Circle class
圆形/椭圆绘制内容
支持两种绘制模式：
- 从圆心开始绘制：起点为圆心，终点决定半径
- 从对角开始绘制：起点和终点为对角，自动计算圆心和半径
Circle/Ellipse Drawing Content
Supports two drawing modes:
- Draw from center: start point is center, end point determines radius
- Draw from diagonal: start and end points are diagonal, automatically calculates center and radius
- Inheritance
-
- Object
- PaintContent
- Circle
Constructors
- Circle({bool isEllipse = false, bool startFromCenter = true})
- Circle.data({bool isEllipse = false, bool startFromCenter = true, required Offset center, required double radius, required Offset startPoint, required Offset endPoint, required Paint paint})
-
Circle.fromJson(Map<
String, dynamic> data) -
factory
Properties
- center ↔ Offset
-
圆心坐标
getter/setter pair
- contentType → String
-
内容类型标识（用于JSON序列化）
no setteroverride
- endPoint ↔ Offset
-
结束点坐标
getter/setter pair
- hashCode → int
-
The hash code for this object.
no setterinherited
- isEllipse → bool
-
是否为椭圆
final
- paint ↔ Paint
-
画笔配置
getter/setter pairinherited
- radius ↔ double
-
半径
getter/setter pair
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
- startFromCenter → bool
-
是否从圆心开始绘制
final
- startPoint ↔ Offset
-
起始点坐标
getter/setter pair
Methods
-
copy(
) → Circle -
复制实例，避免对象引用传递
override
-
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）override -
drawing(
Offset nowPoint) → void -
绘制过程中调用（手指移动时）
override
-
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）
override
-
toContentJson(
) → Map< String, dynamic> -
转换为JSON内容（子类实现）
override
-
toJson(
) → Map< String, dynamic> -
转换为JSON对象
inherited
-
toString(
) → String -
A string representation of this object.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited