called during drag-n-drop, when some item of the component should be marked as an active drop target
|context||object||a drag-n-drop context|
|ev||Event||a native HTML event|
|boolean||returning false will prevent a drag operation|
The method isn't purposed for direct call! It is an extension point.
You can override it with your own logic, but check drag-n-drop related events first, as they provide a much more convenient way of drag-n-drop handling.
The drag-and-drop context can have the following properties: