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 boolean isAnnotationIndicationInOverviewRulerEnabled(AnnotationType annotationType) {
		IPreferenceStore store= getPreferenceStore();
		AnnotationInfo info= (AnnotationInfo) ANNOTATION_MAP.get(annotationType);
		if (info != null)
			return store.getBoolean(info.fOverviewRulerPreference);
		return false;
	}
	
	private void showAnnotationIndicationInOverviewRuler(AnnotationType annotationType, boolean show) {
		AdaptedSourceViewer asv= (AdaptedSourceViewer) getSourceViewer();
		OverviewRuler ruler= asv.getOverviewRuler();
		if (ruler != null) {
			ruler.setColor(annotationType, getColor(annotationType));
			ruler.showAnnotation(annotationType, show);
			ruler.update();
		}
	}
	private void setColorInOverviewRuler(AnnotationType annotationType, Color color) {
		AdaptedSourceViewer asv= (AdaptedSourceViewer) getSourceViewer();
		OverviewRuler ruler= asv.getOverviewRuler();
		if (ruler != null) {
			ruler.setColor(annotationType, color);
			ruler.update();
		}
	}
	private void configureTabConverter() {
		if (fTabConverter != null) {
			IDocumentProvider provider= getDocumentProvider();