title: GXT Drag and drop from tree label to a widget
body: <p>I just want to drag and drop an label from tree to a widget. I am using the below code and it is not getting dropped as a widget. Can you please help me how to display a widget as a dropped item.</p>
  
  <pre><code> final FlowLayoutContainer dropContainer = new FlowLayoutContainer();
   dropContainer.setBorders(true);
  
   DropTarget target = new DropTarget(dropContainer) {
     @Override
     protected void onDragDrop(DndDropEvent event) {
       super.onDragDrop(event);
       Widget window = (Widget) event.getData();
       dropContainer.add(window);
     }
   };
   target.setGroup("test");
   target.setOverStyle("drag-ok");
  </code></pre>