public virtual signal bool scroll_event (EventScroll event)
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 Window associated to the widget needs to enable the SCROLL_MASK mask.
This signal will be sent to the grab widget if there is one.
the EventScroll which triggered this signal.
true to stop other handlers from being invoked for the event. false to propagate the event further.