if(size.width < minSize.width)
  _size = Size(minSize.width, size.height)
if(size.height < minSize.height)
  _size = Size(size.width, minSize.height)
if(size.width > maxSize.width)
  _size = Size(maxSize.width, size.height)
if(size.height > maxSize.height)
  _size = Size(size.width, maxSize.height)