CaptureActivity.java

package com.zxing.activity;

import java.io.IOException;
import java.util.Vector;

import android.app.Activity;
import android.content.Intent;
import android.content.res.AssetFileDescriptor;
import android.graphics.Bitmap;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.os.Bundle;
import android.os.Handler;
import android.os.Vibrator;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;
import android.view.Window;
import android.widget.Toast;

import com.ericssonlabs.R;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.Result;
import com.zxing.camera.CameraManager;
import com.zxing.decoding.CaptureActivityHandler;
import com.zxing.decoding.CaptureActivityHandler.DecodeCallback;
import com.zxing.decoding.InactivityTimer;
import com.zxing.view.ViewfinderView;
/**
 * Initial the camera
 * @author Ryan.Tang
 * @modifier Lemon
 * @use extends CaptureActivity并且在setContentView方法后调用init方法
 */
public abstract class CaptureActivity extends Activity implements Callback, DecodeCallback {
	//	private static final String TAG = "CaptureActivity";

	protected Activity context;
	protected SurfaceView surfaceView;
	protected ViewfinderView viewfinderView;
	/**初始化，必须在setContentView之后
	 * @param context
	 * @param viewfinderView
	 */
	protected void init(Activity context, SurfaceView surfaceView, ViewfinderView viewfinderView) {
		this.context = context;
		this.surfaceView = surfaceView;
		this.viewfinderView = viewfinderView;

		CameraManager.init(getApplication());

		hasSurface = false;
		inactivityTimer = new InactivityTimer(this);
	}
	
	private boolean isOn = false;
	protected final boolean isOn() {
		return isOn;
	}
	/**打开或关闭闪关灯
	 * @param open
	 */
	protected void switchLight(boolean on) {
		if (on == isOn()) {
			return;
		}
		isOn = CameraManager.get().switchLight(on);
	}
	

	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		requestWindowFeature(Window.FEATURE_NO_TITLE);
	}


	private CaptureActivityHandler handler;
	private boolean hasSurface;
	private Vector<BarcodeFormat> decodeFormats;
	private String characterSet;
	private InactivityTimer inactivityTimer;
	private MediaPlayer mediaPlayer;
	private boolean playBeep;
	private static final float BEEP_VOLUME = 0.10f;
	private boolean vibrate;


	@Override
	protected void onResume() {
		super.onResume();
		SurfaceHolder surfaceHolder = surfaceView.getHolder();
		if (hasSurface) {
			initCamera(surfaceHolder);
		} else {
			surfaceHolder.addCallback(this);
			surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
		}
		decodeFormats = null;
		characterSet = null;

		playBeep = true;
		AudioManager audioService = (AudioManager) getSystemService(AUDIO_SERVICE);
		if (audioService.getRingerMode() != AudioManager.RINGER_MODE_NORMAL) {
			playBeep = false;
		}
		initBeepSound();
		vibrate = true;
	}

	@Override
	protected void onPause() {
		super.onPause();
		if (handler != null) {
			handler.quitSynchronously();
			handler = null;
		}
		isOn = false;
		CameraManager.get().closeDriver();
	}
	

	@Override
	protected void onDestroy() {
		inactivityTimer.shutdown();
		super.onDestroy();
	}


	public static final String RESULT_QRCODE_STRING = "RESULT_QRCODE_STRING";
	/**
	 * Handler scan result
	 * @param result
	 * @param barcode
	 */
	public void handleDecode(Result result, Bitmap barcode) {
		inactivityTimer.onActivity();
		playBeepSoundAndVibrate();
		String resultString = result.getText();
		//FIXME
		if (resultString.equals("")) {
			Toast.makeText(CaptureActivity.this, "Scan failed!", Toast.LENGTH_SHORT).show();
		}

		setResult(RESULT_OK, new Intent().putExtra(RESULT_QRCODE_STRING, resultString));
		finish();
	}

	private void initCamera(SurfaceHolder surfaceHolder) {
		try {
			CameraManager.get().openDriver(surfaceHolder);
		} catch (IOException ioe) {
			return;
		} catch (RuntimeException e) {
			return;
		}
		if (handler == null) {
			handler = new CaptureActivityHandler(this, decodeFormats,
					characterSet, viewfinderView, this);
		}
	}

	@Override
	public void drawViewfinder() {
		viewfinderView.drawViewfinder();		
	}


	@Override
	public void surfaceChanged(SurfaceHolder holder, int format, int width,
			int height) {

	}

	@Override
	public void surfaceCreated(SurfaceHolder holder) {
		if (!hasSurface) {
			hasSurface = true;
			initCamera(holder);
		}

	}

	@Override
	public void surfaceDestroyed(SurfaceHolder holder) {
		hasSurface = false;

	}


	public Handler getHandler() {
		return handler;
	}


	private void initBeepSound() {
		if (playBeep && mediaPlayer == null) {
			// The volume on STREAM_SYSTEM is not adjustable, and users found it
			// too loud,
			// so we now play on the music stream.
			setVolumeControlStream(AudioManager.STREAM_MUSIC);
			mediaPlayer = new MediaPlayer();
			mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
			mediaPlayer.setOnCompletionListener(beepListener);

			AssetFileDescriptor file = getResources().openRawResourceFd(
					R.raw.beep);
			try {
				mediaPlayer.setDataSource(file.getFileDescriptor(),
						file.getStartOffset(), file.getLength());
				file.close();
				mediaPlayer.setVolume(BEEP_VOLUME, BEEP_VOLUME);
				mediaPlayer.prepare();
			} catch (IOException e) {
				mediaPlayer = null;
			}
		}
	}

	private static final long VIBRATE_DURATION = 200L;

	private void playBeepSoundAndVibrate() {
		if (playBeep && mediaPlayer != null) {
			mediaPlayer.start();
		}
		if (vibrate) {
			Vibrator vibrator = (Vibrator) getSystemService(VIBRATOR_SERVICE);
			vibrator.vibrate(VIBRATE_DURATION);
		}
	}

	/**
	 * When the beep has finished playing, rewind to queue up another one.
	 */
	private final OnCompletionListener beepListener = new OnCompletionListener() {
		public void onCompletion(MediaPlayer mediaPlayer) {
			mediaPlayer.seekTo(0);
		}
	};

}