/*

$Id: AnimationSample.java,v 1.4 1999/08/11 16:26:02 gjb Exp $
----------------------------------------------------------------------
yasuhara@cs.washington.edu, badros@cs.washington.edu
CSE 341, Assignment 6
August 1999

*/


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

import AnimationApplet;

/** AnimationSample is a demonstration applet exercising the
	AnimationApplet framework. */
public class AnimationSample
	extends AnimationApplet {

	///////////////////////// variables

	Ball ball;

	// default window title, size when running from main
	static protected final String mainWindowTitle = "AnimationSample";
	static protected final int defaultWidth = 300,	defaultHeight = 300;

	///////////////////////// methods

	// 
	// constructors
	//

	public AnimationSample() {
		super();
		initFields();
	}


	public AnimationSample(int w, int h) {
		super(w,h);
		initFields();
	}

	private void initFields() {
		ball = new Ball(width/2, height/2, 5, Color.red, -2, 3);
	}

	//
	// AnimationApplet overrides
	//

	public void prepareNextFrame() {
		ball.move();
		
		if (ball.x < 0 || ball.x > width) {
			ball.dx = -ball.dx;

			if (ball.x < 0) 
				ball.x = 0;
			else
				ball.x = width;
		}

		if (ball.y < 0 || ball.y > height) {
			ball.dy = -ball.dy;

			if (ball.y < 0) 
				ball.y = 0;
			else
				ball.y = height;
		}

		ball.accelerate(0, 1);
	}		

	public void drawNextFrame(Graphics g) {
		g.setColor(getBackground());
		g.fillRect(0, 0, width, height);
		ball.paint(g);
	}

	public void keyPressed(KeyEvent ke) {
		super.keyPressed(ke);
		switch (ke.getKeyChar()) {
		case '+':
			sleepTime += 10;
			if (debug)
				System.out.println("sleepTime = " + sleepTime);
			break;

		case '-':
			if (sleepTime > 10) 
				sleepTime -= 10;
			if (debug)
				System.out.println("sleepTime = " + sleepTime);
			break;
		}
	}

	///////////////////////// main

	public static void main(String[] args) {
		AnimationSample applet = 
								new AnimationSample(defaultWidth,defaultHeight);
		applet.init();
		applet.startInFrame();
	}

	public void startInFrame() {
		Frame frame = new Frame(mainWindowTitle);
		frame.setSize(defaultWidth, defaultHeight);
		frame.add("Center", this);
		frame.show();
		start();
	}
}



class Ball {
	// position, radius, velocity components, color
	public int x, y, radius, dx, dy;
	public Color color;

	public Ball(int x, int y, int radius, Color color,
				int dx, int dy) {
		this.x = x;
		this.y = y;
		this.radius = radius;
		this.color = color;
		this.dx = dx;
		this.dy = dy;
	} 

	public void paint(Graphics g) {
		g.setColor(color);
		g.fillOval(x - radius, y - radius, 
				   radius * 2, radius * 2);
	}

	public void move() {
		x += dx;
		y += dy;
		//System.out.println(x + ", " + y);
	}

	public void accelerate(int ddx, int ddy) {
		dx += ddx;
		dy += ddy;
	}
}

/* Local Variables: */
/* tab-width: 4 */
/* c-basic-offset: 4 */
/* End: */