/****************************************************************************** * Compilation: javac MovingJoker.java * Execution: java MovingJoker * Dependencies: Draw.java DrawListener.java joker.gif * * Display the joker and move it when the user types one of the * keys 'i', 'j', 'k', or 'l'. * ******************************************************************************/ import java.awt.Color; public class MovingJoker implements DrawListener { private Draw draw = new Draw(); private double x = 0.5, y = 0.5; public MovingJoker() { draw.addListener(this); draw.enableDoubleBuffering(); draw.clear(Color.GRAY); draw.picture(x, y, "joker.gif"); draw.text(.5, .1, "Press 'i', 'j', 'k' or 'l' to move"); draw.show(); draw.pause(10); } // this method is called whenever a key is typed in the Draw window public void keyTyped(char c) { if (c == 'i') y += 0.02; // up else if (c == 'j') x -= 0.02; // left else if (c == 'k') y -= 0.02; // down else if (c == 'l') x += 0.02; // right x = (1 + x) % 1; // periodic boundary conditions y = (1 + y) % 1; draw.clear(Color.GRAY); draw.picture(x, y, "joker.gif"); draw.show(); draw.pause(10); } // test client public static void main(String[] args) { MovingJoker m = new MovingJoker(); } }