Bug 28698 Ctrl+O (show outline) does not work if the file being shown in the editor is read only
M4 The summary tells all. Works if the file is not read only. Is this by design?
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
private final static AnnotationType[] ANNOTATION_LAYERS= new AnnotationType[] {
		AnnotationType.UNKNOWN,
		AnnotationType.BOOKMARK,
		AnnotationType.TASK,
		AnnotationType.SEARCH_RESULT,
		AnnotationType.WARNING,
		AnnotationType.ERROR
	};
		
	
	
	protected ISavePolicy fSavePolicy;
	
	private JavaEditorErrorTickUpdater fJavaEditorErrorTickUpdater;
	
	private PaintManager fPaintManager;
	
	private BracketPainter fBracketPainter;
	
	private JavaPairMatcher fBracketMatcher;
	
	private LinePainter fLinePainter;
	
	private PrintMarginPainter fPrintMarginPainter;
	
	private ProblemPainter fProblemPainter;
	
	private TabConverter fTabConverter;