drawing method

  1. @override
void drawing(
  1. Offset nowPoint
)
override

绘制过程中调用（手指移动时）

Called during drawing (when finger is moving)

Implementation

@override
void drawing(Offset nowPoint) {
  endPoint = nowPoint;
  center = Offset((startPoint.dx + endPoint.dx) / 2, (startPoint.dy + endPoint.dy) / 2);
  radius = (endPoint - (startFromCenter ? startPoint : center)).distance;
}