The ::destroy-event signal is emitted when a GdkWindow is destroyed.
You rarely get this signal, because most widgets disconnect themselves
from their window before they destroy it, so no widget owns the
window at destroy time.
To receive this signal, the GdkWindow associated to the widget needs
to enable the GDK_STRUCTURE_MASK mask. GDK will enable this mask
automatically for all new windows.
The ::destroy-event signal is emitted when a GdkWindow is destroyed. You rarely get this signal, because most widgets disconnect themselves from their window before they destroy it, so no widget owns the window at destroy time. To receive this signal, the GdkWindow associated to the widget needs to enable the GDK_STRUCTURE_MASK mask. GDK will enable this mask automatically for all new windows.