' Made in PlantUml. You can try it out here: http://plantuml.com/plantuml
' Based on commit eb7a60fcf83cd4e7a41ae5955e57935e39928fbd

@startuml
hide empty members
hide circles
hide stereotypes

skinparam class {
    BorderColor Black
    ArrowColor Black
    
    ' Using stereotypes to define the background colors
    BackgroundColor<<qt>> #e5f2da
    BackgroundColor<<pg>> #e5e5f4
}
skinparam shadowing false


'----------- Qt package ----------`


class QGraphicsGridLayout <<qt>>

class QGraphicsItem <<qt>>

class QGraphicsLayout <<qt>>

class QGraphicsLayoutItem <<qt>>

class QGraphicsObject <<qt>>

class QGraphicsScene <<qt>> { 
    items 
}

class QGraphicsWidget <<qt>>

class QGraphicsView <<qt>> {
    scene
}

class QObject <<qt>>

class QPaintDevice <<qt>>

class QWidget <<qt>>


'----------- PyQtGraph package ----------`


class GraphicsItem <<pg>>

class GraphicsLayout <<pg>> {
    layout
}

class GraphicsLayoutWidget <<pg>> {
    graphicsLayout
}

class GraphicsObject <<pg>>

class GraphicsView <<pg>>

class GraphicsWidget <<pg>> 

class ImageItem <<pg>>

class ImageView <<pg>> {
    graphicsView
    imageItem
    scene
    view
}

class PlotCurveItem <<pg>>

class PlotDataItem <<pg>> {
    curve
    scatter
}

class PlotItem <<pg>> {
    layout
    vb
}

class PlotWidget <<pg>> {
    plotItem
}

class ScatterPlotItem <<pg>>

class ViewBox <<pg>>


'---------- Inheritance within Qt ----------'
QObject <|-- QGraphicsObject
QGraphicsItem <|-- QGraphicsObject
QGraphicsObject <|-- QGraphicsWidget
QGraphicsLayoutItem <|-- QGraphicsWidget
QGraphicsLayoutItem <|-- QGraphicsLayout
QGraphicsLayout <|-- QGraphicsGridLayout
QPaintDevice <|-- QWidget
QObject <|-- QWidget
QObject <|-- QGraphicsScene
QWidget <|-- QGraphicsView

 
'---------- Inheritance from Qt to PyQtGraph ----------'
QGraphicsWidget <|-- GraphicsWidget
QGraphicsObject <|-- GraphicsObject
QGraphicsView <|-- GraphicsView
QWidget <|-- ImageView


'---------- Inheritance  within PyQtGraph ----------'
GraphicsItem <|-- GraphicsObject
GraphicsItem <|-- GraphicsWidget
GraphicsWidget <|-- GraphicsLayout
GraphicsWidget <|-- PlotItem
GraphicsWidget <|-- ViewBox
GraphicsObject <|-- ScatterPlotItem
GraphicsObject <|-- PlotCurveItem
GraphicsObject <|-- ImageItem
GraphicsObject <|-- PlotDataItem
GraphicsView <|-- PlotWidget
GraphicsView <|-- GraphicsLayoutWidget


'---------- Aggregation ----------'

' Shorter arrow so at same height in the diagram
QGraphicsScene::items o- QGraphicsItem                      #b8b8b8
QGraphicsView::scene o- QGraphicsScene                      #b8b8b8

' Longer (regular) arrows
PlotWidget::plotItem o-- PlotItem                           #b8b8b8
GraphicsLayoutWidget::graphicsLayout o-- GraphicsLayout     #b8b8b8
PlotDataItem::curve o-- PlotCurveItem                       #b8b8b8
PlotDataItem::scatter o-- ScatterPlotItem                   #b8b8b8
PlotItem::vb o-- ViewBox                                    #b8b8b8
PlotItem::layout o-- QGraphicsGridLayout                    #b8b8b8
GraphicsLayout::layout o-- QGraphicsGridLayout              #b8b8b8
ImageView::graphicsView o-- GraphicsView                    #b8b8b8
ImageView::imageItem o-- ImageItem                          #b8b8b8
ImageView::scene o-- QGraphicsScene                         #b8b8b8
ImageView::view o-- ViewBox                                 #b8b8b8


@enduml