ToggleablePainter constructor Null safety

1. Flutter
2. material
3. ToggleablePainter
4. ToggleablePainter constructor

ToggleablePainter class

1. Constructors
2. ToggleablePainter
3. Properties
4. activeColor
5. downPosition
6. focusColor
7. hashCode
8. hasListeners
9. hoverColor
10. inactiveColor
11. inactiveReactionColor
12. isFocused
13. isHovered
14. position
15. reaction
16. reactionColor
17. reactionFocusFade
18. reactionHoverFade
19. runtimeType
20. semanticsBuilder
21. splashRadius
22. Methods
23. addListener
24. dispose
25. hitTest
26. noSuchMethod
27. notifyListeners
28. paint
29. paintRadialReaction
30. removeListener
31. shouldRebuildSemantics
32. shouldRepaint
33. toString
34. Operators
35. operator ==