void gtk_widget_destroyed ( GtkWidget* widget, GtkWidget** widget_pointer )
This function sets *
NULL. It’s intended to be used as a callback connected to the
“destroy” signal of a widget. You connect
as a signal handler, and pass the address of your widget variable
as user data. Then when the widget is destroyed, the variable will
be set to
NULL. Useful for example to avoid multiple copies
of the same dialog.
Address of a variable that contains
The argument will be modified by the function. The data is owned by the caller of the function.