Bug 32656 Open/Close project in package explorer looses selection on java-projects. [package explorer]
Not on non-java projects, which looks wrong when multiple java- and non-java-projects are opened/closed.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
/**
	 * Returns the package explorer part of the active perspective. If 
	 * there isn't any package explorer part <code>null</code> is returned.
	 */
	public static PackageExplorerPart getFromActivePerspective() {
		IWorkbenchPage activePage= JavaPlugin.getActivePage();
		if (activePage == null)
			return null;
		IViewPart view= activePage.findView(VIEW_ID);
		if (view instanceof PackageExplorerPart)
			return (PackageExplorerPart)view;
		return null;	
	}
	
	/**
	 * Makes the package explorer part visible in the active perspective. If there
	 * isn't a package explorer part registered <code>null</code> is returned.
	 * Otherwise the opened view part is returned.
	 */
	public static PackageExplorerPart openInActivePerspective() {
		try {
			return (PackageExplorerPart)JavaPlugin.getActivePage().showView(VIEW_ID);
		} catch(PartInitException pe) {
			return null;
		}
	} 
		
	 public void dispose() {
		if (fContextMenu != null && !fContextMenu.isDisposed())
			fContextMenu.dispose();