void gdk_window_fullscreen ( GdkWindow* window )
Moves the window into fullscreen mode. This means the window covers the entire screen and is above any panels or task bars.
If the window was already fullscreen, then this function does nothing.
On X11, asks the window manager to put
window in a fullscreen
state, if the window manager supports this operation. Not all
window managers support this, and some deliberately ignore it or
don’t have a concept of “fullscreen”; so you can’t rely on the
fullscreenification actually happening. But it will happen with
most standard window managers, and GDK makes a best effort to get
it to happen.
Available since: 2.2