Camera Preview

CameraPreview.java

package com.swizel.android.widget;

import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.graphics.ImageFormat;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.support.v4.content.ContextCompat;
import android.util.AttributeSet;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

import java.io.IOException;
import java.util.List;

/**
 * A SurfaceView that'll show a preview from the device camera.
 */
@SuppressWarnings("deprecation")
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
    private static final int AUTO_FOCUS_DELAY = 250;
    private Camera mCamera;
    private CameraReadyListener mListener = null;
    private Runnable doAutoFocusRunnable = new Runnable() {
        @Override
        public void run() {
            mCamera.cancelAutoFocus();
            mCamera.autoFocus(new Camera.AutoFocusCallback() {
                @Override
                public void onAutoFocus(boolean success, Camera camera) {
                    postDelayed(doAutoFocusRunnable, AUTO_FOCUS_DELAY);
                }
            });
        }
    };

    public interface CameraReadyListener {
        void onCameraReady(Camera camera);
    }

    public CameraPreview(Context context) {
        super(context);
        initView();
    }

    public CameraPreview(Context context, AttributeSet attrs) {
        super(context, attrs);
        initView();
    }

    private void initView() {
        getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        getHolder().addCallback(this);
        setFocusable(true);
        setFocusableInTouchMode(true);
        requestFocus();
    }

    public void setCameraReadyListener(CameraReadyListener listener) {
        this.mListener = listener;
    }

    @Override
    public void surfaceChanged(SurfaceHolder sh, int format, int width, int height) {
        // Now that the size is known, set up the camera parameters and begin
        // the preview.

        // Application is hard-coded to portrait so rotate landscape camera by 90
        // degrees.
        mCamera.setDisplayOrientation(90);

        Parameters parameters = mCamera.getParameters();

        boolean autoFocus = getContext().getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_AUTOFOCUS);
//        boolean continuousModeSupported = false;
//        boolean macroModeSupported = false;
//        boolean autoModeSupported = false;
//
//        // Try and set a useful focus mode.
//        if (autoFocus) {
//            List<String> focusModes = parameters.getSupportedFocusModes();
//            for (String mode : focusModes) {
//                if (Parameters.FOCUS_MODE_CONTINUOUS_PICTURE.equalsIgnoreCase(mode)) {
//                    continuousModeSupported = true;
//                } else if (Parameters.FOCUS_MODE_MACRO.equalsIgnoreCase(mode)) {
//                    macroModeSupported = true;
//                } else if (Parameters.FOCUS_MODE_AUTO.equalsIgnoreCase(mode)) {
//                    autoModeSupported = true;
//                }
//            }
//
//            if (continuousModeSupported) {
//                parameters.setFocusMode(Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
//
//            } else if (macroModeSupported) {
//                parameters.setFocusMode(Parameters.FOCUS_MODE_MACRO);
//
//            } else if (autoModeSupported) {
//                parameters.setFocusMode(Parameters.FOCUS_MODE_AUTO);
//            }
//        }

        // Get best preview resolution.
        List<Camera.Size> previewSizes = parameters.getSupportedPreviewSizes();

        Camera.Size highestRes = previewSizes.get(0);
        int highestPixels = highestRes.width * highestRes.height;

        for (Camera.Size size : previewSizes) {
            int currentPixels = size.width * size.height;
            if (currentPixels > highestPixels) {
                highestRes = size;
                highestPixels = currentPixels;
            }
        }

        parameters.setPreviewSize(highestRes.width, highestRes.height);
        parameters.setPreviewFormat(ImageFormat.NV21);
        
        // Set scene mode for scanning barcodes.
        if (parameters.getSupportedSceneModes() != null && parameters.getSupportedSceneModes().contains(Parameters.SCENE_MODE_BARCODE)) {
            parameters.setSceneMode(Parameters.SCENE_MODE_BARCODE);
        }

        mCamera.setParameters(parameters);
        mCamera.startPreview();

        if (autoFocus) {
            postDelayed(doAutoFocusRunnable, AUTO_FOCUS_DELAY);
        }
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, acquire the camera and tell it where
        // to draw.

        if (mCamera != null) {
            mCamera.release();
            mCamera = null;
        }

        // API 23 requires us to check for permissions at runtime.
        int permissionCheck = ContextCompat.checkSelfPermission(getContext(), Manifest.permission.CAMERA);
        if (permissionCheck == PackageManager.PERMISSION_GRANTED) {
            mCamera = Camera.open(Camera.CameraInfo.CAMERA_FACING_BACK);
            try {
                mCamera.setPreviewDisplay(holder);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (mListener != null) {
                mListener.onCameraReady(mCamera);
            }
        }
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        // Surface will be destroyed when we return, so stop the preview.
        // Because the CameraDevice object is not a shared resource, it's very
        // important to release it when the activity is paused.
        cleanUpCamera();
    }

    public void cleanUpCamera() {
        if (mCamera != null) {

            removeCallbacks(doAutoFocusRunnable);

            mCamera.cancelAutoFocus();
            mCamera.setPreviewCallback(null);
            mCamera.stopPreview();
            mCamera.release();
            mCamera = null;
        }
    }
}

fragment_scan_barcode.xml

    <com.swizel.android.widget.CameraPreview
        android:id="@+id/camera_preview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

ScanBarcodeFragment.java

    @Bind(R.id.camera_preview)
    CameraPreview mCameraPreview;

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        // Inject views
        ButterKnife.bind(this, view);
      
        setupCameraPreview();
    }

    private void setupCameraPreview() {
        mCameraPreview.setCameraReadyListener(new CameraPreview.CameraReadyListener() {

            @Override
            public void onCameraReady(Camera camera) {
                camera.setPreviewCallback(new Camera.PreviewCallback() {

                    @Override
                    public void onPreviewFrame(byte[] data, Camera camera) {
                        Camera.Parameters parameters = camera.getParameters();
                        Camera.Size size = parameters.getPreviewSize();

                        // Convert uncompressed data to a JPEG
                        YuvImage yuvimage = new YuvImage(data, ImageFormat.NV21, size.width, size.height, null);
                        ByteArrayOutputStream baos = new ByteArrayOutputStream();
                        yuvimage.compressToJpeg(new Rect(0, 0, size.width, size.height), 80, baos);
                        byte[] jpegData = baos.toByteArray();

                        // Create a Bitmap of the JPEG
                        Bitmap frame = BitmapFactory.decodeByteArray(jpegData, 0, jpegData.length);

                        if (frame != null) {
                          // Do something with frame,e.g. pass to ZXING for barcode analysis.

                        }
                    }
                });

            }

        });
    }