CaptureActivityHandler.java

/*
 * 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.client.android;

import idv.Zero.KerKerInput.R;
import com.google.zxing.Result;

import android.graphics.Bitmap;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;

/**
 * This class handles all the messaging which comprises the state machine for capture.
 *
 * @author dswitkin@google.com (Daniel Switkin)
 */
public final class CaptureActivityHandler extends Handler {
  private final ASyncBarcodeDecoder activity;
  private final DecodeThread decodeThread;
  private State state;

  private enum State {
    PREVIEW,
    SUCCESS,
    DONE
  }

  public CaptureActivityHandler(ASyncBarcodeDecoder activity, boolean beginScanning) {
    this.activity = activity;
    decodeThread = new DecodeThread(activity);
    decodeThread.start();
    state = State.SUCCESS;

    // Start ourselves capturing previews and decoding.
    CameraManager.get().startPreview();
    if (beginScanning) {
      restartPreviewAndDecode();
    }
  }

  @Override
  public void handleMessage(Message message) {
    switch (message.what) {
      case R.id.auto_focus:
        // 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);
        }
        break;
      case R.id.restart_preview:
        restartPreviewAndDecode();
        break;
      case R.id.decode_succeeded:
        state = State.SUCCESS;
        Bundle bundle = message.getData();
        Bitmap barcode = bundle == null ? null : (Bitmap) bundle.getParcelable(DecodeThread.BARCODE_BITMAP);
        activity.handleDecode((Result) message.obj, barcode);
        restartPreviewAndDecode();
        break;
      case 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);
        break;
    }
  }

  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) {
    }

    // Be absolutely sure we don't send any queued up messages
    removeMessages(R.id.decode_succeeded);
    removeMessages(R.id.decode_failed);
  }

  private void restartPreviewAndDecode() {
	try{
      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();
      }
    }
    catch(Exception e)
    {
    	e.printStackTrace();
    }
  }
}