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.app.Activity;
  import android.content.Intent;
  import android.graphics.Bitmap;
  import android.net.Uri;
  import android.os.Bundle;
  import android.os.Handler;
  import android.os.Message;
  import android.util.Log;
  
  import com.google.zxing.BarcodeFormat;
  import com.google.zxing.R;
  import com.google.zxing.Result;
  import com.google.zxing.activity.CaptureActivity;
  import com.google.zxing.camera.CameraManager;
  import com.google.zxing.view.ViewfinderResultPointCallback;
  
  import java.util.Vector;
  
  
  /**
   * This class handles all the messaging which comprises the state machine for capture.
   */
  public final class CaptureActivityHandler extends Handler {
  
      private static final String TAG = CaptureActivityHandler.class.getSimpleName();
  
      private final CaptureActivity activity;
      private final DecodeThread decodeThread;
      private State state;
  
      private enum State {
          PREVIEW,
          SUCCESS,
          DONE
      }
  
      public CaptureActivityHandler(CaptureActivity activity, Vector<BarcodeFormat> decodeFormats,
                                    String characterSet) {
          this.activity = activity;
          decodeThread = new DecodeThread(activity, decodeFormats, characterSet,
                  new ViewfinderResultPointCallback(activity.getViewfinderView()));
          decodeThread.start();
          state = State.SUCCESS;
          // Start ourselves capturing previews and decoding.
          CameraManager.get().startPreview();
          restartPreviewAndDecode();
      }
  
      @Override
      public void handleMessage(Message message) {
          int id = message.what;
          if (id == R.id.auto_focus) {
              //Log.d(TAG, "Got auto-focus message");
              // When one auto focus pass finishes, start another. This is the closest thing to
              // continuous AF. It does seem to hunt a bit, but I'm not sure what else to do.
              if (state == State.PREVIEW) {
                  CameraManager.get().requestAutoFocus(this, R.id.auto_focus);
              }
          } else if (id == R.id.restart_preview) {
              Log.d(TAG, "Got restart preview message");
              restartPreviewAndDecode();
          } else if (id == R.id.decode_succeeded) {
              Log.d(TAG, "Got decode succeeded message");
              state = State.SUCCESS;
              Bundle bundle = message.getData();
  
              /***********************************************************************/
              Bitmap barcode = bundle == null ? null :
                      (Bitmap) bundle.getParcelable(DecodeThread.BARCODE_BITMAP);//���ñ����߳�
  
              activity.handleDecode((Result) message.obj, barcode);//���ؽ��
              /***********************************************************************/
          } else if (id == R.id.decode_failed) {
              // We're decoding as fast as possible, so when one decode fails, start another.
              state = State.PREVIEW;
              CameraManager.get().requestPreviewFrame(decodeThread.getHandler(), R.id.decode);
          } else if (id == R.id.return_scan_result) {
              Log.d(TAG, "Got return scan result message");
              activity.setResult(Activity.RESULT_OK, (Intent) message.obj);
              activity.finish();
          } else if (id == R.id.launch_product_query) {
              Log.d(TAG, "Got product query message");
              String url = (String) message.obj;
              Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
              intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
              activity.startActivity(intent);
          }
      }
  
      public void quitSynchronously() {
          state = State.DONE;
          CameraManager.get().stopPreview();
          Message quit = Message.obtain(decodeThread.getHandler(), R.id.quit);
          quit.sendToTarget();
          try {
              decodeThread.join();
          } catch (InterruptedException e) {
              // continue
          }
  
          // Be absolutely sure we don't send any queued up messages
          removeMessages(R.id.decode_succeeded);
          removeMessages(R.id.decode_failed);
      }
  
      private void restartPreviewAndDecode() {
          if (state == State.SUCCESS) {
              state = State.PREVIEW;
              CameraManager.get().requestPreviewFrame(decodeThread.getHandler(), R.id.decode);
              CameraManager.get().requestAutoFocus(this, R.id.auto_focus);
              activity.drawViewfinder();
          }
      }
  
  }
  