Serhii Bykov: macOS development from iOS developer’s perspective

Serhii Bykov shares his experience about switching from iOS development to macOS. Is there a lot of differences? What is similar? How did it feel, did it require much time and effort?

1. macOS development from iOS developer’s perspective Serhii Bykov macOS Developer, Setapp 1
2. Agenda • What’s similar • What’s different • What’s unique for macOS 2
3. Intro 3
4. Who am I • 5+ years of iOS Development • ≈ 10 different projects • 6 months of macOS Development 4
5. Why did I switch to macOS • All my iOS projects were not so big • Most of the time I was the only one iOS developer in a team • I thought there were more challenging tasks in macOS development 5
6. ❓ Why am I giving this talk • Cocoa community is big and it keeps growing • 90-95% people of Cocoa community are iOS developers • I am still struggling while developing for macOS • So I’ve decided to provide an easy ramp-up for iOS developers to start developing for macOS 6
7. Technical comparison 7
8. ♊ What’s similar 8
9. ♊ What’s similar • Environment • Frameworks • Classes 9
10. ♊ What’s similar - Environment • macOS • Xcode (or AppCode) • Swift, Objective-C 10
11. ♊ What’s similar - Frameworks • Foundation • Core Animation • Core Graphics • Core Text • Core Data • libdispatch • etc. 11
12. ♊ What’s similar - UI frameworks • UIKit - lightweight version of AppKit • UIKit & AppKit are sharing a lot of concepts 12
13. ♊ What’s similar - UI frameworks - Class names 13 UIKit AppKit UIWindow NSWindow UIViewController NSViewController UIView NSView UIResponder NSResponder
14. 14 Isn’t it enough to replace UI with NS in your iOS app to get macOS app?
16. What’s different 16
17. What’s different • Windows • Views • Collections • Images • Colors • Restrictions 17
18. Windows 18
19. UIWindow vs NSWindow • UIWindow - cannot be modified, since it takes up the whole screen • NSWindow - can be resized, zoomed, minimised, hidden, closed, etc. 19
20. NSWindowController NSWindowController NSWindow NSViewController
21. Windows - Parent Class 21 @interface NSWindow : NSResponder @interface UIWindow : UIView
22. Views 22
23. Views • View system works very differently on the Mac • On iOS, views were backed by Core Animation layers by default • AppKit integrated Core Animation into views much later 23
24. Views - Different Kinds • Layer-Backed Views • Layer-Hosting Views 24
25. Layer-Backed Views • A layer-backed view is a view that is backed by a Core Animation layer • Any drawing done by the view is cached to the underlying layer object • You should never interact directly with the layer 25
26. Modifying UIKit layer someUIView.layer.backgroundColor = UIColor.red.cgColor someUIView.backgroundColor = .red 26
27. NSView has no backgroundColor 27
28. Modifying AppKit layer class ColoredView: NSView { override init(frame frameRect: NSRect) { super.init(frame: frameRect) wantsLayer = true } var backgroundColor: NSColor! { didSet { needsDisplay = true } } override var wantsUpdateLayer: Bool { return true } override func updateLayer() { layer?.backgroundColor = backgroundColor?.cgColor ?? nil } } 28
29. Layer-Hosting View • A layer-hosting view is a view that contains a Core Animation layer that you intend to manipulate directly • You are responsible for managing the view’s layer • Do not rely on the view for drawing • Do not add subviews 29
30. Layer-Hosting View - Example class LayerHostingView: NSView { override init(frame frameRect: NSRect) { super.init(frame: frameRect) layer = CALayer() wantsLayer = true } } 30
31. Layer-Hosting View - Why 31 • Why would one create a layer-hosting view? • When you need some advanced operations with layer or when you want to configure a hierarchy of layers associated with a single view
32. Views - Different Kinds - Recap 32 • Layer-Backed Views • Basic operations with views • Layer-Hosting Views • Advanced operations that need some manipulations with layer
33. ⚙ Other View-Related Gotchas • Coordinate system • Listening mouse events • Label • NSCell 33
34. UIKit coordinate system 34 (0; 0)
35. AppKit coordinate system 35 (0; 0)
36. Fix AppKit coordinate system class FlippedView: NSView { override var isFlipped: Bool { return true } } 36
37. Receiving events from mouse class MouseTrackingView: NSView { override func mouseMoved(with event: NSEvent) { // this method won't be called } } 37
38. Receiving events from mouse class MouseTrackingView: NSView { private var trackingArea: NSTrackingArea? override func mouseMoved(with event: NSEvent) { // now this method will be called } override func updateTrackingAreas() { if let area = trackingArea { removeTrackingArea(area) } let options: NSTrackingArea.Options = [.mouseMoved, .activeAlways] let area = NSTrackingArea(rect: bounds, options: options, owner: self, userInfo: nil) addTrackingArea(area) self.trackingArea = area } } 38
39. Label • In AppKit there’s no such class as NSLabel 39 let label = NSTextField() label.drawsBackground = false label.isBezeled = false label.isEditable = false label.isSelectable = false
40. NSCell • AppKit controls have been traditionally backed by NSCell subclasses • NSCell ≠ NSTableCellView ≠ NSCollectionCellView • Apple is deprecating this approach 40
41. ⚙ NSCell - Poor Little Bryan 41
42. Collections 42
43. Collections - Common • No scroll view by default • You had to install your NSTableView or NSCollectionView to NSScrollView via documentView property 43
44. Collections - NSTableView • Columns • Cells 44
45. NSTableView - Columns 45
46. NSTableView - Different cell classes • NSTableView can present the following objects • NSCell subclasses • NSTableCellView subclasses 46
47. NSTableView - NSCell-based 47
48. NSTableView - NSView-based 48
49. NSCell-based vs NSView-based 49 • NSCell-based - when you don’t need more than 1 control in cell • NSView-based - all other cases
50. Images 50
51. NSImage • NSImage is more powerful than UIImage 51 NSImage UIImage
52. NSImage - Key Differences • NSImage can be backed by one or more image representations • NSImageRep - representations for BMP, EPS, PDF, etc • NSImage will cache the result when it’s drawn to the screen 52
53. Colors 53
54. Colors • macOS supports fully color-calibrated workflows, so anything having to do with colors is potentially more complicated • A common task is to use a color in your app that your designers have specified for you • Make sure you’re using same color space for Xcode & <your_design_app> 54
55. Restrictions 55
56. Restrictions • Sandboxing • Permissions 56
57. Sandboxing - What is Sandbox 57
58. Sandboxing - Limitations A sandboxed app must explicitly state its intent to use any of the following resources 58 • Hardware (, , ) • Network Connections (⬆, ⬇) • App Data (, , ) • User Files (, , , , )
59. 59 macOS sandbox = iOS sandbox?
60. Sandboxing - Mac App Store • Apps distributed through the Mac App Store must adopt App Sandbox. • Apps signed and distributed outside of the Mac App Store with Developer ID can use App Sandbox as well. 60
61. Can we do whatever we want? 61
63. Permissions - Pre-Catalina • Calendar, Reminders - 10.9 • Contacts - 10.11 • Photos - 10.13 • Full Disk Access - 10.14 63
64. Permissions - Catalina • Camera, Microphone , • Screen Recording • Keyboard Input Monitoring ⌨ • User Folders • Accessibility 64
65. What’s unique 65
66. What’s unique • AppKit-only controls • Cocoa Bindings • Interaction with system 66
67. AppKit-only controls 67
68. AppKit-only controls • Basic • Collections • Other 68
69. AppKit - Basic controls • Buttons • Text Inputs • Sliders 69
70. Buttons - Styles 70
71. Buttons - Behaviors 71
72. ⌨ NSTextField 72
73. ⌨ NSComboBox 73
74. ⌨ NSSearchField 74
75. ⌨ NSTokenField 75
76. NSSlider - Types 76
77. NSSliders - Tick Marks 77
78. Collections • NSOutlineView • NSGridView • NSSplitView 78
79. NSOutlineView 79
80. NSGridView 80
81. UIKit - UISplitViewController 81
82. AppKit - NSSplitView 82
83. NSSplitView - 3 or more panels 83
84. NSSplitView - Hozontal/Vertical Mode 84
85. NSSplitView - Free Resize 85
86. AppKit - Other • NSDatePicker • NSLevelIndicator • NSPathControl • NSColorPicker • NSFontPicker 86
87. UIDatePicker 87
88. NSDatePicker - Textual Mode 88
89. NSDatePicker - Graphical Mode 89
90. NSLevelIndicator 90
91. NSPathControl 91
92. NSColorPicker 92
93. NSFontPicker 93
94. Cocoa Bindings 94
95. Cocoa Bindings - What are they • Cocoa bindings technology provides a way of keeping model and view values synchronised 95
96. Bindings - Basic Example • Text Field text content changes string variable • String variable changes Text Field text content 96
97. NSTextField - Enable binding 97
98. NSTextField - 0 LoC binding 98
99. 99 NSTextField - 0 LoC binding
100. Bindings - NSController & subclasses The other key part of Cocoa Bindings is the abstract class NSController and its 3 subclasses • NSObjectController • NSArrayController • NSTreeController 100
101. Bindings - NSTableView • NSArrayController w/ NSTableView simplifies following operations: • Add, remove, edit • Sorting, filtering • Manage selection • etc. 101
102. Bindings - PONSO Model class Speaker : NSObject { @objc dynamic var firstName : String = "" @objc dynamic var lastName : String = "" init(firstName: String, lastName: String) { super.init() self.firstName = firstName self.lastName = lastName } } 102
103. NSViewController - Sample Data class ViewController: NSViewController { @objc dynamic var speakers: [Speaker] = [ Speaker(firstName: "Serhii", lastName: "Bykov"), Speaker(firstName: "Sergey", lastName: "Krivoblotsky"), Speaker(firstName: "Bohdan", lastName: "Mihiliev"), ] } 103
104. Bindings - Add NSArrayController 104
105. Bind NSArrayController to NSTableView 105
106. Bind NSArrayController to NSTableView 106
107. Bind NSArrayController to NSViewController 107
108. Bind properties to cells 108
109. Bind properties to cells 109
110. NSTableView w/ data (0 LoC) 110
111. Interaction with a system 111
112. Interaction with a system • NSWorkspace • NSRunningApplication • NSTask / Process 112
113. NSWorkspace A workspace that can launch other apps and perform a variety of file- handling services • File operations • System operations 113
114. NSWorkspace - Files Operations • Open files & URLs • Duplicating files ♊ • Moving files to the trash • Revealing a file location in Finder • Getting icons for files 114
115. NSWorkspace - System Operations • Launching an application ⬇ • Hiding all other applications • Getting a list of all running apps or the frontmost app • Get or modify the Desktop picture • etc. 115
116. NSRunningApplication • Getting running application instances • Activate, hide & unhide applications ✒ • Getting application info ℹ • Terminating applications ☠ 116
117. NSTask / Process • NSTask run another program as a process • Apple API are feature-rich, but sometimes all you need is some command line tool • Some apps are just GUI shells for command line tools (e.g. any git clients) 117
118. More and more • Documents • Background processes • Cross-process communication • AppleScript • Plugin Infrastructure • etc. 118
119. Catalyst 119
120. Catalyst - Pros • New framework • Code sharing • Development pace 120
121. Catalyst - Cons • New framework • You will still need to write a platform-specific code • macOS 10.15+ 121
122. iOS Adoption Rate • iOS 13 - 81.5% • iOS 12 - 14.2% • Other - 4.3% Other 4% iOS 12 14% iOS 13 82% Data: https://www.idownloadblog.com/2019/10/17/ios-13-adoption-rate-fifty-percent/ 122
123. macOS Adoption Rate • Mojave - 33.49% • Catalina - 27.12% • High Sierra - 17.11% • Sierra - 8.2% • Other - 14.1% Data: https://gs.statcounter.com/macos-version-market-share/desktop/worldwide/#monthly-201911-201911-bar Other 14% Sierra 8% High Sierra 17% Catalina 27% Mojave 33% 123
124. Catalyst - Wrap Up • Catalyst can wait till it becomes stable and more users will update to Catalina • It is still worth trying since it’s a good way to try a lil bit of desktop development 124
125. Conclusions 125
126. Conclusions • All missing API’s will be probably covered by code written by your colleagues • Despite all the differences between platforms, your daily development process will look pretty close to your iOS tasks, if you’re not doing something extraordinary • Setapp will soon have iOS application, so feel free to apply to us • https://macpaw.com/careers/macos-setapp 126
127. Resources • https://www.objc.io/issues/14-mac/ • https://nshipster.com/ • https://pilky.me • https://www.highcaffeinecontent.com/blog/ • https://onmyway133.github.io/tags/macOS/ • http://www.cocoawithlove.com • https://eclecticlight.co 127
128. 128 iOS Developer macOS Developer
129. Thank you! 129
130. Q&A 130
131. Contacts • facebook.com/esphynox • t.me/esphynox • twitter.com/esphynox • github.com/esphynox 131