kivy的类层次```mermaid classDiagram %%基类 WidgetBase <|-- Widget

classDiagram

direction LR


EventDispatcher <|-- App

%% WidgetBase线
WidgetBase <|-- Widget
note for WidgetBase"基类"

Widget <|-- Layout

Layout <|-- GridLayout
Layout <|-- AnchorLayout
Layout <|-- BoxLayout
Layout <|-- PageLayout
Layout <|-- RelativeLayout
Layout <|-- ScatterLayout
Layout <|-- FloatLayout
Layout <|-- StackLayout

RelativeLayout <|-- ColorPicker

Widget <|-- TextInput
Widget <|-- CheckBox
Widget <|-- Switch

Widget <|-- TreeView

Widget <|-- StencilView

Widget <|-- Label

StencilView <|-- ScrollView
StencilView <|-- Carousel
StencilView <|-- DropDown

DropDown <|-- ActionDropDown

ScrollView <|-- RecycleView


Label <|-- Button
Button <|-- Spinner
Button <|-- SpinnerOption
Button <|-- BubbleButton
Button <|-- SplitterStrip
Button <|-- ToggleButton
Button <|-- ActionButton
Button <|-- ActionGroup

ActionGroup <|-- ActionOverflow
ActionGroup  --|> ActionItem

ToggleButton <|-- ActionToggleButton
ToggleButton <|-- TabbedPanelHeader

TabbedPanelHeader <|-- TabbedPanelItem

ActionButton --|> ActionItem
ActionToggleButton  --|> ActionItem



class GridLayout{
    cols
    rows
    spacing
    padding
}
class Layout{
    do_layout()
}
class Widget{
    + add_widget()
}