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      1 /*
      2  * Copyright (C) 2008 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.Result;
     20 import com.google.zxing.client.android.camera.CameraManager;
     21 
     22 import android.app.Activity;
     23 import android.content.Intent;
     24 import android.graphics.Bitmap;
     25 import android.net.Uri;
     26 import android.os.Bundle;
     27 import android.os.Handler;
     28 import android.os.Message;
     29 import android.util.Log;
     30 
     31 /**
     32  * This class handles all the messaging which comprises the state machine for capture.
     33  *
     34  * @author dswitkin (at) google.com (Daniel Switkin)
     35  */
     36 public final class CaptureActivityHandler extends Handler {
     37 
     38   private static final String TAG = CaptureActivityHandler.class.getSimpleName();
     39 
     40   private final CaptureActivity activity;
     41   private final DecodeThread decodeThread;
     42   private State state;
     43   private final CameraManager cameraManager;
     44 
     45   private enum State {
     46     PREVIEW,
     47     SUCCESS,
     48     DONE
     49   }
     50 
     51   CaptureActivityHandler(CaptureActivity activity,
     52                          String characterSet,
     53                          CameraManager cameraManager) {
     54     this.activity = activity;
     55     decodeThread = new DecodeThread(activity, characterSet,
     56         new ViewfinderResultPointCallback(activity.getViewfinderView()));
     57     decodeThread.start();
     58     state = State.SUCCESS;
     59 
     60     // Start ourselves capturing previews and decoding.
     61     this.cameraManager = cameraManager;
     62     cameraManager.startPreview();
     63     restartPreviewAndDecode();
     64   }
     65 
     66   @Override
     67   public void handleMessage(Message message) {
     68     if (message.what == R.id.auto_focus) {
     69       //Log.d(TAG, "Got auto-focus message");
     70       // When one auto focus pass finishes, start another. This is the closest thing to
     71       // continuous AF. It does seem to hunt a bit, but I'm not sure what else to do.
     72       if (state == State.PREVIEW) {
     73         cameraManager.requestAutoFocus(this, R.id.auto_focus);
     74       }
     75     } else if (message.what == R.id.restart_preview) {
     76       Log.d(TAG, "Got restart preview message");
     77       restartPreviewAndDecode();
     78     } else if (message.what == R.id.decode_succeeded) {
     79       Log.d(TAG, "Got decode succeeded message");
     80       state = State.SUCCESS;
     81       Bundle bundle = message.getData();
     82       Bitmap barcode = bundle == null ? null :
     83           (Bitmap) bundle.getParcelable(DecodeThread.BARCODE_BITMAP);
     84       activity.handleDecode((Result) message.obj, barcode);
     85     } else if (message.what == R.id.decode_failed) {
     86       // We're decoding as fast as possible, so when one decode fails, start another.
     87       state = State.PREVIEW;
     88       cameraManager.requestPreviewFrame(decodeThread.getHandler(), R.id.decode);
     89     } else if (message.what == R.id.return_scan_result) {
     90       Log.d(TAG, "Got return scan result message");
     91       activity.setResult(Activity.RESULT_OK, (Intent) message.obj);
     92       activity.finish();
     93     } else if (message.what == R.id.launch_product_query) {
     94       Log.d(TAG, "Got product query message");
     95       String url = (String) message.obj;
     96       Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
     97       intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
     98       activity.startActivity(intent);
     99     }
    100   }
    101 
    102   public void quitSynchronously() {
    103     state = State.DONE;
    104     cameraManager.stopPreview();
    105     Message quit = Message.obtain(decodeThread.getHandler(), R.id.quit);
    106     quit.sendToTarget();
    107     try {
    108       // Wait at most half a second; should be enough time, and onPause() will timeout quickly
    109       decodeThread.join(500L);
    110     } catch (InterruptedException e) {
    111       // continue
    112     }
    113 
    114     // Be absolutely sure we don't send any queued up messages
    115     removeMessages(R.id.decode_succeeded);
    116     removeMessages(R.id.decode_failed);
    117   }
    118 
    119   private void restartPreviewAndDecode() {
    120     if (state == State.SUCCESS) {
    121       state = State.PREVIEW;
    122       cameraManager.requestPreviewFrame(decodeThread.getHandler(), R.id.decode);
    123       cameraManager.requestAutoFocus(this, R.id.auto_focus);
    124       activity.drawViewfinder();
    125     }
    126   }
    127 
    128 }
    129