Bug 32224 [Show In]Back-linking doesn't work for .class files in jars
Build 20030218 1. Enable back-linking in Package Explorer 2. Open Object (in rt.jar) Observe: An editor on Object.class opens (it shows the attached source). However Object.class is not shown in Package Explorer Note that Alt-Shift-s->Package Explorer doesn't work either.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
fContentProvider= createContentProvider();
		fContentProvider.setIsFlatLayout(fIsCurrentLayoutFlat);
		fViewer.setContentProvider(fContentProvider);
	
		fLabelProvider= createLabelProvider();
		fLabelProvider.setIsFlatLayout(fIsCurrentLayoutFlat);
		fViewer.setLabelProvider(new DecoratingJavaLabelProvider(fLabelProvider, false, false));
		
	}
	
	void toggleLayout() {
		
		fIsCurrentLayoutFlat= !fIsCurrentLayoutFlat;
		saveLayoutState(null);
		
		fContentProvider.setIsFlatLayout(isFlatLayout());
		fLabelProvider.setIsFlatLayout(isFlatLayout());
		
		fViewer.getControl().setRedraw(false);
		fViewer.refresh();
		fViewer.getControl().setRedraw(true);
	}
	
	/**
	 * This method should only be called inside this class
	 * and from test cases.
	 */
	public PackageExplorerContentProvider createContentProvider() {
		IPreferenceStore store= PreferenceConstants.getPreferenceStore();