Generated when a selection is requested or ownership of a selection is taken over by another client application.
the property in which to place the result of the conversion.
the window on which to place property or NULL if none.
TRUE if the event was sent explicitly.
the target to which the selection should be converted.
the time of the event in milliseconds.
the type of the event (GDK_SELECTION_CLEAR, GDK_SELECTION_NOTIFY or GDK_SELECTION_REQUEST).
the window which received the event.