Android Open Source - zxingfragmentlib Decode Handler

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Back to project page zxingfragmentlib.

License

The source code is released under:

Apache License

Java Source Code

package com.welcu.android.zxingfragmentlib;
//from w w  w.  j  a  v  a  2 s . c o m
import android.graphics.Bitmap;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.util.Log;

import com.google.zxing.BinaryBitmap;
import com.google.zxing.DecodeHintType;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.PlanarYUVLuminanceSource;
import com.google.zxing.ReaderException;
import com.google.zxing.Result;
import com.google.zxing.common.HybridBinarizer;

import java.io.ByteArrayOutputStream;
import java.util.Map;

final class DecodeHandler extends Handler {

  private static final String TAG = DecodeHandler.class.getSimpleName();

  private final BarCodeScannerFragment fragment;
  private final MultiFormatReader multiFormatReader;
  private boolean running = true;

  DecodeHandler(BarCodeScannerFragment fragment, Map<DecodeHintType,Object> hints) {
    multiFormatReader = new MultiFormatReader();
    multiFormatReader.setHints(hints);
    this.fragment = fragment;
  }

  @Override
  public void handleMessage(Message message) {
    if (!running) {
      return;
    }
    switch (message.what) {
      case IConstants.DECODE:
        decode((byte[]) message.obj, message.arg1, message.arg2);
        break;
      case IConstants.QUIT:
        running = false;
        Looper.myLooper().quit();
        break;
    }
  }

  /**
   * Decode the data within the viewfinder rectangle, and time how long it took. For efficiency,
   * reuse the same reader objects from one decode to the next.
   *
   * @param data   The YUV preview frame.
   * @param width  The width of the preview frame.
   * @param height The height of the preview frame.
   */
  private void decode(byte[] data, int width, int height) {
    long start = System.currentTimeMillis();
    Result rawResult = null;
    PlanarYUVLuminanceSource source = fragment.getCameraManager().buildLuminanceSource(data, width, height);
    if (source != null) {
      BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
      try {
        rawResult = multiFormatReader.decodeWithState(bitmap);
      } catch (ReaderException re) {
        // continue
      } finally {
        multiFormatReader.reset();
      }
    }

    Handler handler = fragment.getHandler();
    if (rawResult != null) {
      // Don't log the barcode contents for security.
      long end = System.currentTimeMillis();
      Log.d(TAG, "Found barcode in " + (end - start) + " ms");
      if (handler != null) {
        Message message = Message.obtain(handler, IConstants.DECODE_SUCCEDED, rawResult);
        Bundle bundle = new Bundle();
        bundleThumbnail(source, bundle);
        message.setData(bundle);
        message.sendToTarget();
      }
    } else {
      if (handler != null) {
        Message message = Message.obtain(handler, IConstants.DECODE_FAILED);
        message.sendToTarget();
      }
    }
  }

  private static void bundleThumbnail(PlanarYUVLuminanceSource source, Bundle bundle) {
    int[] pixels = source.renderThumbnail();
    int width = source.getThumbnailWidth();
    int height = source.getThumbnailHeight();
    Bitmap bitmap = Bitmap.createBitmap(pixels, 0, width, width, height, Bitmap.Config.ARGB_8888);
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    bitmap.compress(Bitmap.CompressFormat.JPEG, 50, out);
    bundle.putByteArray(DecodeThread.BARCODE_BITMAP, out.toByteArray());
    bundle.putFloat(DecodeThread.BARCODE_SCALED_FACTOR, (float) width / source.getWidth());
  }

}

Java Source Code List

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