Bug 198904 [DataBinding] Listeners in swt Observables are not removed on dispose
tests/org.eclipse.jface.tests.databinding/src/org/eclipse/jface/tests/internal/databinding/internal/swt/TextObservableValueTest.java
assertEquals(1, listener.count);
		
		text.setText(value);
		assertEquals("listener not notified", 1, listener.count);
	}
	
	/**
	 * https://bugs.eclipse.org/bugs/show_bug.cgi?id=171132
	 * 
	 * @throws Exception
	 */
	public void testGetValueBeforeFocusOutChangeEventsFire() throws Exception {
		TextObservableValue observableValue = new TextObservableValue(text, SWT.FocusOut);
		observableValue.addValueChangeListener(listener);
		
		String a = "a";
		String b = "b";
		
		text.setText(a);
		assertEquals(a, observableValue.getValue()); 
		
		text.setText(b);
		text.notifyListeners(SWT.FocusOut, null);
		
		assertEquals(1, listener.count);
		assertEquals(a, listener.event.diff.getOldValue());
		assertEquals(b, listener.event.diff.getNewValue());
	}
}