In some cases, an application might need to be notified when items are dragged away from a target. For example, if an application had hooked the dragOverCallback to show target emphasis, it would need to be notified when the drag had left that target widget so that it could erase the emphasis.

To support this, the dragLeaveCallback on the target adapter is activated whenever the items are dragged away from the target of the last dragOverCallback. The callData includes only the source widget, the source model, and the source items. None of these fields can be changed; this callback is for notification only.