## Following Qt

abstract Object


abstract Widget <: Object


abstract Observable <: Object
abstract AbstractModel <: Observable



abstract Container <: Widget
abstract Layout <: Object


abstract Control <: Widget
abstract WidgetModel <: Control
abstract WidgetVectorModel <: WidgetModel
abstract Style <: Widget



## imlement these?
abstract AbstractButton <: Widget
abstract AbstractSlider <: Widget
abstract AbstractSpinBox <: Widget


