paint_contents library
绘制内容导出文件
包含所有绘制内容类型：线条、形状、橡皮擦等
Drawing contents export file
Contains all drawing content types: lines, shapes, eraser, etc.
Classes
- Circle
- 圆形/椭圆绘制内容
- EmptyContent
- Eraser
- 橡皮擦绘制内容
- PaintContent
- 绘制内容抽象基类
- Rectangle
- 矩形绘制内容
- SimpleLine
- 自由线条绘制内容
- SmoothLine
- 笔触线条
- StraightLine
- 直线绘制内容