PaintContent class abstract

绘制内容抽象基类

所有绘制内容（线条、形状等）的基类 定义了绘制的生命周期方法和序列化接口

Paint Content Abstract Base Class

Base class for all drawing content (lines, shapes, etc.) Defines the lifecycle methods and serialization interface for drawing

Implementers

• Circle
• EmptyContent
• Eraser
• Rectangle
• SimpleLine
• SmoothLine
• StraightLine

Constructors

PaintContent()

PaintContent.paint(Paint paint)

Properties

contentType → String

内容类型标识（用于JSON序列化）

no setter

hashCode → int

The hash code for this object.

no setter, inherited

paint ↔ Paint

画笔配置

getter/setter pair

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

copy() → PaintContent

复制实例，避免对象引用传递

draw(Canvas canvas, Size size, bool deeper) → void

绘制核心方法 canvas 画布对象 size 画布尺寸 deeper 当前是否为底层绘制（true为历史记录层，false为实时绘制层）

drawing(Offset nowPoint) → void

绘制过程中调用（手指移动时）

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

startDraw(Offset startPoint) → void

开始绘制（手指按下时）

toContentJson() → Map<String, dynamic>

转换为JSON内容（子类实现）

toJson() → Map<String, dynamic>

转换为JSON对象

toString() → String

A string representation of this object.

override

Operators

operator ==(Object other) → bool

The equality operator.

inherited