Android Open Source - ZXingFragment Zxing Fragment

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License

The source code is released under:

Apache License

Java Source Code

package de.klimek.zxingfragment;
//from   w  ww. j av a 2  s.  c o m
import java.util.List;

import android.app.Fragment;
import android.hardware.Camera;
import android.hardware.Camera.CameraInfo;
import android.hardware.Camera.Parameters;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.Display;
import android.view.LayoutInflater;
import android.view.Surface;
import android.view.View;
import android.view.ViewGroup;
import de.klimek.zxingfragment.Decoder.OnDecodedCallback;

public class ZxingFragment extends Fragment {
  private static final String TAG = ZxingFragment.class.getSimpleName();

  private static final boolean USE_FLASH = true;

  private ScannerView mScannerView;
  private Reticle mReticle;

  private Camera mCamera;
  private int mCameraId;
  private CameraInfo mCameraInfo;
  private AsyncTask<Void, Void, Exception> mStartCameraTask;

  private Decoder mDecoder;

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    mCameraId = chooseCamera();
    mCameraInfo = new CameraInfo();
    Camera.getCameraInfo(mCameraId, mCameraInfo);

    mDecoder = new Decoder(getActivity());
  }

  private int chooseCamera() {
    // TODO choose camera here
    return 0;
  }

  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,
      Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_zxing, container,
        false);

    mScannerView = (ScannerView) rootView.findViewById(R.id.scanner_view);
    mReticle = (Reticle) rootView.findViewById(R.id.reticle);

    return rootView;
  }

  @Override
  public void onPause() {
    super.onPause();
    stopScanning();
  }


  public void setOnDecodedCallback(OnDecodedCallback callback) {
    mDecoder.setOnDecodedCallback(callback);
  }

  public void startScanning() {
    // Task for smooth UI interaction while camera loads
    mStartCameraTask = new AsyncTask<Void, Void, Exception>() {

      @Override
      protected Exception doInBackground(Void... v) {
        try {
          mCamera = Camera.open(mCameraId);
        } catch (RuntimeException e) {
          return e;
        }
        optimizeCameraParams(mCamera);
        return null;
      }

      @Override
      protected void onPostExecute(Exception e) {
        if (e != null) {
          Log.w(TAG, "Exception while opening camera", e);
        } else {
          Display display = getActivity().getWindowManager()
              .getDefaultDisplay();
          int displayOrientation = getCameraDisplayOrientation(
              display, mCameraInfo);
          mCamera.setDisplayOrientation(displayOrientation);
          mScannerView.startPreview(mCamera, displayOrientation);
          mDecoder.startDecoding(mCamera, displayOrientation);
          mReticle.setDisplayOrientation(displayOrientation);
          mScannerView.setVisibility(View.VISIBLE);
          mReticle.setVisibility(View.VISIBLE);
        }
      }
    };

    mStartCameraTask.execute();
  }

  public void stopScanning() {
    if (mStartCameraTask != null) {
      mStartCameraTask.cancel(true);
    }
    if (mCamera != null) {
      mDecoder.stopDecoding();
      mScannerView.stopPreview();
      mCamera.release();
      mCamera = null;
    }
    mScannerView.setVisibility(View.INVISIBLE);
    mReticle.setVisibility(View.INVISIBLE);
  }

  private static void optimizeCameraParams(Camera camera) {
    Parameters params = camera.getParameters();
    
    // focus mode
    List<String> focusModes = params.getSupportedFocusModes();
    if (focusModes.contains(Parameters.FOCUS_MODE_CONTINUOUS_PICTURE)) {
      params.setFocusMode(Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
    }
    
    // flash mode
    if(USE_FLASH) {
      List<String> flashModes = params.getSupportedFlashModes();
      if (flashModes != null
          && flashModes.contains(Parameters.FLASH_MODE_TORCH)) {
        params.setFlashMode(Parameters.FLASH_MODE_TORCH);
      }
    }
    
    // smoother on some devices
    params.setRecordingHint(true);
    
    camera.setParameters(params);
  }

  private static int getCameraDisplayOrientation(Display display, CameraInfo cameraInfo) {
    int degrees = 0;
    switch (display.getRotation()) {
    case Surface.ROTATION_0:
      degrees = 0;
      break;
    case Surface.ROTATION_90:
      degrees = 90;
      break;
    case Surface.ROTATION_180:
      degrees = 180;
      break;
    case Surface.ROTATION_270:
      degrees = 270;
      break;
    }
    
    int result;
    if (cameraInfo.facing == CameraInfo.CAMERA_FACING_FRONT) {
      result = (cameraInfo.orientation + degrees) % 360;
      result = (360 - result) % 360; // compensate the mirror
    } else { // back-facing
      result = (cameraInfo.orientation - degrees + 360) % 360;
    }
    
    return result;
  }

}

Java Source Code List

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