QtEmbedded

1. Qt tales from the embedded trenches Cabledogs (savago, igolivei) 2011

2. About us Adenilson Cavalcanti (Savago): KDE-pim, KDE-Plasma, IMTK, libgcal, amora Igor Trindade Oliveira (igolive): KDE-pim, KDE-plasma, Gallium

3. Structure A problem is given A solution is proposed Discussion

4. Topics 1 Kinectic scrolling pain 2 Meego UI without libmeegotouch? 3 Sliding Widgets 4 JSON parsing 5 D-BUS 6 Responsiveness 7 Symbian on Linux

5. Kinetic Scrolling

6. Kinetic example: iPhone 2007

7. Prior art? Bill Buxton: Two-handed input in HCI, 1982 Canola 2007 etc

11. A personal favorite: Canola 2007

12. What about Qt? flickable 2008

13. How scrolling works?

14. How kinetic scrolling works? Displacement is defined in factor of: attenuation given by Easing curve time elapsed between the drag event other factors (e.g. friction, etc) optimizations: clipping, lazy loading, ring buffer, snapshots, etc

15. Demo time C++: toyflick QML Looking at the pros

16. Currently known Qt-based implementations Ariya’s Flickable 2008 toyflick 2009 Plasma ScrollWidget 2009 IMTK ImtkKinecticListView 2010 QML Flickable 2010

17. Meego UI without libmeegotouch?

18. Meego app Ok, somewhat old example...

19. Can it run on Symbian? Short answer: NOT! Long answer: it could be ported... You have 1 day! Solution: cheat!

24. UI elements

25. UI elements

26. UI elements

27. UI elements

28. UI elements

29. Final result

30. Pure blood Qt runs everywhere!

31. ’Minor’ details: 7 months ago Forgot the Buttons... Rescalable button backgrounds Borders on background Centered Icons Layouts/sizeHints sometimes are tricky

36. ’Minor’ details: today Rescalable button backgrounds: QML BorderImage Borders: QML BorderImage Centered Icons: maybe Qt components Layouts/sizeHints: QML anchors

40. Demo time C++: frame Animated layout items

41. Sliding widgets

42. Example: iPhone contact list

43. How to do it?

44. step1: have a specialized layout

45. step2: put widget side by side

46. step3: make both visible...

47. step4: animate!

48. step5: hide the old widget

49. Demo time C++: slider

50. ’Minor’ details: 7 months ago QGraphicsLayout is not a QObject Multiple heritance is nasty! Parenting issues of widgets No documentation, of course...

54. ’Minor’ details: today Qt Components has PageStack

55. JSON parsing

56. Qt doesn’t parse JSON?

57. Qt doesn’t parse JSON? SAY WHAAAT!!?

58. Solution: QJSON Really easy to use Tested on embedded platforms License is LGPL Use it. Really.

62. D-BUS

63. The-BUS

64. Rules of thumb Small batches of items Marshalling/de-marshall: operator<< Your item must be a QObject D-Feet is your friend

68. Responsiveness

69. Responsiveness

70. Simple! Threads!

71. Why sometimes is a bad idea... Hard to debug Resource consumption Embedded limitations

74. "Are for people who can’t use state machines." Solution: Divide and conquer

75. "Are for people who can’t use state machines." Solution: Divide and conquer

76. Demo time D-BUS server JSON data QML UI

77. Symbian: Can Tux sing the Blues?

78. Symbian?

79. Yes!

80. Demo time Compiling a shared library Compiling an app

81. The end?

82. Vacations, of course!

83. Vacations

84. Vacations

85. Vacations

86. Vacations

87. By the way...

88. Thanks! E-mail: adenilson.silva@openbossa.org Site: http://savago.wordpress.com Site: http://www.openbossa.org.br

QtEmbedded

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