GdkDisplayManager
Maintains a list of all open GdkDisplays
The purpose of the #GdkDisplayManager singleton object is to offer
notification when displays appear or disappear or the default display
changes.
The GdkDisplayManager struct has no interesting
fields.
@Returns:
@display_manager:
@Returns:
@display_manager:
@display:
@display_manager:
@Returns:
@display:
@Returns:
@gdkdisplaymanager: the object which received the signal.
@arg1: