Dart Web Programming for Beginners: 30 Dropping

In this video, we review the methods used for elements on which we drop other elements. The element upon which you drop things have 3 stages of firing the events (they are drop type of actions, even though they all start with 'drag':

onDragEnter - fires when a dragged object first enters the borders of the element on which to drop.
onDragOver - fires continuously while the dragged object is over the drop object.
onDragLeave - fires when the dragged object moves away from the drop object.