A SurfaceHolder implementation for QRCode Detection

TourchSurface.java

package cultura.ministerio.culturi.utils;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.ImageFormat;
import android.graphics.Matrix;
import android.graphics.Rect;
import android.graphics.YuvImage;
import android.hardware.Camera;
import android.util.Log;
import android.util.SparseArray;
import android.view.SurfaceHolder;

import com.google.android.gms.vision.Frame;
import com.google.android.gms.vision.barcode.Barcode;
import com.google.android.gms.vision.barcode.BarcodeDetector;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Timer;
import java.util.TimerTask;

/**
 * Created by Jordan on 04/04/2016.
 */
public class TorchSurface implements SurfaceHolder.Callback, Camera.PreviewCallback {

    private Camera mCamera;

    private BarcodeDetector detector;

    protected Activity act;

    private Timer timer;
    private QrCodeListener listener;


    public TorchSurface(Activity act, QrCodeListener listener) {
        detector = new BarcodeDetector.Builder(act)
                .setBarcodeFormats(Barcode.QR_CODE)
                .build();
        this.listener = listener;
        this.act = act;

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        mCamera.stopPreview();
        mCamera.release();
        mCamera = null;
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        mCamera = Camera.open();
        try {
            mCamera.setPreviewDisplay(holder);
        } catch (IOException exception) {
            mCamera.release();
            mCamera = null;
        }
    }

    public void runBarcodeFinder() {
        Log.v(getClass().getSimpleName(), "load Finder");

        timer = new Timer();
        int interval = 3000;
        timer.scheduleAtFixedRate(new TimerTask() {
            @Override
            public void run() {
                act.runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        if (detector.isOperational()) {
                            Log.v(TorchSurface.class.getSimpleName(), "Searching for barcodes");
                            mCamera.setOneShotPreviewCallback(TorchSurface.this);
                        }
                    }
                });
            }
        }, interval, interval);
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width,
                               int height) {
        mCamera.startPreview();
        mCamera.setDisplayOrientation(90);
    }

    @Override
    public void onPreviewFrame(byte[] data, Camera camera) {
        try {
            Camera.Parameters parameters = camera.getParameters();
            int format = parameters.getPreviewFormat();
            //YUV formats require more conversion
            if (format == ImageFormat.NV21 || format == ImageFormat.YUY2 || format == ImageFormat.NV16) {
                int w = parameters.getPreviewSize().width;
                int h = parameters.getPreviewSize().height;
                // Get the YuV image
                YuvImage yuv_image = new YuvImage(data, format, w, h, null);
                // Convert YuV to Jpeg
                Rect rect = new Rect(0, 0, w, h);
                ByteArrayOutputStream output_stream = new ByteArrayOutputStream();
                yuv_image.compressToJpeg(rect, 100, output_stream);
                byte[] byt = output_stream.toByteArray();

                Bitmap bitmap = BitmapFactory.decodeByteArray(byt, 0, byt.length);

                Matrix matrix = new Matrix();
                matrix.postRotate(90);
                bitmap = Bitmap.createBitmap(bitmap, 0, 0,
                        bitmap.getWidth(), bitmap.getHeight(),
                        matrix, true);

                Frame frame = new Frame.Builder().setBitmap(bitmap).build();
                SparseArray<Barcode> barcodes = detector.detect(frame);

                if (barcodes != null && barcodes.size() > 0) {
                    Log.v(TorchSurface.class.getSimpleName(), "Found barcode");
                    listener.qrCodeFound(barcodes.valueAt(0).rawValue);
                    timer.cancel();
                } else
                    Log.v(TorchSurface.class.getSimpleName(), "Not Found: " + barcodes.size());
            } else
                Log.v(TorchSurface.class.getSimpleName(), "Detector is not operational yet");
        } catch (Exception error) {
            error.printStackTrace();
        }

        mCamera.autoFocus(new Camera.AutoFocusCallback() {
            @Override
            public void onAutoFocus(boolean success, Camera camera) {

            }
        });
    }

    public interface QrCodeListener {
        void qrCodeFound(String tokenFound);
    }

    public void onPause() {
        if(timer!=null)
            timer.cancel();
    }

    public void onResume() {
        runBarcodeFinder();
    }

}