Зум щипать камеру2api

Question

Я очень новичок в Android. Может кто-нибудь сказать мне, как использовать масштабирование пинч в Android Studio? Я собирался использовать код в Zoom Camera2 Preview, используя TextureView , но функция масштабирования все еще не работала. И код, который я использую от https://github.com/android/camera-samples/tree/master/Camera2Basic

Это код, который я пытаюсь использовать:

/**
 * A {@link TextureView} that can be adjusted to a specified aspect ratio.
 */
public class AutoFitTextureView extends TextureView{

    private int mRatioWidth = 0;
    private int mRatioHeight = 0;
    protected CameraCharacteristics cameraCharacteristics;
    protected CameraCaptureSession captureSession;
    protected CaptureRequest.Builder previewRequestBuilder;


    //Zooming
    protected float fingerSpacing = 0;
    protected float zoomLevel = 1f;
    protected float maximumZoomLevel;
    protected Rect zoom;

    public AutoFitTextureView(Context context) {
        this(context, null);
    }
    private CaptureRequest mPreviewRequest;

    /**
     * The current state of camera state for taking pictures.
     *
     * @see #captureCallback
     */

    public AutoFitTextureView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }
    /**
     * A {@link CameraCaptureSession } for camera preview.
     */

    public AutoFitTextureView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    /**
     * Sets the aspect ratio for this view. The size of the view will be measured based on the ratio
     * calculated from the parameters. Note that the actual sizes of parameters don't matter, that
     * is, calling setAspectRatio(2, 3) and setAspectRatio(4, 6) make the same result.
     *
     * @param width  Relative horizontal size
     * @param height Relative vertical size
     */

    public void setAspectRatio(int width, int height) {
        if (width < 0 || height < 0) {
            throw new IllegalArgumentException("Size cannot be negative.");
        }
        mRatioWidth = width;
        mRatioHeight = height;
        requestLayout();
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        int width = MeasureSpec.getSize(widthMeasureSpec);
        int height = MeasureSpec.getSize(heightMeasureSpec);
        if (0 == mRatioWidth || 0 == mRatioHeight) {
            setMeasuredDimension(width, height);
        } else {
            if (width < height * mRatioWidth / mRatioHeight) {
                setMeasuredDimension(width, width * mRatioHeight / mRatioWidth);
            } else {
                setMeasuredDimension(height * mRatioWidth / mRatioHeight, height);
            }
        }
    }
    public boolean onTouchEvent(MotionEvent event) {
        try {
            Rect rect = cameraCharacteristics.get(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE);
            if (rect == null) return false;
            float currentFingerSpacing;

            if (event.getPointerCount() == 2) { //Multi touch.
                currentFingerSpacing = getFingerSpacing(event);
                float delta = 0.05f; //Control this value to control the zooming sensibility
                if (fingerSpacing != 0) {
                    if (currentFingerSpacing > fingerSpacing) { //Don't over zoom-in
                        if ((maximumZoomLevel - zoomLevel) <= delta) {
                            delta = maximumZoomLevel - zoomLevel;
                        }
                        zoomLevel = zoomLevel + delta;
                    } else if (currentFingerSpacing < fingerSpacing){ //Don't over zoom-out
                        if ((zoomLevel - delta) < 1f) {
                            delta = zoomLevel - 1f;
                        }
                        zoomLevel = zoomLevel - delta;
                    }
                    float ratio = (float) 1 / zoomLevel; //This ratio is the ratio of cropped Rect to Camera's original(Maximum) Rect
                    //croppedWidth and croppedHeight are the pixels cropped away, not pixels after cropped
                    int croppedWidth = rect.width() - Math.round((float)rect.width() * ratio);
                    int croppedHeight = rect.height() - Math.round((float)rect.height() * ratio);
                    //Finally, zoom represents the zoomed visible area
                    zoom = new Rect(croppedWidth/2, croppedHeight/2,
                            rect.width() - croppedWidth/2, rect.height() - croppedHeight/2);
                    previewRequestBuilder.set(CaptureRequest.SCALER_CROP_REGION, zoom);
                }
                fingerSpacing = currentFingerSpacing;
            } else { //Single touch point, needs to return true in order to detect one more touch point
                return true;
            }
            captureSession.setRepeatingRequest(previewRequestBuilder.build(), captureCallback, null);
            return true;
        } catch (final Exception e) {
            //Error handling up to you
            return true;
        }
    }
    private float getFingerSpacing(MotionEvent event) {
        float x = event.getX(0) - event.getX(1);
        float y = event.getY(0) - event.getY(1);
        return (float) Math.sqrt(x * x + y * y);
    }
}