Loading presentation styles

Presentation styles are defined in an XML file with a 4st extension. In order to load the presentation styles, the runtime system needs to locate the appropriate style file.

By default, the runtime system searches for default.4st in several directories, as described in the FGLRESOURCEPATH reference topic. If the file is not found using the FGLRESOURCEPATH/DBPATH environment variables, default presentation styles are loaded from the $FGLDIR/lib/default.4st file.

Overwrite the default search by loading a specific presentation style file with the ui.Interface.loadStyles() method:

  CALL ui.Interface.loadStyles("mystyles")

This method accepts an absolute path with the .4st extension, or a simple filename without the .4st extension. If you give a simple file name, for example "mystyles", the runtime system searches for the mystyles.4st file in the current directory or in the application directory. If the file does not exist, it searches in the directories defined by the FGLRESOURCEPATH environment variable. If FGLRESOURCEPATH is not defined, it searches in the directories defined by the DBPATH environment variable.

The presentation styles must be defined in a unique .4st file. When loading a styles file with the ui.Interface.loadStyles() method, current styles created from the default file or from a prior load will be replaced. The styles will not be combined when loading several files.

The default styles file located in $FGLDIR/lib should not be modified directly: your changes would be lost if you upgrade the product. Make a copy of the original file into the program directory of your application, then modify the copied file.