Bug 315281 update copyrights for 3.6
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/NavigatorActivationService.java
}
	/**
	 * Request notification when the activation state changes for the given
	 * viewer id.
	 * 
	 * @param aListener
	 *            An implementation of {@link IExtensionActivationListener}
	 */
	public void addExtensionActivationListener(
			IExtensionActivationListener aListener) {
		listeners.add(aListener);
	}
	/**
	 * No longer receive notification when activation state changes.
	 * 
	 * @param aListener
	 *            An implementation of {@link IExtensionActivationListener}
	 */
	public void removeExtensionActivationListener(
			IExtensionActivationListener aListener) {
		listeners.remove(aListener);
	}
	private void notifyListeners(String[] navigatorExtensionIds,
			boolean toEnable) {
		
		if(navigatorExtensionIds != null) { 
			if(navigatorExtensionIds.length > 1)
				Arrays.sort(navigatorExtensionIds);
			
			Object[] listenerArray = listeners.getListeners();