the crossing mode (GDK_CROSSING_NORMAL, GDK_CROSSING_GRAB,
GDK_CROSSING_UNGRAB, GDK_CROSSING_GTK_GRAB, GDK_CROSSING_GTK_UNGRAB or
GDK_CROSSING_STATE_CHANGED). GDK_CROSSING_GTK_GRAB, GDK_CROSSING_GTK_UNGRAB,
and GDK_CROSSING_STATE_CHANGED were added in 2.14 and are always synthesized,
never native.
the crossing mode (GDK_CROSSING_NORMAL, GDK_CROSSING_GRAB, GDK_CROSSING_UNGRAB, GDK_CROSSING_GTK_GRAB, GDK_CROSSING_GTK_UNGRAB or GDK_CROSSING_STATE_CHANGED). GDK_CROSSING_GTK_GRAB, GDK_CROSSING_GTK_UNGRAB, and GDK_CROSSING_STATE_CHANGED were added in 2.14 and are always synthesized, never native.