ChangeListener.java

/*******************************************************************************
 * Copyright 2011 See AUTHORS file.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 ******************************************************************************/

package com.badlogic.gdx.scenes.scene2d.utils;

import com.badlogic.gdx.scenes.scene2d.Actor;
import com.badlogic.gdx.scenes.scene2d.Event;
import com.badlogic.gdx.scenes.scene2d.EventListener;

/**
 * Listener for {@link ChangeEvent}.
 * 
 * @author Nathan Sweet
 */
abstract public class ChangeListener implements EventListener {
	public boolean handle(Event event) {
		if (!(event instanceof ChangeEvent))
			return false;
		changed((ChangeEvent) event, event.getTarget());
		return false;
	}

	/**
	 * @param actor
	 *            The event target, which is the actor that emitted the change event.
	 */
	abstract public void changed(ChangeEvent event, Actor actor);

	/**
	 * Fired when something in an actor has changed. This is a generic event, exactly what changed in an actor will
	 * vary.
	 * 
	 * @author Nathan Sweet
	 */
	static public class ChangeEvent extends Event {
	}
}