Gtk.Widget::scroll-event

function callback(widget, event:Gdk.EventScroll, ):Boolean;

The ::scroll-event signal is emitted when a button in the 4 to 7 range is pressed. Wheel mice are usually configured to generate button press events for buttons 4 and 5 when the wheel is turned.

To receive this signal, the Gdk.Window associated to the widget needs to enable the #GDK_SCROLL_MASK mask.

This signal will be sent to the grab widget if there is one.

widget: instance of Gtk.Widget that is emitting the signal
event: the Gdk.EventScroll which triggered this signal.
Returns: true to stop other handlers from being invoked for the event. false to propagate the event further.