Bug 76439 Classfile editor: Allow source attachment option for classes in class folders
20041017 When you open a class file for a class folder that has no source attchment you see a message 'No source available...' but no button that brings you to the source attachment page like it is done for JARs. ClassfileEditor line 225 is too restrictive, the test .isArchive() seems to be too much
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/ClassFileEditor.java
private final IClassFile fFile;
			private ScrolledComposite fScrolledComposite;
			private Color fBackgroundColor;
			private Color fForegroundColor;
			private Color fSeparatorColor;
			private List fBannerLabels= new ArrayList();
			private List fHeaderLabels= new ArrayList();
			private Font fFont;
			
			/**
			 * Creates a source attachment form for a class file. 
			 */
			public SourceAttachmentForm(IClassFile file) {
				fFile= file;
			}
		
			/**
			 * Returns the package fragment root of this file.
			 */
			private IPackageFragmentRoot getPackageFragmentRoot(IClassFile file) {
		
				IJavaElement element= file.getParent();
				while (element != null && element.getElementType() != IJavaElement.PACKAGE_FRAGMENT_ROOT)
					element= element.getParent();
		
				return (IPackageFragmentRoot) element;		
			}