Zoom to previous position (x y coordinates and scale)

I'm using Photoview for showing pictures. So user can zoom the image and then draw some point.

There is also a function to delete this point. In this case I redraw whole bitmap:

```
matrix = new Matrix();
canvas.drawBitmap(bmp, matrix, paint);
setImageBitmap(bmp);
```

But now I want to zoom image to previous position/coordinates.

This should work:

`setScale(scale, focalX, focalY, false);`
I know the scale but I need focalX, focalY.

How can I get it? Maybe I should somehow calculate it from the

`getSuppMatrix(matrix);`
But I'm not sure if it's possible and how.

Do you have some tips? Help?