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.global.setAllowedBackends
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.global.setAllowedBackends to limit what backends can be used.