The GNOME Libraries

The GNOME projects is one of several projects to provide a complete desktop to Linux users. The GNOME project includes a panel to hold application launchers and mini-applications called applets, several standard applications to do things such as file management, session management, and configuration, and an API for creating applications which fit in with the way the rest of the system works.

One thing to notice about the GNOME libraries is that they constantly create and give you pointers to large data structures, but you never need to know how they are laid out in memory. All manipulation of the GUI data structures are done entirely through function calls. This is a characteristic of good library design. Libraries change from version to version, and so does the data that each data structure holds. If you had to access and manipulate that data yourself, then when the library is updated you would have to modify your programs to work with the new library, or at least recompile them. When you access the data through functions, the functions take care of knowing where in the structure each piece of data is. The pointers you receive from the library are opaque - you don't need to know specifically what the structure they are pointing to looks like, you only need to know the functions that will properly manipulate it. When designing libraries, even for use within only one program, this is a good practice to keep in mind.

This chapter will not go into details about how GNOME works. If you would like to know more, visit the GNOME developer web site at http://developer.gnome.org/. This site contains tutorials, mailing lists, API documentation, and everything else you need to start programming in the GNOME environment.