ballcanvas.java

用来测试手机java的音效程序,是我作手机开发的时候写的

/*
 * @(#)BallCanvas.java	1.9 02/08/15 @(#)
 *
 * Copyright (c) 1999-2002 Sun Microsystems, Inc.  All rights reserved.
 * PROPRIETARY/CONFIDENTIAL
 * Use is subject to license terms.
 */

package com.qualcomm.demo.sound;

import javax.microedition.lcdui.*;
import javax.microedition.media.*;
import javax.microedition.media.control.*;

public class BallCanvas extends Canvas implements CommandListener, PlayerListener {

    private Display display;
    private Player player;

    private int[] notes = {68, 72, 70, 74, 76};
    private int[] colors = {0xff, 0xff00, 0xff0000, 0xffff, 0xff00ff};

    // a set of free roaming balls
    private SmallBall[] balls;
    private int numBalls;
    private int width, height;
    private boolean paused;
    private int bg;

    private Command backCommand = new Command("Back", Command.BACK, 1);
    private Command pauseCommand = new Command("Pause", Command.BACK, 1);
    private Command playCommand = new Command("Play", Command.BACK, 1);

    private boolean playerCreated;

    public BallCanvas(Display d, int maxBalls, int bg) {
        display = d;
        this.bg = bg;

        // initialize the array of balls
        balls = new SmallBall[maxBalls];

        width = getWidth();
        height = getHeight();

        playerCreated = initPlayer(bg);

        // Start with one ball
        balls[0] = new SmallBall(this, 0, 0,width,height-12, bg);
        balls[0].setColor(colors[0]);
        numBalls = 1;
        paused = true;

        this.addCommand(backCommand);
        this.addCommand(pauseCommand);
        setCommandListener(this);
    }

    boolean needAlert() {
        return (!playerCreated);
    }


    boolean initPlayer(int bg) {
        try {
            switch (bg) {
            case 1: // wave bg
                player = Manager.createPlayer(BBall.wavbgUrl);
                player.setLoopCount(-1);
                break;
            case 2: // tone seq bg
                {
                    byte d = 8;
                    byte C4 = ToneControl.C4;
                    byte D4 = ToneControl.C4 + 2; // a whole step
                    byte E4 = ToneControl.C4 + 4; // a major third
                    byte G4 = ToneControl.C4 + 7; // a fifth
                    byte rest = ToneControl.SILENCE; // eighth-note rest

                    byte[] mySequence = new byte[] {
                        ToneControl.VERSION, 1,
                            ToneControl.TEMPO, 30,
                            ToneControl.BLOCK_START, 0,
                            E4,d,D4,d,C4,d,D4,d,E4,d,E4,d,E4,d,rest,d,
                            ToneControl.BLOCK_END,0,
                            ToneControl.PLAY_BLOCK,0,
                            D4,d,D4,d,D4,d,rest,d,E4,d,G4,d,G4,d,rest,d,//play "B" section
                            ToneControl.PLAY_BLOCK,0, // content of "A" section
                            D4,d,D4,d,E4,d,D4,d,C4,d,rest,d// play "C" section
                            };
                    player = Manager.createPlayer(Manager.TONE_DEVICE_LOCATOR);
                    player.realize();
                    ToneControl c = (ToneControl)player.getControl("ToneControl");
                    c.setSequence(mySequence);
                    player.setLoopCount(2);
                }
                break;
            case 3: // jts file bg
                player = Manager.createPlayer(BBall.jtsFileUrl);
                player.realize();
                break;
            case 4: // jts stream bg
                player = Manager.createPlayer(BBall.jtsStreamUrl);
                player.realize();
                break;
            default:
                player = null;
            }

            if (player != null) {
                //player.setLoopCount(-1);
                player.addPlayerListener(this);
                player.start();
            }
        } catch (Exception ex) {
            if ( player != null )
                player.close();
            player = null;
            return false;
        }

        return true;
    }

    /**
     * Draws the drawing frame (which also contains the ball) and the
     * controls.
     */
    protected void paint(Graphics g) {
        // Draw the frame
        g.setColor(0xffffff);
        g.fillRect(0,0, width-1, height-1);
        g.setColor(0);
        g.drawRect(0+1,0+1,width-2,height-2);

        // Draw each ball
        for(int i = 0; i < numBalls; i++) {
            balls[i].paint(g);
        }
    }

    /**
     * Handle a pen down event.
     */
    public void keyPressed( int keyCode) {

        int action = getGameAction(keyCode);

        switch (action) {
        case LEFT:
            // Reduce the number of threads
            if (numBalls > 0) {

                // decrement the counter
                numBalls = numBalls - 1;

                // stop the thread and remove the reference to it
                balls[numBalls].stop = true;
                balls[numBalls] = null;
            }
            break;

        case RIGHT:
            // Increase the number of threads
            if (numBalls < balls.length) {

                // create a new ball and start it moving
                balls[numBalls] = new SmallBall(this, 0, 0, width,height-12, bg);
                balls[numBalls].setNote(notes[numBalls]);
                balls[numBalls].setColor(colors[numBalls]);

                new Thread(balls[numBalls]).start();

                // increment the counter
                numBalls = numBalls + 1;
            }
            break;

        case UP:
            // Make them move faster
            SmallBall.faster();
            break;

        case DOWN:
            // Make them move slower
            SmallBall.slower();
            break;
        }
        repaint();
    }

    /**
     * Destroy
     */
    void destroy() {
        // kill all the balls and terminate
        for (int i = 0; i < balls.length; i++) {
            if (balls[i] != null) {
                balls[i].stop = true;
                balls[i] = null;
            }
        }
        numBalls = 0;
        if ( player != null) {
            player.close();
            player = null;
        }
        BBall.getInstance().game = null;
    }


    /*
     * Return whether the canvas is paused or not.
     */
    boolean isPaused() {
        return paused;
    }

    /**
     * Pause the balls by signaling each of them to stop.
     * The ball object still exists and holds the current position
     * of the ball.  It may be restarted later.
     * the current thread will be terminated.
     */
    void pause() {
        if (!paused) {
            paused = true;
            for (int i = 0; i < balls.length && balls[i] != null; i++) {
                balls[i].stop = true;
            }

            try {
                if (player != null)
                    player.stop();
            } catch (MediaException e) {
                // There's nothing much we can do here.
            }
        }
        repaint();
    }

    /*
     * Start creates a new thread for each ball and start it.
     */
    void start() {
        if (paused) {
            paused = false;
            // display.setCurrent(this);
            for (int i = 0; i < balls.length && balls[i] != null; i++) {
                Thread t = new Thread(balls[i]);
                // System.out.println("Ball " + i + " starts...");
                t.start();
            }

            if ( player != null) {
                try {
                    player.start();
                } catch (Exception ex) {}
            }

            repaint();
        }
    }

    public void commandAction(Command c, Displayable s) {
        if (c == backCommand) {
            destroy();
            display.setCurrent(BBall.getList());
        } else if ( c == pauseCommand) {
            pause();
            removeCommand(pauseCommand);
            addCommand(playCommand);
        } else if ( c == playCommand) {
            removeCommand(playCommand);
            addCommand(pauseCommand);
            start();
        }
    }

    public void playerUpdate(Player player, String event, Object eventData)
    {
      if (event == PlayerListener.END_OF_MEDIA)
      {
        System.out.println("END_OF_MEDIA received");
        
        while (numBalls < balls.length)
        {
          // create a new ball and start it moving
          balls[numBalls] = new SmallBall(this, 0, 0, width,height-12, bg);
          balls[numBalls].setNote(notes[numBalls]);
          balls[numBalls].setColor(colors[numBalls]);
          new Thread(balls[numBalls]).start();
          // increment the counter
          numBalls = numBalls + 1;
        }
        
      }
    }
}