draw method

@override void draw(Canvas canvas, Size size, bool deeper)

绘制核心方法

• deeper 当前是否为底层绘制
• 出于性能考虑
• 绘制过程为表层绘制，绘制完成抬起手指时会进行底层绘制

Implementation

@override
void draw(Canvas canvas, Size size, bool deeper) {
  if (deeper) {
    canvas.drawPath(
        drawPath.path, paint.copyWith(blendMode: BlendMode.clear));
  } else {
    canvas.drawPath(drawPath.path, paint.copyWith(color: color));
  }
}