onDragLeave property

ElementStream<MouseEvent> onDragLeave

A stream of dragleave events fired when an object being dragged over this element leaves this element's target area.

Other resources

Drag and drop sample based on the tutorial from HTML5Rocks. Drag and drop specification from WHATWG.

Implementation 

ElementStream<MouseEvent> get onDragLeave => dragLeaveEvent.forElement(this);