Bug 91072 F2/Hover for external javadoc does not work
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/JavadocConfigurationBlock.java
private final Image IMG_JAR=
			JavaUI.getSharedImages().getImage(org.eclipse.jdt.ui.ISharedImages.IMG_OBJS_JAR);
		private final Image IMG_FOLDER=
			PlatformUI.getWorkbench().getSharedImages().getImage(ISharedImages.IMG_OBJ_FOLDER);
	
		private ZipFileStructureProvider fProvider;
	
		public ZipDialogLabelProvider(ZipFileStructureProvider provider) {
			fProvider= provider;
		}
	
		public Image getImage(Object element) {
			if (element == fProvider.getRoot()) {
				return IMG_JAR;
			} else {
				return IMG_FOLDER;
			}
		}
	
		public String getText(Object element) {
			if (element == fProvider.getRoot()) {
				return fProvider.getZipFile().getName();
			}
			return fProvider.getLabel(element);
		}
	}
	
	private static class ZipDialogValidator implements ISelectionStatusValidator {