Bug 33016 Show In...: "Package Explorer" is enabled when opening a file from cvs repository
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
static final String TAG_SELECTION= "selection"; 
	static final String TAG_EXPANDED= "expanded"; 
	static final String TAG_ELEMENT= "element"; 
	static final String TAG_PATH= "path"; 
	static final String TAG_VERTICAL_POSITION= "verticalPosition"; 
	static final String TAG_HORIZONTAL_POSITION= "horizontalPosition"; 
	static final String TAG_FILTERS = "filters"; 
	static final String TAG_FILTER = "filter"; 
	static final String TAG_LAYOUT= "layout"; 
	
	private PackageExplorerContentProvider fContentProvider;
	
	private PackageExplorerActionGroup fActionSet;
	private ProblemTreeViewer fViewer; 
	private Menu fContextMenu;		
	
	private IMemento fMemento;	
	private ISelectionChangedListener fSelectionListener;
	
	private String fWorkingSetName;
	
	private IPartListener fPartListener= new IPartListener() {
		public void partActivated(IWorkbenchPart part) {
			if (part instanceof IEditorPart)
				editorActivated((IEditorPart) part);
		}
		public void partBroughtToTop(IWorkbenchPart part) {
		}