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 isBracketHighlightingEnabled() {
		IPreferenceStore store= getPreferenceStore();
		return store.getBoolean(MATCHING_BRACKETS);
	}
	
	private void startLineHighlighting() {
		if (fLinePainter == null) {
			ISourceViewer sourceViewer= getSourceViewer();
			fLinePainter= new LinePainter(sourceViewer);
			fLinePainter.setHighlightColor(getColor(CURRENT_LINE_COLOR));
			fPaintManager.addPainter(fLinePainter);
		}
	}
	
	private void stopLineHighlighting() {
		if (fLinePainter != null) {
			fPaintManager.removePainter(fLinePainter);
			fLinePainter.deactivate(true);
			fLinePainter.dispose();
			fLinePainter= null;
		}
	}
	
	private boolean isLineHighlightingEnabled() {
		IPreferenceStore store= getPreferenceStore();
		return store.getBoolean(CURRENT_LINE);
	}