getPreferredSize method

  1. @override
Size getPreferredSize(
  1. bool isEnabled,
  2. bool isDiscrete
)
override

Returns the preferred size of the shape, based on the given conditions.

Implementation

@override
Size getPreferredSize(bool isEnabled, bool isDiscrete) {
  onThumbSizeChange?.call(thumbSize); // 通过回调返回 thumb 大小
  return Size(thumbSize, thumbSize); // 返回 thumb 的尺寸
}