Bug 52474 UI Blocked when opening Java Perspective during CVS check out
build I20040218 - start eclipse with a new workspace - switch to CVS Repository Exploring perspective - check out a number of projects ( i checkout Platform UI module) - now attempt to switch to the Java Perspective NOTE that at this point the "UI is blocked" dialog is opened. Probably due to the fact that starting the Java Perspective requires the workbench lock? The point here is that this will be a common pattern and it would be nice if we could investigate makeing this scenario work more smoothly.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
*/
	public void menuAboutToShow(IMenuManager menu) {
		JavaPlugin.createStandardGroups(menu);
		
		fActionSet.setContext(new ActionContext(getSelection()));
		fActionSet.fillContextMenu(menu);
		fActionSet.setContext(null);
	}
	private void makeActions() {
		fActionSet= new PackageExplorerActionGroup(this);
	}
	
	
	
	private void initDragAndDrop() {
		initDrag();
		initDrop();
	}
	private void initDrag() {
		int ops= DND.DROP_COPY | DND.DROP_MOVE | DND.DROP_LINK;
		Transfer[] transfers= new Transfer[] {
			LocalSelectionTransfer.getInstance(), 
			ResourceTransfer.getInstance(),
			FileTransfer.getInstance()};
		TransferDragSourceListener[] dragListeners= new TransferDragSourceListener[] {
			new SelectionTransferDragAdapter(fViewer),
			new ResourceTransferDragAdapter(fViewer),
			new FileTransferDragAdapter(fViewer)
		};
		fViewer.addDragSupport(ops, transfers, new JdtViewerDragAdapter(fViewer, dragListeners));