dragEnterEvent constant

EventStreamProvider<MouseEvent> const dragEnterEvent = const EventStreamProvider<MouseEvent>('dragenter')

A stream of dragenter events fired when a dragged object is first dragged over an element.

Other resources

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

Implementation 

static const EventStreamProvider<MouseEvent> dragEnterEvent =
    const EventStreamProvider<MouseEvent>('dragenter')