GtkWidget::set_events
This method is used to set the GdkEventMask
flags on a widget, extending the type of event that the widget
can capture from its default capabilities. You may need to do this,
for instance, to capture a key press event on a widget that does not
normally capture such events.
set_events() can be used
at any point in the widget's life-cycle.
Staying with the key-press example, the syntax would be:
$widget->set_events(GDK_KEY_PRESS_MASK | GDK_KEY_RELEASE_MASK);
This would enable a previously keyboard-insensitive widget to emit
"key-press-event" and
"key-release-event" signals.
