Pileus Git - ~andy/freeotp/blob - src/org/fedorahosted/freeotp/DecodeAsyncTask.java

   1 /*
   2  * FreeOTP
   3  *
   4  * Authors: Nathaniel McCallum <npmccallum@redhat.com>
   5  *
   6  * Copyright (C) 2013  Nathaniel McCallum, Red Hat
   7  *
   8  * Licensed under the Apache License, Version 2.0 (the "License");
   9  * you may not use this file except in compliance with the License.
  10  * You may obtain a copy of the License at
  11  *
  12  *     http://www.apache.org/licenses/LICENSE-2.0
  13  *
  14  * Unless required by applicable law or agreed to in writing, software
  15  * distributed under the License is distributed on an "AS IS" BASIS,
  16  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  17  * See the License for the specific language governing permissions and
  18  * limitations under the License.
  19  */
  20
  21 package org.fedorahosted.freeotp;
  22
  23 import java.util.concurrent.BlockingQueue;
  24 import java.util.concurrent.LinkedBlockingQueue;
  25
  26 import android.hardware.Camera;
  27 import android.hardware.Camera.PreviewCallback;
  28 import android.os.AsyncTask;
  29
  30 import com.google.zxing.BinaryBitmap;
  31 import com.google.zxing.ChecksumException;
  32 import com.google.zxing.FormatException;
  33 import com.google.zxing.LuminanceSource;
  34 import com.google.zxing.NotFoundException;
  35 import com.google.zxing.PlanarYUVLuminanceSource;
  36 import com.google.zxing.Reader;
  37 import com.google.zxing.Result;
  38 import com.google.zxing.common.HybridBinarizer;
  39 import com.google.zxing.qrcode.QRCodeReader;
  40
  41 public class DecodeAsyncTask extends AsyncTask<Void, Void, String> implements PreviewCallback {
  42         private static class Data {
  43                 public byte[] data;
  44                 Camera.Size size;
  45         }
  46
  47         private final BlockingQueue<Data> mBlockingQueue;
  48         private final Reader mReader;
  49
  50         public DecodeAsyncTask() {
  51                 mBlockingQueue = new LinkedBlockingQueue<Data>(5);
  52                 mReader = new QRCodeReader();
  53         }
  54
  55         @Override
  56         protected String doInBackground(Void... args) {
  57                 while (true) {
  58                         try {
  59                                 Data data = mBlockingQueue.take();
  60                                 LuminanceSource ls = new PlanarYUVLuminanceSource(data.data,
  61                                                                         data.size.width, data.size.height, 0, 0,
  62                                                                         data.size.width, data.size.height, false);
  63                                 Result r = mReader.decode(new BinaryBitmap(new HybridBinarizer(ls)));
  64                                 return r.getText();
  65                         } catch (InterruptedException e) {
  66                                 return null;
  67                         } catch (NotFoundException e) {
  68                         } catch (ChecksumException e) {
  69                         } catch (FormatException e) {
  70                         } catch (ArrayIndexOutOfBoundsException e) {
  71                         } finally {
  72                                 mReader.reset();
  73                         }
  74                 }
  75         }
  76
  77         @Override
  78         public void onPreviewFrame(byte[] data, Camera camera) {
  79                 Data d = new Data();
  80                 d.data = data;
  81                 d.size = camera.getParameters().getPreviewSize();
  82                 mBlockingQueue.offer(d);
  83         }
  84 }