content: /*
   * Copyright (C) 2008 ZXing authors
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.google.zxing.decoding;
  
  import android.os.Handler;
  import android.os.Looper;
  
  import com.google.zxing.BarcodeFormat;
  import com.google.zxing.DecodeHintType;
  import com.google.zxing.ResultPointCallback;
  import com.google.zxing.activity.CaptureActivity;
  
  import java.util.Hashtable;
  import java.util.Vector;
  import java.util.concurrent.CountDownLatch;
  
  /**
   * This thread does all the heavy lifting of decoding the images.
   * �����߳�
   */
  final class DecodeThread extends Thread {
  
      public static final String BARCODE_BITMAP = "barcode_bitmap";
      private final CaptureActivity activity;
      private final Hashtable<DecodeHintType, Object> hints;
      private Handler handler;
      private final CountDownLatch handlerInitLatch;
  
      DecodeThread(CaptureActivity activity,
                   Vector<BarcodeFormat> decodeFormats,
                   String characterSet,
                   ResultPointCallback resultPointCallback) {
  
          this.activity = activity;
          handlerInitLatch = new CountDownLatch(1);
  
          hints = new Hashtable<DecodeHintType, Object>(3);
  
          if (decodeFormats == null || decodeFormats.isEmpty()) {
              decodeFormats = new Vector<BarcodeFormat>();
              decodeFormats.addAll(DecodeFormatManager.ONE_D_FORMATS);
              decodeFormats.addAll(DecodeFormatManager.QR_CODE_FORMATS);
              decodeFormats.addAll(DecodeFormatManager.DATA_MATRIX_FORMATS);
          }
  
          hints.put(DecodeHintType.POSSIBLE_FORMATS, decodeFormats);
  
          if (characterSet != null) {
              hints.put(DecodeHintType.CHARACTER_SET, characterSet);
          }
  
          hints.put(DecodeHintType.NEED_RESULT_POINT_CALLBACK, resultPointCallback);
      }
  
      Handler getHandler() {
          try {
              handlerInitLatch.await();
          } catch (InterruptedException ie) {
              // continue?
          }
          return handler;
      }
  
      @Override
      public void run() {
          Looper.prepare();
          handler = new DecodeHandler(activity, hints);
          handlerInitLatch.countDown();
          Looper.loop();
      }
  
  }
  