Bug 32680 Print margin is in wrong location
Eclipse 2.1 (RC1) After changing my font to "Courier New", then turning on the Print Margin, I had to realize that it was located in the wrong place (off by some characters)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
* related editor properties.
	 * 
	 * @param event the property change event
	 */
	protected void handlePreferencePropertyChanged(org.eclipse.core.runtime.Preferences.PropertyChangeEvent event) {
		if (COMPILER_TASK_TAGS.equals(event.getProperty())) {
			ISourceViewer sourceViewer= getSourceViewer();
			if (sourceViewer != null && affectsTextPresentation(new PropertyChangeEvent(event.getSource(), event.getProperty(), event.getOldValue(), event.getNewValue())))
				sourceViewer.invalidateTextPresentation();
		}
	}
	
	/**
	 * Shows the line number ruler column.
	 */
	private void showLineNumberRuler() {
		IVerticalRuler v= getVerticalRuler();
		if (v instanceof CompositeRuler) {
			CompositeRuler c= (CompositeRuler) v;
			c.addDecorator(1, createLineNumberRulerColumn());
		}
	}
	
	/**
	 * Hides the line number ruler column.
	 */
	private void hideLineNumberRuler() {
		IVerticalRuler v= getVerticalRuler();
		if (v instanceof CompositeRuler) {
			CompositeRuler c= (CompositeRuler) v;