/*
* Copyright 2003-2010 Tufts University  Licensed under the
 * Educational Community 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.osedu.org/licenses/ECL-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 tufts.vue.gui;

import java.awt.*;
import java.awt.event.*;

import java.io.Serializable;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;

import javax.swing.JComponent;
import javax.swing.Timer;


class Autoscroller extends MouseAdapter implements Serializable
{
	transient MouseEvent event;
	transient Timer timer;
	TimedASComponent component;


	Autoscroller(TimedASComponent c) {
		if (c == null) {
			throw new IllegalArgumentException("component must be non null");
		}
		component = c;
		timer = new Timer(tufts.vue.VueResources.getInt("autoscroller.delay"), new AutoScrollTimerAction());

		component.addMouseListener(this);
	}

	class AutoScrollTimerAction implements ActionListener {
		public void actionPerformed(ActionEvent x) {

			if(!component.isShowing() || (event == null)) {
				stop();
				return;
			}
			Point screenLocation = component.getLocationOnScreen();
			MouseEvent e = new MouseEvent(component, event.getID(),
					event.getWhen(), event.getModifiers(),
					event.getX() - screenLocation.x,
					event.getY() - screenLocation.y,
					event.getClickCount(), event.isPopupTrigger());
			component.superProcessMouseMotionEvent(e);

		}
	}

	void stop() {
		timer.stop();
		event = null;
	}

	void dispose() {
		stop();
		component.removeMouseListener(this);
	}

	public void mouseReleased(MouseEvent e) {
		stop();
	}

	public void mouseDragged(MouseEvent e) {
		Rectangle visibleRect = component.getVisibleRect();
		boolean contains = visibleRect.contains(e.getX(), e.getY());

		if (contains) {
			if (timer.isRunning()) {
				stop();
			}
		} else {
			Point screenLocation = component.getLocationOnScreen();

			event = new MouseEvent(component, e.getID(), e.getWhen(), e.getModifiers(),
					e.getX() + screenLocation.x,
					e.getY() + screenLocation.y,
					e.getClickCount(), e.isPopupTrigger());
			if (!timer.isRunning()) {
				timer.start();
			}
		}
	}

	private void writeObject(ObjectOutputStream s) throws IOException {
		s.defaultWriteObject();
	}

	private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException 
	{
		s.defaultReadObject();
		timer = new Timer(100, new AutoScrollTimerAction());
	}
}