/*
 *  "COM.bensoft.widgets" Copyright (C) by Michael Benson - 7/27/97
 *
 *  "ImageAnimator" - rotates through a series of images for
 *				simple animation.
 */

package COM.bensoft.widgets;

import java.awt.*;
import java.applet.Applet;
import java.util.*;
import java.io.*;
import java.net.*;


/**
 * ImageAnimator implements an ImageCanvas which rotates through
 * a sequence of images for simple animation.
 *  
 * @author	Michael Benson
 */
public class ImageAnimator extends ImageCanvas implements Runnable
{
	private Thread	_animator_thread = null;		// Animation thread.
	private Vector	_images;
	private int		_numImages;
	private int		_curImage;
	private int		_sleep;

	/**
	 * ImageAnimator constructor.  The image file name is the base name
	 * of a "family" of files named like this:
	 *  
	 *		codebase/fileN.gif
	 *  
	 * In the above case, the image file name is "file" and the family of
	 * file names would be "file0.gif", "file1.gif", "file2.gif", etc.
	 *
	 * @param	applet		the parent applet (used for code base).
	 * @param	name		base name of image files.
	 * @param	width		width of the image.
	 * @param	height		height of the image.
	 * @param	numImages	number of images in the family.
	 * @param	sleep		number of milliseconds to sleep between images.
	 */
	public ImageAnimator (Applet applet, String name, int width, int height, int numImages, int sleep)
	{
		super(applet, width, height);
		
		_fileName = name;
		_numImages = numImages;
		_images = new Vector();
		_sleep = sleep;
		
		// Initialize the images:
		for (int i = 0;  i < _numImages;  i++) {
			_images.addElement(_applet.getImage(_applet.getCodeBase(), _fileName + i + ".gif"));
		}
		_image = (Image)(_images.elementAt(0));
		_curImage = 0;
	}
		
	/**
	 * Start the animation thread.
	 */
	public void start()
	{
		if (_animator_thread == null) {
			_animator_thread = new Thread(this);
			_animator_thread.setPriority(Thread.MAX_PRIORITY);
			_animator_thread.start();
		}
	}
	
	/**
	 * Stop the animation thread.
	 */
	public void stop()
	{
		if ((_animator_thread != null) && _animator_thread.isAlive()) {
			_animator_thread.stop();
		}
		_animator_thread = null;
	}
	
	/**
	 * Run the animation thread until it is interruped.
	 */
	public void run()
	{
		while (true) {
			if (++_curImage >= _numImages) _curImage = 0;
			setImage((Image)(_images.elementAt(_curImage)));
			try { Thread.sleep(_sleep); }
			catch (InterruptedException e) {}
		}
	}
	
}