Bug 126839 [DataBinding] IObservable refactoring
bundles/org.eclipse.jface.databinding/src/org/eclipse/jface/internal/databinding/swt/CComboUpdatableValue.java
/**
	 * 
	 */
	private final CCombo ccombo;
	private final String attribute;
	private boolean updating = false;
	/**
	 * @param ccombo
	 * @param attribute
	 */
	public CComboUpdatableValue(CCombo ccombo, String attribute) {
		this.ccombo = ccombo;
		this.attribute = attribute;
		if (attribute.equals(ViewersProperties.CONTENT)) {
			attribute = SWTProperties.TEXT;
		}
		if (attribute.equals(SWTProperties.SELECTION) || 
			attribute.equals(SWTProperties.TEXT)) {
			ccombo.addModifyListener(new ModifyListener() {
				public void modifyText(ModifyEvent e) {
					if (!updating) {
						fireChangeEvent(ChangeEvent.CHANGE, null, null);
					}
				}
			});
		} else {
			throw new IllegalArgumentException();
		}