "Test"

In addition to numerical coordinates, each cell in a sheet has a name, for example, the top left cell (0,0) of a spreadsheet is called A1. The letter A stands for the column and the number 1 for the row. It is important that the name and position of a cell are not confused because row counting for names begins with 1 but the counting for position begins with 0.

If the position of the cell is fixed, it is more clear to use the following code:

Dim Doc As Object
Dim Sheet As Object
Dim Cell As Object

Doc = ThisComponent
Sheet = Doc.Sheets(0)

Cell = Sheet.getCellRangeByName("A1")
Cell.String = "Test"

The above code also works with a named cell.

In LibreOffice, a table cell can be empty or contain text, numbers, or formulas. The cell type is not determined by the content that is saved in the cell, but rather the object property which was used for its entry. Numbers can be inserted and called up with the Value property, text with the String property, and formulas with the Formula property.

Dim Doc As Object
Dim Sheet As Object
Dim Cell As Object

Doc = ThisComponent
Sheet = Doc.Sheets(0)

Cell = Sheet.getCellByPosition(0, 0)
Cell.Value = 100

Cell = Sheet.getCellByPosition(0, 1)
Cell.String = "Test"

Cell = Sheet.getCellByPosition(0, 2)
Cell.Formula = "=A1"

The example inserts one number, one text, and one formula in the fields A1 to A3.

Note: StarOffice 5 : The Value, String, and Formula properties supersede the old PutCell method of StarOffice 5 for setting the values of a table cell.

LibreOffice treats cell content that is entered using the String property as text, even if the content is a number. Numbers are left-aligned in the cell instead of right-aligned. You should also note the difference between text and numbers when you use formulas:

Dim Doc As Object
Dim Sheet As Object
Dim Cell As Object

Doc = ThisComponent
Sheet = Doc.Sheets(0)

Cell = Sheet.getCellByPosition(0, 0)
Cell.Value = 100

Cell = Sheet.getCellByPosition(0, 1)
Cell.String = 1000

Cell = Sheet.getCellByPosition(0, 2)
Cell.Formula = "=A1+A2"

MsgBox Cell.Value

Although cell A1 contains the value 100 and cell A2 contains the value 1000, the A1+A2 formula returns the value 100. This is because the contents of cell A2 were entered as a string and not as a number.

To check if the contents of a cell contains a number or a string, use the Type property:

Dim Doc As Object
Dim Sheet As Object
Dim Cell As Object

Doc = ThisComponent
Sheet = Doc.Sheets(0)
Cell = Sheet.getCellByPosition(1,1)

Cell.Value = 1000

Select Case Cell.Type
Case com.sun.star.table.CellContentType.EMPTY
  MsgBox "Content: Empty"
Case com.sun.star.table.CellContentType.VALUE
  MsgBox "Content: Value"
Case com.sun.star.table.CellContentType.TEXT
  MsgBox "Content: Text"
Case com.sun.star.table.CellContentType.FORMULA
  MsgBox "Content: Formula"
End Select

The Cell.Type property returns a value for the com.sun.star.table.CellContentType enumeration which identifies the contents type of a cell. The possible values are:

EMPTY

no value

VALUE

number

TEXT

strings

FORMULA

formula

Inserting, Deleting, Copying and Moving Cells

In addition to directly modifying cell content, LibreOffice Calc also provides an interface that allows you to insert, delete, copy, or merge cells. The interface (com.sun.star.sheet.XCellRangeMovement) is available through the spreadsheet object and provides four methods for modifying cell content.

The insertCell method is used to insert cells into a sheet.

Dim Doc As Object
Dim Sheet As Object
Dim CellRangeAddress As New com.sun.star.table.CellRangeAddress

Doc = ThisComponent
Sheet = Doc.Sheets(0)

CellRangeAddress.Sheet = 0
CellRangeAddress.StartColumn = 1
CellRangeAddress.StartRow = 1
CellRangeAddress.EndColumn = 2
CellRangeAddress.EndRow = 2

Sheet.insertCells(CellRangeAddress, com.sun.star.sheet.CellInsertMode.DOWN)

This example inserts a cells range that is two rows by two columns in size into the second column and row (each bear the number 1) of the first sheet (number 0) in the spreadsheet. Any existing values in the specified cell range are moved below the range.

To define the cell range that you want to insert, use the com.sun.star.table.CellRangeAddress structure. The following values are included in this structure:

Sheet (short)

number of the sheet (numbering begins with 0).

StartColumn (long)

first column in the cell range (numbering begins with 0).

StartRow (long)

first row in the cell range (numbering begins with 0).

EndColumn (long)

final column in the cell range (numbering begins with 0).

EndRow (long)

final row in the cell range (numbering begins with 0).

The completed CellRangeAddress structure must be passed as the first parameter to the insertCells method. The second parameter of insertCells contains a value of the com.sun.star.sheet.CellInsertMode enumeration and defines what is to be done with the values that are located in front of the insert position. The CellInsertMode enumeration recognizes the following values:

NONE

the current values remain in their present position.

DOWN

the cells at and under the insert position are moved downwards.

RIGHT

the cells at and to the right of the insert position are moved to the right.

ROWS

the rows after the insert position are moved downwards.

COLUMNS

the columns after the insert position are moved to the right.

The removeRange method is the counterpart to the insertCells method. This method deletes the range that is defined in the CellRangeAddress structure from the sheet.

Dim Doc As Object
Dim Sheet As Object
Dim CellRangeAddress As New com.sun.star.table.CellRangeAddress

Doc = ThisComponent
Sheet = Doc.Sheets(0)

CellRangeAddress.Sheet = 0
CellRangeAddress.StartColumn = 1
CellRangeAddress.StartRow = 1
CellRangeAddress.EndColumn = 2
CellRangeAddress.EndRow = 2

Sheet.removeRange(CellRangeAddress, com.sun.star.sheet.CellDeleteMode.UP)

This example removes the B2:C3 cell range from the sheet and then shifts the underlying cells up by two rows. The type of removal is defined by one of the following values from the com.sun.star.sheet.CellDeleteMode enumeration:

NONE

the current values remain in their current position.

UP

the cells at and below the insert position are moved upwards.

LEFT

the cells at and to the right of the insert position are moved to the left.

ROWS

the rows after the insert position are moved upwards.

COLUMNS

the columns after the insert position are moved to the left.

The XRangeMovement interface provides two additional methods for moving (moveRange) or copying (copyRange) cell ranges. The following example moves the B2:C3 range so that the range starts at position A6:

Dim Doc As Object
Dim Sheet As Object
Dim CellRangeAddress As New com.sun.star.table.CellRangeAddress
Dim CellAddress As New com.sun.star.table.CellAddress

Doc = ThisComponent
Sheet = Doc.Sheets(0)

CellRangeAddress.Sheet = 0
CellRangeAddress.StartColumn = 1
CellRangeAddress.StartRow = 1
CellRangeAddress.EndColumn = 2
CellRangeAddress.EndRow = 2

CellAddress.Sheet = 0
CellAddress.Column = 0
CellAddress.Row = 5

Sheet.moveRange(CellAddress, CellRangeAddress)

In addition to the CellRangeAdress structure, the moveRange method expects a com.sun.star.table.CellAddress structure to define the origin of the move's target region. The CellAddress structure provides the following values:

Sheet (short)

number of the spreadsheet (numbering begins with 0).

Column (long)

number of the addressed column (numbering begins with 0).

Row (long)

number of the addressed row (numbering begins with 0).

The cell contents in the target range are always overwritten by the moveRange method. Unlike in the InsertCells method , a parameter for performing automatic moves is not provided in the moveRange method.

The copyRange method functions in the same way as the moveRange method, except that copyRange inserts a copy of the cell range instead of moving it.

Note: VBA : In terms of their function, the LibreOffice Basic insertCell, removeRange, and copyRange methods are comparable with the VBA Range.Insert, Range.Delete ,and Range.Copy methods. Whereas in VBA, the methods are applied to the corresponding Range object, in LibreOffice Basic they are applied to the associated Sheet object.

Formatting Spreadsheet Documents

A spreadsheet document provides properties and methods for formatting cells and pages.

Cell Properties

There are numerous options for formatting cells, such as specifying the font type and size for text. Each cell supports the com.sun.star.style.CharacterProperties and com.sun.star.style.ParagraphProperties services, the main properties of which are described in #Text Documents. Special cell formatting is handled by the com.sun.star.table.CellProperties service. The main properties of this service are described in the following sections.

You can apply all the named properties to individual cells and to cell ranges.

Note: VBA : The CellProperties object in the LibreOffice API is comparable with the Interior object from VBA which also defines cell-specific properties.

Background Color and Shadows

The com.sun.star.table.CellProperties service provides the following properties for defining background colors and shadows:

CellBackColor (Long)

background color of the table cell

IsCellBackgroundTransparent (Boolean)

sets the background color to transparent

ShadowFormat (struct)

specifies the shadow for cells (structure in accordance with com.sun.star.table.ShadowFormat)

The com.sun.star.table.ShadowFormat structure and the detailed specifications for cell shadows have the following structure:

Location (enum)

position of shadow (value from the com.sun.star.table.ShadowLocation structure).

ShadowWidth (Short)

size of shadow in hundredths of a millimeter

IsTransparent (Boolean)

sets the shadow to transparent

Color (Long)

color of shadow

The following example writes the number 1000 to the cell B2, changes the background color to red using the CellBackColor property, and then creates a light gray shadow for the cell that is moved 1 mm to the left and down.

Dim Doc As Object
Dim Sheet As Object
Dim Cell As Object
Dim ShadowFormat As New com.sun.star.table.ShadowFormat

Doc = ThisComponent
Sheet = Doc.Sheets(0)
Cell = Sheet.getCellByPosition(1,1)

Cell.Value = 1000

Cell.CellBackColor = RGB(255, 0, 0)

ShadowFormat.Location = com.sun.star.table.ShadowLocation.BOTTOM_RIGHT
ShadowFormat.ShadowWidth = 100
ShadowFormat.Color = RGB(160, 160, 160)

Cell.ShadowFormat = ShadowFormat

Justification

LibreOffice provides various functions that allow you to change the justification of a text in a table cell.

The following properties define the horizontal and vertical justification of a text:

HoriJustify (enum)

horizontal justification of the text (value from com.sun.star.table.CellHoriJustify)

VertJustify (enum)

vertical justification of the text (value from com.sun.star.table.CellVertJustify)

Orientation (enum)

orientation of text (value in accordance with com.sun.star.table.CellOrientation)

IsTextWrapped (Boolean)

permits automatic line breaks within the cell

RotateAngle (Long)

angle of rotation of text in hundredths of a degree

The following example shows how you can "stack" the contents of a cell so that the individual characters are printed one under another in the top left corner of the cell. The characters are not rotated.

Dim Doc As Object
Dim Sheet As Object
Dim Cell As Object

Doc = ThisComponent
Sheet = Doc.Sheets(0)
Cell = Sheet.getCellByPosition(1,1)

Cell.Value = 1000

Cell.HoriJustify = com.sun.star.table.CellHoriJustify.LEFT
Cell.VertJustify = com.sun.star.table.CellVertJustify.TOP
Cell.Orientation = com.sun.star.table.CellOrientation.STACKED

Number, Date and Text Format

LibreOffice provides a whole range of predefined date and time formats. Each of these formats has an internal number that is used to assign the format to cells using the NumberFormat property. LibreOffice provides the queryKey and addNew methods so that you can access existing number formats as well as create your own number formats. The methods are accessed through the following object call:

NumberFormats = Doc.NumberFormats

A format is specified using a format string that is structured in a similar way to the format function of LibreOffice Basic. However there is one major difference: whereas the command format expects English abbreviations and decimal points or characters as thousands separators, the country-specified abbreviations must be used for the structure of a command format for the NumberFormats object.

The following example formats the B2 cell so that numbers are displayed with three decimal places and use commas as a thousands separator.

Dim Doc As Object
Dim Sheet As Object
Dim Cell As Object
Dim NumberFormats As Object
Dim NumberFormatString As String
Dim NumberFormatId As Long
Dim LocalSettings As New com.sun.star.lang.Locale

Doc = ThisComponent
Sheet = Doc.Sheets(0)
Cell = Sheet.getCellByPosition(1,1)

Cell.Value = 23400.3523565

LocalSettings.Language = "en"
LocalSettings.Country = "us"

NumberFormats = Doc.NumberFormats
NumberFormatString = "#,##0.000"

NumberFormatId = NumberFormats.queryKey(NumberFormatString, LocalSettings, True)
If NumberFormatId = -1 Then
  NumberFormatId = NumberFormats.addNew(NumberFormatString, LocalSettings)
End If

MsgBox NumberFormatId
Cell.NumberFormat = NumberFormatId

The Format Cells dialog in LibreOffice Calc provides an overview of the different formatting options for cells.

Page Properties

Page properties are the formatting options that position document content on a page as well as visual elements that are repeated page after page. These include

• Paper formats
• Page margins
• Headers and footers.

The procedure for defining page formats differs from other forms of formatting. Whereas cell, paragraph, and character elements can be formatted directly, page formats can also be defined and indirectly applied using page styles. For example, headers or footers are added to the page style.

The following sections describe the main formatting options for spreadsheet pages. Many of the styles that are described are also available for text documents. The page properties that are valid for both types of documents are defined in the com.sun.star.style.PageProperties service. The page properties that only apply to spreadsheet documents are defined in the com.sun.star.sheet.TablePageStyle service.

Note: VBA : The page properties (page margins, borders, and so on) for a Microsoft Office document are defined by means of a PageSetup object at the Worksheet object (Excel) or Document object (Word) level. In LibreOffice, these properties are defined using a page style which in turn is linked to the associated document.

Page Background

The com.sun.star.style.PageProperties service defines the following properties of a pages background:

BackColor (long)

color of background

BackGraphicURL (String)

URL of the background graphics that you want to use

BackGraphicFilter (String)

name of the filter for interpreting the background graphics

BackGraphicLocation (Enum)

position of the background graphics (value according to enumeration)

BackTransparent (Boolean)

makes the background transparent

Page Format

The page format is defined using the following properties of the com.sun.star.style.PageProperties service:

IsLandscape (Boolean)

landscape format

Width (long)

width of page in hundredths of a millimeter

Height (long)

height of page in hundredths of a millimeter

PrinterPaperTray (String)

name of the printer paper tray that you want to use

The following example sets the page size of the "Default" page style to the DIN A5 landscape format (height 14.8 cm, width 21 cm):

Dim Doc As Object
Dim Sheet As Object
Dim StyleFamilies As Object
Dim PageStyles As Object
Dim DefPage As Object

Doc = ThisComponent
StyleFamilies = Doc.StyleFamilies
PageStyles = StyleFamilies.getByName("PageStyles")
DefPage = PageStyles.getByName("Default")

DefPage.IsLandscape = True
DefPage.Width = 21000
DefPage.Height = 14800

Page Margin, Border, and Shadow

The com.sun.star.style.PageProperties service provides the following properties for adjusting page margins as well as borders and shadows:

LeftMargin (long)

width of the left hand page margin in hundredths of a millimeter

RightMargin (long)

width of the right hand page margin in hundredths of a millimeter

TopMargin (long)

width of the top page margin in hundredths of a millimeter

BottomMargin (long)

width of the bottom page margin in hundredths of a millimeter

LeftBorder (struct)

specifications for left-hand line of page border (com.sun.star.table.BorderLine structure)

RightBorder (struct)

specifications for right-hand line of page border (com.sun.star.table.BorderLine structure)

TopBorder (struct)

specifications for top line of page border (com.sun.star.table.BorderLine structure)

BottomBorder (struct)

specifications for bottom line of page border (com.sun.star.table.BorderLine structure)

LeftBorderDistance (long)

distance between left-hand page border and page content in hundredths of a millimeter

RightBorderDistance (long)

distance between right-hand page border and page content in hundredths of a millimeter

TopBorderDistance (long)

distance between top page border and page content in hundredths of a millimeter

BottomBorderDistance (long)

distance between bottom page border and page content in hundredths of a millimeter

ShadowFormat (struct)

specifications for shadow of content area of page (com.sun.star.table.ShadowFormat structure)

The following example sets the left and right-hand borders of the "Default" page style to 1 centimeter.

Dim Doc As Object
Dim Sheet As Object
Dim StyleFamilies As Object
Dim PageStyles As Object
Dim DefPage As Object

Doc = ThisComponent
StyleFamilies = Doc.StyleFamilies
PageStyles = StyleFamilies.getByName("PageStyles")
DefPage = PageStyles.getByName("Default")

DefPage.LeftMargin = 1000
DefPage.RightMargin = 1000

Headers and Footers

The headers and footers of a document form part of the page properties and are defined using the com.sun.star.style.PageProperties service. The properties for formatting headers are:

HeaderIsOn (Boolean)

header is activated

HeaderLeftMargin (long)

distance between header and left-hand page margin in hundredths of a millimeter

HeaderRightMargin (long)

distance between header and right-hand page margin in hundredths of a millimeter

HeaderBodyDistance (long)

distance between header and main body of document in hundredths of a millimeter

HeaderHeight (long)

height of header in hundredths of a millimeter

HeaderIsDynamicHeight (Boolean)

height of header is automatically adapted to content

HeaderLeftBorder (struct)

details of the left-hand border of frame around header (com.sun.star.table.BorderLine structure)

HeaderRightBorder (struct)

details of the right-hand border of frame around header (com.sun.star.table.BorderLine structure)

HeaderTopBorder (struct)

details of the top line of the border around header (com.sun.star.table.BorderLine structure)

HeaderBottomBorder (struct)

details of the bottom line of the border around header (com.sun.star.table.BorderLine structure)

HeaderLeftBorderDistance (long)

distance between left-hand border and content of header in hundredths of a millimeter

HeaderRightBorderDistance (long)

distance between right-hand border and content of header in hundredths of a millimeter

HeaderTopBorderDistance (long)

distance between top border and content of header in hundredths of a millimeter

HeaderBottomBorderDistance (long)

distance between bottom border and content of header in hundredths of a millimeter

HeaderIsShared (Boolean)

headers on even and odd pages have the same content (refer to HeaderText , HeaderTextLeft, and HeaderTextRight )

HeaderBackColor (long)

background color of header

HeaderBackGraphicURL (String)

URL of the background graphics that you want to use

HeaderBackGraphicFilter (String)

name of the filter for interpreting the background graphics for the header

HeaderBackGraphicLocation (Enum)

position of the background graphics for the header (value according to com.sun.star.style.GraphicLocation enumeration)

HeaderBackTransparent (Boolean)

shows the background of the header as transparent

HeaderShadowFormat (struct)

details of shadow of header (com.sun.star.table.ShadowFormat structure)

The properties for formatting footers are:

FooterIsOn (Boolean)

footer is activated

FooterLeftMargin (long)

distance between footer and left-hand page margin in hundredths of a millimeter

FooterRightMargin (long)

distance between footer and right-hand page margin in hundredths of a millimeter

FooterBodyDistance (long)

distance between footer and main body of document in hundredths of a millimeter

FooterHeight (long)

height of footer in hundredths of a millimeter

FooterIsDynamicHeight (Boolean)

height of footer is adapted automatically to the content

FooterLeftBorder (struct)

details of left-hand line of border around footer (com.sun.star.table.BorderLine structure)

FooterRightBorder (struct)

details of right-hand line of border around footer (com.sun.star.table.BorderLine structure)

FooterTopBorder (struct)

details of top line of border around footer (com.sun.star.table.BorderLine structure)

FooterBottomBorder (struct)

details of bottom line of border around footer (com.sun.star.table.BorderLine structure)

FooterLeftBorderDistance (long)

distance between left-hand border and content of footer in hundredths of a millimeter

FooterRightBorderDistance (long)

distance between right-hand border and content of footer in hundredths of a millimeter

FooterTopBorderDistance (long)

distance between top border and content of footer in hundredths of a millimeter

FooterBottomBorderDistance (long)

distance between bottom border and content of footer in hundredths of a millimeter

FooterIsShared (Boolean)

the footers on the even and odd pages have the same content (refer to FooterText, FooterTextLeft, and FooterTextRight )

FooterBackColor (long)

background color of footer

FooterBackGraphicURL (String)

URL of the background graphics that you want to use

FooterBackGraphicFilter (String)

name of the filter for interpreting the background graphics for the footer

FooterBackGraphicLocation (Enum)

position of background graphics for the footer (value according to com.sun.star.style.GraphicLocation enumeration)

FooterBackTransparent (Boolean)

shows the background of the footer as transparent

FooterShadowFormat (struct)

details of shadow of footer (com.sun.star.table.ShadowFormat structure)

Changing the Text of Headers and Footers

The content of headers and footers in a spreadsheet is accessed through the following properties:

LeftPageHeaderContent (Object)

content of headers for even pages (com.sun.star.sheet.HeaderFooterContent service)

RightPageHeaderContent (Object)

content of headers for odd pages (com.sun.star.sheet.HeaderFooterContent service)

LeftPageFooterContent (Object)

content of footers for even pages (com.sun.star.sheet.HeaderFooterContent service)

RightPageFooterContent (Object)

content of footers for odd pages (com.sun.star.sheet.HeaderFooterContent service)

If you do not need to distinguish between headers or footers for odd and even pages (the FooterIsShared property is False), then set the properties for headers and footers on odd pages.

All the named objects return an object that supports the com.sun.star.sheet.HeaderFooterContent service. By means of the (non-genuine) properties LeftText, CenterText, and RightText, this service provides three text elements for the headers and footers of LibreOffice Calc.

The following example writes the "Just a Test." value in the left-hand text field of the header from the "Default" template.

Dim Doc As Object
Dim Sheet As Object
Dim StyleFamilies As Object
Dim PageStyles As Object
Dim DefPage As Object
Dim HText As Object
Dim HContent As Object
Doc = ThisComponent
StyleFamilies = Doc.StyleFamilies
PageStyles = StyleFamilies.getByName("PageStyles")
DefPage = PageStyles.getByName("Default")

DefPage.HeaderIsOn = True
HContent = DefPage.RightPageHeaderContent
HText = HContent.LeftText
HText.String = "Just a Test."
DefPage.RightPageHeaderContent = HContent

Note the last line in the example: Once the text is changed, the TextContent object must be assigned to the header again so that the change is effective.

Another mechanism for changing the text of headers and footers is available for text documents (LibreOffice Writer) because these consist of a single block of text. The following properties are defined in the com.sun.star.style.PageProperties service:

HeaderText (Object)

text object with content of the header (com.sun.star.text.XText service)

HeaderTextLeft (Object)

text object with content of headers on left-hand pages (com.sun.star.text.XText service)

HeaderTextRight (Object)

text object with content of headers on right-hand pages (com.sun.star.text.XText service)

FooterText (Object)

text object with content of the footer (com.sun.star.text.XText service)

FooterTextLeft (Object)

text object with content of footers on left-hand pages (com.sun.star.text.XText service)

FooterTextRight (Object)

text object with content of footers on right-hand pages (com.sun.star.text.XText service)

The following example creates a header in the "Default" page style for text documents and adds the text "Just a Test" to the header.

Dim Doc As Object
Dim Sheet As Object
Dim StyleFamilies As Object
Dim PageStyles As Object
Dim DefPage As Object
Dim HText As Object

Doc = ThisComponent
StyleFamilies = Doc.StyleFamilies
PageStyles = StyleFamilies.getByName("PageStyles")
DefPage = PageStyles.getByName("Default")

DefPage.HeaderIsOn = True
HText = DefPage.HeaderText

HText.String = "Just a Test."

In this instance, access is provided directly through the HeaderText property of the page style rather than the HeaderFooterContent object.

Centering (Spreadsheets Only)

The com.sun.star.sheet.TablePageStyle service is only used in LibreOffice Calc page styles and allows cell ranges that you want printed to be centered on the page. This service provides the following properties:

CenterHorizontally (Boolean)

table content is centered horizontally

CenterVertically (Boolean)

table content is centered vertically

Definition of Elements to be Printed (Spreadsheets Only)

When you format sheets, you can define whether page elements are visible. For this purpose, the com.sun.star.sheet.TablePageStyle service provides the following properties:

PrintAnnotations (Boolean)

prints cell comments

PrintGrid (Boolean)

prints the cell gridlines

PrintHeaders (Boolean)

prints the row and column headings

PrintCharts (Boolean)

prints charts contained in a sheet

PrintObjects (Boolean)

prints embedded objects

PrintDrawing (Boolean)

prints draw objects

PrintDownFirst (Boolean)

if the contents of a sheet extend across several pages, they are first printed in vertically descending order, and then down the right-hand side.

PrintFormulas (Boolean)

prints the formulas instead of the calculated values

PrintZeroValues (Boolean)

prints the zero values

Editing Spreadsheet Documents

Whereas the previous section described the main structure of spreadsheet documents, this section describes the services that allow you to easily access individual cells or cell ranges.

Cell Ranges

In addition to an object for individual cells (com.sun.star.table.Cell service), LibreOffice also provides objects that represent cell ranges. Such CellRange objects are created using the getCellRangeByName call of the spreadsheet object:

Dim Doc As Object
Dim Sheet As Object
Dim CellRange As Object

Doc = ThisComponent
Sheet = Doc.Sheets.getByName("Sheet 1")
CellRange = Sheet.getCellRangeByName("A1:C15")

A colon (:) is used to specify a cell range in a spreadsheet document. For example, A1:C15 represents all the cells in rows 1 to 15 in columns A, B, and C.

If the position of the cell range is only known at runtime, use the following code:

Dim Doc As Object
Dim Sheet As Object
Dim CellRange As Object

Doc = ThisComponent
Sheet = Doc.Sheets.getByName("Sheet 1")
CellRange = Sheet.getCellRangeByPosition(0, 0, 2, 14)

The arguments of com.sun.star.sheet.XCellRangesAccess:getCellRangeByPosition are the position of the upper left cell of the range, followed by the position of the bottom right cell of the same range.

The location of individual cells in a cell range can be determined using the getCellByPosition method, where the coordinates of the top left cell in the cell range is (0, 0). The following example uses this method to create an object of cell C3.

Dim Doc As Object
Dim Sheet As Object
Dim CellRange As Object
Dim Cell As Object

Doc = ThisComponent
Sheet = Doc.Sheets.getByName("Sheet 1")
CellRange = Sheet.getCellRangeByName("B2:D4")
Cell = CellRange.GetCellByPosition(1, 1)

Formatting Cell Ranges

Just like individual cells, you can apply formatting to cell ranges using the com.sun.star.table.CellProperties service. For more information and examples of this service, see #Formatting Spreadsheet Documents.

Computing With Cell Ranges

You can use the computeFunction method to perform mathematical operations on cell ranges. The computeFunction expects a constant as the parameter that describes the mathematical function that you want to use. The associated constants are defined in the com.sun.star.sheet.GeneralFunction enumeration. The following values are available:

SUM

sum of all numerical values

COUNT

total number of all values (including non-numerical values)

COUNTNUMS

total number of all numerical values

AVERAGE

average of all numerical values

MAX

largest numerical value

MIN

smallest numerical value

PRODUCT

product of all numerical values

STDEV

standard deviation

VAR

variance

STDEVP

standard deviation based on the total population

VARP

variance based on the total population

The following example computes the average value of the A1:C3 range and prints the result in a message box:

Dim Doc As Object
Dim Sheet As Object
Dim CellRange As Object

Doc = ThisComponent
Sheet = Doc.Sheets.getByName("Sheet 1")
CellRange = Sheet.getCellRangeByName("A1:C3")

MsgBox CellRange.computeFunction(com.sun.star.sheet.GeneralFunction.AVERAGE)

Warning: Functions VAR, VARP, STDVERP return an incorrect value when applied to a properly defined range. See Issue 22625 .

Deleting Cell Contents

The clearContents method simplifies the process of deleting cell contents and cell ranges in that it deletes one specific type of content from a cell range.

The following example removes all the strings and the direct formatting information from the B2:C3 range.

Dim Doc As Object
Dim Sheet As Object
Dim CellRange As Object
Dim Flags As Long

Doc = ThisComponent
Sheet = Doc.Sheets(0)
CellRange = Sheet.getCellRangeByName("B2:C3")

Flags = com.sun.star.sheet.CellFlags.STRING + _
      com.sun.star.sheet.CellFlags.HARDATTR

CellRange.clearContents(Flags)

The flags specified in clearContents come from the com.sun.star.sheet.CellFlags constants list. This list provides the following elements:

VALUE

numerical values that are not formatted as date or time

DATETIME

numerical values that are formatted as date or time

STRING

strings

ANNOTATION

comments that are linked to cells

FORMULA

formulas

HARDATTR

direct formatting of cells

STYLES

indirect formatting

OBJECTS

drawing objects that are connected to cells

EDITATTR

character formatting that only applies to parts of the cells

You can also add the constants together to delete different information using a call from clearContents.

Searching and Replacing Cell Contents

Spreadsheet documents, like text documents, provide a function for searching and replacing.

The descriptor objects for searching and replacing in spreadsheet documents are not created directly through the document object, but rather through the Sheets list. The following is an example of a search and replace process:

Dim Doc As Object
Dim Sheet As Object
Dim ReplaceDescriptor As Object
Dim I As Integer

Doc = ThisComponent
Sheet = Doc.Sheets(0)

ReplaceDescriptor = Sheet.createReplaceDescriptor()
ReplaceDescriptor.SearchString = "is"
ReplaceDescriptor.ReplaceString = "was"
For I = 0 to Doc.Sheets.Count - 1
  Sheet = Doc.Sheets(I)
  Sheet.ReplaceAll(ReplaceDescriptor)
Next I

This example uses the first page of the document to create a ReplaceDescriptor and then applies this to all pages in a loop.

Drawings and Presentations

This chapter provides an introduction to the macro-controlled creation and editing of drawings and presentations.

The first section describes the structure of drawings, including the basic elements that contain drawings. The second section addresses more complex editing functions, such as grouping, rotating, and scaling objects. The third section deals with presentations.

Information about creating, opening, and saving drawings can be found in #Working With Documents.

The Structure of Drawings

Pages

• A Draw (or Impress) document is composed of pages, also called slides. What is written here also applies to Impress documents.

LibreOffice does not limit the number of pages in a drawing document. You can design each page separately. There is also no limit to the number of drawing elements that you can add to a page.

The pages of a drawing document are available through the DrawPages container. You can access individual pages either through their number or their name. If a document has one page and this is called Slide 1, then the following examples are identical.

Example 1: access by means of the number (numbering begins with 0)

Dim Doc As Object
Dim Page As Object

Doc = ThisComponent
Page = Doc.DrawPages(0)

{{Note|1=The expression ''Doc.DrawPages(0)'' is a Basic simplification of the API call : ''Doc.getDrawPages.getByIndex(0)''}}

'''Example 2: access by means of the name'''

Dim Doc As Object
Dim Page As Object

Doc = ThisComponent
Page = Doc.DrawPages.getByName("Slide 1")

In Example 1, the page is accessed by its number (counting begins at 0). In the second example, the page is accessed by its name and the getByName method.

Properties of a page

The preceding call returns a page object that supports the com.sun.star.drawing.DrawPage service. The service recognizes the following properties:

BorderLeft (Long)

left-hand border in hundredths of a millimeter

BorderRight (Long)

right-hand border in hundredths of a millimeter

BorderTop (Long)

top border in hundredths of a millimeter

BorderBottom (Long)

bottom border in hundredths of a millimeter

Width (Long)

page width in hundredths of a millimeter

Height (Long)

page height in hundredths of a millimeter

Number (Short)

number of pages (numbering begins at 1), read-only

Orientation (Enum)

page orientation (in accordance with com.sun.star.view.PaperOrientation enumeration)

If these settings are changed, then all of the pages in the document are affected.

The following example sets the page size of a drawing document which has just been opened to 20 x 20 centimeters with a page margin of 0.5 centimeters:

Dim Doc As Object
Dim Page As Object

Doc = ThisComponent
Page = Doc.DrawPages(0)

Page.BorderLeft = 500
Page.BorderRight = 500
Page.BorderTop = 500
Page.BorderBottom = 500

Page.Width = 20000
Page.Height = 20000

Renaming Pages

Warning: If a new page is inserted in a drawing document of several pages, all subsequent pages which have not been renamed will automatically see their default name change, e.g. Slide 3 will be changed into Slide 4, etc. This automatic renaming works also in reverse when a page is deleted. The only way to have a fixed page name is to rename the page, by the user interface or by programming.

A page provides methods getName and setName to read and modify its name. Basic can handle both methods like a property Name. Here we rename the first page of the drawing document.

Dim Doc As Object
Dim Page As Object

Doc = ThisComponent
Page = Doc.DrawPages(0)
Page.Name = "First"

Creating and Deleting Pages

The DrawPages container of a drawing document is also used to create and delete individual pages. The following example uses the hasByName method to check if a page called MyPage exists. If it does, the method determines a corresponding object reference by using the getByName method and then saves the reference in a variable in Page. If the corresponding page does not exist, it is created and inserted in the drawing document by the insertNewByIndex method. The argument of the method is the position, counted from 0, of the existing page after which the new page will be inserted. Then the new page is renamed.

Dim Doc As Object
Dim Page As Object

Doc = ThisComponent

If Doc.Drawpages.hasByName("MyPage") Then
  Page = Doc.Drawpages.getByName("MyPage")
Else
  Page = Doc.Drawpages.insertNewByIndex(2)
  Page.Name = "MyPage" ' you should always rename a new page
  ' MyPage is the fourth page of the document, i.e. position 3
End If

The hasByName and getByName methods are obtained from the com.sun.star.container.XNameAccess interface.

The insertNewByIndex method is obtained from the com.sun.star.drawing.XDrawPages interface. The same interface provides the method remove to delete (remove) a page:

Dim Doc As Object

Doc = ThisComponent

If Doc.Drawpages.hasByName("MyPage") Then
  Page = Doc.Drawpages.getByName("MyPage")
  Doc.Drawpages.remove(Page)
End If

Duplicating a Page

A copy of a given page is created, not from the DrawPages container, but from the drawing document itself with the method duplicate. The copy is created at the next position after the original page, with a default name.

Dim Doc As Object
Dim Page As Object, ClonedPage As Object

Doc = ThisComponent
Page = Doc.Drawpages.getByName("MyPage")
ClonedPage = Doc.duplicate(Page)
ClonedPage.Name = "MyCopy" ' you should always rename a new page

Moving a Page

The API does not provide a method to change the position of a page inside a drawing document.

Elementary Properties of Drawing Objects

Drawing objects include shapes (rectangles, circles, and so on), lines, and text objects. All of these share a number of common features and support the com.sun.star.drawing.Shape service. This service defines the Size and Position properties of a drawing object.

LibreOffice Basic also offers several other services through which you can modify such properties, as formatting or apply fills. The formatting options that are available depend on the type of drawing object.

The following example creates and inserts a rectangle in a drawing document:

Dim Doc As Object
Dim Page As Object
Dim RectangleShape As Object
Dim Point As New com.sun.star.awt.Point
Dim Size As New com.sun.star.awt.Size

Doc = ThisComponent
Page = Doc.DrawPages(0)

Point.x = 1000
Point.y = 1000
Size.Width = 10000
Size.Height = 10000

RectangleShape = Doc.createInstance("com.sun.star.drawing.RectangleShape")
RectangleShape.Size = Size
RectangleShape.Position = Point

Page.add(RectangleShape)

The Point and Size structures with the point of origin (left hand corner) and the size of the drawing object are then initialized. The lengths are specified in hundredths of a millimeter.

The program code then uses the Doc.createInstance call to create the rectangle drawing object as specified by the com.sun.star.drawing.RectangleShape service. At the end, the drawing object is assigned to a page using a Page.add call.

Fill Properties

This section describes four services and in each instance the sample program code uses a rectangle shape element that combines several types of formatting. Fill properties are combined in the com.sun.star.drawing.FillProperties service.

LibreOffice recognizes four main types of formatting for a fill area. The simplest variant is a single-color fill. The options for defining color gradients and hatches let you create other colors into play. The fourth variant is the option of projecting existing graphics into the fill area.

The fill mode of a drawing object is defined using the FillStyle property. The permissible values are defined in com.sun.star.drawing.FillStyle.

Single Color Fills

The main property for single-color fills is:

FillColor (Long)

fill color of area

To use the fill mode, you must the FillStyle property to the SOLID fill mode.

The following example creates a rectangle shape and fills it with red (RGB value 255, 0, 0):

Dim Doc As Object
Dim Page As Object
Dim RectangleShape As Object
Dim Point As New com.sun.star.awt.Point
Dim Size As New com.sun.star.awt.Size

Point.x = 1000
Point.y = 1000
Size.Width = 10000
Size.Height = 10000

Doc = ThisComponent
Page = Doc.DrawPages(0)

RectangleShape = Doc.createInstance("com.sun.star.drawing.RectangleShape")
RectangleShape.Size = Size
RectangleShape.Position = Point

RectangleShape.FillStyle = com.sun.star.drawing.FillStyle.SOLID
RectangleShape.FillColor = RGB(255,0,0)

Page.add(RectangleShape)

Color Gradient

If you set the FillStyle property to GRADIENT, you can apply a color gradient to any fill area of a LibreOffice document.

If you want to apply a predefined color gradient, you can assign the associated name of the FillTransparenceGradientName property. To define your own color gradient, you need to complete a com.sun.star.awt.Gradient structure to assign the FillGradient property. This property provides the following options:

Style (Enum)

type of gradient, for example, linear or radial (default values in accordance with com.sun.star.awt.GradientStyle)

StartColor (Long)

start color of color gradient

EndColor (Long)

end color of color gradient

Angle (Short)

angle of color gradient in tenths of a degree

XOffset (Short)

X-coordinate at which the color gradient starts, specified in hundredths of a millimeter

YOffset (Short)

Y-coordinate at which the color gradient begins, specified in hundredths of a millimeter

StartIntensity (Short)

intensity of StartColor as a percentage (in LibreOffice Basic, you can also specify values higher than 100 percent)

EndIntensity (Short)

intensity of EndColor as a percentage (in LibreOffice Basic, you can also specify values higher than 100 percent)

StepCount (Short)

number of color graduations which LibreOffice is to calculate for the gradients

The following example demonstrates the use of color gradients with the aid of the com.sun.star.awt.Gradient structure:

Dim Doc As Object
Dim Page As Object
Dim RectangleShape As Object
Dim Point As New com.sun.star.awt.Point
Dim Size As New com.sun.star.awt.Size
Dim Gradient As New com.sun.star.awt.Gradient

Point.x = 1000
Point.y = 1000
Size.Width = 10000
Size.Height = 10000

Doc = ThisComponent
Page = Doc.DrawPages(0)

RectangleShape = Doc.createInstance("com.sun.star.drawing.RectangleShape")
RectangleShape.Size = Size
RectangleShape.Position = Point
Gradient.Style = com.sun.star.awt.GradientStyle.LINEAR
Gradient.StartColor = RGB(255,0,0)
Gradient.EndColor = RGB(0,255,0)
Gradient.StartIntensity = 150
Gradient.EndIntensity = 150
Gradient.Angle = 450
Gradient.StepCount = 100

RectangleShape.FillStyle = com.sun.star.drawing.FillStyle.GRADIENT
RectangleShape.FillGradient = Gradient

Page.add(RectangleShape)

This example creates a linear color gradient (Style = LINEAR). The gradient starts with red (StartColor) in the top left corner, and extends at a 45 degree angle (Angle) to green (EndColor) in the bottom right corner. The color intensity of the start and end colors is 150 percent (StartIntensity and EndIntensity) which results in the colors seeming brighter than the values specified in the StartColor and EndColor properties. The color gradient is depicted using a hundred graduated individual colors (StepCount).

Hatches

To create a hatch fill, the FillStyle property must be set to HATCH. The program code for defining the hatch is very similar to the code for color gradients. Again an auxiliary structure, in this case com.sun.star.drawing.Hatch, is used to define the appearance of hatches. The structure for hatches has the following properties:

Style (Enum)

type of hatch: simple, squared, or squared with diagonals (default values in accordance with com.sun.star.awt.HatchStyle)

Color (Long)

color of lines

Distance (Long)

distance between lines in hundredths of a millimeter

Angle (Short)

angle of hatch in tenths of a degree

The following example demonstrates the use of a hatch structure:

Dim Doc As Object
Dim Page As Object
Dim RectangleShape As Object
Dim Point As New com.sun.star.awt.Point
Dim Size As New com.sun.star.awt.Size
Dim Hatch As New com.sun.star.drawing.Hatch

Point.x = 1000
Point.y = 1000
Size.Width = 10000
Size.Height = 10000

Doc = ThisComponent
Page = Doc.DrawPages(0)

RectangleShape = Doc.createInstance("com.sun.star.drawing.RectangleShape")
RectangleShape.Size = Size
RectangleShape.Position = Point

RectangleShape.FillStyle = com.sun.star.drawing.FillStyle.HATCH

Hatch.Style = com.sun.star.drawing.HatchStyle.SINGLE
Hatch.Color = RGB(64,64,64)
Hatch.Distance = 20
Hatch.Angle = 450

RectangleShape.FillHatch = Hatch

Page.add(RectangleShape)

This code creates a simple hatch structure (HatchStyle = SINGLE) whose lines are rotated 45 degrees (Angle). The lines are dark gray (Color) and are spaced is 0.2 millimeters (Distance) apart.

Bitmaps

To use bitmap projection as a fill, you must set the FillStyle property to BITMAP. If the bitmap is already available in LibreOffice, you just need to specify its name in the FillBitMapName property and its display style (simple, tiled, or elongated) in the FillBitmapMode property (default values in accordance with com.sun.star.drawing.BitmapMode).

If you want to use an external bitmap file, you can specify its URL in the FillBitmapURL property.

The following example creates a rectangle and tiles the Sky bitmap that is available in LibreOffice to fill the area of the rectangle:

Dim Doc As Object
Dim Page As Object
Dim RectangleShape As Object
Dim Point As New com.sun.star.awt.Point
Dim Size As New com.sun.star.awt.Size

Point.x = 1000
Point.y = 1000
Size.Width = 10000
Size.Height = 10000

Doc = ThisComponent
Page = Doc.DrawPages(0)

RectangleShape = Doc.createInstance("com.sun.star.drawing.RectangleShape")
RectangleShape.Size = Size
RectangleShape.Position = Point

RectangleShape.FillStyle = com.sun.star.drawing.FillStyle.BITMAP
RectangleShape.FillBitmapName = "Sky"
RectangleShape.FillBitmapMode = com.sun.star.drawing.BitmapMode.REPEAT

Page.add(RectangleShape)

Transparency

You can adjust the transparency of any fill that you apply. The simplest way to change the transparency of a drawing element is to use the FillTransparence property.

The following example creates a red rectangle with a transparency of 50 percent.

Dim Doc As Object
Dim Page As Object
Dim RectangleShape As Object
Dim Point As New com.sun.star.awt.Point
Dim Size As New com.sun.star.awt.Size

Point.x = 1000
Point.y = 1000
Size.Width = 10000
Size.Height = 10000

Doc = ThisComponent
Page = Doc.DrawPages(0)

RectangleShape = Doc.createInstance("com.sun.star.drawing.RectangleShape")
RectangleShape.Size = Size
RectangleShape.Position = Point

RectangleShape.FillStyle = com.sun.star.drawing.FillStyle.SOLID
RectangleShape.FillTransparence = 50
RectangleShape.FillColor = RGB(255,0,0)

Page.add(RectangleShape)

To make the fill transparent, set the FillTransparence property to 100.

In addition to the FillTransparence property, the com.sun.star.drawing.FillProperties service also provides the FillTransparenceGradient property. This is used to define a gradient that specifies the transparency of a fill area.

Line Properties

All drawing objects that can have a border line support the com.sun.star.drawing.LineStyle service. Some of the properties that this service provides are:

LineStyle (Enum)

line type (default values in accordance with com.sun.star.drawing.LineStyle)

LineColor (Long)

line color

LineTransparence (Short)

line transparency

LineWidth (Long)

line thickness in hundredths of a millimeter

LineJoint (Enum)

transitions to connection points (default values in accordance with com.sun.star.drawing.LineJoint )

The following example creates a rectangle with a solid border (LineStyle = SOLID) that is 5 millimeters thick (LineWidth) and 50 percent transparent. The right and left-hand edges of the line extend to their points of intersect with each other (LineJoint = MITER) to form a right-angle.

Dim Doc As Object
Dim Page As Object
Dim RectangleShape As Object
Dim Point As New com.sun.star.awt.Point
Dim Size As New com.sun.star.awt.Size

Point.x = 1000
Point.y = 1000
Size.Width = 10000
Size.Height = 10000

Doc = ThisComponent
Page = Doc.DrawPages(0)

RectangleShape = Doc.createInstance("com.sun.star.drawing.RectangleShape")
RectangleShape.Size = Size
RectangleShape.Position = Point

RectangleShape.LineColor = RGB(128,128,128)
RectangleShape.LineTransparence = 50
RectangleShape.LineWidth = 500
RectangleShape.LineJoint = com.sun.star.drawing.LineJoint.MITER

RectangleShape.LineStyle = com.sun.star.drawing.LineStyle.SOLID

Page.add(RectangleShape)

In addition to the listed properties, the com.sun.star.drawing.LineStyle service provides options for drawing dotted and dashed lines. For more information, see the LibreOffice API reference.

Text Properties (Drawing Objects)

The com.sun.star.style.CharacterProperties and com.sun.star.style.ParagraphProperties services can format text in drawing objects. These services relate to individual characters and paragraphs and are described in detail in #Text Documents.

The following example inserts text in a rectangle and formats the font com.sun.star.style.CharacterProperties service.

Dim Doc As Object
Dim Page As Object
Dim RectangleShape As Object
Dim Point As New com.sun.star.awt.Point
Dim Size As New com.sun.star.awt.Size
Point.x = 1000
Point.y = 1000
Size.Width = 10000
Size.Height = 10000
Doc = ThisComponent
Page = Doc.DrawPages(0)

RectangleShape = Doc.createInstance("com.sun.star.drawing.RectangleShape")
RectangleShape.Size = Size
RectangleShape.Position = Point

Page.add(RectangleShape)

RectangleShape.String = "This is a test" RectangleShape.CharWeight = com.sun.star.awt.FontWeight.BOLD RectangleShape.CharFontName = "Arial"

This code uses the String-property of the rectangle to insert the text and the CharWeight and CharFontName properties from the com.sun.star.style.CharacterProperties service to format the text font.

The text can only be inserted after the drawing object has been added to the drawing page. You can also use the com.sun.star.drawing.Text service to position and format text in drawing object. The following are some of the important properties of this service:

TextAutoGrowHeight (Boolean)

adapts the height of the drawing element to the text it contains

TextAutoGrowWidth (Boolean)

adapts the width of the drawing element to the text it contains

TextHorizontalAdjust (Enum)

horizontal position of text within the drawing element (default values in accordance with com.sun.star.drawing.TextHorizontalAdjust)

TextVerticalAdjust (Enum)

vertical position of text within the drawing element (default values in accordance with com.sun.star.drawing.TextVerticalAdjust)

TextLeftDistance (Long)

left-hand distance between drawing element and text in hundredths of a millimeter

TextRightDistance (Long)

right-hand distance between drawing element and text in hundredths of a millimeter

TextUpperDistance (Long)

upper distance between drawing element and text in hundredths of a millimeter

TextLowerDistance (Long)

lower distance between drawing element and text in hundredths of a millimeter

The following example demonstrates use of the named properties.

Dim Doc As Object
Dim Page As Object
Dim RectangleShape As Object
Dim Point As New com.sun.star.awt.Point
Dim Size As New com.sun.star.awt.Size

Point.x = 1000
Point.y = 1000
Size.Width = 10000
Size.Height = 10000

Doc = ThisComponent
Page = Doc.DrawPages(0)

RectangleShape = Doc.createInstance("com.sun.star.drawing.RectangleShape")
RectangleShape.Size = Size
RectangleShape.Position = Point

Page.add(RectangleShape)

RectangleShape.String = "This is a test"  ' May only take place after Page.add!

RectangleShape.TextVerticalAdjust = com.sun.star.drawing.TextVerticalAdjust.TOP
RectangleShape.TextHorizontalAdjust = com.sun.star.drawing.TextHorizontalAdjust.LEFT

RectangleShape.TextLeftDistance = 300
RectangleShape.TextRightDistance = 300
RectangleShape.TextUpperDistance = 300
RectangleShape.TextLowerDistance = 300

This code inserts a drawing element in a page and then adds text to the top left corner of the drawing object using the TextVerticalAdjust and TextHorizontalAdjust properties. The minimum distance between the text edge of the drawing object is set to three millimeters.

Shadow Properties

You can add a shadow to most drawing objects with the com.sun.star.drawing.ShadowProperties service. The properties of this service are:

Shadow (Boolean)

activates the shadow

ShadowColor (Long)

shadow color

ShadowTransparence (Short)

transparency of the shadow

ShadowXDistance (Long)

vertical distance of the shadow from the drawing object in hundredths of a millimeter

ShadowYDistance (Long)

horizontal distance of the shadow from the drawing object in hundredths of a millimeter

The following example creates a rectangle with a shadow that is vertically and horizontally offset from the rectangle by 2 millimeters. The shadow is rendered in dark gray with 50 percent transparency.

Dim Doc As Object
Dim Page As Object
Dim RectangleShape As Object
Dim Point As New com.sun.star.awt.Point
Dim Size As New com.sun.star.awt.Size

Point.x = 1000
Point.y = 1000
Size.Width = 10000
Size.Height = 10000

Doc = ThisComponent
Page = Doc.DrawPages(0)

RectangleShape = Doc.createInstance("com.sun.star.drawing.RectangleShape")
RectangleShape.Size = Size
RectangleShape.Position = Point

RectangleShape.Shadow = True
RectangleShape.ShadowColor = RGB(192,192,192)
RectangleShape.ShadowTransparence = 50
RectangleShape.ShadowXDistance = 200
RectangleShape.ShadowYDistance = 200

Page.add(RectangleShape)

An Overview of Various Drawing Objects

Rectangle Shapes

Rectangle shape objects (com.sun.star.drawing.RectangleShape) support the following services for formatting objects:

Fill properties

com.sun.star.drawing.FillProperties

Line properties

com.sun.star.drawing.LineProperties

Text properties

com.sun.star.drawing.Text (with com.sun.star.style.CharacterProperties and com.sun.star.style.ParagraphProperties)

Shadow properties

com.sun.star.drawing.ShadowProperties

CornerRadius (Long)

radius for rounding corners in hundredths of a millimeter

Circles and Ellipses

The Service com.sun.star.drawing.EllipseShape service is responsible for circles and ellipses and supports the following services:

Fill properties

com.sun.star.drawing.FillProperties

Line properties

com.sun.star.drawing.LineProperties

Text properties

com.sun.star.drawing.Text (with com.sun.star.style.CharacterProperties and com.sun.star.style.ParagraphProperties)

Shadow properties

com.sun.star.drawing.ShadowProperties

In addition to these services, circles and ellipses also provide these properties:

CircleKind (Enum)

type of circle or ellipse (default values in accordance with com.sun.star.drawing.CircleKind )

CircleStartAngle (Long)

start angle in tenths of a degree (only for circle or ellipse segments)

CircleEndAngle (Long)

end angle in tenths of a degree (only for circle or ellipse segments)

The CircleKind property determines if an object is a complete circle, a circular slice, or a section of a circle. The following values are available:

com.sun.star.drawing.CircleKind.FULL

full circle or full ellipse

com.sun.star.drawing.CircleKind.CUT

section of circle (partial circle whose interfaces are linked directly to one another)

com.sun.star.drawing.CircleKind.SECTION

circle slice

com.sun.star.drawing.CircleKind.ARC

angle (not including circle line)

The following example creates a circular slice with a 70 degree angle (produced from difference between start angle of 20 degrees and end angle of 90 degrees)

Dim Doc As Object
Dim Page As Object
Dim EllipseShape As Object
Dim Point As New com.sun.star.awt.Point
Dim Size As New com.sun.star.awt.Size

Point.x = 1000
Point.y = 1000
Size.Width = 10000
Size.Height = 10000

Doc = ThisComponent
Page = Doc.DrawPages(0)

EllipseShape = Doc.createInstance("com.sun.star.drawing.EllipseShape")
EllipseShape.Size = Size
EllipseShape.Position = Point

EllipseShape.CircleStartAngle = 2000
EllipseShape.CircleEndAngle = 9000
EllipseShape.CircleKind = com.sun.star.drawing.CircleKind.SECTION

Page.add(EllipseShape)

Lines

LibreOffice provides the com.sun.star.drawing.LineShape service for line objects. Line objects support all the general formatting services with the exception of areas. The following are all the properties that are associated with the LineShape service:

Line properties

com.sun.star.drawing.LineProperties

Text properties

com.sun.star.drawing.Text (with com.sun.star.style.CharacterProperties and com.sun.star.style.ParagraphProperties)

Shadow properties

com.sun.star.drawing.ShadowProperties

The following example creates and formats a line with the help of the named properties. The origin of the line is specified in the Location property, whereas the coordinates listed in the Size property specify the end point of the line.

Dim Doc As Object
Dim Page As Object
Dim LineShape As Object
Dim Point As New com.sun.star.awt.Point
Dim Size As New com.sun.star.awt.Size

Point.x = 1000
Point.y = 1000
Size.Width = 10000
Size.Height = 10000

Doc = ThisComponent
Page = Doc.DrawPages(0)

LineShape = Doc.createInstance("com.sun.star.drawing.LineShape")
LineShape.Size = Size
LineShape.Position = Point

Page.add(LineShape)

Polypolygon Shapes

LibreOffice also supports complex polygonal shapes through the com.sun.star.drawing.PolyPolygonShape service. Strictly speaking, a PolyPolygon is not a simple polygon but a multiple polygon. Several independent lists containing corner points can therefore be specified and combined to form a complete object.

As with rectangle shapes, all the formatting properties of drawing objects are also provided for polypolygons:

Fill properties

com.sun.star.drawing.FillProperties

Line properties

com.sun.star.drawing.LineProperties

Text properties

com.sun.star.drawing.Text (with com.sun.star.style.CharacterProperties and com.sun.star.style.ParagraphProperties)

Shadow properties

com.sun.star.drawing.ShadowProperties

The PolyPolygonShape service also has a property that lets you define the coordinates of a polygon:

• PolyPolygon (Array) – field containing the coordinates of the polygon (double array with points of the com.sun.star.awt.Point type)

The following example shows how you can define a triangle with the PolyPolygonShape service.

Dim Doc As Object
Dim Page As Object
Dim PolyPolygonShape As Object
Dim PolyPolygon As Variant
Dim Coordinates(2) As New com.sun.star.awt.Point

Doc = ThisComponent
Page = Doc.DrawPages(0)

PolyPolygonShape = Doc.createInstance("com.sun.star.drawing.PolyPolygonShape")
Page.add(PolyPolygonShape)  ' Page.add must take place before the coordinates are set

Coordinates(0).x = 1000
Coordinates(1).x = 7500
Coordinates(2).x = 10000
Coordinates(0).y = 1000
Coordinates(1).y = 7500
Coordinates(2).y = 5000

PolyPolygonShape.PolyPolygon = Array(Coordinates())

Since the points of a polygon are defined as absolute values, you do not need to specify the size or the start position of a polygon. Instead, you need to create an array of the points, package this array in a second array (using the Array(Coordinates()) call), and then assign this array to the polygon. Before the corresponding call can be made, the polygon must be inserted into the document.

The double array in the definition allows you to create complex shapes by merging several polygons. For example, you can create a rectangle and then insert another rectangle inside it to create a hole in the original rectangle:

Dim Doc As Object
Dim Page As Object
Dim PolyPolygonShape As Object
Dim PolyPolygon As Variant
Dim Square1(3) As New com.sun.star.awt.Point
Dim Square2(3) As New com.sun.star.awt.Point
Dim Square3(3) As New com.sun.star.awt.Point

Doc = ThisComponent
Page = Doc.DrawPages(0)

PolyPolygonShape = Doc.createInstance("com.sun.star.drawing.PolyPolygonShape")

Page.add(PolyPolygonShape)  ' Page.add must take place before the coordinates are set

Square1(0).x = 5000
Square1(1).x = 10000
Square1(2).x = 10000
Square1(3).x = 5000
Square1(0).y = 5000
Square1(1).y = 5000
Square1(2).y = 10000
Square1(3).y = 10000

Square2(0).x = 6500
Square2(1).x = 8500
Square2(2).x = 8500
Square2(3).x = 6500
Square2(0).y = 6500
Square2(1).y = 6500
Square2(2).y = 8500
Square2(3).y = 8500

Square3(0).x = 6500
Square3(1).x = 8500
Square3(2).x = 8500
Square3(3).x = 6500
Square3(0).y = 9000
Square3(1).y = 9000
Square3(2).y = 9500
Square3(3).y = 9500

PolyPolygonShape.PolyPolygon = Array(Square1(), Square2(), Square3())

With respect as to which areas are filled and which areas are holes, LibreOffice applies a simple rule: the edge of the outer shape is always the outer border of the polypolygon. The next line inwards is the inner border of the shape and marks the transition to the first hole. If there is another line inwards, it marks the transition to a filled area.

Graphics

The last of the drawing elements presented here are graphic objects that are based on the com.sun.star.drawing.GraphicObjectShape service. These can be used with any graphic within LibreOffice whose appearance can be adapted using a whole range of properties.

Graphic objects support two of the general formatting properties:

Text properties

com.sun.star.drawing.Text (with com.sun.star.style.CharacterProperties and com.sun.star.style.ParagraphProperties)

Shadow properties

com.sun.star.drawing.ShadowProperties

Additional properties that are supported by graphic objects are:

GraphicURL (String)

URL of the graphic

AdjustLuminance (Short)

luminance of the colors, as a percentage (negative values are also permitted)

AdjustContrast (Short)

contrast as a percentage (negative values are also permitted)

AdjustRed (Short)

red value as a percentage (negative values are also permitted)

AdjustGreen (Short)

green value as a percentage (negative values are also permitted)

AdjustBlue (Short)

blue value as a percentage (negative values are also permitted)

Gamma (Short)

gamma value of a graphic

Transparency (Short)

transparency of a graphic as a percentage

GraphicColorMode (enum)

color mode, for example, standard, gray stages, black and white (default value in accordance with com.sun.star.drawing.ColorMode )

The following example shows how to insert a page into a graphics object.

Dim Doc As Object
Dim Page As Object
Dim GraphicObjectShape As Object
Dim Point As New com.sun.star.awt.Point
Dim Size As New com.sun.star.awt.Size

Point.x = 1000        ' specifications, insignificant because latter
                     coordinates are binding
Point.y = 1000
Size.Width = 10000
Size.Height = 10000

Doc = ThisComponent
Page = Doc.DrawPages(0)

GraphicObjectShape = Doc.createInstance("com.sun.star.drawing.GraphicObjectShape")

GraphicObjectShape.Size = Size
GraphicObjectShape.Position = Point

GraphicObjectShape.GraphicURL = "file:///c:/test.jpg"
GraphicObjectShape.AdjustBlue = -50
GraphicObjectShape.AdjustGreen = 5
GraphicObjectShape.AdjustBlue = 10
GraphicObjectShape.AdjustContrast = 20
GraphicObjectShape.AdjustLuminance = 50
GraphicObjectShape.Transparency = 40
GraphicObjectShape.GraphicColorMode = com.sun.star.drawing.ColorMode.STANDARD

Page.add(GraphicObjectShape)

This code inserts the test.jpg graphic and adapts its appearance using the Adjust properties. In this example, the graphics are depicted as 40 percent transparent with no other color conversions do not take place (GraphicColorMode = STANDARD).

Editing Drawing Objects

Grouping Objects

In many situations, it is useful to group several individual drawing objects together so that they behave as a single large object.

The following example combines two drawing objects:

Dim Doc As Object
Dim Page As Object
Dim Square As Object
Dim Circle As Object
Dim Shapes As Object
Dim Group As Object
Dim Point As New com.sun.star.awt.Point
Dim Size As New com.sun.star.awt.Size
Dim NewPos As New com.sun.star.awt.Point
Dim Height As Long
Dim Width As Long

Doc = ThisComponent
Page = Doc.DrawPages(0)
Point.x = 3000
Point.y = 3000
Size.Width = 3000
Size.Height = 3000
' create square drawing element
Square = Doc.createInstance("com.sun.star.drawing.RectangleShape")
Square.Size = Size
Square.Position = Point
Square.FillColor = RGB(255,128,128)
Page.add(Square)

' create circle drawing element
Circle = Doc.createInstance("com.sun.star.drawing.EllipseShape")
Circle.Size = Size
Circle.Position = Point
Circle.FillColor = RGB(255,128,128)
Circle.FillColor = RGB(0,255,0)
Page.add(Circle)

' combine square and circle drawing elements
Shapes = createUnoService("com.sun.star.drawing.ShapeCollection")
Shapes.add(Square)

Shapes.add(Circle)
Group = Page.group(Shapes)
' centre combined drawing elements
Height = Page.Height
Width = Page.Width
NewPos.X = Width / 2
NewPos.Y = Height / 2
Height = Group.Size.Height
Width = Group.Size.Width
NewPos.X = NewPos.X - Width / 2
NewPos.Y = NewPos.Y - Height / 2
Group.Position = NewPos

This code creates a rectangle and a circle and inserts them into a page. It then creates an object that supports the com.sun.star.drawing.ShapeCollection service and uses the Add method to add the rectangle and the circle to this object. The ShapeCollection is added to the page using the Group method and returns the actual Group object that can be edited like an individual Shape.

If you want to format the individual objects of a group, apply the formatting before you add them to the group. You cannot modify the objects once they are in the group.

Rotating and Shearing Drawing Objects

All of the drawing objects that are described in the previous sections can also be rotated and sheared using the com.sun.star.drawing.RotationDescriptor service.

The service provides the following properties:

RotateAngle (Long)

rotary angle in hundredths of a degree

ShearAngle (Long)

shear angle in hundredths of a degree

The following example creates a rectangle and rotates it by 30 degrees using the RotateAngle property:

Dim Doc As Object
Dim Page As Object
Dim RectangleShape As Object
Dim Point As New com.sun.star.awt.Point
Dim Size As New com.sun.star.awt.Size

Point.x = 1000
Point.y = 1000
Size.Width = 10000
Size.Height = 10000

Doc = ThisComponent
Page = Doc.DrawPages(0)

RectangleShape = Doc.createInstance("com.sun.star.drawing.RectangleShape")
RectangleShape.Size = Size
RectangleShape.Position = Point

RectangleShape.RotateAngle = 3000

Page.add(RectangleShape)

The next example creates the same rectangle as in the previous example, but instead shears it through 30 degrees using the ShearAngle property.

Dim Doc As Object
Dim Page As Object
Dim RectangleShape As Object
Dim Point As New com.sun.star.awt.Point
Dim Size As New com.sun.star.awt.Size

Point.x = 1000
Point.y = 1000
Size.Width = 10000
Size.Height = 10000

Doc = ThisComponent
Page = Doc.DrawPages(0)
RectangleShape = Doc.createInstance("com.sun.star.drawing.RectangleShape")
RectangleShape.Size = Size
RectangleShape.Position = Point

RectangleShape.ShearAngle = 3000

Page.add(RectangleShape)

Searching and Replacing

As in text documents, drawing documents provide a function for searching and replace. This function is similar to the one that is used in text documents as described in #Text Documents. However, in drawing documents the descriptor objects for searching and replacing are not created directly through the document object, but rather through the associated character level. The following example outlines the replacement process within a drawing:

Dim Doc As Object
Dim Page As Object
Dim ReplaceDescriptor As Object
Dim I As Integer

Doc = ThisComponent
Page = Doc.DrawPages(0)

ReplaceDescriptor = Page.createReplaceDescriptor()
ReplaceDescriptor.SearchString = &is&;
ReplaceDescriptor.ReplaceString = &was&;

For I = 0 to Doc.DrawPages.Count - 1
  Page = Doc.DrawPages(I)
  Page.ReplaceAll(ReplaceDescriptor)
Next I

This code uses the first page of the document to create a ReplaceDescriptor and then applies this descriptor in a loop to all the pages in the drawing document.

Presentations

LibreOffice presentations are based on drawing documents. Each page in the presentation is a slide. You can access slides in the same way as a standard drawing is accessed through the DrawPages list of the document object. The com.sun.star.presentation.PresentationDocument service, responsible for presentation documents, also provides the complete com.sun.star.drawing.DrawingDocument service.

Working With Presentations

In addition to the drawing functions that are provided by the Presentation property, the presentation document has a presentation object that provides access to the main properties and control mechanisms for presentations. For example, this object provides a start method that can start presentations.

Dim Doc As Object
Dim Presentation As Object

Doc = ThisComponent
Presentation = Doc.Presentation
Presentation.start()

The code used in this example creates a Doc object that references the current presentation document and establishes the associated presentation object. The start() method of the object is used to start the example and run the screen presentation.

The following methods are provided as presentation objects:

start

starts the presentation

end

ends the presentation

rehearseTimings

starts the presentation from the beginning and establishes its runtime

The following properties are also available:

AllowAnimations (Boolean)

runs animations in the presentation

CustomShow (String)

allows you to specify the name of the presentation so that you can reference the name in the presentation

FirstPage (String)

name of slide that you want to start the presentation with

IsAlwaysOnTop (Boolean)

always displays the presentation window as the first window on the screen

IsAutomatic (Boolean)

automatically runs through the presentation

IsEndless (Boolean)

restarts the presentation from the beginning once it ends

IsFullScreen (Boolean)

automatically starts the presentation in full screen mode

IsMouseVisible (Boolean)

displays the mouse during the presentation

Pause (long)

the amount of time that a blank screen is displayed at the end of the presentation

StartWithNavigator (Boolean)

displays the navigator window when the presentation starts

UsePn (Boolean)

displays the pointer during the presentation

Charts (Diagrams)

LibreOffice can display data as a chart, which creates graphical representations of numerical data in the form of bars, pie charts, lines or other elements. Data can either be displayed as 2D or 3D graphics, and the appearance of the chart elements can be individually adapted in a way similar to the process used for drawing elements.

Charts are not treated as independent documents in LibreOffice, but as objects that are embedded in an existing document.

A chart may contain its own data or may display data from the container document. For example charts in spreadsheets can display data obtained from the cell ranges and charts in text documents can display data obtained from writer tables.

Using Charts in Spreadsheets

Charts within spreadsheets can display the data from an assigned cell range within the spreadsheet. Any modifications made to the data within the spreadsheet will also be reflected in the assigned chart. The following example shows how to create a chart assigned to some cell ranges within a spreadsheet document:

Dim Doc As Object
Dim Charts As Object
Dim Chart as Object
Dim Rect As New com.sun.star.awt.Rectangle
Dim RangeAddress(0) As New com.sun.star.table.CellRangeAddress

Doc = ThisComponent
Charts = Doc.Sheets(0).Charts

Rect.X = 8000
Rect.Y = 1000
Rect.Width = 10000
Rect.Height = 7000
RangeAddress(0).Sheet = 0
RangeAddress(0).StartColumn = 0
RangeAddress(0).StartRow = 0
RangeAddress(0).EndColumn = 2
RangeAddress(0).EndRow = 12

Charts.addNewByName("MyChart", Rect, RangeAddress(), True, True)

Although the code used in the example may appear to be complex, the central processes are limited to three lines. The first central line creates the Doc document variable, which references the current spreadsheet document (Doc line = StarDesktop.CurrentComponent). The code used in the example then creates a list containing all charts of the first spreadsheet (Charts line = Doc.Sheets(0).Charts). Finally, in the last line, a new chart is added to this list using the addNewByName method. This new chart is then visible to the user. The variable RangeAddress determines the assigned cell range whose data will be displayed within the chart. The variable Rect determines the position and size of the chart within the first sheet in the spreadsheet document.

The previous example creates a bar chart. If a different chart type is needed, then the bar chart must be explicitly replaced:

Chart = Charts.getByName("MyChart").embeddedObject
Chart.Diagram = Chart.createInstance("com.sun.star.chart.LineDiagram")

The first line defines the corresponding chart object. The second line replaces the current chart with a new one — in this example, a line chart.

Note: VBA : In Microsoft Excel, a distinction is made between charts which have been inserted as a separate page in a Microsoft Excel document and charts which are embedded in a table page. Correspondingly, two different access methods are defined there for charts. This distinction is not made in LibreOffice Basic, because charts in LibreOffice Calc are always created as embedded objects of a table page. The charts are always accessed using the Charts list of the associated Sheet object.

The Structure of Charts

The structure of a chart, and therefore the list of services and interfaces supported by it, depends on the chart type. For example, the methods and properties of the Z-axis, are available in 3D charts, but not in 2D charts, and in pie charts, there are no interfaces for working with axes.

Title, Subtitle and Legend

Title, subtitle and legend are basic elements provided for every chart. The Chart object provides the following properties for administrating these elements:

HasMainTitle (Boolean)

activates the title

Title (Object)

object with detailed information about the chart title (supports the com.sun.star.chart.ChartTitle service)

HasSubTitle(Boolean)

activates the subtitle

Subtitle (Object)

object with detailed information about the chart subtitle (supports the com.sun.star.chart.ChartTitle service)

HasLegend (Boolean)

activates the legend

Legend (Object)

object with detailed information about the legend (supports the com.sun.star.chart.ChartLegend service)

Both services com.sun.star.chart.ChartTitle and com.sun.star.chart.ChartLegend do support the service com.sun.star.drawing.Shape. This allows to determine the position and size of the elements using the Position and Size properties. As the size of the legend and the titles is calculated automatically based on the current content and the character height for example, the size property provides read access only.

Fill and line properties (com.sun.star.drawing.FillProperties and com.sun.star.drawing.LineProperties services) as well as the character properties (com.sun.star.style.CharacterProperties service) are provided for further formatting of the elements.

com.sun.star.chart.ChartTitle contains not only the listed formatting properties, but also two other properties:

String (String)

text which to be displayed as the title or subtitle

TextRotation (Long)

angle of rotation of text in 100ths of a degree

The legend (com.sun.star.chart.ChartLegend) contains the following additional property:

Alignment (Enum)

position at which the legend appears (value of type com.sun.star.chart.ChartLegendPosition)

The following example creates a chart with a title "Main Title String", a subtitle "Subtitle String" and a legend. The legend has a gray background color, is placed at the bottom of the chart, and has a character size of 7 points.

Dim Doc As Object
Dim Charts As Object
Dim Chart as Object
Dim Rect As New com.sun.star.awt.Rectangle
Dim RangeAddress(0) As New com.sun.star.table.CellRangeAddress

Rect.X = 8000
Rect.Y = 1000
Rect.Width = 10000
Rect.Height = 7000
RangeAddress(0).Sheet = 0
RangeAddress(0).StartColumn = 0
RangeAddress(0).StartRow = 0
RangeAddress(0).EndColumn = 2
RangeAddress(0).EndRow = 12

Doc = ThisComponent

Charts = Doc.Sheets(0).Charts
Charts.addNewByName("MyChart", Rect, RangeAddress(), True, True)
Chart = Charts.getByName("MyChart").EmbeddedObject
Chart.HasMainTitle = True
Chart.Title.String = "Main Title String"
Chart.HasSubTitle = True
Chart.Subtitle.String = "Subtitle String"
Chart.HasLegend = True
Chart.Legend.Alignment = com.sun.star.chart.ChartLegendPosition.BOTTOM
Chart.Legend.FillStyle = com.sun.star.drawing.FillStyle.SOLID
Chart.Legend.FillColor = RGB(210, 210, 210)
Chart.Legend.CharHeight = 7

Background

Every chart has a background area. The Chart object provides the property Area to format the background:

Area (Object)

background area of the chart (supports com.sun.star.chart.ChartArea service)

The background of a chart covers its complete area, including the area under the title, subtitle and legend. The associated com.sun.star.chart.ChartArea service supports line and fill properties.

Diagram

The Chart object provides the property Diagram which forms the coordinate system with axes and grids, where the data finally is displayed:

Diagram (Object)

object forming the coordinate system where the data is plotted. It supports com.sun.star.chart.Diagram service and:

• com.sun.star.chart.StackableDiagram
• com.sun.star.chart.ChartAxisXSupplier
• com.sun.star.chart.ChartAxisYSupplier
• com.sun.star.chart.ChartAxisZSupplier
• com.sun.star.chart.ChartTwoAxisXSupplier
• com.sun.star.chart.ChartTwoAxisYSupplier

Different services are supported depending on the chart type (see #Chart Types).

Wall and Floor

The chart wall is the background of the coordinate system where the data is plotted. Two chart walls usually exist for 3D charts: one behind the plotted data and one as the left-hand or right-hand demarcation. This depends on the rotation of the chart. 3D charts usually also have a floor.

The Diagram object provides the properties Wall and Floor:

Wall (Object)

background wall of the coordinate system (supports com.sun.star.chart.ChartArea service)

Floor (Object)

floor panel of coordinate system (only for 3D charts, supports com.sun.star.chart.ChartArea service)

The specified objects support the com.sun.star.chart.ChartArea service, which provides the usual fill and line properties (com.sun.star.drawing.FillProperties and com.sun.star.drawing.LineProperties services, refer to #Drawings and Presentations).

The following example shows how graphics (named Sky) already contained in LibreOffice can be used as a background for a chart. The wall is set to be blue.

Dim Doc As Object
Dim Charts As Object
Dim Chart as Object
Dim Rect As New com.sun.star.awt.Rectangle
Dim RangeAddress(0) As New com.sun.star.table.CellRangeAddress

Rect.X = 8000
Rect.Y = 1000
Rect.Width = 10000
Rect.Height = 7000
RangeAddress(0).Sheet = 0
RangeAddress(0).StartColumn = 0
RangeAddress(0).StartRow = 0
RangeAddress(0).EndColumn = 2
RangeAddress(0).EndRow = 12

Doc = ThisComponent

Charts = Doc.Sheets(0).Charts
Charts.addNewByName("MyChart", Rect, RangeAddress(), True, True)
Chart = Charts.getByName("MyChart").EmbeddedObject
Chart.Area.FillStyle = com.sun.star.drawing.FillStyle.BITMAP
Chart.Area.FillBitmapName = "Sky"
Chart.Area.FillBitmapMode = com.sun.star.drawing.BitmapMode.REPEAT

Chart.Diagram.Wall.FillStyle = com.sun.star.drawing.FillStyle.SOLID
Chart.Diagram.Wall.FillColor = RGB(00,132,209)

Axes

LibreOffice recognizes five different axes that can be used in a chart. In the simplest scenario, these are the X and Y-axes. When working with 3D charts, a Z-axis is also sometimes provided. For charts in which the values of the various rows of data deviate significantly from one another, LibreOffice provides a second X and Y-axis for second scaling operations.

The Diagram object provides the following properties to access the axes:

HasXAxis (Boolean)

activates the X-axis

XAxis (Object)

object with detailed information about the X-axis (supports com.sun.star.chart.ChartAxis service)

HasXAxisDescription (Boolean)

activates the labels for the interval marks for the X-axis

HasYAxis (Boolean)

activates the Y-axis

YAxis (Object)

object with detailed information about the Y-axis (supports com.sun.star.chart.ChartAxis service)

HasYAxisDescription (Boolean)

activates the labels for the interval marks for the Y-axis

HasZAxis (Boolean)

activates the Z-axis

ZAxis (Object)

object with detailed information about the Z-axis (supports com.sun.star.chart.ChartAxis service)

HasZAxisDescription (Boolean)

activates the labels for the interval marks for the Z-axis

HasSecondaryXAxis (Boolean)

activates the secondary X-axis

SecondaryXAxis (Object)

object with detailed information about the secondary X-axis (supports com.sun.star.chart.ChartAxis service)

HasSecondaryXAxisDescription (Boolean)

activates the labels for the interval marks for the secondary X-axis

HasSecondaryYAxis (Boolean)

activates the secondary Y-axis

SecondaryYAxis (Object)

object with detailed information about the secondary Y-axis (supports com.sun.star.chart.ChartAxis service)

HasSecondaryYAxisDescription (Boolean)

activates the labels for the interval marks for the secondary Y-axis

Properties of Axes

The axis objects of a LibreOffice chart support the com.sun.star.chart.ChartAxis service. In addition to the properties for characters (com.sun.star.style.CharacterProperties service, refer to #Text Documents) and lines (com.sun.star.drawing.LineStyle service, refer to #Drawings and Presentations), it provides the following properties:

Scaling properties

Max (Double)

maximum value for axis

Min (Double)

minimum value for axis

Origin (Double)

point of intersect for crossing axes

StepMain (Double)

distance between the major interval marks

StepHelpCount (Long)

Contains the number of minor intervals within a major interval. E.g. a StepHelpCount of 5 divides the major interval into 5 pieces and thus produces 4 minor tick marks. (available since OpenOffice.org 3.0)

AutoMax (Boolean)

the maximum value for the axis is calculated automatically when set to true

AutoMin (Boolean)

the minimum value for the axis is calculated automatically when set to true

AutoOrigin (Boolean)

the origin is determined automatically when set to true

AutoStepMain (Boolean)

StepMain is determined automatically when set to true

AutoStepHelp (Boolean)

StepHelpCount is determined automatically when set to true

Logarithmic (Boolean)

scales the axes in logarithmic manner (rather than linear)

ReverseDirection (Boolean)

determines if the axis orientation is mathematical or reversed. (available since OpenOffice.org 2.4)

Label properties

DisplayLabels (Boolean)

activates the text label at the interval marks

TextRotation (Long)

angle of rotation of text label in 100ths of a degree

ArrangeOrder (enum)

the label may be staggered, thus they are positioned alternately over two lines (values according to com.sun.star.chart.ChartAxisArrangeOrderType)

TextBreak (Boolean)

permits line breaks within the axes labels

TextCanOverlap (Boolean)

permits an overlap of the axes labels

NumberFormat (Long)

number format to be used with the axes labels

LinkNumberFormatToSource (Boolean)

determines whether to use the number format given by the container document, or from the property NumberFormat. (since OpenOffice.org 2.3)

Interval mark properties

Marks (Const)

determines the position of the major interval marks (values in accordance with com.sun.star.chart.ChartAxisMarks)

HelpMarks (Const)

determines the position of the minor interval marks (values in accordance with com.sun.star.chart.ChartAxisMarks)

Only for bar charts

Overlap (Long)

percentage which specifies the extent to which the bars of different sets of data may overlap (at 100%, the bars are shown as completely overlapping, at -100%, there is a distance of the width of one bar between them)

GapWidth (long)

percentage which specifies the distance there may be between the different groups of bars of a chart (at 100%, there is a distance corresponding to the width of one bar)

Grids

For the primary axes grids and sub grids can be displayed, matching to the major and minor intervals. The Diagram object provides the following properties to access the grids:

HasXAxisGrid (Boolean)

activates major grid for X-axis

XMainGrid (Object)

object with detailed information about the major grid for X-axis (supports com.sun.star.chart.ChartGrid service)

HasXAxisHelpGrid (Boolean)

activates minor grid for X-axis

XHelpGrid (Object)

object with detailed information about the minor grid for X-axis (supports com.sun.star.chart.ChartGrid service)

the same for y and z:

HasYAxisGrid (Boolean)

activates major grid for Y-axis

YMainGrid (Object)

object with detailed information about the major grid for Y-axis (supports com.sun.star.chart.ChartGrid service)

HasYAxisHelpGrid (Boolean)

activates minor grid for Y-axis

YHelpGrid (Object)

object with detailed information about the minor grid for Y-axis (supports com.sun.star.chart.ChartGrid service)

HasZAxisGrid (Boolean)

activates major grid for Z-axis

ZMainGrid (Object)

object with detailed information about the major grid for Z-axis (supports com.sun.star.chart.ChartGrid service)

HasZAxisHelpGrid (Boolean)

activates minor grid for Z-axis

ZHelpGrid (Object)

object with detailed information about the minor grid for Z-axis (supports com.sun.star.chart.ChartGrid service)

The grid object is based on the com.sun.star.chart.ChartGrid service, which in turn supports the line properties of the com.sun.star.drawing.LineStyle support service (refer to #Drawings and Presentations).

Axes Title

For all axes an additional title can be displayed. The Diagram object provides the following properties to access the axes title:

HasXAxisTitle (Boolean)

activates title of X-axis

XAxisTitle (Object)

object with detailed information about title of the X-axis (supports com.sun.star.chart.ChartTitle service)

same y and z:

HasYAxisTitle (Boolean)

activates title of Y-axis

YAxisTitle (Object)

object with detailed information about title of the Y-axis (supports com.sun.star.chart.ChartTitle service)

HasZAxisTitle (Boolean)

activates title of Z-axis

ZAxisTitle (Object)

object with detailed information about title of the Z-axis (supports com.sun.star.chart.ChartTitle service)

and for the secondary axes (available since OpenOffice.org 3.0):

HasSecondaryXAxisTitle (Boolean)

activates title of the secondary X-axis.

SecondXAxisTitle (Object)

object with detailed information about title of the secondary X-axis (supports com.sun.star.chart.ChartTitle service)

HasSecondaryYAxisTitle (Boolean)

activates title of the secondary Y-axis.

SecondYAxisTitle (Object)

object with detailed information about title of the secondary Y-axis (supports com.sun.star.chart.ChartTitle service)

The objects for formatting the axes title are based on the com.sun.star.chart.ChartTitle service, which is also used for chart titles.

Example

The following example creates a line chart. The color for the rear wall of the chart is set to white. Both the X and Y-axes have a gray grid for visual orientation. The minimum value of the Y-axis is fixed to 0 and the maximum value is fixed to 100 so that the resolution of the chart is retained even if the values are changed. The X-axis points in reverse direction from right to left. And a title for the X-axis was added.

Dim Doc As Object
Dim Charts As Object
Dim Chart as Object
Dim Rect As New com.sun.star.awt.Rectangle
Dim RangeAddress(0) As New com.sun.star.table.CellRangeAddress

Doc = ThisComponent
Charts = Doc.Sheets(0).Charts

Rect.X = 8000
Rect.Y = 1000
Rect.Width = 10000
Rect.Height = 7000
RangeAddress(0).Sheet = 0
RangeAddress(0).StartColumn = 0
RangeAddress(0).StartRow = 0
RangeAddress(0).EndColumn = 2
RangeAddress(0).EndRow = 12

Charts.addNewByName("MyChart", Rect, RangeAddress(), True, True)
Chart = Charts.getByName("MyChart").embeddedObject
Chart.Diagram = Chart.createInstance("com.sun.star.chart.LineDiagram")
Chart.Diagram.Wall.FillColor = RGB(255, 255, 255)
Chart.Diagram.HasXAxisGrid = True
Chart.Diagram.XMainGrid.LineColor = RGB(192, 192, 192)
Chart.Diagram.HasYAxisGrid = True
Chart.Diagram.YMainGrid.LineColor = RGB(192, 192, 192)
Chart.Diagram.YAxis.Min = 0
Chart.Diagram.YAxis.Max = 100

Chart.Diagram.XAxis.ReverseDirection = true 'needs OpenOffice.org 2.4 or newer
Chart.Diagram.HasXAxisTitle = true
Chart.Diagram.XAxisTitle.String = "Reversed X Axis Example"

3D Charts

Most charts in LibreOffice can also be displayed with 3D graphics. The following properties are provided for 3D charts at the Diagram object:

Dim3D (Boolean)

activates 3D display

Deep (Boolean)

the series will be arranged behind each other in z-direction

RightAngledAxes (Boolean)

activates a 3D display mode where X- and Y-axes form a right angle within the projection. (available since OpenOffice.org 2.3)

D3DScenePerspective (Enum)

defines whether the 3D objects are to be drawn in perspective or parallel projection.(values according to com.sun.star.drawing.ProjectionMode)

Perspective (Long)

Perspective of 3D charts ( [0,100] ) (available since OpenOffice.org 2.4.1)

RotationHorizontal (Long)

Horizontal rotation of 3D charts in degrees ( [-180,180] ) (available since OpenOffice.org 2.4.1)

RotationVertical (Long)

Vertical rotation of 3D charts in degrees ( [-180,180] ) (available since OpenOffice.org 2.4.1)

The following example creates a 3D area chart.

Dim Doc As Object
Dim Charts As Object
Dim Chart as Object
Dim Rect As New com.sun.star.awt.Rectangle
Dim RangeAddress(0) As New com.sun.star.table.CellRangeAddress

Doc = ThisComponent
Charts = Doc.Sheets(0).Charts

Rect.X = 8000
Rect.Y = 1000
Rect.Width = 10000
Rect.Height = 7000
RangeAddress(0).Sheet = 0
RangeAddress(0).StartColumn = 0
RangeAddress(0).StartRow = 0
RangeAddress(0).EndColumn = 2
RangeAddress(0).EndRow = 12

Charts.addNewByName("MyChart", Rect, RangeAddress(), True, True)
Chart = Charts.getByName("MyChart").embeddedObject
Chart.Diagram = Chart.createInstance("com.sun.star.chart.AreaDiagram")
Chart.Diagram.Dim3D = true
Chart.Diagram.Deep = true
Chart.Diagram.RightAngledAxes = true 'needs OpenOffice.org 2.3 or newer
Chart.Diagram.D3DScenePerspective = com.sun.star.drawing.ProjectionMode.PERSPECTIVE
Chart.Diagram.Perspective = 100 'needs OpenOffice.org 2.4.1 or newer
Chart.Diagram.RotationHorizontal = 60 'needs OpenOffice.org 2.4.1 or newer
Chart.Diagram.RotationVertical = 30 'needs OpenOffice.org 2.4.1 or newer

Stacked Charts

Stacked charts are charts that are arranged with several individual values on top of one another to produce a total value. This view shows not only the individual values, but also an overview of all the values.

In LibreOffice, various types of charts can be displayed in a stacked form. All of these charts support the com.sun.star.chart.StackableDiagram service, which in turn provides the following properties:

Stacked (Boolean)

activates the stacked viewing mode

Percent (Boolean)

rather than absolute values, displays their percentage distribution

Chart Types

Line Charts

Line charts (com.sun.star.chart.LineDiagram) support two X-axes, two Y-axes and one Z-axis. They can be displayed as 2D or 3D graphics (com.sun.star.chart.Dim3Ddiagramservice). The lines can be stacked (com.sun.star.chart.StackableDiagram).

Line charts provide the following properties:

SymbolType (const)

symbol for displaying the data points (constant in accordance with com.sun.star.chart.ChartSymbolType)

SymbolSize (Long)

size of symbol for displaying the data points in 100ths of a millimeter

SymbolBitmapURL (String)

file name of graphics for displaying the data points

Lines (Boolean)

links the data points by means of lines

SplineType (Long)

spline function for smoothing the lines (0: no spline function, 1: cubic splines, 2: B splines)

SplineOrder (Long)

polynomial weight for splines (only for B splines)

SplineResolution (Long)

number of support points for spline calculation

Area Charts

Area charts (com.sun.star.chart.AreaDiagram service) support two X-axes, two Y-axes and one Z-axis. They can be displayed as 2D or 3D graphics (com.sun.star.chart.Dim3Ddiagram service). The areas can be stacked (com.sun.star.chart.StackableDiagram).

Bar Charts

Bar charts (com.sun.star.chart.BarDiagram) support two X-axes, two Y-axes and one Z-axis. They can be displayed as 2D or 3D graphics (com.sun.star.chart.Dim3Ddiagram service). The bars can be stacked (com.sun.star.chart.StackableDiagram).

They provide the following properties:

Vertical (Boolean)

displays the bars vertically, otherwise they are depicted horizontally

Deep (Boolean)

in 3D viewing mode, positions the bars behind one another rather than next to one another

StackedBarsConnected (Boolean)

links the associated bars in a stacked chart by means of lines (only available with horizontal charts)

NumberOfLines (Long)

number of lines to be displayed in a stacked chart as lines rather than bars

GroupBarsPerAxis (Boolean)

displays bars attached to different axes behind or next to each other (available since OpenOffice.org 2.4)

Pie Charts

Pie charts (com.sun.star.chart.PieDiagram) do not contain any axes and cannot be stacked. They can be displayed as 2D or 3D graphics (com.sun.star.chart.Dim3DDiagram service).

The following properties are provided for pie and donut charts with the Diagram object:

StartingAngle (Long)

angle of the first piece of a pie in degrees (available since OpenOffice.org 3.0)

Databases

LibreOffice has an integrated database interface (independent of any systems) called Star Database Connectivity (SDBC). The objective of developing this interface was to provide access to as many different data sources as possible.

To make this possible, data sources are accessed by drivers. The sources from which the drivers take their data is irrelevant to a SDBC user. Some drivers access file-based databases and take the data directly from them. Others use standard interfaces such as JDBC or ODBC. There are, however, also special drivers which access the MAPI address book, LDAP directories or LibreOffice spreadsheets as data sources.

Since the drivers are based on UNO components, other drivers can be developed and therefore open up new data sources. You will find details about this in the LibreOffice Developer's Guide.

Note: VBA : In terms of its concept, SDBC is comparable with the ADO and DAO libraries available in VBA. It permits high level access to databases, regardless of the underlying database backends.

SQL: a Query Language

The SQL language is provided as a query language for users of SDBC. To compare the differences between different SQL dialects, the SDBC components from LibreOffice have their own SQL parser. This uses the query window to check the SQL commands typed and corrects simple syntax errors, such as those associated with uppercase and lowercase characters.

If a driver permits access to a data source that does not support SQL, then it must independently convert the transferred SQL commands to the native access needed.

Types of Database Access

The database interface from LibreOffice is available in the LibreOffice Writer and LibreOffice Calc applications, as well as in the database forms.

In LibreOffice Writer, standard letters can be created with the assistance of SDBC data sources and these can then be printed out. You can also move data from the database window into text documents using the drag-and-drop function.

If you move a database table into a spreadsheet, LibreOffice creates a table area which can be updated at the click of the mouse if the original data has been modified. Conversely, spreadsheet data can be moved to a database table and a database import performed.

Finally, LibreOffice provides a mechanism for forms based on databases. To do this, you first create a standard LibreOffice Writer or LibreOffice Calc form and then link the fields to a database.

All the options specified here are based on the user interface from LibreOffice. No programming knowledge is needed to use the corresponding functions.

This section, however, provides little information about the functions specified, but instead concentrates on the programming interface from SDBC, which allows for automated database querying and therefore permits a much greater range of applications to be used.

Basic knowledge of the way in which databases function and the SQL query language is however needed to fully understand the following sections.

Data Sources

A database is incorporated into LibreOffice by creating what is commonly referred to as a data source. The user interface provides a corresponding option for creating data sources in the Extras menu. You can also create data sources and work with them using LibreOffice Basic.

A database context object that is created using the createUnoService function serves as the starting point for accessing a data source. This based on the com.sun.star.sdb.DatabaseContext service and is the root object for all database operations.

The following example shows how a database context can be created and then used to determine the names of all data sources available. It displays the names in a message box.

Dim DatabaseContext As Object
Dim Names
Dim I As Integer

DatabaseContext = createUnoService("com.sun.star.sdb.DatabaseContext")

Names = DatabaseContext.getElementNames()

For I = 0 To UBound(Names())
  MsgBox Names(I)
Next I

The individual data sources are based on the com.sun.star.sdb.DataSource service and can be determined from the database context using the getByName method:

Dim DatabaseContext As Object
Dim DataSource As Object

DatabaseContext = createUnoService("com.sun.star.sdb.DatabaseContext")
DataSource = DatabaseContext.getByName("Customers")

The example creates a DataSource object for a data source called Customers.

Data sources provide a range of properties, which in turn provide general information about the origin of the data and information about access methods. The properties are:

Name (String)

name of data source

URL (String)

URL of data source in the form of jdbc: subprotocol : subname or sdbc: subprotocol : subname

Settings (Array)

array containing PropertyValue-pairs with connection parameters (usually at least username and password)

User (String)

username

Password (String)

user password (is not saved)

IsPasswordRequired (Boolean)

the password is needed and is interactively requested from the user.

IsReadOnly (Boolean)

permits read-only access to the database

NumberFormatsSupplier (Object)

object containing the number formats available for the database (supports the com.sun.star.util.XNumberFormatsSupplier interface)

TableFilter (Array)

list of table names to be displayed

TableTypeFilter (Array)

list of table types to be displayed. Values available are TABLE, VIEW and SYSTEM TABLE

SuppressVersionColumns (Boolean)

suppresses the display of columns that are used for version administration

Note: The data sources from LibreOffice are not 1:1 comparable with the data sources in ODBC. Whereas an ODBC data source only covers information about the origin of the data, a data source in LibreOffice also includes a range of information about how the data is displayed within the database windows of LibreOffice.

Queries

Predefined queries can be assigned to a data source. LibreOffice notes the SQL commands of queries so that they are available at all times. Queries are used to simplify working with databases because they can be opened with a simple mouse click and also provide users without any knowledge of SQL with the option of issuing SQL commands.

An object which supports the com.sun.star.sdb.QueryDefinition service is concealed behind a query. The queries are accessed by means of the QueryDefinitions method of the data source.

The following example lists the names of data source queries can be established in a message box.

Dim DatabaseContext As Object
Dim DataSource As Object
Dim QueryDefinitions As Object
Dim QueryDefinition As Object
Dim I As Integer

DatabaseContext = createUnoService("com.sun.star.sdb.DatabaseContext")
DataSource = DatabaseContext.getByName("Customers")
QueryDefinitions = DataSource.getQueryDefinitions()

For I = 0 To QueryDefinitions.Count() - 1
  QueryDefinition = QueryDefinitions(I)
  MsgBox QueryDefinition.Name
Next I

In addition to the Name property used in the example, the com.sun.star.sdb.QueryDefinition provides a whole range of other properties. These are:

Name (String)

query name

Command (String)

SQL command (typically a SELECT command)

The following example shows how a query object can be created in a program-controlled manner and can be assigned to a data source.

Dim DatabaseContext As Object
Dim DataSource As Object
Dim QueryDefinitions As Object
Dim QueryDefinition As Object
Dim I As Integer

DatabaseContext = createUnoService("com.sun.star.sdb.DatabaseContext")
DataSource = DatabaseContext.getByName("Customers")
QueryDefinitions = DataSource.getQueryDefinitions()
QueryDefinition = createUnoService("com.sun.star.sdb.QueryDefinition")
QueryDefinition.Command = "SELECT * FROM Customer"
QueryDefinitions.insertByName("NewQuery", QueryDefinition)

The query object is first created using the createUnoService call, then initialized, and then inserted into the QueryDefinitions object by means of insertByName.

Database Access

A database connection is needed for access to a database. This is a transfer channel which permits direct communication with the database. Unlike the data sources presented in the previous section, the database connection must therefore be re-established every time the program is restarted.

LibreOffice provides various ways of establishing database connections. This example shows how to connect to an existing data source.

Dim DatabaseContext As Object
Dim DataSource As Object
Dim Connection As Object
Dim InteractionHandler as Object

DatabaseContext = createUnoService("com.sun.star.sdb.DatabaseContext")
DataSource = DatabaseContext.getByName("Customers")

If Not DataSource.IsPasswordRequired Then
  Connection = DataSource.GetConnection("","")
Else
  InteractionHandler = createUnoService("com.sun.star.sdb.InteractionHandler")
  Connection = DataSource.ConnectWithCompletion(InteractionHandler)
End If

The code used in the example first checks whether the database is password protected. If not, it creates the database connection required using the GetConnection call. The two empty strings in the command line stand for the user name and password.

If the database is password protected, the example creates an InteractionHandler and opens the database connection using the ConnectWithCompletion method. The InteractionHandler ensures that LibreOffice asks the user for the required login data.

Iteration of Tables

A table is usually accessed in LibreOffice through the ResultSet object. A ResultSet is a type of marker that indicates a current set of data within a volume of results obtained using the SELECT command.

This example shows how a ResultSet can be used to query values from a database table.

Dim DatabaseContext As Object
Dim DataSource As Object
Dim Connection As Object
Dim InteractionHandler as Object
Dim Statement As Object
Dim ResultSet As Object

DatabaseContext = createUnoService("com.sun.star.sdb.DatabaseContext")
DataSource = DatabaseContext.getByName("Customers")

If Not DataSource.IsPasswordRequired Then
  Connection = DataSource.GetConnection("","")
Else
  InteractionHandler = createUnoService("com.sun.star.sdb.InteractionHandler")
  Connection = DataSource.ConnectWithCompletion(InteractionHandler)
End If

Statement = Connection.createStatement()
ResultSet = Statement.executeQuery("SELECT ""CustomerNumber"" FROM ""Customer""")

If Not IsNull(ResultSet) Then
  While ResultSet.next
    MsgBox ResultSet.getString(1)
  Wend
End If

Once the database connection has been established, the code used in the example first uses the Connection.createObject call to create a Statement object. This Statement object then uses the executeQuery call to return the actual ResultSet. The program now checks whether the ResultSet actually exists and traverses the data records using a loop. The values required (in the example, those from the CustomerNumber field) returns the ResultSet using the getString method, whereby the parameter 1 determines that the call relates to the values of the first column.

Note: VBA : The ResultSet object from SDBC is comparable with the Recordset object from DAO and ADO, since this also provides iterative access to a database.

Note: StarOffice 5 : The database is actually accessed in LibreOffice through a ResultSet object. This reflects the content of a table or the result of a SQL-SELECT command. In the past, the ResultSet object provided the resident methods in the Application object for navigation within the data, for example, DataNextRecord ).

Type-Specific Methods for Retrieving Values

As can be seen in the example from the previous section, LibreOffice provides a getString method for accessing table contents. The method provides the result in the form of a string. The following get methods are available:

getByte()

supports the SQL data types for numbers, characters and strings

getShort()

supports the SQL data types for numbers, characters and strings

getInt()

supports the SQL data types for numbers, characters and strings

getLong()

supports the SQL data types for numbers, characters and strings

getFloat()

supports the SQL data types for numbers, characters and strings

getDouble()

supports the SQL data types for numbers, characters and strings

getBoolean()

supports the SQL data types for numbers, characters and strings

getString()

supports all SQL data types

getBytes()

supports the SQL data types for binary values

getDate()

supports the SQL data types for numbers, strings, date and time stamp

getTime()

supports the SQL data types for numbers, strings, date and time stamp

getTimestamp()

supports the SQL data types for numbers, strings, date and time stamp

getCharacterStream()

supports the SQL data types for numbers, strings and binary values

getUnicodeStream()

supports the SQL data types for numbers, strings and binary values

getBinaryStream()

binary values

getObject()

supports all SQL data types

In all instances, the number of columns should be listed as a parameter whose values should be queried.

The ResultSet Variants

Accessing databases is often a matter of critical speed. LibreOffice provides several ways of optimizing ResultSets and thereby controlling the speed of access. The more functions a ResultSet provides, the more complex its implementation usually is and therefore the slower the functions are.

A simple ResultSet, provides the minimum scope of functions available. It only allows iteration to be applied forward, and for values to be interrogated. More extensive navigation options, such as the possibility of modifying values, are therefore not included.

The Statement object used to create the ResultSet provides some properties which allow the functions of the ResultSet to be influenced:

ResultSetConcurrency (const)

specifications as to whether the data can be modified (specifications in accordance with com.sun.star.sdbc.ResultSetConcurrency).

ResultSetType (const)

specifications regarding type of ResultSets ( specifications in accordance with com.sun.star.sdbc.ResultSetType).

The values defined in com.sun.star.sdbc.ResultSetConcurrency are:

UPDATABLE

ResultSet permits values to be modified

READ_ONLY

ResultSet does not permit modifications

The com.sun.star.sdbc.ResultSetType group of constants provides the following specifications:

FORWARD_ONLY

ResultSet only permits forward navigation

SCROLL_INSENSITIVE

ResultSet permits any type of navigation, changes to the original data are, however, not noted

SCROLL_SENSITIVE

ResultSet permits any type of navigation, changes to the original data impact on the ResultSet

Note: VBA : A ResultSet containing the READ_ONLY and SCROLL_INSENSITIVE properties corresponds to a record set of the Snapshot type in ADO and DAO.

When using the ResultSet's UPDATEABLE and SCROLL_SENSITIVE properties, the scope of function of a ResultSet is comparable with a Dynaset type Recordset from ADO and DAO.

Methods for Navigation in ResultSets

If a ResultSet is a SCROLL_INSENSITIVE or SCROLL_SENSITIVE type, it supports a whole range of methods for navigation in the stock of data. The central methods are:

next()

navigation to the next data record

previous()

navigation to the previous data record

first()

navigation to the first data record

last()

navigation to the last data record

beforeFirst()

navigation to before the first data record

afterLast()

navigation to after the last data record

All methods return a Boolean parameter which specifies whether the navigation was successful.

To determine the current cursor position, the following test methods are provided and all return a Boolean value:

isBeforeFirst()

ResultSet is before the first data record

isAfterLast()

ResultSet is after the last data record

isFirst()

ResultSet is the first data record

isLast()

ResultSet is the last data record

Modifying Data Records

If a ResultSet has been created with the ResultSetConcurrency = UPDATEABLE value, then its content can be edited. This only applies for as long as the SQL command allows the data to be re-written to the database (depends on principle). This is not, for example, possible with complex SQL commands with linked columns or accumulated values.

The ResultSet object provides Update methods for modifying values, which are structured in the same way as the get methods for retrieving values. The updateString method, for example, allows a string to be written.

After modification, the values must be transferred into the database using the updateRow()method. The call must take place before the next navigation command, otherwise the values will be lost.

If an error is made during the modifications, this can be undone using the cancelRowUpdates()method. This call is only available provided that the data has not be re-written into the database using updateRow().

Dialogs

You can add custom dialog windows and forms to LibreOffice documents. These in turn can be linked to LibreOffice Basic macros to considerably extend the usage range of LibreOffice Basic. Dialogs can, for example, display database information or guide users through a step-by-step process of creating a new document in the form of a Wizard.

• You will find another description of dialogs in the Developer's Guide:

chapter #LibreOffice_Basic_IDE describes more fully the IDE chapter #Programming Dialogs and Dialog Controls shows more examples in Basic.

Working With Dialogs

LibreOffice Basic dialogs consist of a dialog window that can contain text fields, list boxes, radio buttons, and other control elements.

Creating Dialogs

You can create and structure dialogs using the LibreOffice dialog editor:

Create and structure dialogs in the dialog editor

You can drag the control elements from the design pallet (right) into the dialog area, and define their position and size.

The example shows a dialog that contains a label and a list box.

File:Pictures/10000200000001FA0000020FA21E926E.gif A dialog containing a label and a list box

You can open a dialog with the following code:

Dim Dlg As Object

DialogLibraries.LoadLibrary("Standard")
Dlg = CreateUnoDialog(DialogLibraries.Standard.DlgDef)
Dlg.Execute()
Dlg.dispose()

CreateUnoDialog creates an object called Dlg that references the associated dialog. Before you can create the dialog, you must ensure that the library it uses (in this example, the Standard library) is loaded. The LoadLibrary method performs this task.

Once the Dlg dialog object has been initialized, you can use the Execute method to display the dialog. Dialogs such as this one are described as modal because they do not permit any other program action until they are closed. While this dialog is open, the program remains in the Execute call.

The dispose method at the end of the code releases the resources used by the dialog once the program ends.

Closing Dialogs

Closing With OK or Cancel

If a dialog contains an OK or a Cancel button, the dialog is automatically closed when you click one of these buttons. More information about working with these buttons is discussed in #Control Elements in Detail.

If you close a dialog by clicking the OK button, the Execute method returns a return value of 1, otherwise a value of 0 is returned.

Dim Dlg As Object

DialogLibraries.LoadLibrary("Standard")
Dlg = CreateUnoDialog(DialogLibraries.Standard.MyDialog)
Select Case Dlg.Execute()
Case 1
  MsgBox "Ok pressed"
Case 0
  MsgBox "Cancel pressed"
End Select

Closing With the Close Button in the Title Bar

You can close a dialog by clicking the close button on the title bar of the dialog window. The Execute method of the dialog returns the value 0, which is the same as when you click Cancel.

Closing With an Explicit Program Call

From a routine called by an event of a control, e.g. push of a normal button, you can also close an open dialog window with the endExecute method:

Dlg.endExecute()

The dialog object must be accessible from the event routine. A simple way is to declare it as a Private or Public variable common to the main dialog routine and the event routine.

The execute method of the dialog returns the value 0, which is the same as when you click Cancel.

The endDialog method of the dialog is an improvement of endExecute. Its argument specifies the value that will be returned by execute method.

Dlg.endDialog(2)  ' Dlg.execute will return 2

Access to Individual Control Elements

A dialog can contain any number of control elements. You can access these elements through the getControl method that returns the control element by name.

Dim Ctl As Object

Ctl = Dlg.getControl("MyButton")
Ctl.Label = "New Label"

This code determines the object for the MyButton control element and then initializes the Ctl object variable with a reference to the element. Finally the code sets the Label property of the control element to the New Label value.

Note: Unlike LibreOffice Basic identifiers, the names of control elements are case sensitive.

Working With the Model of Dialogs and Control Elements

The division between visible program elements (View) and the data or documents behind them (Model) occurs at many places in LibreOffice API. In addition to the methods and properties of control elements, both dialog and control element objects have a subordinate Model object. This object allows you to directly access the content of a dialog or control element.

In dialogs, the distinction between data and depiction is not always as clear as in other API areas of LibreOffice. Elements of the API are available through both the View and the Model.

The Model property provides program-controlled access to the model of dialog and control element objects.

Dim cmdNext As Object

cmdNext = Dlg.getControl("cmdNext")
cmdNext.Model.Enabled = False

This example deactivates the cmdNext button in the Dlg dialog with the aid of the model object from cmdNext.

Properties

Name and Title

Every control element has its own name that can be queried using the following model property:

Model.Name (String)

control element name

You can specify the title that appears in the title bar of a dialog with the following model property:

Model.Title (String)

dialog title (only applies to dialogs)

Position and Size

You can query the size and position of a control element using the following properties of the model object:

Model.Height (long)

height of control element (in ma units)

Model.Width (long)

width of control element (in ma units)

Model.PositionX (long)

X-position of control element, measured from the left inner edge of the dialog (in ma units)

Model.PositionY (long)

Y-position of control element, measured from top inner edge of the dialog (in ma units)

To ensure platform independence for the appearance of dialogs, LibreOffice uses the Map AppFont (ma) internal unit to specify the position and size within dialogs. An ma unit is defined as being one eighth of the average height of a character from the system font defined in the operating system and one quarter of its width. By using ma units, LibreOffice ensures that a dialog looks the same on different systems under different system settings.

If you want to change the size or position of control elements for runtime, determine the total size of the dialog and adjust the values for the control elements to the corresponding part ratios.

Note: The Map AppFont (ma) replaces the Twips unit to achieve better platform independence.

Focus and Tabulator Sequence

You can navigate through the control elements in any dialog by pressing the Tab ↹ key. The following properties are available in this context in the control elements model:

Model.Enabled (Boolean)

activates the control element

Model.Tabstop (Boolean)

allows the control element to be reached through the Tab ↹ key

Model.TabIndex (Long)

position of control element in the order of activation

Finally, the control element provides a setFocus method that ensures that the underlying control element receives the focus:

setFocus

control element receives the focus (only for dialogs)

Multi-Page Dialogs

A dialog in LibreOffice can have more than one tab page. The Step property of a dialog defines the current tab page of the dialog whereas the Step property for a control element specifies the tab page where the control element is to be displayed.

The Step-value of 0 is a special case. If you set this value to zero in a dialog, all the control elements are visible regardless of their Step value. Similarly, if you set this value to zero for a control element, the element is displayed on all the tab pages in a dialog.

File:Pictures/10000200000001FA0000020F3B892B46.gif Designing Page 1 of the dialog

In the preceding example, you can also assign the Step value of 0 to the dividing line as well as the Cancel, Prev, Next, and Done buttons to display these elements on all pages. You can also assign the elements to an individual tab page (for example page 1).

The following program code shows how the Step value in event handlers of the Next and Prev buttons can be increased or reduced and changes the status of the buttons.

Sub cmdNext_Initiated

  Dim cmdNext As Object
  Dim cmdPrev As Object

  cmdPrev = Dlg.getControl("cmdPrev")
  cmdNext = Dlg.getControl("cmdNext")
  cmdPrev.Model.Enabled = Not cmdPrev.Model.Enabled
  cmdNext.Model.Enabled = False
  Dlg.Model.Step = Dlg.Model.Step + 1

End Sub

Sub cmdPrev_Initiated

  Dim cmdNext As Object
  Dim cmdPrev As Object

  cmdPrev = Dlg.getControl("cmdPrev")
  cmdNext = Dlg.getControl("cmdNext")
  cmdPrev.Model.Enabled = False
  cmdNext.Model.Enabled = True
  Dlg.Model.Step = Dlg.Model.Step - 1

End Sub

A global Dlg variable that references an open dialog must be included to make this example possible. The dialog then changes its appearance as follows:

File:Pictures/10000200000001270000012EAB84B2A2.gif Page 1

File:Pictures/10000200000001500000012ECA44E201.gif Page 2

• You can find an #OOoBasic example here.

Dialogs supporting several languages

The strings of a Dialog can be localized, see the Developer's Guide chapter #Dialog Localization.

Events

LibreOffice dialogs and forms are based on an event-oriented programming model where you can assign event handlers to the control elements. An event handler runs a predefined procedure when a particular action occurs. You can also edit documents or open databases with event handling as well as access other control elements.

LibreOffice control elements recognize different types of events that can be triggered in different situations. These event types can be divided into four groups:

• Mouse control: Events that correspond to mouse actions (for example, simple mouse movements or a click on a particular screen location).
• Keyboard control: Events that are triggered by keyboard strokes.
• Focus modification: Events that LibreOffice performs when control elements are activated or deactivated.
• Control element-specific events: Events that only occur in relation to certain control elements.

When you work with events, make sure that you create the associated dialog in the LibreOffice development environment and that it contains the required control elements or documents (if you apply the events to a form).

File:Pictures/10000200000001FA0000020F3B892B46.gifThe LibreOffice Basic development environment

The figure above shows the LibreOffice Basic development environment with a dialog window that contains two list boxes. You can move the data from one list to the other using the buttons between the two list boxes.

If you want to display the layout on screen, then you should create the associated LibreOffice Basic procedures so that they can be called up by the event handlers. Even though you can use these procedures in any module, it is best to limit their use to two modules. To make your code easier to read, you should assign meaningful names to these procedures. Jumping directly to a general program procedure from a macro can result in unclear code. Instead, to simplify code maintenance and troubleshooting, you should create another procedure to serve as an entry point for event handling - even if it only executes a single call to the target procedure.

The code in the following example moves an entry from the left to the right list box of a dialog.

Sub cmdSelect_Initiated

  Dim lstEntries As Object
  Dim lstSelection As Object

  lstEntries = Dlg.getControl("lstEntries")
  lstSelection = Dlg.getControl("lstSelection")

  If lstEntries.SelectedItem > 0 Then
    lstSelection.AddItem(lstEntries.SelectedItem, 0)
    lstEntries.removeItems(lstEntries.SelectItemPos, 1)
  Else
    Beep
  End If

End Sub

If this procedure was created in LibreOffice Basic, you can assign it to an event required using the property window of the dialog editor.

The Assign Action dialog

The Assign Action dialog lists all the available Events. To assign a macro to an event:

1. Select the event
2. Click Macro...
3. Browse to and select the macro you want to assign
4. Click OK

Parameters

The occurrence of a particular event is not always enough for an appropriate response. Additional information may be required. For example, to process a mouse click, you may need the screen position where the mouse button was pressed.

In LibreOffice Basic, you can use object parameters to provide more information about an event to a procedure, for example:

Sub ProcessEvent(Event As Object)

End Sub

The structure and properties of the Event object depend on the type of event that triggers the procedure call.

Regardless of the type of event, all objects provide access to the relevant control element and its model. The control element can be reached using Event.Source and its model using Event.Source.Model. The dialog can be reached using Event.Source.Context.

You can use these properties to trigger an event within an event handler.

Mouse Events

LibreOffice Basic recognizes the following mouse events:

Mouse moved

user moves mouse

Mouse moved while key pressed

user drags mouse while holding down a key

Mouse button pressed

user presses a mouse button

Note: This event is also used for notifying requests for a popup context menu on the control. In this case, the member PopupTrigger of the event passed to your macro function will be TRUE. In particular, if such a request is made by pressing the right mouse button on the control, the event will be fired twice: once for the popup menu request, and once for the real mouse event. If you are interested in only the mouse click, your macro should ignore all calls where PopupTrigger is TRUE.

Mouse button released

user releases a mouse button

Mouse outside

user moves mouse outside of the current window

The structure of the associated event objects is defined in the com.sun.star.awt.MouseEvent structure which provides the following information:

Buttons (short)

button pressed (one or more constants in accordance with com.sun.star.awt.MouseButton)

X (long)

X-coordinate of mouse, measured in pixels from the top left corner of the control element

Y (long)

Y-coordinate of mouse, measured in pixels from the top left corner of the control element

ClickCount (long)

number of clicks associated with the mouse event (if LibreOffice can respond fast enough, ClickCount is also 1 for a double-click because only an individual event is initiated)

The constants defined in com.sun.star.awt.MouseButton for the mouse buttons are:

LEFT

left mouse button

RIGHT

right mouse button

MIDDLE

middle mouse button

The following example outputs the mouse position as well as the mouse button that was pressed:

Sub MouseUp(Event As Object)

  Dim Msg As String

  Msg = "Keys: "
  If Event.Buttons AND com.sun.star.awt.MouseButton.LEFT Then
    Msg = Msg & "LEFT "
  End If

  If Event.Buttons AND com.sun.star.awt.MouseButton.RIGHT Then
    Msg = Msg & "RIGHT "
  End If

  If Event.Buttons AND com.sun.star.awt.MouseButton.MIDDLE Then
    Msg = Msg & "MIDDLE "
  End If

  Msg = Msg & Chr(13) & "Position: "
  Msg = Msg & Event.X & "/" & Event.Y
  MsgBox Msg

End Sub

Note: VBA : The VBA Click and Doubleclick events are not available in LibreOffice Basic. Instead use the LibreOffice Basic MouseUp event for the click event and imitate the Doubleclick event by changing the application logic.

Keyboard Events

The following keyboard events are available in LibreOffice Basic:

Key pressed

user presses a key.

Key released

user releases a key

Both events relate to logical key actions and not to physical actions. If the user presses several keys to output a single character (for example, to add an accent to a character), then LibreOffice Basic only creates one event.

A single key action on a modification key, such as the ⇧ Shift key or the Alt key does not create an independent event.

Information about a pressed key is provided by the event object that LibreOffice Basic supplies to the procedure for event handling. It contains the following properties:

KeyCode (short)

code of the pressed key (default values in accordance with com.sun.star.awt.Key)

KeyChar (String)

character that is entered (taking the modification keys into consideration)

The following example uses the KeyCode property to establish if the ↵ Enter key, the Tab ↹ key, or one of the other control keys has been pressed. If one of these keys has been pressed, the name of the key is returned, otherwise the character that was typed is returned:

Sub KeyPressed(Event As Object)

  Dim Msg As String

  Select Case Event.KeyCode
  Case com.sun.star.awt.Key.RETURN
    Msg = "Return pressed"
  Case com.sun.star.awt.Key.TAB
    Msg = "Tab pressed"
  Case com.sun.star.awt.Key.DELETE
    Msg = "Delete pressed"
  Case com.sun.star.awt.Key.ESCAPE
    Msg = "Escape pressed"
  Case com.sun.star.awt.Key.DOWN
    Msg = "Down pressed"
  Case com.sun.star.awt.Key.UP
    Msg = "Up pressed"
  Case com.sun.star.awt.Key.LEFT
    Msg = "Left pressed"
  Case com.sun.star.awt.Key.RIGHT
    Msg = "Right pressed"
  Case Else
    Msg = "Character " & Event.KeyChar & " entered"
  End Select
  MsgBox Msg

End Sub

Information about other keyboard constants can be found in the API Reference under the com.sun.star.awt.Key group of constants.

Focus Events

Focus events indicate if a control element receives or loses focus. You can use these events to, for example, determine if a user has finished processing a control element so that you can update other elements of a dialog. The following focus events are available:

When receiving focus

element receives focus

When losing focus

element loses focus

The Event objects for the focus events are structured as follows:

FocusFlags (short)

cause of focus change (default value in accordance with com.sun.star.awt.FocusChangeReason )

NextFocus (Object)

object that receives focus (only for the When losing focus event)

Temporary (Boolean)

the focus is temporarily lost

Control Element-Specific Events

In addition to the preceding events, which are supported by all control elements, there are also some control element-specific events that are only defined for certain control elements. The most important of these events are:

When Item Changed

the value of a control element changes

Item Status Changed

the status of a control element changes

Text modified

the text of a control element changes

When initiating

an action that can be performed when the control element is triggered (for example, a button is pressed)

When you work with events, note that some events, such as the When initiating event, can be initiated each time you click the mouse on some control elements (for example, on radio buttons). No action is performed to check if the status of the control element has actually changed. To avoid such “blind events”, save the old control element value in a global variable, and then check to see if the value has changed when an event is executing.

The When initiating event is also noteworthy for the following reasons:

• This event is initiated by either a key-press or a mouse button. Thus, it provides a consistent interface for users who navigate by mouse or by keyboard.
• When the Repeat property of a command button is set to True, this event is the one which is repeatedly sent, as long as the triggering action (key down or mouse-button down) remains in effect.

The properties for the Item Status Changed event are:

Selected (long)

currently selected entry

Highlighted (long)

currently highlighted entry

ItemId (long)

ID of entry

Dialog Control Elements

LibreOffice Basic recognizes a range of control elements which can be divided into the following groups:

Entry fields	Buttons	Selection lists	Other
Text fields Date fields Time fields Numerical fields Currency fields Fields adopting any format	Standard buttons Checkboxes Radio Buttons	List boxes Combo boxes Tree Control	Scrollbars (horizontal and vertical) Fields of groups Progress bars Dividing lines (horizontal and vertical) Graphics File selection fields

Buttons

A button performs an action when you click it.

The simplest scenario is for the button to trigger a When Initiating event when it is clicked by a user. You can also link another action to the button to close a dialog using the PushButtonType property. When you click a button that has this property set to the value of 0, the dialog remains unaffected. If you click a button that has this property set to the value of 1, the dialog is closed, and the Execute method of the dialog returns the value 1 (dialog sequence has been ended correctly). If the PushButtonType has the value of 2, the dialog is closed and the Execute method of the dialog returns the value 0 (dialog closed). In the Dialog Editor, the property values are shown symbolically, as Default (0), Okay (1), and Cancel (2).

The following are some of the properties that are available through the button model:

Model.BackgroundColor (long)

color of background

Model.DefaultButton (Boolean)

The button is used as the default value and responds to the Enter key if it has no focus

Model.FontDescriptor (struct)

structure that specifies the details of the font to be used (in accordance with com.sun.star.awt.FontDescriptor structure)

Model.Label (String)

label that is displayed on the button

Model.Printable (Boolean)

the control element can be printed

Model.TextColor (Long)

text color of the control element

Model.HelpText (String)

help text that is displayed when you move the mouse cursor over the control element

Model.HelpURL (String)

URL of the online help for the corresponding control element

PushButtonType (short)

action that is linked to the button (0: no action, 1: OK, 2: Cancel)

Example

The following example shows some of the properties for the buttons:

Sub cmdButton()
Dim oDialog As Object Dim ocmdButton As Object
    DialogLibraries.LoadLibrary( "Standard" )
    oDialog = CreateUnoDialog( DialogLibraries.Standard.getByName("myDialog") )
    ocmdButton = oDialog.getControl("cmdOK")
    With ocmdButton.getModel
        .Align = 1                'Orientation; 0 = left, 1 = center, 2 = right
        .FontHeight = 12            'Size
        .FontName = "FreeSans"        'Font type
        .ImageURL = ConvertToUrl("/home/mau/bien.jpg")    'Image to show
        .ImagePosition = 1        'Position 1 = center right
        .PushButtonType = 1        'Type of button 1 = Accept
    End With

    ocmdButton = oDialog.getControl("cmdCancel")
    With ocmdButton.getModel
        .Align = 1
        .FontHeight = 12
        .FontName = "FreeSans"
        .ImageURL = ConvertToUrl("/home/mau/mal.jpg")
        .ImagePosition = 1
        .PushButtonType = 2        'Type of button 2 = Cancel
    End With

    oDialog.execute()
    oDialog.dispose()
 
End Sub

Checkboxes

Checkboxes are used to record a Yes or No value and depending on the mode, they can adopt two or three states. In addition to the Yes and No states, a check box can have an in-between state if the corresponding Yes or No status has more than one meaning or is unclear.

Checkboxes provide the following properties:

State (Short)

state of the checkbox (0: no, 1: yes, 2: in-between state)

Label (String)

label for the control element

enableTriState (Boolean)

in addition to the activated and deactivated states, you can also use the in-between state

The model object of a checkbox provides the following properties:

Model.FontDescriptor (struct)

structure with details of the font used (in accordance with com.sun.star.awt.FontDescriptor structure)

Model.Label (String)

label for the control element

Model.Printable (Boolean)

the control element can be printed

Model.State (Short)

state of the checkbox (0: no, 1: yes, 2: in-between state)

Model.Tabstop (Boolean)

the control element can be reached with the Tab key

Model.TextColor (Long)

text color of control element

Model.HelpText (String)

help text that is displayed when you rest the mouse cursor over the control element

Model.HelpURL (String)

URL of online help for the corresponding control element

Example

The following example shows some of the properties for the checkboxes:

Sub Checkbox1()
Dim oDialog As Object
Dim oControl As Object

DialogLibraries.LoadLibrary( "Standard" )
     oDialog = CreateUnoDialog( DialogLibraries.Standard.getByName("MyDialog") )      'Image control
     oControl = oDialog.getControl("icFoto")     'we hide it
     oControl.Visible = False      'Checkbox
     oControl = oDialog.getControl("chkImprimir")
      With oControl.getModel
         .TriState = True        'Triple state
     End With
 
oDialog.execute()
oDialog.dispose()
 
End Sub

Option Buttons

These buttons are generally used in groups and allow you to select from one of several options. When you select an option, all the other options in the group are deactivated. This ensures that at any one time, only one option button is set.

An option button control element provides two properties:

State (Boolean)

activates the button

Label (String)

label that is displayed on the button

You can also use the following properties from the model of the option buttons:

Model.FontDescriptor (struct)

structure with details of the font to be used (in accordance with com.sun.star.awt.FontDescriptor)

Model.Label (String)

label that is displayed on the control element

Model.Printable (Boolean)

control element can be printed

Model.State (Short)

if this property is equal to 1, the option is activated, otherwise it is deactivated

Model.TextColor (Long)

text color of control element

Model.HelpText (String)

help text that is displayed when the mouse cursor rests over the control element

Model.HelpURL (String)

URL of online help for the corresponding control element

To combine several option buttons in a group, you must position them one after another in the activation sequence without any gaps (Model.TabIndex property, described as Order in the dialog editor). If the activation sequence is interrupted by another control element, then LibreOffice automatically starts with a new control element group that can be activated regardless of the first group of control elements.

Note: VBA : Unlike VBA, you cannot insert option buttons in a group of control elements in LibreOffice Basic. The grouping of control elements in LibreOffice Basic is only used to ensure a visual division by drawing a frame around the control elements.

Example

An example for the grouped option button:

Sub OptionButton1()
Dim oDialog As Object
Dim oControl As Object
 
   DialogLibraries.LoadLibrary( "Standard" )
     oDialog = CreateUnoDialog( DialogLibraries.Standard.getByName("MyDialog") )      'Hide the previous controls.
     oControl = oDialog.getControl("icFoto") : oControl.Visible = False
     oControl = oDialog.getControl("chkImprimir") : oControl.Visible = False
 
     'First option button
     oControl = oDialog.getControl("optUbuntu")
     MsgBox oControl.State 

     'Second option button
     oControl = oDialog.getControl("optFedora")
     MsgBox oControl.State
 
     'Third option button
     oControl = oDialog.getControl("optArch")
     MsgBox oControl.State
 
oDialog.execute()
oDialog.dispose()
 
End Sub

Text Fields

Text fields allow users to type numbers and text. The com.sun.star.awt.UnoControlEdit service forms the basis for text fields.

A text field can contain one or more lines and can be edited or blocked for user entries. Text fields can also be used as special currency and numerical fields as well as screen fields for special tasks. As these control elements are based on the UnoControlEdit Uno service, their program-controlled handling is similar.

Text fields provide the following properties:

Text (String)

current text

SelectedText (String)

currently highlighted text

Selection (Struct)

read-only highlighting of details (structure in accordance with com.sun.star.awt.Selection, with the Min and Max properties to specify the start and end of the current highlighting)

MaxTextLen (short)

maximum number of characters that you can type in the field

Editable (Boolean)

True activates the option for entering text, False blocks the entry option (the property cannot be called up directly but only through IsEditable)

IsEditable (Boolean)

the content of the control element can be changed, read-only

The following properties are provided through the associated model object:

Model.Align (short)

orientation of text (0: left-aligned, 1: centered, 2: right-aligned)

Model.BackgroundColor (long)

color of the background of the control element

Model.Border (short)

type of border (0: no border, 1: 3D border, 2: simple border)

Model.EchoChar (String)

echo character for password fields

Model.FontDescriptor (struct)

structure with details of font used (in accordance with com.sun.star.awt.FontDescriptor structure)

Model.HardLineBreaks (Boolean)

automatic line breaks are permanently inserted in the control element text

Model.HScroll (Boolean)

the text has a horizontal scrollbar

Model.MaxTextLen (Short)

maximum length of text, where 0 corresponds to no length limit

Model.MultiLine (Boolean)

permits entry to spans several lines

Model.Printable (Boolean)

the control element can be printed

Model.ReadOnly (Boolean)

the content of the control element is read-only

Model.Tabstop (Boolean)

the control element can be reached with the Tab key

Model.Text (String)

text associate with the control element

Model.TextColor (Long)

text color of control element

Model.VScroll (Boolean)

the text has a vertical scrollbar

Model.HelpText (String)

help text that is displayed when the mouse cursor rests over the control element

Model.HelpURL (String)

URL of online help for the corresponding control element

Example

Sub TextField1()
Dim oDialog As Object
Dim oControl As Object 
    DialogLibraries.LoadLibrary( "Standard" )
     oDialog = CreateUnoDialog( DialogLibraries.Standard.getByName("MyDialog") )      'The text field control
     oControl = oDialog.getControl("txtNombre")
     'Set an align property
     oControl.getModel.Align=1
     'Show the dialog box
     oDialog.execute()     'we show the control on close
     MsgBox oControl.Text
     oDialog.dispose()
 
End Sub

Date Fields

A date field makes it possible to enter, display and edit date values. com.sun.star.awt.UnoControlDateField

Time Fields

A time field makes it possible to enter, display, and edit time values. com.sun.star.awt.UnoControlTimeField

Numerical Fields

A numeric field makes it possible to enter, display and edit formatted numeric values. com.sun.star.awt.UnoControlNumericalField

Currency Fields

A currency field makes it possible to enter, display and edit currency values. com.sun.star.awt.UnoControlCurrencyField

List Boxes

List boxes (com.sun.star.awt.UnoControlListBox service) support the following properties:

ItemCount (Short)

number of elements, read-only

SelectedItem (String)

text of highlighted entry, read-only

SelectedItems (Array Of Strings)

data field with highlighted entries, read-only

SelectedItemPos (Short)

number of the entry highlighted at present, read-only

SelectedItemsPos (Array of Short)

data field with the number of highlighted entries (for lists which support multiple selection), read-only

MultipleMode (Boolean)

True activates the option for multiple selection of entries, False blocks multiple selections (the property cannot be called up directly but only through IsMultipleMode)

IsMultipleMode (Boolean)

permits multiple selection within lists, read-only

List boxes provide the following methods:

addItem (Item, Pos)

enters the string specified in the Item into the list at the Pos position

addItems (ItemArray, Pos)

enters the entries listed in the string's ItemArray data field into the list at the Pos position

removeItems (Pos, Count)

removes Count entries as of the Pos position

selectItem (Item, SelectMode)

activates or deactivates highlighting for the element specified in the string Item depending on the SelectMode Boolean variable

makeVisible (Pos)

scrolls through the list field so that the entry specified with Pos is visible

The model object of the list boxes provides the following properties:

Model.BackgroundColor (long)

background color of control element

Model.Border (short)

type of border (0: no border, 1: 3D border, 2: simple border)

Model.FontDescriptor (struct)

structure with details of font used (in accordance with com.sun.star.awt.FontDescriptor structure)

Model.LineCount (Short)

number of lines in control element

Model.MultiSelection (Boolean)

permits multiple selection of entries

Model.SelectedItems (Array of Strings)

list of highlighted entries

Model.StringItemList (Array of Strings)

list of all entries

Model.Printable (Boolean)

the control element can be printed

Model.ReadOnly (Boolean)

the content of the control element is read-only

Model.Tabstop (Boolean)

the control element can be reached with the Tab key

Model.TextColor (Long)

text color of control element

Model.HelpText (String)

automatically displayed help text which is displayed if the mouse cursor is above the control element

Model.HelpURL (String)

URL of online help for the corresponding control element

Note: VBA : The VBA option for issuing list entries with a numerical additional value (ItemData) does not exist in LibreOffice Basic. If you want to administer a numerical value (for example a database ID) in addition to the natural language text, you must create an auxiliary data field that administers in parallel to the list box.

Combo-Boxes

Combo boxes (com.sun.star.awt.UnoControlComboBox service) support the following properties:

Tree-Control

Tree boxes (com.sun.star.awt.tree.TreeControlModel service) support the following properties:

Forms

In many respects, the structure of LibreOffice forms corresponds to the #dialogs. There are, however, a few key differences:

• Dialogs appear in the form of one single dialog window, which is displayed over the document and does not permit any actions other than dialog processing until the dialog is ended. Forms, on the other hand, are displayed directly in the document, just like drawing elements.
• A dialog editor is provided for creating dialogs, and this can be found in the LibreOffice Basic development environment. Forms are created using the Form Controls and the Form Design Toolbar directly within the document.
• Whereas the dialog functions are available in all LibreOffice documents, the full scope of the form functions are only available in text and spreadsheets.
• The control elements of a form can be linked with an external database table. This function is not available in dialogs.
• The control elements of dialogs and forms differ in several aspects.

Users who want to provide their forms with their own methods for event handling, should refer to the #Dialogs chapter. The mechanisms explained there are identical to those for forms.

Working With Forms

LibreOffice forms may contain text fields, list boxes, radio buttons, and a range of other control elements, which are inserted directly in a text or spreadsheet. The Form Functions Toolbar is used for editing forms.

A LibreOffice form may adopt one of two modes: the draft mode and the display mode. In draft mode, the position of control elements can be changed and their properties can be edited using a properties window.

The Form Functions Toolbar is also used to switch between modes.

Determining Object Forms

LibreOffice positions the control elements of a form at drawing object level. The actual object form can be accessed through the Forms list at the drawing level. The objects are accessed as follows in text documents:

Dim Doc As Object
Dim DrawPage As Object
Dim Form As Object

Doc = ThisComponent
DrawPage = Doc.DrawPage
Form = DrawPage.Forms.GetByIndex(0)

The GetByIndex method returns the form with the index number 0.

When working with spreadsheets, an intermediate stage is needed for the Sheets list because the drawing levels are not located directly in the document but in the individual sheets:

Dim Doc As Object
Dim Sheet As Object
Dim DrawPage As Object
Dim Form As Object

Doc = ThisComponent
Sheet = Doc.Sheets.GetByIndex(0)
DrawPage = Sheet.DrawPage
Form = DrawPage.Forms.GetByIndex(0)

As is already suggested by the GetByIndex method name, a document may contain several forms. This is useful, for example, if the contents of different databases are displayed within one document, or if a 1:n database relationship is displayed within a form. The option of creating sub-forms is also provided for this purpose.

The Three Aspects of a Control Element Form

A control element of a form has three aspects:

• The Model of the control element is the key object for the LibreOffice Basic-programmer when working with control element forms.
• The counterpart to this is the View of the control element, which administers the display information.
• Since control element forms within the documents are administered like a special drawing element, there is also a Shape object which reflects the drawing element-specific properties of the control element (in particular its position and size).

Accessing the Model of Control Element Forms

The models of the control elements of a form are available through the GetByName method of the Object form:

Dim Doc As Object
Dim Form As Object
Dim Ctl As Object

Doc = ThisComponent
Form = Doc.DrawPage.Forms.GetByIndex(0)
Ctl = Form.getByName("MyListBox")

The example determines the model of the MyListBox control element, which is located in the first form of the text document currently open.

If you are not sure of the form of a control element, you can use the option for searching through all forms for the control element required:

Dim Doc As Object
Dim Forms As Object
Dim Form As Object
Dim Ctl As Object
Dim I as Integer

Doc = ThisComponent
Forms = Doc.Drawpage.Forms

For I = 0 To Forms.Count - 1
  Form = Forms.GetbyIndex(I)
  If Form.HasByName("MyListBox") Then
    Ctl = Form.GetbyName("MyListBox")
    Exit Function
  End If
Next I

The example uses the HasByName method to check all forms of a text document to determine whether they contain a control element model called MyListBox. If a corresponding model is found, then a reference to this is saved in the Ctl variable and the search is terminated. The example is shown as in-line code, for clarity; in practice, the search would be inside a function, called with the name as a string parameter, and include error processing.

Accessing the View of Control Element Forms

To access the view of a control element form, you need the associated model. The view of the control element can then be determined with the assistance of the model and using the document controller.

Dim Doc As Object
Dim DocCrl As Object
Dim Forms As Object
Dim Form As Object
Dim Ctl As Object
Dim CtlView As Object
Dim I as Integer

Doc = ThisComponent
DocCrl = Doc.getCurrentController()
Forms = Doc.Drawpage.Forms

For I = 0 To Forms.Count - 1
  Form = Forms.GetbyIndex(I)
  If Form.HasByName("MyListBox") Then
    Ctl = Form.GetbyName("MyListBox")
    CtlView = DocCrl.GetControl(Ctl)
    Exit Function
  End If
Next I

The code listed in the example is very similar to the code listed in the previous example for determining a control element model. It uses not only the Doc document object but also the DocCrl document controller object which makes reference to the current document window. With the help of this controller object and the model of the control element, it then uses the GetControl method to determine the view (CtlView variable) of the control element form.

Accessing the Shape Object of Control Element Forms

The method for accessing the shape objects of a control element also uses the corresponding drawing level of the document. To determine a special control element, all drawing elements of the drawing level must be searched through.

Dim Doc As Object
Dim Shape as Object
Dim I as integer

Doc = ThisComponent

For i = 0 to Doc.DrawPage.Count - 1
  Shape = Doc.DrawPage(i)
  If HasUnoInterfaces(Shape, "com.sun.star.drawing.XControlShape") Then
    If Shape.Control.Name = "MyListBox" Then
      Exit Function
    End If
  End If
Next

The example checks all drawing elements to determine whether they support the com.sun.star.drawing.XControlShape interface needed for control element forms. If this is the case, the Control.Name property then checks whether the name of the control element is MyListBox. If this is true, the function ends the search.

Determining the Size and Position of Control Elements

As already mentioned, the size and position of control elements can be determined using the associated shape object. The control element shape, like all other shape objects, provides the Size and Position properties for this purpose:

Size (struct)

size of control element (com.sun.star.awt.Size data structure)

Position (struct)

position of control element (com.sun.star.awt.Point data structure)

The following example shows how the position and size of a control element can be set using the associated shape object:

Dim Shape As Object
Dim Point As New com.sun.star.awt.Point
Dim Size As New com.sun.star.awt.Size

' ... Initialize Shape object, as previously shown ...

Point.x = 1000
Point.y = 1000
Size.Width = 10000
Size.Height = 10000

Shape.Size = Size
Shape.Position = Point

The shape object of the control element must already be known if the code is to function. If this is not the case, it must be determined using the preceding code.

Control Element Forms

The control elements available in forms are similar to those of dialogs. The selection ranges from simple text fields through list and combo boxes to various buttons.

Below, you will find a list of the most important properties for control element forms. All properties form part of the associated model objects.

In addition to the standard control elements, a table control element is also available for forms, which enables the complete incorporation of database tables. This is described in the #Database Forms chapter.

Buttons

The model object of a form button provides the following properties:

BackgroundColor (long)

background color

DefaultButton (Boolean)

the button serves as a default value. In this case, it also responds to the entry button if it has no focus

Enabled (Boolean)

the control element can be activated

Tabstop (Boolean)

the control element can be reached through the tabulator button

TabIndex (Long)

position of control element in activation sequence

FontName (String)

name of font type

FontHeight (Single)

height of character in points (pt)

Tag (String)

string containing additional information, which can be saved in the button for program-controlled access

TargetURL (String)

target URL for buttons of the URL type

TargetFrame (String)

name of window (or frame) in which TargetURL is to be opened when activating the button (for buttons of the URL type)

Label (String)

button label

TextColor (Long)

text color of control element

HelpText (String)

automatically displayed help text which is displayed if the mouse cursor is above the control element

HelpURL (String)

URL of online help for the corresponding control element

ButtonType (Enum)

action that is linked with the button (default value from com.sun.star.form.FormButtonType)

State (Short)

in toggle button, 1 = pushed, 0 = normal

Through the ButtonType property, you have the opportunity to define an action that is automatically performed when the button is pressed. The associated com.sun.star.form.FormButtonType group of constants provides the following values:

PUSH

standard button

SUBMIT

end of form entry (particularly relevant for HTML forms)

RESET

resets all values within the form to their original values

URL

call of the URL defined in TargetURL (is opened within the window which was specified through TargetFrame)

The OK and Cancel button types provided in dialogs are not supported in forms.

Option Buttons

The following properties of an option button are available through its model object:

Enabled (Boolean)

the control element can be activated

Tabstop (Boolean)

the control element can be reached through the tab key

TabIndex (Long)

position of control element in the activation sequence

FontName (String)

name of font type

FontHeight (Single)

height of character in points (pt)

Tag (String)

string containing additional information, which can be saved in the button for program-controlled access

Label (String)

inscription of button

Printable (Boolean)

the control element can be printed

State (Short)

if 1, the option is activated, otherwise it is deactivated

RefValue (String)

string for saving additional information (for example, for administering data record IDs)

TextColor (Long)

text color of control element

HelpText (String)

automatically displayed help text, which is displayed if the mouse cursor is above the control element

HelpURL (String)

URL of online help for the corresponding control element

The mechanism for grouping option buttons distinguishes between the control elements for dialogs and forms. Whereas control elements appearing one after another in dialogs are automatically combined to form a group, grouping in forms is performed on the basis of names. To do this, all option buttons of a group must contain the same name. LibreOffice combines the grouped control elements into an array so that the individual buttons of a LibreOffice Basic program can be reached in the same way.

The following example shows how the models of the control elements of a group can be iterated, exemplary displaying the states of all control elements in a given group:

Function test
  Dim oGroup as object
  Dim Doc As Object
  Dim Forms As Object
  Dim Form As Object
  Dim Ctl As Object
  Dim I as Integer
 
  Doc = ThisComponent
  Forms = Doc.Drawpage.Forms
 
  Form = Forms.GetbyIndex(0)
 
  oForm.getGroupByName("MyOptions", oGroup)
  msg = ""
  for i = LBound(oGroup) to UBound(oGroup)
    oCtl = oGroup(i)
    msg = msg + oCtl.Name + ": " + (str(oCtl.State)) + chr(10)
  next i
  MsgBox msg 
 
end Function

The code corresponds to the previous example for determining a simple control element model. It accesses the array of models using the GetGroupByName method (rather than the GetByName method to determine simple models).

Checkboxes

The model object of a checkbox form provides the following properties:

Enabled (Boolean)

the control element can be activated

Tabstop (Boolean)

the control element can be reached through the tab key

TabIndex (Long)

position of control element in the activation sequence

FontName (String)

name of font type

FontHeight (Single)

height of character in points (pt)

Tag (String)

string containing additional information, which can be saved in the button for program-controlled access

Label (String)

button label

Printable (Boolean)

the control element can be printed

State (Short)

if 1, the option is activated, otherwise it is deactivated

RefValue (String)

string for saving additional information (for example, for administrating data record IDs)

TextColor (Long)

text color of control element

HelpText (String)

automatically displayed help text, which is displayed if the mouse cursor is above the control element

HelpURL (String)

URL of online help for the corresponding control element

Text Fields

The model objects of text field forms offer the following properties:

Align (short)

orientation of text (0: left-aligned, 1: centered, 2: right-aligned)

BackgroundColor (long)

background color of control element

Border (short)

type of border (0: no border, 1: 3D border, 2: simple border)

EchoChar (String)

echo character for password field

FontName (String)

name of font type

FontHeight (Single)

height of character in points (pt)

HardLineBreaks (Boolean)

the automatic line breaks are permanently inserted in the text of the control element

HScroll (Boolean)

the text has a horizontal scrollbar

MaxTextLen (Short)

maximum length of text; if 0 is specified, there are no limits

MultiLine (Boolean)

permits multi-line entries

Printable (Boolean)

the control element can be printed

ReadOnly (Boolean)

the content of the control element is read-only

Enabled (Boolean)

the control element can be activated

Tabstop (Boolean)

the control element can be reached through the tab key

TabIndex (Long)

position of the control element in the activation sequence

FontName (String)

name of font type

FontHeight (Single)

height of character in points (pt)

Text (String)

text of control element

TextColor (Long)

text color of control element

VScroll (Boolean)

the text has a vertical scrollbar

HelpText (String)

automatically displayed help text, which is displayed if the mouse cursor is above the control element

HelpURL (String)

URL of online help for the corresponding control element

List Boxes

The model object of the list box forms provides the following properties:

BackgroundColor (long)

background color of control element

Border (short)

type of border (0: no border, 1: 3D frame, 2: simple frame)

FontDescriptor (struct)

structure with details of font to be used (in accordance with com.sun.star.awt.FontDescriptor structure)

LineCount (Short)

number of lines of control element

MultiSelection (Boolean)

permits multiple selection of entries

SelectedItems (Array of Strings)

list of highlighted entries

StringItemList (Array of Strings)

list of all entries

ValueItemList (Array of Variant)

list containing additional information for each entry (for example, for administrating data record IDs)

Printable (Boolean)

the control element can be printed

ReadOnly (Boolean)

the content of the control element is read-only

Enabled (Boolean)

the control element can be activated

Tabstop (Boolean)

the control element can be reached through the tab key

TabIndex (Long)

position of control element in the activation sequence

FontName (String)

name of font type

FontHeight (Single)

height of character in points (pt)

Tag (String)

string containing additional information which can be saved in the button for program-controlled access

TextColor (Long)

text color of control element

HelpText (String)

automatically displayed help text, which is displayed if the mouse cursor is above the control element

HelpURL (String)

URL of online help for the corresponding control element

Note: VBA : Through their ValueItemList property, list box forms provide a counterpart to the VBA property, ItemData, through which you can administer additional information for individual list entries.

Furthermore, the following methods are provided through the view object of the list box:

addItem (Item, Pos)

inserts the string specified in the Item at the Pos position in the list

addItems (ItemArray, Pos)

inserts the entries listed in the string's ItemArray data field in the list at the Pos position

removeItems (Pos, Count)

removes Count entries as of the Pos position

selectItem (Item, SelectMode)

activates or deactivates the highlighting for the element specified in the string Item depending on the SelectMode variable

makeVisible (Pos)

scrolls through the list field so that the entry specified by Pos is visible

Database Forms

LibreOffice forms can be directly linked to a database. The forms created in this way provide all the functions of a full database front end without requiring independent programming work.

You can page through and search in the selected tables and queries, as well as change data records and insert new data records. LibreOffice automatically ensures that the relevant data is retrieved from the database, and that any changes made are written back to the database.

A database form corresponds to a standard LibreOffice form. In addition to the standard properties, the following database-specific properties must also be set in the form:

DataSourceName (String)

name of data source (refer to Database Access; the data source must be globally created in LibreOffice)

Command (String)

name of table, query, or the SQL select command to which a link is to be made

CommandType (Const)

specifies whether the Command is a table, a query or a SQL command (value from com.sun.star.sdb.CommandType enumeration)

The com.sun.star.sdb.CommandType enumeration covers the following values:

TABLE

Table

QUERY

Query

COMMAND

SQL command

The database fields are assigned to the individual control elements through this property:

DataField (String)

name of linked database field

Tables

Another control element is provided for work with databases, the table control element. This represents the content of a complete database table or query. In the simplest scenario, a table control element is linked to a database using the autopilot form, which links all columns with the relevant database fields in accordance with the user specifications.

Content on this page is licensed under the Public Documentation License (PDL).