راهنمایی جهت استفاده از زوم دوربین در روش surface view

سلام دوستان.

من یک کد از اینترنت پیدا کردم برای استفاده از دوربین توسط surface view بعد خواستم بهش قابلیت زوم اضافه کنم که الآن دو سه روزه درگیرش هستم و نمیشه ! توی اینترنت سرچ کردم میگن بعضی از گوشی ها قابلیت زوم ندارند اصلا. خوب چون من گوشی ندارم و فقط امولاتور هست، امکان دارم بخاطر امولاتور موفق به زوم نشده باشم؟

بعد یک سوال خیلی مهم اینکه کد مربوط به زوم زیاد هست توی اینترنت ولی من نمیدونم این کدهارو کجا دقیقا قرار بدم ؟ توی متدی که دوربین رو اوپن میکنه باشه یا توی کانتنت ویو باشه یا خارج از کانتنت ویو باشه یا ....

بعد یک سوال از اون مهم تر اینکه چرا اکثرا برای اجرای دوربین دوتا اکتیویتی درست میکنند؟

مثلا کد های خودم رو قرار میدم ببینید.

 class Preview extends ViewGroup implements SurfaceHolder.Callback {

    private final String TAG = "Preview";

    SurfaceView          mSurfaceView;
    SurfaceHolder        mHolder;
    Size                 mPreviewSize;
    List<Size>           mSupportedPreviewSizes;
    Camera               mCamera;


    Preview(Context context, SurfaceView sv) {
        super(context);

        mSurfaceView = sv;
        //        addView(mSurfaceView);

        mHolder = mSurfaceView.getHolder();
        mHolder.addCallback(this);
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }


    public void setCamera(Camera camera) {
        mCamera = camera;
        if (mCamera != null) {
            mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
            requestLayout();

            // get Camera parameters
            Camera.Parameters params = mCamera.getParameters();

            List<String> focusModes = params.getSupportedFocusModes();
            if (focusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
                // set the focus mode
                params.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
                // set Camera parameters
                mCamera.setParameters(params);
            }
        }
    }


    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        // We purposely disregard child measurements because act as a
        // wrapper to a SurfaceView that centers the camera preview instead
        // of stretching it.
        final int width = resolveSize(getSuggestedMinimumWidth(), widthMeasureSpec);
        final int height = resolveSize(getSuggestedMinimumHeight(), heightMeasureSpec);
        setMeasuredDimension(width, height);

        if (mSupportedPreviewSizes != null) {
            mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height);
        }
    }


    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        if (changed && getChildCount() > 0) {
            final View child = getChildAt(0);

            final int width = r - l;
            final int height = b - t;

            int previewWidth = width;
            int previewHeight = height;
            if (mPreviewSize != null) {
                previewWidth = mPreviewSize.width;
                previewHeight = mPreviewSize.height;
            }

            // Center the child SurfaceView within the parent.
            if (width * previewHeight > height * previewWidth) {
                final int scaledChildWidth = previewWidth * height / previewHeight;
                child.layout((width - scaledChildWidth) / 2, 0,
                        (width + scaledChildWidth) / 2, height);
            } else {
                final int scaledChildHeight = previewHeight * width / previewWidth;
                child.layout(0, (height - scaledChildHeight) / 2,
                        width, (height + scaledChildHeight) / 2);
            }
        }
    }


    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, acquire the camera and tell it where
        // to draw.
        try {
            if (mCamera != null) {
                mCamera.setPreviewDisplay(holder);

            }
        }
        catch (IOException exception) {
            Log.e(TAG, "IOException caused by setPreviewDisplay()", exception);
        }
    }


    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        // Surface will be destroyed when we return, so stop the preview.
        if (mCamera != null) {
            mCamera.stopPreview();

        }
    }


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

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

        int targetHeight = h;

        // Try to find an size match aspect ratio and size
        for (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);
            }
        }

        // Cannot find the one match the aspect ratio, ignore the requirement
        if (optimalSize == null) {
            minDiff = Double.MAX_VALUE;
            for (Size size: sizes) {
                if (Math.abs(size.height - targetHeight) < minDiff) {
                    optimalSize = size;
                    minDiff = Math.abs(size.height - targetHeight);
                }
            }
        }
        return optimalSize;
    }


    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        if (mCamera != null) {
            Camera.Parameters parameters = mCamera.getParameters();
            parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
            requestLayout();

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

}

این یکی بود و 

 public class CamTestActivity extends Activity {

    private static final String TAG = "CamTestActivity";
    Preview                     preview;
    Button                      buttonClick;
    Camera                      camera;
    Activity                    act;
    Context                     ctx;


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ctx = this;
        act = this;
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);

        setContentView(R.layout.main);

        preview = new Preview(this, (SurfaceView) findViewById(R.id.surfaceView));
        preview.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
        ((FrameLayout) findViewById(R.id.layout)).addView(preview);
        preview.setKeepScreenOn(true);

        preview.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {
                //                camera.takePicture(shutterCallback, rawCallback, jpegCallback);

            }
        });

        Toast.makeText(ctx, "hello", Toast.LENGTH_LONG).show();

           }


    @Override
    protected void onResume() {
        super.onResume();
        int numCams = Camera.getNumberOfCameras();
        if (numCams > 0) {
            try {
                camera = Camera.open(1);
                camera.startPreview();

                preview.setCamera(camera);

            }
            catch (RuntimeException ex) {
                Toast.makeText(ctx, "اشکال در باز شدن دوربین", Toast.LENGTH_LONG).show();
            }
        }
    }


    @Override
    protected void onPause() {
        if (camera != null) {
            camera.stopPreview();
            preview.setCamera(null);
            camera.release();
            camera = null;
        }
        super.onPause();
    }


    private void resetCam() {
        camera.startPreview();
        preview.setCamera(camera);
    }


    private void refreshGallery(File file) {
        Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
        mediaScanIntent.setData(Uri.fromFile(file));
        sendBroadcast(mediaScanIntent);
    }

    ShutterCallback shutterCallback = new ShutterCallback() {

                                        @Override
                                        public void onShutter() {
                                            //			 Log.d(TAG, "onShutter'd");
                                        }
                                    };

    PictureCallback rawCallback     = new PictureCallback() {

                                        @Override
                                        public void onPictureTaken(byte[] data, Camera camera) {
                                            //			 Log.d(TAG, "onPictureTaken - raw");
                                        }
                                    };

    PictureCallback jpegCallback    = new PictureCallback() {

                                        @Override
                                        public void onPictureTaken(byte[] data, Camera camera) {
                                            new SaveImageTask().execute(data);
                                            resetCam();
                                            Log.d(TAG, "onPictureTaken - jpeg");
                                        }
                                    };


    private class SaveImageTask extends AsyncTask<byte[], Void, Void> {

        @Override
        protected Void doInBackground(byte[]... data) {
            FileOutputStream outStream = null;

            // Write to SD Card
            try {
                File sdCard = Environment.getExternalStorageDirectory();
                File dir = new File(sdCard.getAbsolutePath() + "/camtest");
                dir.mkdirs();

                String fileName = String.format("%d.jpg", System.currentTimeMillis());
                File outFile = new File(dir, fileName);

                outStream = new FileOutputStream(outFile);
                outStream.write(data[0]);
                outStream.flush();
                outStream.close();

                Log.d(TAG, "onPictureTaken - wrote bytes: " + data.length + " to " + outFile.getAbsolutePath());

                refreshGallery(outFile);
            }
            catch (FileNotFoundException e) {
                e.printStackTrace();
            }
            catch (IOException e) {
                e.printStackTrace();
            } finally {}
            return null;
        }

    }
}

هم یکی دیگه !

اگه براتون امکان داره این هارو یک توضیح کلی بدید من خیلی ممنون میشم !

پیشاپیش دستتون درد نکنه.