RenderProxyBox
...
RenderVisibilityDetector
+bounds:Rect
RenderObjectWidget
Widget
+key:Key
VisibilityDetector
+ onVisibilityChanged: Function(VisibilityInfo)?
RenderVisibilityDetectorBase
RenderObject
AbstractNode
VisibilityInfo
+visibleBounds:Rect+clipRect:Rect+visibleFraction:get
RenderBox
SingleChildRenderObjectWidget
DiagnosticableTree
![[UML]类图](https://www.processon.com/chart_image/template/thumb/6369f5a15653bb5ba36ab322.png?tid=6369f5a15653bb5ba36ab321)
