GXT Problem with method override

Using GXT I would like to override the 'drop' in the 'Drag & Drop Grid' example on the GXT开发者_开发技巧 examples webpage.

Does anyone have an idea as to the method I should override? The API is so vast and verbose that is is a near impossibility to find anything in this mess!

To set a grid to do drag and drop is simply adding it as a Drag source as below

GridDragSource gridDragSource = new GridDragSource(yourGrid);

You then can add your own listener to handle drag

gridDragSource.addDNDListener(new DNDListener() {
   public void dragMove(DNDEvent e) {
  }

  public void dragStart(DNDEvent e) {
  }

  public void dragEnter(DNDEvent e) {
  }

  public void dragLeave(DNDEvent e) {
  }

  public void dragDrop(DNDEvent e) {
  }

}