The document discusses design principles for accessibility on Mac OS X. It covers three main focus areas: users, technologies, and developers. For users, it discusses considerations for visual, auditory, cognitive and physical disabilities. It provides examples of built-in accessibility features like VoiceOver, adjustable font sizes, sound alternatives to audio feedback, full keyboard support, and simplifying interfaces. For developers, it recommends following principles of perceivable, operable, understandable and robust design when implementing universal access.

1. Design principles for accessibility on Mac OS X
Gregory Hughes, Ph.D.
Software Engineer
Usable by Everybody
2

2. What Is Universal Design?
3

3. Three Main Focus Areas
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4. Yellow Dog Productions · Digital Vision · Getty Images
5

5. Focus Areas
Users
6

6. 7

7. Technologies
Focus Areas
Users
8

8. 9

9. Developers
Technologies
Focus Areas
Users
10

10. Developers
Technologies
Focus Areas
Users
11

11. 10 Million
Americans are visually impaired
www.afb.org/info_documents.asp?collectionid=15 [Mar 25, 2008]
12

12. S. Kochkin. Marketrak vii: Hearing loss population tops 31 million. The Hearing Review, (2005), July 2005.
31 Million
Americans are hearing impaired
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13. 12 Million
Americans have a learning disability
C. Smith and L. Strick. Learning Disabilities: A to Z. The Free Press, 1997.
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14. 50 Million
1 in 5
Americans have a disability
http://www.census.gov/Press-Release/www/releases/archives/facts_for_features_special_editions/001823.html
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15. User Considerations
Visual Auditory
Cognitive
Physical
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16. Developers
Technologies
Focus Areas
Users
17

17. Developers
Technologies
Focus Areas
Users
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18. 19

19. 20

20. 21

21. Talking iPods
22

22. VoiceOver
5 Years
Macs with VoiceOver
Millions
23

23. ?>>>>
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24. Developers
Technologies
Focus Areas
Users
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25. Developers
Technologies
Focus Areas
Users
26

26. Universal Design Considerations
Visual Auditory
Cognitive
Physical
27

27. Implementing Universal Design
Perceivable
Operable
Understandable
Robust
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28. How to Implement Universal Design?
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29. Perceivable
Visual Considerations
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30. 31

31. Resolution
•Usable at low resolutions
■ 1024x768 recommended
■ Aids users with visual impairments
■ Aids elderly users
■ Helps when displaying on a projector
32

32. 33

33. Blurry on
purpose
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34. Blurry on purpose
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35. 36

36. Font Size
•Provide adjustable font sizes for key UI
■ Aids users with visual impairments
■ Aids elderly users
■ Helps during demonstrations
37

37. - (NSUInteger)adjustedSystemFontSize
{
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
CGFloat fontSize = [defaults floatForKey:@”fontSize”];
if ( fontSize < 8.0f )
{
return [NSFont systemFontSize];
}
return fontSize;
}
Adjust UI Font Size
38

38. - (NSFont *)adjustedSystemFont
{
CGFloat newSize = [self adjustedSystemFontSize];
return [NSFont systemFontOfSize:newSize];
}
Adjust system fonts
Adjust UI Font Size
39

39. - (void)updateFonts
{
[myTextLabel setFont:[self offsetFontForElement:myTextLabel];
[myTextLabel2 setFont:[self offsetFontForElement:myTextLabel2];
}
Apply to an element
Adjust UI Font Size
40

40. - (void)updateFonts
{
NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
NSFont *newFont = [self adjustedSystemFont];
for ( NSTableColumn *column in [myTable tableColumns] )
{
id dataCell = [column dataCell];
[dataCell setFont:newFont];
}
CGFloat desiredHeight = [layoutManager defaultLineHeightForFont:newFont];
[myTable setRowHeight:desiredHeight + 1];
[layoutManager release];
}
Apply to an NSTable
Adjust UI Font Size
41

41. DOW J 0.30 %
Nasdaq 0.12 %
DOW J + 0.30 %
Nasdaq - 0.12 %
42

42. DOW J 0.30 %
Nasdaq 0.12 %
DOW J + 0.30 %
Nasdaq - 0.12 %
43

43. Blank on purpose
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44. Accessibility API
Most items can be given a description in Interface Builder
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45. - (void)accessibilitySetOverrideValue:(id)value
forAttribute:(NSString *)attribute
Programmatic accessibility
•Convenience method for anything that can be set in IB
NSAccessibility
46

46. Demo
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47. Perceivable
Auditory Considerations
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48. Blank on purpose
49

49. 50

50. Blank on purpose
51

51. Every Mac includes a
range of built in features
to address those
with disabilities,
vision, hearing,
motor skills,
and learning disabilities and
all of these technologies
come standard on
every new Mac.
52

52. Blank on purpose
53

53. Auditory Considerations
•Don’t provide audio-only feedback
•All sounds should work in mono audio
•Be conscious of sound frequency choices
•Consider allowing user-selectable sounds
54

54. NSBeep()
55

55. NSBeep()
56

56. Dock Icon
Change icon to represent state
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57. Dock Icon
Change icon to represent state
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58. Dock Icon
Change icon to represent state
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59. Dock Icon
Change icon to represent state
NSImage *myImage = [NSImage imageNamed:imageName];
[NSApp setApplicationIconImage: myImage];
60

60. Dock Icon
Badge the icon
[[NSApp dockTile] setBadgeLabel:@"1"];
1
61

61. Dock Icon
Bounce your icon
[NSApp requestUserAttention:NSCriticalRequest];
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62. Dock Icon
Bounce your icon
[NSApp requestUserAttention:NSCriticalRequest];
63

63. Dock Icon
Bounce your icon
[NSApp requestUserAttention:NSCriticalRequest];
64

64. Demo
65

65. Operable
Physical Considerations
66

66. 67

67. Physical Considerations
Provide interaction alternatives
•Provide keyboard shortcuts for common tasks
•Ensure full keyboard navigation
•Provide keyboard alternatives to mouse actions
68

68. Drag and Drop Keyboard Support
Provide a keyboard shortcut
•Add commands to change ordering
•Add cut/copy/paste support alongside
drag and drop
69

69. Enable Full Keyboard Access
Check tab order
70

70. Demo
71

71. Understandable
Cognitive Considerations
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72. 73

73. 74

74. 75

75. 76

76. Fullscreen Mode
Bring an NSView into fullscreen to limit distractions
- (IBAction)enterFullScreen:(id)sender
{
[fullScreenView enterFullScreenMode:[NSScreen mainScreen] withOptions:nil];
}
77

77. Hiding Advanced UI
78

78. Hiding Advanced UI
79

79. Hiding Advanced UI
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80. Demo
81

81. Summary
Resolution
Font size
Color choice
NSAccessibility API
Non-audible feedback
Closed captions
Mono audio
Full keyboard access
Tab order
Menu shortcuts
Simplify interface
Hide advanced options
Fullscreen mode
82

82. Bill Dudney
Application Technologies Evangelist
dudney@apple.com
Accessibility Mailing List
Public developer list
accessibility-dev@lists.apple.com
Documentation
http://developer.apple.com/wwdc
Apple Developer Forums
http://devforums.apple.com
More Information
83

83. Accessibility Web Page
www.apple.com/accessibility
84

84. Accessibility on iPhone OS Nob Hill
Wednesday 4:30PM
Related Sessions
85

85. OS X Accessibility Lab
Application Frameworks
Lab B
Tuesday 2:00PM
iPhone Accessibility Lab
Application Frameworks
Lab B
Thursday 9:00AM
Labs
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86. 87

87. 88

88. 89