Computer Science 252
Problem Solving with Java

Spring 2014, The College of Saint Rose

Home     Syllabus     Schedule     Examples     Style Guide

PatheticPong Demo

A working demo of PatheticPong will appear below. Click inside the applet to interact with it.

PatheticPong BlueJ Project

Click here to download a BlueJ project for PatheticPong.

PatheticPong Source Code

The Java source code for PatheticPong is below. Click on a file name to download it.

PatheticPong.java

import objectdraw.*;
import java.awt.*;

/*
 * Example PatheticPong: a too-simple "Pong" game that features
 * a paddle and a falling ball that, sadly, do not interact.
 *
 * Jim Teresco, Siena College, CSIS 120, Spring 2011
 * The College of Saint Rose, Fall 2013
 * Based on similar example from CSCI 134, Williams College
 *
 * $Id: PatheticPong.java 2218 2013-10-18 14:06:39Z terescoj $
 */

public class PatheticPong extends WindowController {

    // position and dimensions of the court
    private static final int COURT_LEFT = 50;
    private static final int COURT_TOP = 50;
    private static final int COURT_HEIGHT = 300;
    private static final int COURT_WIDTH = 300;
    private static final int COURT_RIGHT = COURT_LEFT + COURT_WIDTH;

    // dimensions of the paddle
    private static final int PADDLE_WIDTH = 50;
    private static final int PADDLE_HEIGHT = 20;

    private static final int PADDLE_Y = COURT_TOP + COURT_HEIGHT - PADDLE_HEIGHT - 1;

    private FilledRect paddle;
    private FramedRect boundary; // the boundary of the playing area.

    public void begin() {
        // make the playing area
        boundary = new FramedRect(COURT_LEFT, COURT_TOP,
            COURT_WIDTH, COURT_HEIGHT,
            canvas);

        // make the paddle
        paddle = new FilledRect(COURT_LEFT + (COURT_WIDTH-PADDLE_WIDTH)/2,
            PADDLE_Y, PADDLE_WIDTH, PADDLE_HEIGHT,
            canvas);
    }

    // create a new falling ball
    public void onMousePress(Location point) {

        // create the ball at the top of the playing area
        // at the mouse point's x coordinate
        if (boundary.contains(point)) {
            new FallingBall(new Location(point.getX(), COURT_TOP), canvas);
        }
    }

    // move the paddle to follow the mouse's x coordinate
    public void onMouseMove(Location point) {

        if (point.getX() < COURT_LEFT) {
            // place paddle at left edge of the court
            paddle.moveTo(COURT_LEFT, PADDLE_Y);
        } else if (point.getX() + PADDLE_WIDTH > COURT_RIGHT) {
            // place paddle at right edge of the court
            paddle.moveTo(COURT_RIGHT - PADDLE_WIDTH, PADDLE_Y);
        } else {
            // keep the edge of the paddle lined up with the mouse
            paddle.moveTo(point.getX(), PADDLE_Y);
        }

    }
}

FallingBall.java

import objectdraw.*;
import java.awt.*;

/*
 * 
 * A simple active object that controls a ball that falls down the
 * canvas
 *
 * Jim Teresco, Siena College, CSIS 120, Spring 2011
 * The College of Saint Rose, Fall 2013
 *
 * $Id: FallingBall.java 2218 2013-10-18 14:06:39Z terescoj $
 */

public class FallingBall extends ActiveObject {

    // size and speed of falling balls
    private static final int BALLSIZE = 30;
    private static final double Y_SPEED = 8;
    private static final int DELAY_TIME = 33;

    // the ball controlled by this instance
    private FilledOval ball;

    // how far to fall before stopping and disappearing?
    private double yMax;

    // Draw a ball and start it falling.
    public FallingBall(Location start, DrawingCanvas aCanvas) {

        // draw the ball at its initial position
        ball = new FilledOval(start.getX() - BALLSIZE/2,
            start.getY() - BALLSIZE/2,
            BALLSIZE, BALLSIZE, aCanvas);

        // ask the canvas how big it is so we know when to stop
        yMax = aCanvas.getHeight();

        // activate!
        start();
    }

    // move the ball repeatedly until it falls off screen
    public void run() {
        while (ball.getY() <= yMax) {
            ball.move(0, Y_SPEED);
            pause(DELAY_TIME);
        }
        ball.removeFromCanvas();
    }
}