GtkWidget::add_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 button press event on a widget that does
not normally capture such events.
add_events() can only be used
after a widget has had realize()
called on it. Note that realization is a part of the
show() routine as well as being
a method/signal pair in its own right.
Staying with the button-press example, the syntax would be:
$widget->add_events(GDK_BUTTON_PRESS_MASK|GDK_BUTTON_RELEASE_MASK);
This would enable a previously mouse-insensitive widget to emit
"button-press-event" and
"button-release-event" signals.
