Bug 31999 Error when opening editor on class file not hosted in a Java project
I20030214 - create Simple project - create a file A.class - open it observe: you get an error saying that Simple doesn't exist.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/ClassFileEditor.java
*/
	protected ISourceViewer createJavaSourceViewer(Composite parent, IVerticalRuler ruler, int styles) {
		return new SourceViewer(parent, ruler, styles) {
			public boolean requestWidgetToken(IWidgetTokenKeeper requester) {
				if (WorkbenchHelp.isContextHelpDisplayed())
					return false;
				return super.requestWidgetToken(requester);
			}
		};	
	}
	
	/*
	 * @see org.eclipse.ui.IWorkbenchPart#dispose()
	 */
	public void dispose() {
		
		IDocumentProvider documentProvider= getDocumentProvider();
		if (documentProvider instanceof ClassFileDocumentProvider)
			((ClassFileDocumentProvider) documentProvider).removeInputChangeListener(this);
		super.dispose();
	}
	/*
	 * @see org.eclipse.ui.IWorkbenchPart#setFocus()
	 */
	public void setFocus() {
		super.setFocus();
		if (fSourceAttachmentForm != null && !fSourceAttachmentForm.isDisposed())
			fSourceAttachmentForm.setFocus();
	}
}