Bug 205248 [Databinding] Observables on Text with FOCUS_OUT event incorrectly notify with no change
If you get an observable on a Text for the FOCUS_OUT event, the model is updated every time, even if there is no change in the value. The observable should not trigger a model change if the Text value is the same as the model value.
bundles/org.eclipse.jface.databinding/src/org/eclipse/jface/internal/databinding/provisional/swt/AbstractSWTVetoableValue.java
private final Widget widget;
	/**
	 * Standard constructor for an SWT VetoableValue.  Makes sure that
	 * the observable gets disposed when the SWT widget is disposed.
	 * 
	 * @param widget
	 */
	protected AbstractSWTVetoableValue(Widget widget) {
		super(SWTObservables.getRealm(widget.getDisplay()));
		this.widget = widget;
		if (widget == null) {
			throw new IllegalArgumentException("The widget parameter is null."); 
		}
		widget.addDisposeListener(disposeListener);
	}
	
	private DisposeListener disposeListener = new DisposeListener() {
		public void widgetDisposed(DisposeEvent e) {
			AbstractSWTVetoableValue.this.dispose();
		}
	};
	/**
	 * @return Returns the widget.
	 */
	public Widget getWidget() {
		return widget;
	}
}