Improving your Existing Apps with Swift

Transcription

1 Developer Tools #WWDC15 Improving your Existing Apps with Swift Getting Swifty with It Session 403 Woody L. in the Sea of Swift 2015 Apple Inc. All rights reserved. Redistribution or public display not permitted without written permission from Apple.

2 Demo Set the Time Machine to 2012 The Elements has been restored from a vault

3 Agenda The before app Modernizing UI Mix and match Swift Structs Availability Live filtering

4 Modernizing UI Walk. Walk. Fashion, Baby.

5 Tile Sizes Small Tile Detail Tile

6 18 Ar Argon Atomic Weight: State: Gas Period: 3 Group: 18 Discovered: 1849 A.D.

7 18 Ar Argon Atomic Weight: State: Gas Period: 3 Group: 18 Discovered: 1849 A.D.

8 Pre-Rendered Backgrounds 37px 256px

9 Pre-Rendered Backgrounds 37px 256px

10 256px = 1x 512px = 2x 768px = 3x

11 Does Not Exist Does Not Exist 256px = 1x 512px = 2x 768px = 3x

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16 18 Ar Argon Atomic Weight: State: Gas Period: 3 Group: 18 Discovered: 1849 A.D.

17 Tile Appearance 18 Ar Argon Atomic Weight: State: Gas Period: 3 Group: 18 Discovered: 1849 A.D.

18 Tile Appearance 18 Ar Argon Atomic Weight: State: Gas Period: 3 Group: 18 Discovered: 1849 A.D.

19 Tile Appearance 18 Ar Argon Atomic Weight: State: Gas Period: 3 Group: 18 Discovered: 1849 A.D.

20 Benefits of Custom Drawing Code Goals Custom Drawing Code Modernize the Look Crisp, Sharp Corners Resolution Independence

21 Mix and Match Extending Objective-C Classes with Swift An interoperability overture in the key of Swift.

22 Class Design Base Class Base Class Definition

23 Class Design Base Class + Category Base Category Class Definition

24 Class Design Base Class + Categories Base Category Category Category Category Category Class Definition

25 Class Design Base Class + Categories Base Category Category Category Category Category Class Definition

26 Class Design Base Class + Categories + Swift Extensions Base Extension Category Category Category Category Class Definition

27 Class Design Base Class + Categories Base Extension Category Extension Extension Category Class Definition

28 Class Design Mixed-Language Classes Generated Header Base Bridging Header Extension

29 Class Design Mixed-Language Classes Bridging Header Generated Header Created by Xcode Created by Compiler Maintained by you Maintained by Compiler Contains #import MyClass.h #import Product-Swift.h into MyClass.m Exists in File Navigator Exists in DerrivedData

30 Demo Modernizing The Elements UI Boasting 120% daily intake of vitamin Swift.

31 Partially Rounded Corners

32 Partially Rounded Corners

33 Swift Structs With Playground prototyping Global utility functions: shake em off.

34 Bezier Path 18 Ar Argon Atomic Weight: State: Gas Period: 3 Group: 18 Discovered: 1849 A.D.

35 Bounding Rectangle 18 Ar Argon Atomic Weight: State: Gas Period: 3 Group: 18 Discovered: 1849 A.D.

36 Draw Stroke Stroke s midpoint is the Bezier Path 18 Ar Argon Atomic Weight: State: Gas Period: 3 Group: 18 Discovered: 1849 A.D.

37 Draw Stroke Stroke s midpoint is the Bezier Path 18 Ar Argon Atomic Weight: State: Gas Period: 3 Group: 18 Discovered: 1849 A.D.

38 Draw Stroke Clipping 18 Ar Argon Atomic Weight: State: Gas Period: 3 Group: 18 Discovered: 1849 A.D.

39 Draw Stroke Clipping 18 Ar Argon Atomic Weight: State: Gas Period: 3 Group: 18 Discovered: 1849 A.D.

40 Solution Inset the Bezier Path 18 Ar Argon Atomic Weight: State: Gas Period: 3 Group: 18 Discovered: 1849 A.D.

41 Utility Functions Core Graphics API CGRect CGRectZero() CGRectMake() CGRectGetMaxY() CGRectGetWidth() CGRectUnion() CGRectInset() Struct Global Utility Functions

42 Utility Functions Core Graphics API CGRect CGRectZero() CGRectMake() CGRectGetMaxY() CGRectGetWidth() CGRectUnion() CGRectInset() Struct Methods

43 Utility Functions Core Graphics API.zeroRect (x:,y:,w:,h:).maxy CGRect.width.union(r).rectByInsetting(dx:,dy:) Struct Initializers + Methods

44 Utility Functions Core Graphics API Consistent.zeroRect (x:,y:,w:,h:).maxy CGRect.width.union(r).rectByInsetting(dx:,dy:) Initializer Syntax Encapsulation Code Completion API Discovery Struct Initializers + Methods

45 Playgrounds for Prototyping Tweak-build loop Commit Tweak Code Check Work Build / Compile Navigate to UI Copy into Simulator

46 Playgrounds for Prototyping Tweak-build loop Commit Tweak Code Check Work Navigate to UI Risk of Destabilizing Known-Good Code Slow Build / Compile Copy into Simulator

47 Playgrounds for Prototyping The plan Reduce roundtrip time Tweak Code Iterative + experimental development Check Work

48 Demo Struct Methods With Playground Prototyping

49 Availability: the Next Generation Put down your if respondstoselector() and step away from Xcode.

50 Runtime Interrogation The classic way if ([UIImagePickerController { // Method is available for use. } else { // Method is not available. }

51 Availability Based on OS Version The officially endorsed, modern way if #available(ios 8.3, *) { viewcontroller.modalpresentationstyle =.Popover if let popoverpc = viewcontroller.popoverpresentationcontroller { let cell = tableview.cellforrowatindexpath(indexpath) popoverpc.sourceview = cell popoverpc.delegate = self } presentviewcontroller(viewcontroller, animated: true, completion: nil) } else { // Earlier than ios 8.3 APIs navigationcontroller?.pushviewcontroller(viewcontroller, animated: true) }

52 Compile-Time Availability Checking viewcontroller.modalpresentationstyle =.Popover if let popoverpc = viewcontroller.popoverpresentationcontroller { let cell = tableview.cellforrowatindexpath(indexpath) popoverpc.sourceview = cell popoverpc.delegate = self }

53 Compile-Time Availability Checking error: popoverpresentationcontroller is only available on ios 8.0 or newer viewcontroller.modalpresentationstyle =.Popover if let popoverpc = viewcontroller.popoverpresentationcontroller { let cell = tableview.cellforrowatindexpath(indexpath) popoverpc.sourceview = cell popoverpc.delegate = self }

54 Demo Availability APIs must be this tall to ride.

55 Availability New in Swift 2 Compilation-time checking of API Availability Runtime checks inserted automatically Swift in Practice Presidio Thursday 2:30PM

56 Live Search Filtering elements since antiquity.

57 TableView View Controller Fe Na Cs Ni Cu IRON SODIUM CESIUM NICKEL COPPER Content

58 TableView View Controller <UITableViewDataSource> Content Fe IRON Na SODIUM Cs CESIUM Ni NICKEL Cu COPPER

59 TableView View Controller <UITableViewDataSource, UISearchBarDelegate> Content Fe IRON Na SODIUM Cs CESIUM Ni NICKEL Cu COPPER

60 TableView searchbar:textdidchange: View Controller <UITableViewDataSource, UISearchBarDelegate> Content Fe IRON Na SODIUM Cs CESIUM Ni NICKEL Cu COPPER

61 Filter searchbar:textdidchange: func searchbar(searchbar: UISearchBar, textdidchange searchtext: String) { if searchtext.isempty { content = atomicelements } else { content = atomicelements.filter{$0.name.hasprefix(searchtext)} } tableview?.reload() }

62 Filter searchbar:textdidchange: func searchbar(searchbar: UISearchBar, textdidchange searchtext: String) { if searchtext.isempty { content = atomicelements } else { content = atomicelements.filter{$0.name.hasprefix(searchtext)} } tableview?.reload() }

63 Filter searchbar:textdidchange: func searchbar(searchbar: UISearchBar, textdidchange searchtext: String) { if searchtext.isempty == true { content = atomicelements } else { content = atomicelements.filter{$0.name.hasprefix(searchtext)} } tableview?.reload() } Original Array: Closure: Filtered Array:

64 Filter searchbar:textdidchange: func searchbar(searchbar: UISearchBar, textdidchange searchtext: String) { if searchtext.isempty == true { content = atomicelements } else { content = atomicelements.filter{$0.name.hasprefix(searchtext)} } tableview?.reload() } Original Array: Closure: Filtered Array:

65 Demo Filtering Only the worthy may pass.

66 Sums of Atomic Weights Introducing Map & Reduce, in harmony like Ebony & Ivory.

67 Sum of Atomic Weights

68 Sum of Atomic Weights Two or more rows selected

69 Intermediate Objective Array of selected atomic elements content Cu 29 Db 105 Dy 66 Er 68 Es 99 Eu 63 F 9

70 Intermediate Objective Array of selected atomic elements content Cu 29 Db 105 Dy 66 Er 68 Es 99 Eu 63 F 9 selectedatomicelements Cu 29 Dy 66 Es 99 Eu 63 F 9

71 Intermediate Objective Array of selected atomic elements indexpath.row content Cu 29 Db 105 Dy 66 Er 68 Es 99 Eu 63 F selectedatomicelements Cu 29 Dy 66 Es 99 Eu 63 F 9

72 Intermediate Objective Array of selected atomic elements content Cu 29 Db 105 Dy 66 Er 68 Es 99 Eu 63 F 9 indexpathsforselectedrows selectedatomicelements Cu 29 Dy 66 Es 99 Eu 63 F 9

73 Traditional Approach For in var selectedelements = [AtomicElement]() if let indexpaths = tv?.indexpathsforselectedrows { for ip in indexpaths { let currentelement = content[ip.row] selectedelements.append(currentelement) } }

74 Swiftier Way Map var selectedelements = [AtomicElement]() if let indexpaths = tv?.indexpathsforselectedrows { for ip in indexpaths { let currentelement = content[ip.row] selectedelements.append(currentelement) } } let selectedelements = tv?.indexpathsforselectedrows?.map{content[$0.row]}

75 Adding Values of Items Traditional way selectedatomicelements Cu 29 Dy 66 Es 99 Eu 63 F 9.atomicWeight

76 Adding Values of Items Traditional way selectedatomicelements Cu 29 Dy 66 Es 99 Eu 63 F 9.atomicWeight Using a for-in loop var d = 0.0 for element in selectedatomicelements { d = d + element.atomicweight }

77 Sum of Atomic Element Weights Swift s reduce() method selectedatomicelements Cu 29 Dy 66 Es 99 Eu 63 F 9.atomicWeight Using a for-in loop var d = 0.0 for element in selectedatomicelements { d = d + element.atomicweight } With Reduce() reduce(0.0, combine: {$0 + $1.atomicWeight})

78 Final Code Snippet All together, now tableview?.indexpathsforselectedrows?.map{self.content[$0.row]}.reduce(0.0, combine: {$0 + $1.atomicWeight})

79 Demo Map & Reduce Obtaining closure through closures.

80 Summary You have existing Objective-C code? Keep it. You re adding new code? Consider writing it in Swift.

81 More Information Stefan Lesser Swift Evangelist Swift Language Documentation Apple Developer Forums developer.apple.com/forums

82 Related Sessions What s new in Swift Presidio Tuesday 11:10AM Swift and Objective-C Interoperability Mission Tuesday 1:30PM Protocol Oriented Programming in Swift Marina Wednesday 2:30PM Optimizing Performance in Swift Presidio Thursday 9:00AM Swift in Practice Presidio Thursday 2:30PM Building Better UIKit Apps with Swift Mission Wednesday 2:00PM

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