public virtual signal bool extend_selection (TextExtendSelection granularity, TextIter location, TextIter start, TextIter end)
The extend_selection signal is emitted when the selection needs to be extended at
the granularity type
the location where to extend the selection
where the selection should start
where the selection should end
gdk_event_stop to stop other handlers from being invoked for the event. gdk_event_propagate to propagate the event further.