Bug 86515 [Drag and Drop] Drag and drop (move) for project
Drag and drop (move) for project onto Explorer deletes the project from the file system. But this is not reflected in the workspace. Pressing refresh - provides dialog "location deleted" and remove project from the workspace.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/FileTransferDragAdapter.java
if (o instanceof IResource) {
				r= (IResource)o;
			} else if (o instanceof IAdaptable) {
				r= (IResource)((IAdaptable)o).getAdapter(IResource.class);
			}
			if (r != null)
				result.add(r);
		}
		return result;
	}
	
	private MultiStatus createMultiStatus() {
		return new MultiStatus(JavaPlugin.getPluginId(), 
			IStatus.OK, PackagesMessages.DragAdapter_problem, null); 
	}
	
	private void runOperation(IRunnableWithProgress op, boolean fork, boolean cancelable) {
		try {
			Shell parent= JavaPlugin.getActiveWorkbenchShell();
			new ProgressMonitorDialog(parent).run(fork, cancelable, op);
		} catch (InvocationTargetException e) {
			String message= PackagesMessages.DragAdapter_problem; 
			String title= PackagesMessages.DragAdapter_problemTitle; 
			ExceptionHandler.handle(e, title, message);
		} catch (InterruptedException e) {
			
		}
	}
}