camera.java

A J2ME Weblog Client for mobile devices that allows you to post to your weblog from java-enabled dev

/*
 * Copyright (C) 2004 MobileBlogger Development Team
 */
package net.sourceforge.mobileblogger;

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

public class Camera extends Form implements CommandListener {
  private MIDlet midlet;
  private Display display;


  private Command mExitCommand, mCameraCommand;
  private Command mBackCommand, mCaptureCommand;

  private Player mPlayer;
  private VideoControl mVideoControl;

  /*********************/
  public Camera(MIDlet m, Display d) {
	  super("Photo Blogging");
	  midlet = m;
	  display = d;

      mExitCommand = new Command("Exit", Command.EXIT, 0);
      mCameraCommand = new Command("Camera", Command.SCREEN, 0);
      mBackCommand = new Command("Back", Command.BACK, 0);
      mCaptureCommand = new Command("Capture", Command.SCREEN, 0);
      addCommand(mBackCommand);

    String supports = System.getProperty("video.snapshot.encodings");
    if (supports != null && supports.length() > 0) {
      append("Ready to take pictures.");
      addCommand(mCameraCommand);
    }
    else
      append("Mobile Blogger cannot use this " +
          "device to take pictures.");
    setCommandListener(this);
  }

  /*********************/
  public void commandAction(Command c, Displayable s) {
    if (c.getCommandType() == Command.EXIT) {
      display.setCurrent( new Menu(midlet, display) );
    }
    else if (c == mCameraCommand)
      showCamera();
    else if (c == mBackCommand)
      display.setCurrent( new Menu(midlet, display) );
    else if (c == mCaptureCommand) {
      capture();
    }
  }

  /******************/
  private void showCamera() {
    try {
      mPlayer = Manager.createPlayer("capture://video");
      mPlayer.realize();

      mVideoControl = (VideoControl)mPlayer.getControl("VideoControl");

      Canvas canvas = new CameraCanvas(midlet, mVideoControl, this);
      canvas.addCommand(mBackCommand);
      canvas.addCommand(mCaptureCommand);
      canvas.setCommandListener(this);
      display.setCurrent(canvas);

      mPlayer.start();
    }
    catch (IOException ioe) { handleException(ioe); }
    catch (MediaException me) { handleException(me); }
  }

 /*******************/
  public void capture() {
    try {
      // Get the image.
      byte[] raw = mVideoControl.getSnapshot(null);
      Image image = Image.createImage(raw, 0, raw.length);

      Image thumb = createThumbnail(image);

      // Place it in the main form.
      if (size() > 0 && get(0) instanceof StringItem)
        delete(0);
      append(thumb);

      // Flip back to the main form.
      display.setCurrent(this);

      // Shut down the player.
      mPlayer.close();
      mPlayer = null;
      mVideoControl = null;
    }
    catch (MediaException me) { handleException(me); }
  }
  private void handleException(Exception e) {
    Alert a = new Alert("Exception", e.toString(), null, null);
    a.setTimeout(50);
    append("Mobile Blogger cannot use this " +
          "device to take pictures. Press Back.");

    //display.setCurrent( new Menu(midlet, display) );
  }

  /********************/
  private Image createThumbnail(Image image) {
    int sourceWidth = image.getWidth();
    int sourceHeight = image.getHeight();

    int thumbWidth = 64;
    int thumbHeight = -1;

    if (thumbHeight == -1)
      thumbHeight = thumbWidth * sourceHeight / sourceWidth;

    Image thumb = Image.createImage(thumbWidth, thumbHeight);
    Graphics g = thumb.getGraphics();

    for (int y = 0; y < thumbHeight; y++) {
      for (int x = 0; x < thumbWidth; x++) {
        g.setClip(x, y, 1, 1);
        int dx = x * sourceWidth / thumbWidth;
        int dy = y * sourceHeight / thumbHeight;
        g.drawImage(image, x - dx, y - dy, Graphics.LEFT | Graphics.TOP);
      }
    }

    Image immutableThumb = Image.createImage(thumb);

    return immutableThumb;
  }
}