Bug 4373 Packages View - double clich doesn't expand two hiearchy levels
- enable: Show CU children in packages view - double click on CU observe: only one level gets expanded - now expand a node by clicking on the + observe: two levels get expanded
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
if (key.equals(ISelectionProvider.class))
			return fViewer;
		return super.getAdapter(key);
	}
	/**
	 * Returns the tool tip text for the given element.
	 */
	String getToolTipText(Object element) {
		if (!(element instanceof IResource))
			return ((ILabelProvider) getViewer().getLabelProvider()).getText(element);
		
		IPath path= ((IResource) element).getFullPath();
		if (path.isRoot()) {
			return PackagesMessages.getString("PackageExplorer.title"); 
		}
		else {
			return path.makeRelative().toString();
		}
	}
	
	/**
	 * @see IWorkbenchPart#setFocus()
	 */
	public void setFocus() {
		fViewer.getTree().setFocus();
	}
	/**
	 * Returns the shell to use for opening dialogs.
	 * Used in this class, and in the actions.
	 */