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
17package com.google.zxing.client.android;
18
19import com.google.zxing.BinaryBitmap;
20import com.google.zxing.DecodeHintType;
21import com.google.zxing.MultiFormatReader;
22import com.google.zxing.ReaderException;
23import com.google.zxing.Result;
24import com.google.zxing.common.HybridBinarizer;
25
26import android.os.Bundle;
27import android.os.Handler;
28import android.os.Looper;
29import android.os.Message;
30import android.util.Log;
31
32import java.util.Hashtable;
33
34final 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