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
ContentAssistPreference.changeConfiguration((ContentAssistant) c, getPreferenceStore(), event);
			}
				
		} finally {
			super.handlePreferenceStoreChanged(event);
		}
	}
	/**
	 * Handles a property change event describing a change
	 * of the java core's preferences and updates the preference
	 * related editor properties.
	 * 
	 * @param event the property change event
	 */
	protected void handlePreferencePropertyChanged(org.eclipse.core.runtime.Preferences.PropertyChangeEvent event) {
		AdaptedSourceViewer asv= (AdaptedSourceViewer) getSourceViewer();
		if (asv != null) {
			String p= event.getProperty();					
			if (CODE_FORMATTER_TAB_SIZE.equals(p)) {
				asv.updateIndentationPrefixes();
				if (fTabConverter != null)
					fTabConverter.setNumberOfSpacesPerTab(getTabSize());
			}
		}
	}
	
	/*
	 * @see AbstractTextEditor#affectsTextPresentation(PropertyChangeEvent)
	 */
	protected boolean affectsTextPresentation(PropertyChangeEvent event) {