numColumns property Null safety

1. jrpn
2. view.buttons
3. LandscapeButtonFactory
4. numColumns property

LandscapeButtonFactory class

1. Constructors
2. LandscapeButtonFactory
3. Properties
4. acceleratorTextStyle
5. context
6. controller
7. enterKeyTextOffset
8. fill
9. fKeyTextOffset
10. fTextOffset
11. fTextSmallLabelStyle
12. fTextStyle
13. gKeyTextOffset
14. gTextOffset
15. gTextStyle
16. gTextStyleForLJ
17. hashCode
18. height
19. innerBorder
20. keyTextOffset
21. keyTextStyle
22. lowerSurface
23. numColumns
24. numRows
25. onKeyTextOffset
26. outerBorder
27. padRight
28. runtimeType
29. screen
30. settings
31. shiftDownTweak
32. shiftKeyTextStyle
33. specialButtonTextStyle
34. upperSurface
35. width
36. Methods
37. addUpperGoldLabels
38. buildButtons
39. buttonLayout
40. enterPos
41. noSuchMethod
42. toString
43. totalButtonHeight
44. Operators
45. operator ==