tests/org.eclipse.jface.tests.databinding.conformance/src/org/eclipse/jface/databinding/conformance/util/SetChangeEventTracker.java

package org.eclipse.jface.databinding.conformance.util;

import java.util.List;

import org.eclipse.core.databinding.observable.set.IObservableSet;
import org.eclipse.core.databinding.observable.set.ISetChangeListener;
import org.eclipse.core.databinding.observable.set.SetChangeEvent;

public class SetChangeEventTracker implements ISetChangeListener {
	public int count;

	public SetChangeEvent event;

	/**
	 * Queue that the listener will add itself too when it is notified of an
	 * event. Used to determine order of notifications of listeners.
	 */
	public final List listenerQueue;

	public SetChangeEventTracker() {
		this(null);
	}

	public SetChangeEventTracker(List notificationQueue) {
		this.listenerQueue = notificationQueue;
	}

	public void handleSetChange(SetChangeEvent event) {
		count++;
		this.event = event;
		if (listenerQueue != null) {
			listenerQueue.add(this);
		}
	}
	
	/**
	 * Convenience method to register a new listener.
	 * 
	 * @param observable
	 * @return tracker
	 */
	public static SetChangeEventTracker observe(IObservableSet observable) {
		SetChangeEventTracker tracker = new SetChangeEventTracker();
		observable.addSetChangeListener(tracker);
		return tracker;
	}
}