private void adjustRightByAspectRatio(RectF rect, float aspectRatio) {
    rect.right = rect.left + rect.height() * aspectRatio;
  }
Adjust right edge by current crop window height and the given aspect ratio, the left edge
remains in possition while the left adjusts to keep aspect ratio to the height.
core/src/main/java/com/theartofdev/edmodo/cropper/CropWindowMoveHandler.java