如何在不移动视图的情况下缩放视图

Question

我有一个需要放大和缩小的RecyclerView，但视图本身需要保持在同一个地方。如何仅缩放视图的内容，而不缩放视图本身？我尝试过canvas.scale，但它可以缩放整个视图，因此它可以离开屏幕，也可以缩小。

编辑：RecyclerView代码

public class ZoomRecyclerView extends RecyclerView {
private RecyclerViewHeaderDecorator recyclerViewHeaderDecorator;
private ScaleGestureDetector scaleGestureDetector;
private static final String TAG = ZoomRecyclerView.class.getSimpleName();

private float scaleFactor = 1.f;
private static final float minScale = 1.0f;
private static final float maxScale = 3.0f;

private float focusX;
private float focusY;


public void setRecyclerViewHeaderDecorator(RecyclerViewHeaderDecorator recyclerViewHeaderDecorator) {
    this.recyclerViewHeaderDecorator = recyclerViewHeaderDecorator;
}

public ZoomRecyclerView(Context context, AttributeSet attrs) {
    super(context, attrs);


    scaleGestureDetector = new ScaleGestureDetector(getContext(), new ScaleGestureDetector.OnScaleGestureListener() {
        @Override
        public boolean onScale(ScaleGestureDetector detector) {
            scaleFactor *= detector.getScaleFactor();

            //makes sure user does not zoom in or out past a certain amount
            scaleFactor = Math.max(minScale, Math.min(scaleFactor, maxScale));

            //refresh the view and compute the size of the view in the screen
            invalidate();

            return true;
        }

        @Override
        public boolean onScaleBegin(ScaleGestureDetector detector) {
            return true;
        }

        @Override
        public void onScaleEnd(ScaleGestureDetector detector) {
        }
    });
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    super.onTouchEvent(event);

    if (event.getPointerCount() > 1) {
        //notify the scaleGestureDetector that an event has happened
        scaleGestureDetector.onTouchEvent(event);
    }
    return true;
}

@Override
protected void dispatchDraw(@NonNull Canvas canvas) {

    focusX = scaleGestureDetector.getFocusX();
    focusY = scaleGestureDetector.getFocusY();

    //scales the display, centered on where the user is touching the display
    canvas.scale(scaleFactor, scaleFactor, focusX, focusY);

    super.dispatchDraw(canvas);

}
}

提前致谢！