自定义相机应用旋转到前视图，但不返回到后视图

Question

As the title says, this is my problem.

My camera successfully goes to front camera, but on the second button click, it doesn't change back to back view and stays front view.

CameraActivity.java:

package mano.whatever;

import android.app.Activity;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Picture;
import android.graphics.RectF;
import android.hardware.Camera;
import android.media.Image;
import android.net.Uri;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.annotation.Nullable;
import android.util.Base64;
import android.util.Log;
import android.view.View;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.FrameLayout;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.Toast;
import android.os.AsyncTask;

import com.google.android.gms.identity.intents.AddressConstants;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;


public class CameraActivity extends Activity {

    private Camera.Size mSize = null;
    private Camera mCamera = null;
    private CameraView mCameraView=null;
    private SurfaceView mPreview;
    private SurfaceHolder mSurfaceHolder;
    Camera.PictureCallback jpegCallback;
    final int CAMERA_CAPTURE = 1;
    private Camera.PictureCallback mPictureCallback;
    boolean isFront;
    int camBackId = Camera.CameraInfo.CAMERA_FACING_BACK;
    int camFrontId = Camera.CameraInfo.CAMERA_FACING_FRONT;


    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_camera);

        if (mCamera == null){
            initCamera(0);
        }

        //btn to close the application
        ImageView imgClose = (ImageView) findViewById(R.id.left_button);
        imgClose.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                toThanksActivity();
            }
        });

       ImageView photo = (ImageView) findViewById(R.id.photo_button);
        photo.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mCamera.autoFocus(new Camera.AutoFocusCallback() {
                    @Override
                    public void onAutoFocus(boolean b, Camera camera) {
                        mCamera.takePicture(shutterCall, PictureCallback, mPicture);

                    }
                });
            }
        });

       ImageView rotate = (ImageView) findViewById(R.id.rotate_camera);
        rotate.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                rotateCamera();
            }
        });
    }


   public void rotateCamera() {
       boolean isFront = false;
       int CamId = 0;
       CamId = Camera.getNumberOfCameras();

       int cameraId = Camera.CameraInfo.CAMERA_FACING_BACK;

       Camera.CameraInfo currentCamInfo = new Camera.CameraInfo();


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

       if (currentCamInfo.facing == Camera.CameraInfo.CAMERA_FACING_BACK){
           initCamera(1);
       }
       else{
           initCamera(0);
       }


   }

    public void initCamera(int potato){

        mCamera = Camera.open(potato);//you can use open(int) to use different cameras

        FrameLayout camera_view = (FrameLayout) findViewById(R.id.camera_view);
        camera_view.removeView(mCameraView);

        if (mCamera != null) {
            mCameraView = new CameraView(this, mCamera);//create a SurfaceView to show camera data
            camera_view.addView(mCameraView);//add the SurfaceView to the layout
        }
    }

    public void toThanksActivity() {
        mCamera.stopPreview();
        mCamera.release();
        finish();
    }

    public void toCaptureImage() {
        mCamera.takePicture(shutterCall, PictureCallback, mPicture);
    }

    Camera.ShutterCallback shutterCall = new Camera.ShutterCallback() {
        @Override
        public void onShutter() {

        }
    };

    Camera.PictureCallback PictureCallback = new Camera.PictureCallback() {
        @Override
        public void onPictureTaken(byte[] bytes, Camera camera) {

        }
    };

    Camera.PictureCallback mPicture = new Camera.PictureCallback() {
        @Override
    public void onPictureTaken(byte[] data, Camera camera) {
            SimpleDateFormat dateFormat = new SimpleDateFormat("yyyymmddhhmmss");
            String date = dateFormat.format(new Date());
            String photoFile = "Picture_" + date + ".jpg";
            File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM), "Camera");
            String filename = mediaStorageDir.getPath() + File.separator + photoFile;
            File pictureFile = new File(filename);

            try {
                FileOutputStream fos = new FileOutputStream(pictureFile);
                fos.write(data);
                fos.flush();
                fos.close();


                ByteArrayOutputStream stream = new ByteArrayOutputStream();

                Bitmap bm = BitmapFactory.decodeFile(filename);
                Matrix matrix = new Matrix();
                matrix.postRotate(90);
                Bitmap rotatedBitmap = Bitmap.createBitmap(bm, 0, 0, bm.getWidth(), bm.getHeight(), matrix, true);
                FileOutputStream fos2 = new FileOutputStream(pictureFile);
                rotatedBitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);

                byte[] byteArray = stream.toByteArray();




                mCamera.stopPreview();
                mCamera.release();

                Intent intent = new Intent();
                intent.putExtra("image", byteArray);
                setResult(250, intent);
                finish();

            } catch (IOException e) {
            }

        }
    };

    Camera.AutoFocusCallback myAutoFocusCallback = new Camera.AutoFocusCallback() {
        @Override
        public void onAutoFocus(boolean b, Camera camera) {
        }
    };


}

CameraView.java:

package mano.whatever;

import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.Size;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

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



public class CameraView extends SurfaceView implements SurfaceHolder.Callback {

    private SurfaceHolder mHolder;
    private Camera mCamera;
    private Camera.Size mSize = null;

    public CameraView(Context context, Camera camera) {
        super(context);


        mCamera = camera;
        mCamera.setDisplayOrientation(90);
        //get the holder and set this class as the callback, so we can get camera data here
        mHolder = getHolder();
        mHolder.addCallback(this);
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

    }

    @Override
    public void surfaceCreated(SurfaceHolder surfaceHolder) {
            //when the surface is created, we can set the camera to draw images in this surfaceholder
            Camera.Parameters parameters = mCamera.getParameters();
            List<Camera.Size> previewSizes = parameters.getSupportedPreviewSizes();

            // You need to choose the most appropriate previewSize for your app
           Size optimalSize = getOptimalPreviewSize(previewSizes, getResources().getDisplayMetrics().widthPixels, getResources().getDisplayMetrics().heightPixels);

            parameters.setPreviewSize(optimalSize.width, optimalSize.height);
            mCamera.setParameters(parameters);
            mCamera.startPreview();

    }

    @Override
    public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i2, int i3) {
        //before changing the application orientation, you need to stop the preview, rotate and then start it again
        if (mHolder.getSurface() == null)//check if the surface is ready to receive camera data
            return;

        try {
            mCamera.stopPreview();
        } catch (Exception e) {
            //this will happen when you are trying the camera if it's not running
        }

        //now, recreate the camera preview
        try {
            mCamera.setPreviewDisplay(mHolder);
            mCamera.startPreview();
        } catch (IOException e) {
            Log.d("ERROR", "Camera error on surfaceChanged " + e.getMessage());
        }

    }


    @Override
    public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
        //our app has only one screen, so we'll destroy the camera in the surface
        //if you are unsing with more screens, please move this code your activity
    }


    private Camera.Size getOptimalPreviewSize(List<Camera.Size> sizes, int w, int h) {
        final double ASPECT_TOLERANCE = 0.1;
        double targetRatio=(double)h / w;

        if (sizes == null) return null;

        Camera.Size optimalSize = null;
        double minDiff = Double.MAX_VALUE;

        int targetHeight = h;

        for (Camera.Size size : sizes) {
            double ratio = (double) size.width / size.height;
            if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;
            if (Math.abs(size.height - targetHeight) < minDiff) {
                optimalSize = size;
                minDiff = Math.abs(size.height - targetHeight);
            }
        }

        if (optimalSize == null) {
            minDiff = Double.MAX_VALUE;
            for (Camera.Size size : sizes) {
                if (Math.abs(size.height - targetHeight) < minDiff) {
                    optimalSize = size;
                    minDiff = Math.abs(size.height - targetHeight);
                }
            }
        }
        return optimalSize;
    }


}

I know this is a sketchy code, but I'd love to hear some suggestions.

Thank you in advance.:)

EDIT

I completely reworked my code, got rid of the CameraView.java class and it works fluently thanks to Android camera preview freezes when switching cameras?

Answer 1

Haven't try but try something like this, hope it works?

       public void rotateCamera() {
           boolean isFront = false;
           int CamId = 0;
           CamId = Camera.getNumberOfCameras();

           int cameraId = Camera.CameraInfo.CAMERA_FACING_BACK;

           Camera.CameraInfo currentCamInfo = new Camera.CameraInfo();
           if (mCamera != null) {
               mCamera.stopPreview();
               mCamera.release();
               mCamera = null;
           }

           if (currentCamInfo.facing == Camera.CameraInfo.CAMERA_FACING_BACK){
               camera = Camera.open(Camera.CameraInfo.CAMERA_FACING_BACK);
           }
           else{
               camera = Camera.open(Camera.CameraInfo.CAMERA_FACING_FRONT);
           }
           if (mCamera != null) {
                try {
                    mCamera.setPreviewDisplay(surfaceView.getHolder());
                    mCamera.startPreview();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }

       }