videocanvas.java

一个非常典型的J2ME多媒体应用例子

/*
 *
 * Copyright (c) 2007, Sun Microsystems, Inc.
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *  * Neither the name of Sun Microsystems nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package example.mmademo;

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.media.*;
import javax.microedition.media.control.*;
import java.io.*;

/**
 * Play/Capture Video in a Canvas
 *
 */
public class VideoCanvas extends Canvas
    implements Runnable, CommandListener, PlayerListener {

    private static Player player = null;
    private static boolean isCapturePlayer;
    private int idx = 0;
    private boolean fsmode = false;
    private Display parentDisplay;
    private long duration;
    private long lastTime = -1;
    private Thread sliderThread;
    private Command backCommand = new Command("Back", Command.BACK, 1);
    private Command playCommand = new Command("Play", Command.ITEM, 1);
    private Command snapCommand = new Command("Snapshot", Command.ITEM, 1);
    private Command pauseCommand = new Command("Pause", Command.ITEM, 10);
    private VolumeControl vc;
    private RateControl rc;
    private VideoControl vidc;
    private FramePositioningControl fpc;
    private int CB_Y = 0;   // Control Bar Y location
    private static final int CB_H = 8;   // Control Bar Height
    private static final int TH_W = 6;   // Slider Thumb Width
    private static final int VB_W = 10;  // Video Border Width
    private static final int VB_H = 8;   // Video Border Height
    
    private boolean vis = true;

    private int canvasW;    // Canvas Width
    private int canvasH;    // Canvas Height

    private int videoW;     // Video Display Area Width
    private int videoH;     // Video Display Area Height

    // pause/resume support
    private boolean suspended = false;
    private boolean restartOnResume = false;
    private long restartMediaTime;


    public VideoCanvas(Display parentDisplay) {
        this.idx = 0;
        this.parentDisplay = parentDisplay;
        canvasW = getWidth();
        canvasH = getHeight();
        CB_Y = canvasH - CB_H - VB_H - 20;
        videoW = canvasW - VB_W * 2;
        videoH = CB_Y - VB_H * 2;
        initialize();
    }

    public void paint(Graphics g) {
        // Only video player uses the screen in fullscreen mode
        if (fsmode) return;

        // Draw the GUI and media time slider
        g.setColor(0x9090E0);
        g.fillRect(0, 0, canvasW, canvasH);
        g.setColor(0x202050);
        //Video Border
        g.drawLine(VB_W - 1, VB_H - 1, videoW + VB_W - 1, VB_H - 1);
        g.drawLine(VB_W - 1, VB_H - 1, VB_W - 1, videoH + VB_H - 1);
        //Control Bar
        if (sliderThread != null) {
            g.drawLine(VB_W - 1, CB_Y, videoW + VB_W - 1, CB_Y);
            g.drawLine(VB_W - 1, CB_Y, VB_W - 1, CB_Y + CB_H);
        }
        g.setColor(0xD0D0FF);
        //Video Border
        g.drawLine(videoW + VB_W, VB_H, videoW + VB_W, videoH + VB_H);
        g.drawLine(videoW + VB_W, videoH + VB_H, VB_W, videoH + VB_H);
        //Control Bar
        if (sliderThread != null) {
            g.drawLine(videoW + VB_W, CB_Y + 1,
		       videoW + VB_W, CB_Y + CB_H + 1);
            g.drawLine(videoW + VB_W, CB_Y + CB_H + 1,
		       VB_H, CB_Y + CB_H + 1);
        }
        if (sliderThread != null) {
            int p = time2pix(lastTime);
            g.drawLine(VB_W + p, CB_Y + 1, VB_W + p, CB_Y + CB_H);
            g.drawLine(VB_W + p, CB_Y + 1, VB_W + p + TH_W - 1, CB_Y + 1);
            g.setColor(0x202050);
            g.drawLine(VB_W + p + 1, CB_Y + CB_H, VB_W + p + TH_W, CB_Y + CB_H);
            g.drawLine(VB_W  + p + TH_W, CB_Y + CB_H,
		       VB_W + p + TH_W, CB_Y + 1);
            g.setColor(0xA0A0FF);
            g.fillRect(VB_W + p + 1, CB_Y + 2, TH_W - 2, CB_H - 2);
            g.setColor(0);
            g.drawString("00:00", VB_W, CB_Y + CB_H + 4,
			 Graphics.TOP | Graphics.LEFT);
            g.drawString(time2String(lastTime) + "/" + time2String(duration),
                         VB_W + videoW, CB_Y + CB_H + 4,
                         Graphics.TOP | Graphics.RIGHT);
        }
    }

    private void initialize() {
        addCommand(backCommand);
        addCommand(snapCommand);
        setCommandListener(this);
    }

    private int time2pix(long time) {
        int t2p = (int) ((time * (videoW - 1 - TH_W)) / duration);
        return t2p;
    }

    private String time2String(long time) {
        time = time / 1000000;
        String strTime = "" + (time % 10);
        time = time / 10;
        strTime = (time % 6) + strTime;
        time = time / 6;
        strTime = (time % 10) + ":" + strTime;
        time = time / 10;
        strTime = (time % 6) + strTime;
        time = time / 6;
        return strTime;
    }

    public void run() {
        while (player != null && player.getState() != Player.CLOSED) {         
            try {
                long time = player.getMediaTime();
                if (time2pix(time) != time2pix(lastTime)) {
                    lastTime = time;
                    repaint(VB_W - 2, CB_Y,
    			    videoW + 2, CB_H + 2 + 20);
                }
                // sleep for 250 millis
                // if suspended, sleep until the MIDlet is restarted
                do {
        		    Thread.sleep(250);
                } while (player != null && suspended);
            } catch (Exception e) {
                System.err.println("In run(): "+e);
                break;
            }
    	}
    }

    /*
     * Respond to commands, including back
     */
    public void commandAction(Command c, Displayable s) {
            if (s == this) {
                if (c == backCommand) {
                    close();
                    parentDisplay.setCurrent(VideoTest.getList());
                } else if (vidc != null && c == snapCommand) {
                    doSnapshot();
                } else if (vidc == null && c == pauseCommand) {
                    removeCommand(pauseCommand);
                    addCommand(playCommand);
                    pause();
                } else if (vidc == null && c == playCommand) {
                    start();
                    removeCommand(playCommand);
                    addCommand(pauseCommand);
                }
            }
    }

    /*
     * Process clicking in slider region
     */
    protected void pointerPressed(int x, int y) {
        if (duration == Player.TIME_UNKNOWN || isCapturePlayer)
            return;
        if (y >= CB_Y && y < CB_Y + CB_H) {
            if (x >= VB_W - 2 && x <= VB_W - 2 + videoW) {
                x = x - (VB_W + 1);
                if (x < 0)
		    x = 0;
                if (x > videoW - TH_W)
                    x = videoW - TH_W;
                long time = (duration * x) / (videoW - TH_W);
                try {
                    player.setMediaTime(time);
                } catch (MediaException me) {
		    System.out.println(me);
                }
            }
        }
    }

    protected void pointerDragged(int x, int y) {
        pointerPressed(x, y);
    }

    public void open(String url) {
        try {
            synchronized (this) {
                if ( player == null ) {
                    if (url.startsWith("resource:")) {
                        InputStream ins = getClass().getResourceAsStream(url.substring(9));
            			String ct = Utils.guessContentType(url);
                        player = Manager.createPlayer(ins, ct);
                    } else {
                        player = Manager.createPlayer(url);
                    }
                    player.addPlayerListener(this);
        		    isCapturePlayer = url.startsWith("capture:");
                }
            }
            player.realize();
            if ((vidc = (VideoControl) player.getControl("VideoControl")) != null) {
                vidc.initDisplayMode(VideoControl.USE_DIRECT_VIDEO, this);
                int frameW = vidc.getSourceWidth();
                int frameH = vidc.getSourceHeight();
                // Clip the video to available area
                if (frameW > videoW)
                    frameW = videoW;
                if (frameH > videoH)
                    frameH = videoH;
                int frameX = (videoW - frameW) / 2 + VB_W;
                int frameY = (videoH - frameH) / 2 + VB_H;
                vidc.setDisplayLocation(frameX, frameY);
                vidc.setDisplaySize(frameW, frameH);
                vidc.setVisible(true);
            }
            Control [] controls = player.getControls();