The grab_notify signal is emitted when a widget becomes shadowed by a GTK+ grab (not a pointer or keyboard grab) on another widget, or when it becomes unshadowed due to a grab being removed.
A widget is shadowed by a grab_add when the topmost grab widget in the grab stack of its window group is not its ancestor.
| was_grabbed |
false if the widget becomes shadowed, true if it becomes unshadowed |