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
};
		runOperation(op, true, false);
	}
	
	private  void handleRefresh(DragSourceEvent event) {
		final Set roots= collectRoots(getResources());
		
		WorkspaceModifyOperation op= new WorkspaceModifyOperation() {
			public void execute(IProgressMonitor monitor) throws CoreException {
				try {
					monitor.beginTask(PackagesMessages.DragAdapter_refreshing, roots.size()); 
					MultiStatus status= createMultiStatus();
					Iterator iter= roots.iterator();
					while (iter.hasNext()) {
						IResource r= (IResource)iter.next();
						try {
							r.refreshLocal(IResource.DEPTH_ONE, new SubProgressMonitor(monitor, 1));
						} catch (CoreException e) {
							status.add(e.getStatus());
						}	
					}
					if (!status.isOK()) {
						throw new CoreException(status);
					}
				} finally {
					monitor.done();
				}
			}
		};