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
String p= event.getProperty();
		boolean affects=MATCHING_BRACKETS_COLOR.equals(p) || CURRENT_LINE_COLOR.equals(p) || 
									ERROR_INDICATION_COLOR.equals(p) || WARNING_INDICATION_COLOR.equals(p) || TASK_INDICATION_COLOR.equals(p);
		return affects ? affects : super.affectsTextPresentation(event);
	}
	
	/*
	 * @see JavaEditor#createJavaSourceViewer(Composite, IVerticalRuler, int)
	 */
	protected ISourceViewer createJavaSourceViewer(Composite parent, IVerticalRuler ruler, int styles) {
		return new AdaptedSourceViewer(parent, ruler, styles);
	}
	
	/*
	 * @see JavaEditor#synchronizeOutlinePageSelection()
	 */
	public void synchronizeOutlinePageSelection() {
		
		if (isEditingScriptRunning())
			return;
		
		ISourceViewer sourceViewer= getSourceViewer();
		if (sourceViewer == null || fOutlinePage == null)
			return;
			
		StyledText styledText= sourceViewer.getTextWidget();
		if (styledText == null)
			return;
		
		int modelCaret= 0;