signal callback delegate or function to connect
void callback(gdk.drag.Drag drag, gtk.drag_source.DragSource dragSource)
drag the gdk.drag.Drag object (optional)
dragSource the instance the signal is connected to (optional)
Yes.After to execute callback after default handler, No.After to execute before (default)
Signal ID
Connect to DragBegin signal.
Emitted on the drag source when a drag is started.
It can be used to e.g. set a custom drag icon with gtk.drag_source.DragSource.setIcon.