Bug 40074 [navigation] Selection reset to previous item when arrowing in outline
build I20030710 - open a Java editor on a class with several methods - in the outline, select the first method - use the arrow key to go down one item - as soon as the delay passes and the new text range is selected, use the arrow key to go down another item - after the delay, the selection is reset back to the previous item
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
* 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) {
		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();
		}
	}
	
	/*
	 * @see org.eclipse.ui.texteditor.ITextEditorExtension3#showChangeInformation(boolean)
	 */
	public void showChangeInformation(boolean show) {
		if (show == fIsChangeInformationShown)
			return;
		
		if (fIsChangeInformationShown) {
			uninstallChangeRulerModel();
			showChangeRuler(false); 
		} else {
			ensureChangeInfoCanBeDisplayed(); 
			installChangeRulerModel();
		}
		
		fIsChangeInformationShown= show;