gdkCursorNewFromPixbuf(display, source, x, y)GdkCursor] a new GdkCursor.gdkDisplaySupportsCursorAlpha and
gdkDisplaySupportsCursorColor can be used to determine
whether RGBA cursors are supported;
gdkDisplayGetDefaultCursorSize and
gdkDisplayGetMaximalCursorSize give information about
cursor sizes.
On the X backend, support for RGBA cursors requires a
sufficently new version of the X Render extension. Since 2.4