private void setImageViewMatrix(Matrix matrix) {
        mImageView.setImageMatrix(matrix);

        // Call MatrixChangedListener if needed
        if (mMatrixChangeListener != null) {
            RectF displayRect = getDisplayRect(matrix);
            if (displayRect != null) {
                mMatrixChangeListener.onMatrixChanged(displayRect);
            }
        }
    }
Resets the Matrix back to FIT_CENTER, and then displays its contents
main/src/main/java/com/quxianggif/common/view/photoview/PhotoViewAttacher.java