getClip method

@override Path getClip(Size size)

Returns a description of the clip given that the render object being clipped is of the given size.

Implementation

@override
Path getClip(Size size) {
  // 定义一个矩形路径
  Path outerPath = Path()
    ..addRect(Rect.fromLTWH(0, 0, size.width, size.height));

  // 定义一个内部镂空的矩形路径
  Path innerPath = Path()
    ..addRect(
        Rect.fromLTRB(left, top, size.width - right, size.height - bottom));

  // 使用 Path.combine 进行路径的合并，将内部的矩形镂空
  return Path.combine(PathOperation.difference, outerPath, innerPath);
}