@Override
    public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {
        // Update our base matrix, as the bounds have changed
        if (left != oldLeft || top != oldTop || right != oldRight || bottom != oldBottom) {
            updateBaseMatrix(mImageView.getDrawable());
        }
    }
The component of {@link PhotoView} which does the work allowing for zooming, scaling, panning, etc.
It is made public in case you need to subclass something other than {@link ImageView} and still
gain the functionality that {@link PhotoView} offers
main/src/main/java/com/quxianggif/common/view/photoview/PhotoViewAttacher.java