surface view does not show camera after i gave permission

Question

public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_camera, container, false);
    cameraId = Camera.CameraInfo.CAMERA_FACING_BACK;
    flipCamera = view.findViewById(R.id.flipCamera);
    flashCameraButton = view.findViewById(R.id.flash);
    captureImage = view.findViewById(R.id.captureImage);
    surfaceView = view.findViewById(R.id.surfaceView);
    surfaceHolder = surfaceView.getHolder();
    surfaceHolder.addCallback(this);
    flipCamera.setOnClickListener(this);
    captureImage.setOnClickListener(this);
    flashCameraButton.setOnClickListener(this);
    getActivity().getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

    if (Camera.getNumberOfCameras() > 1) {
        flipCamera.setVisibility(View.VISIBLE);
    }
    if (!getActivity().getBaseContext().getPackageManager().hasSystemFeature(
            PackageManager.FEATURE_CAMERA_FLASH)) {
        flashCameraButton.setVisibility(View.GONE);
    }


    return view;
}

@RequiresApi(api = Build.VERSION_CODES.M)
@Override
public void surfaceCreated(SurfaceHolder holder) {

    if (!openCamera(Camera.CameraInfo.CAMERA_FACING_BACK)) {
        alertCameraDialog();
    }

}


private boolean openCamera(int id) {
    boolean result = false;
    cameraId = id;
    releaseCamera();
    try {
        camera = Camera.open(cameraId);
    } catch (Exception e) {
        e.printStackTrace();
    }
    if (camera != null) {
        try {
            setUpCamera(camera);
            camera.setErrorCallback(new Camera.ErrorCallback() {

                @Override
                public void onError(int error, Camera camera) {

                }
            });
            camera.setPreviewDisplay(surfaceHolder);
            camera.startPreview();
            result = true;
        } catch (IOException e) {
            e.printStackTrace();
            result = false;
            releaseCamera();
        }
    }
    return result;
}

private void setUpCamera(Camera c) {
    Camera.CameraInfo info = new Camera.CameraInfo();
    Camera.getCameraInfo(cameraId, info);
    rotation = getActivity().getWindowManager().getDefaultDisplay().getRotation();
    int degree = 0;
    switch (rotation) {
        case Surface.ROTATION_0:
            degree = 0;
            break;
        case Surface.ROTATION_90:
            degree = 90;
            break;
        case Surface.ROTATION_180:
            degree = 180;
            break;
        case Surface.ROTATION_270:
            degree = 270;
            break;

        default:
            break;
    }

    if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
        // frontFacing
        rotation = (info.orientation + degree) % 330;
        rotation = (360 - rotation) % 360;
    } else {
        // Back-facing
        rotation = (info.orientation - degree + 360) % 360;
    }
    c.setDisplayOrientation(rotation);
    Camera.Parameters params = c.getParameters();

    showFlashButton(params);

    List<String> focusModes = params.getSupportedFlashModes();
    if (focusModes != null) {
        if (focusModes
                .contains(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE)) {
            params.setFlashMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
        }
    }

    params.setRotation(rotation);
}

private void showFlashButton(Camera.Parameters params) {
    boolean showFlash = (getActivity().getPackageManager().hasSystemFeature(
            PackageManager.FEATURE_CAMERA_FLASH) && params.getFlashMode() != null)
            && params.getSupportedFlashModes() != null
            && params.getSupportedFocusModes().size() > 1;

    flashCameraButton.setVisibility(showFlash ? View.VISIBLE
            : View.INVISIBLE);

}

private void releaseCamera() {
    try {
        if (camera != null) {
            camera.setPreviewCallback(null);
            camera.setErrorCallback(null);
            camera.stopPreview();
            camera.release();
            camera = null;
        }
    } catch (Exception e) {
        e.printStackTrace();
        Log.e("error", e.toString());
        camera = null;
    }
}

@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
                           int height) {

}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {

}

@Override
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.flash:
            flashOnButton();
            break;
        case R.id.flipCamera:
            flipCamera();
            break;
        case R.id.captureImage:
            takeImage();
            break;

        default:
            break;
    }
}

private void takeImage() {
    camera.takePicture(null, null, new Camera.PictureCallback() {

        private File imageFile;

        @Override
        public void onPictureTaken(byte[] data, Camera camera) {
            try {
                // convert byte array into bitmap
                Bitmap loadedImage = null;
                Bitmap rotatedBitmap = null;
                loadedImage = BitmapFactory.decodeByteArray(data, 0, data.length);

                // rotate Image
                Matrix rotateMatrix = new Matrix();
                rotateMatrix.postRotate(rotation);
                rotatedBitmap = Bitmap.createBitmap(loadedImage, 0, 0,
                        loadedImage.getWidth(), loadedImage.getHeight(),
                        rotateMatrix, false);
                String state = Environment.getExternalStorageState();
                File folder = null;
                if (state.contains(Environment.MEDIA_MOUNTED)) {
                    folder = new File(Environment
                            .getExternalStorageDirectory() + "/Demo");
                } else {
                    folder = new File(Environment
                            .getExternalStorageDirectory() + "/Demo");
                }

                boolean success = true;
                if (!folder.exists()) {
                    success = folder.mkdirs();
                }
                if (success) {
                    java.util.Date date = new java.util.Date();
                    imageFile = new File(folder.getAbsolutePath()
                            + File.separator
                            + new Timestamp(date.getTime()).toString()
                            + "Image.jpg");

                    imageFile.createNewFile();
                    Toast.makeText(getActivity().getBaseContext(), "Image Saved", Toast.LENGTH_SHORT).show();
                    openCamera(cameraId);
                } else {
                    Toast.makeText(getActivity().getBaseContext(), "Image Not saved", Toast.LENGTH_SHORT).show();
                    return;
                }

                ByteArrayOutputStream ostream = new ByteArrayOutputStream();

                // save image into gallery
                rotatedBitmap.compress(Bitmap.CompressFormat.JPEG, 100, ostream);

                FileOutputStream fout = new FileOutputStream(imageFile);
                fout.write(ostream.toByteArray());
                fout.close();
                ContentValues values = new ContentValues();

                values.put(MediaStore.Images.Media.DATE_TAKEN, System.currentTimeMillis());
                values.put(MediaStore.Images.Media.MIME_TYPE, "image/jpeg");
                values.put(MediaStore.MediaColumns.DATA, imageFile.getAbsolutePath());
                getActivity().getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);

            } catch (Exception e) {
                e.printStackTrace();
            }

        }
    });

}


private void flipCamera() {
    int id = (cameraId == Camera.CameraInfo.CAMERA_FACING_BACK ? Camera.CameraInfo.CAMERA_FACING_FRONT
            : Camera.CameraInfo.CAMERA_FACING_BACK);
    if (!openCamera(id)) {
        alertCameraDialog();
    }
}

private void alertCameraDialog() {
    Toast.makeText(getActivity(), "Error to open camera", Toast.LENGTH_SHORT).show();
}


private void flashOnButton() {
    if (camera != null) {
        try {
            Camera.Parameters param = camera.getParameters();
            param.setFlashMode(!flashmode ? Camera.Parameters.FLASH_MODE_TORCH
                    : Camera.Parameters.FLASH_MODE_OFF);
            camera.setParameters(param);
            flashmode = !flashmode;
        } catch (Exception e) {
            // TODO: handle exception
        }

    }
}

}

This is my camera fragment code. When i give permission at runtime the surfaceview does not show camera. It show camera at onResume() or on any Button click in that fragment.How to solve this issue. How to set When i click on Allow button in permission it shows camera in surface view automatically.

Answer 1

In onCreate set visibilty of surfaceView as INVISIBLE.

 @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_home);

    if (checkCameraHardware(this) == false) {
        showDialogForExit();
    }
    surfaceView = (SurfaceView) findViewById(R.id.surfaceView);
    surfaceView.setVisibility(View.INVISIBLE);
    infoTextview = (TextView) findViewById(R.id.info_text);
    askForPermissions();
}

Then after attaching cameraSource to surfaceView,set visibilty of surfaceView to VISIBLE again.

        surfaceView.setVisibility(View.VISIBLE);