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      1 /*
      2  * Copyright (C) 2010 ZXing authors
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.google.zxing.client.android;
     18 
     19 import com.google.zxing.BinaryBitmap;
     20 import com.google.zxing.DecodeHintType;
     21 import com.google.zxing.MultiFormatReader;
     22 import com.google.zxing.ReaderException;
     23 import com.google.zxing.Result;
     24 import com.google.zxing.common.HybridBinarizer;
     25 
     26 import android.os.Bundle;
     27 import android.os.Handler;
     28 import android.os.Looper;
     29 import android.os.Message;
     30 import android.util.Log;
     31 
     32 import java.util.Hashtable;
     33 
     34 final class DecodeHandler extends Handler {
     35 
     36   private static final String TAG = DecodeHandler.class.getSimpleName();
     37 
     38   private final CaptureActivity activity;
     39   private final MultiFormatReader multiFormatReader;
     40   private boolean running = true;
     41 
     42   DecodeHandler(CaptureActivity activity, Hashtable<DecodeHintType,Object> hints) {
     43     multiFormatReader = new MultiFormatReader();
     44     multiFormatReader.setHints(hints);
     45     this.activity = activity;
     46   }
     47 
     48   @Override
     49   public void handleMessage(Message message) {
     50     if (!running) {
     51       return;
     52     }
     53     if (message.what == R.id.decode) {
     54       decode((byte[]) message.obj, message.arg1, message.arg2);
     55     } else if (message.what == R.id.quit) {
     56       running = false;
     57       Looper.myLooper().quit();
     58     }
     59   }
     60 
     61   /**
     62    * Decode the data within the viewfinder rectangle, and time how long it took. For efficiency,
     63    * reuse the same reader objects from one decode to the next.
     64    *
     65    * @param data   The YUV preview frame.
     66    * @param width  The width of the preview frame.
     67    * @param height The height of the preview frame.
     68    */
     69   private void decode(byte[] data, int width, int height) {
     70     long start = System.currentTimeMillis();
     71     Result rawResult = null;
     72     PlanarYUVLuminanceSource source = activity.getCameraManager().buildLuminanceSource(data, width, height);
     73     if (source != null) {
     74       BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
     75       try {
     76         rawResult = multiFormatReader.decodeWithState(bitmap);
     77       } catch (ReaderException re) {
     78         // continue
     79       } finally {
     80         multiFormatReader.reset();
     81       }
     82     }
     83 
     84     Handler handler = activity.getHandler();
     85     if (rawResult != null) {
     86       // Don't log the barcode contents for security.
     87       long end = System.currentTimeMillis();
     88       Log.d(TAG, "Found barcode in " + (end - start) + " ms");
     89       if (handler != null) {
     90         Message message = Message.obtain(handler, R.id.decode_succeeded, rawResult);
     91         Bundle bundle = new Bundle();
     92         bundle.putParcelable(DecodeThread.BARCODE_BITMAP, source.renderCroppedGreyscaleBitmap());
     93         message.setData(bundle);
     94         message.sendToTarget();
     95       }
     96     } else {
     97       if (handler != null) {
     98         Message message = Message.obtain(handler, R.id.decode_failed);
     99         message.sendToTarget();
    100       }
    101     }
    102   }
    103 
    104 }
    105