如何在android中使用缩放和撤消功能在图像上而不是画布上绘图？

<ImageView
    android:id="@+id/imageView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:scaleType="matrix" />

ImageView imageView = findViewById(R.id.imageView);
imageView.setOnTouchListener(new View.OnTouchListener() {
    private float lastX, lastY;
    private float scaleFactor = 1.0f;
    private float lastScaleFactor = 1.0f;
    private Matrix matrix = new Matrix();
    private Matrix savedMatrix = new Matrix();

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        ImageView view = (ImageView) v;
        switch (event.getAction() & MotionEvent.ACTION_MASK) {
            case MotionEvent.ACTION_DOWN:
                savedMatrix.set(matrix);
                lastX = event.getX();
                lastY = event.getY();
                break;
            case MotionEvent.ACTION_MOVE:
                float deltaX = event.getX() - lastX;
                float deltaY = event.getY() - lastY;
                matrix.set(savedMatrix);
                matrix.postTranslate(deltaX, deltaY);
                break;
            case MotionEvent.ACTION_POINTER_DOWN:
                lastScaleFactor = scaleFactor;
                float distance = getDistance(event);
                scaleFactor = distance / initialDistance;
                break;
            case MotionEvent.ACTION_POINTER_UP:
                scaleFactor = lastScaleFactor;
                break;
        }
        view.setImageMatrix(matrix);
        return true;
    }

    private float getDistance(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);
    }
});

Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.image);
imageView.setImageBitmap(bitmap);