constrainSizeAndAttemptToPreserveAspectRatio method

Size constrainSizeAndAttemptToPreserveAspectRatio (Size size)

Returns a size that attempts to meet the following conditions, in order:

  • The size must satisfy these constraints.
  • The aspect ratio of the returned size matches the aspect ratio of the given size.
  • The returned size as big as possible while still being equal to or smaller than the given size.

Implementation

Size constrainSizeAndAttemptToPreserveAspectRatio(Size size) {
  if (isTight) {
    Size result = smallest;
    assert(() {
      result = _debugPropagateDebugSize(size, result);
      return true;
    }());
    return result;
  }

  double width = size.width;
  double height = size.height;
  assert(width > 0.0);
  assert(height > 0.0);
  final double aspectRatio = width / height;

  if (width > maxWidth) {
    width = maxWidth;
    height = width / aspectRatio;
  }

  if (height > maxHeight) {
    height = maxHeight;
    width = height * aspectRatio;
  }

  if (width < minWidth) {
    width = minWidth;
    height = width / aspectRatio;
  }

  if (height < minHeight) {
    height = minHeight;
    width = height * aspectRatio;
  }

  Size result = Size(constrainWidth(width), constrainHeight(height));
  assert(() {
    result = _debugPropagateDebugSize(size, result);
    return true;
  }());
  return result;
}