When called for the first time, this function consults the
GDK_BACKEND environment variable to find out which
of the supported GDK backends to use (in case GDK has been compiled
with multiple backends). Applications can use gdk_set_allowed_backends()
to limit what backends can be used.
Gets the singleton #GdkDisplayManager object.
When called for the first time, this function consults the GDK_BACKEND environment variable to find out which of the supported GDK backends to use (in case GDK has been compiled with multiple backends). Applications can use gdk_set_allowed_backends() to limit what backends can be used.