Common Types
Until now, literals and common Java types for method parameters and return values have been used as if the Apache OpenOffice API was made for Java. However, it is important to understand that UNO is designed to be language independent and therefore has its own set of types which have to be mapped to the proper types for your language binding. The type mappings are briefly described in this section. Refer to Professional UNO for detailed information about type mappings.
Basic Types
The basic UNO types (where the term “basic” has nothing to do with Apache OpenOffice Basic) occur as members of structs, as method return types or method parameters. The following table shows the basic UNO types and, if available, their exact mappings to Java, C++, and Apache OpenOffice Basic types.
UNO | Type description | Java | C++ | Basic |
---|---|---|---|---|
void | empty type, used only as method return type and in any |
void | void | - |
boolean | Boolean type; true and false | boolean | sal_Bool | Boolean |
byte | signed 8-bit integer type | byte | sal_Int8 | Integer |
short | signed 16-bit integer type | short | sal_Int16 | Integer |
unsigned short | unsigned 16-bit integer type (deprecated) | - | sal_uInt16 | - |
long | signed 32-bit integer type | int | sal_Int32 | Long |
unsigned long | unsigned 32-bit integer type (deprecated) | - | sal_uInt32 | - |
hyper | signed 64-bit integer type | long | sal_Int64 | - |
unsigned hyper | unsigned 64-bit integer type (deprecated) | - | sal_uInt64 | - |
float | IEC 60559 single precision floating point type | float | float (if appropriate) | Single |
double | IEC 60559 double precision floating point type | double | double (if appropriate) | Double |
char | 16-bit Unicode character type (more precisely: UTF-16 code units)- | char | sal_Unicode | - |
There are special conditions for types that do not have an exact mapping in this table. Check for details about these types in the corresponding sections about type mappings in UNO Language Bindings.
Strings
UNO considers strings to be simple types, but since they need special treatment in some environments, we discuss them separately here.
UNO | Description | Java | C++ | Basic |
---|---|---|---|---|
string | Unicode string type (more precisely: strings of Unicode scalar values) | java.lang.String | rtl::OUString | String |
In Java, use UNO strings as if they were native java.lang.String
objects.
In C++, native char
strings must be converted to UNO Unicode strings by means of SAL conversion functions, usually the function createFromAscii()
in the rtl::OUString
class:
//C++ static OUString createFromAscii( const sal_Char * value ) throw();
In Basic, Basic strings are mapped to UNO strings transparently.
Enum Types and Groups of Constants
The Apache OpenOffice API uses many enumeration types (called enums) and groups of constants (called constant groups). Enums are used to list every plausible value in a certain context. The constant groups define possible values for properties, parameters, return values and struct members.
For example, there is an enum com.sun.star.table.CellVertJustify that describes the possible values for the vertical adjustment of table cell content. The vertical adjustment of table cells is determined by their property VertJustify. The possible values for this property are, according to CellVertJustify
, the values STANDARD
, TOP
, CENTER
and BOTTOM
.
// adjust a cell content to the upper cell border // The service com.sun.star.table.Cell includes the service com.sun.star.table.CellProperties // and therefore has a property VertJustify that controls the vertical cell adjustment // we have to use the XPropertySet interface of our Cell to set it xCellProps.setPropertyValue("VertJustify", com.sun.star.table.CellVertJustify.TOP);
Apache OpenOffice Basic understands enumeration types and constant groups. Their usage is straightforward:
'OpenOffice Basic oCellProps.VertJustify = com.sun.star.table.CellVertJustify.TOP
In C++ enums and constant groups are used with the scope operator ::
//C++ rCellProps->setPropertyValue(OUString::createFromAscii( "VertJustify"), ::com::sun::star::table::CellVertJustify.TOP);
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