onDragStart property

ElementStream<MouseEvent> onDragStart
@DocsEditable(), @DomName('Element.ondragstart')

A stream of dragstart events fired when this element starts being dragged.

Other resources

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

Implementation 

@DomName('Element.ondragstart')
@DocsEditable()
ElementStream<MouseEvent> get onDragStart => dragStartEvent.forElement(this);