The ::unrealize signal is emitted when the GdkWindow associated with widget is destroyed, which means that gtk_widget_unrealize() has been called or the widget has been unmapped (that is, it is going to be hidden).
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The ::unrealize signal is emitted when the GdkWindow associated with widget is destroyed, which means that gtk_widget_unrealize() has been called or the widget has been unmapped (that is, it is going to be hidden).