Introduction to iOS Software Development

Presentation shown in the Mobile Developer Summit 2011 in Bangalore, India, in November 2011.

Transcript

1. Introduction to iOS Software Development Adrian Kosmaczewski - akosma software
2. Adrian Kosmaczewski
3. http://www.flickr.com/photos/gi/164281467/
4. http://www.flickr.com/photos/jm3/379494322/
5. http://www.flickr.com/photos/21025851@N00/2168398185/
6. http://www.flickr.com/photos/emiliagarassino/2146648332/
7. akosma software
8. akosma.com github.com/akosma linkedin.com/in/akosma formspring.me/akosma twitter.com/akosma slideshare.com/akosma
12. iOS
13. http://www.flickr.com/photos/oskay/365607662/
14. http://www.flickr.com/photos/oskay/365607591/
15. http://www.flickr.com/photos/blakespot/2379207825/
16. http://www.flickr.com/photos/justdrew1985/4348527596/
18. Some questions
19. Veteran NeXT or Mac OS X developers in the room?
20. iOS devices in the room?
22. Program History Objective-C Cocoa Tools Web vs. Native Apps The App Store Design Books Q&A
24. History
25. “Good design survives” Erich Gamma OOP 2011 Keynote
26. born in the 80s
32. Objective-C
33. "Thin layer around C" Message-dispatch runtime built on C obj_msgSend() Static and dynamic (you choose) The “real” inspiration for Java: http://cs.gmu.edu/~sean/stuff/java-objc.html
34. Single inheritance + interfaces (“@protocols”) @protocols can have @optional methods Fields protected by default All methods are public, virtual and overridable Methods can be added to existing classes ("categories") Full introspection / reflection Messages can be intercepted and forwarded à la AOP
35. Objective-C Java @interface (.h) & @implementation (.m) class (1 file) @protocol interface #import // files! import // classes! categories n/a (C#, “class extensions”) id n/a (generics?) "void*"
36. Objective-C Java / C# @selector n/a (C# delegates) NSObject / NSProxy / ... Object @public / @protected / @private public / protected / private @try / @catch / @finally NSException try / catch / finally Exception n/a package / namespace
37. Classes
38. extends class
39. Methods
40. Syntax inspired from Smalltalk
41. void insertObject(anObject, index)
42. aName.copy() this.alloc().initWithString(aName).autorelease()
43. Memory Management
44. iPhone, iPhone 3G: 128 MB RAM iPhone 3GS, iPad 1: 256 MB RAM iPhone 4, iPhone 4S, iPad 2: 512 MB RAM
45. ±70 MB for the OS!
46. no swap file
47. (no virtual memory)
48. http://www.flickr.com/photos/cheek/699407283/
49. no garbage collection
50. objects have a “retain count”
51. http://cocoadevcentral.com/d/learn_objectivec/
52. basic rule:
53. for every [alloc], [retain], [copy] there must be a [release]
54. beware:
55. Objective-C only allows objects on the heap
56. http://linguiniontheceiling.blogspot.com/2008/10/thats-madame-trash-heap-to-you.html
57. No automatic objects on the stack (C++)
58. http://www.futuregov.net/photologue/photo/2008/aug/30/stack-papers/
59. // C++ // Memory freed when out of scope std::string name(“Adrian”); std::string *name = NULL; name = new std::string(“Adrian”); delete name;
60. iOS memory warnings
62. http://www.flickr.com/photos/tbuser/2763035540/
63. http://akosma.com/2009/01/28/10-iphone-memory-management-tips/
64. http://akosma.com/2009/07/16/objective-c-compiler-warnings/
66. Cocoa
68. UIKit
71. Tools
72. Xcode
74. Instruments
78. Clang Static Analyzer
79. http://llvm.org/
80. http://clang-analyzer.llvm.org/
82. Source: Apple Documentation
83. Source: Apple Documentation
84. Source: Apple Documentation
85. Source: Apple Documentation
87. Web or native apps?
88. update frequency usage frequency UI complexity native apps web apps stocks calculator business forms reports
89. Web Application Native SDK Application Pros Cons Simpler deployment and updates; known technologies, cheaper to maintain; access to GPS information; basic offline support. Faster execution; access to address book, accelerometer, audio and camera; 3D games and animations; push notifications; Bonjour networking support. Slower to execute; no access to hardware. App Store review process; longer update times.
90. Sencha Touch iUI jQTouch WebApp.net XUI Rhodes SproutCore Cappuccino LiquidGear PhoneGap Safire jPint Magic Framework
91. Also remember
92. Not all WebKits are made equal
93. WebKit Compatibility Table http://www.quirksmode.org/webkit.html
95. Native apps advantages
96. 1 offline web catching up!
97. 2 location services web catching up!
98. 3 camera
99. 4 audio & 3D
100. 5 accelerometer & gyroscope web catching up!
101. 6 notifications
102. http://www.flickr.com/photos/epitti/2565572445/
103. 7 monetization!
104. Native components
105. Address Book ABAddressBook ABMultiValue ABMutableMultiValue ABRecord ABGroup ABPerson http://www.flickr.com/photos/kevinmarsh/2315151843/
106. Accelerometer UIAccelerometer UIAccelerometerDelegate http://www.flickr.com/photos/evert-jan/2784525711/ http://www.flickr.com/photos/evert-jan/2785380754/
107. Video MPMoviePlayerController http://www.flickr.com/photos/pingping/1431127181/
108. Location services CLLocation CLLocationManager http://www.flickr.com/photos/thomcochrane/2780365916/
109. Graphics & Animation CALayer CAAnimation UIGraphicsContext CGRect / CGMakeRect UIBezierPath UIColor http://www.flickr.com/photos/alleus/2905293514/
110. Camera & Photo Library UIImagePickerController UIImagePickerControllerDelegate UIImagePickerControllerSourceTypeCamera UIImagePickerControllerSourceTypePhotoLibrary http://www.flickr.com/photos/ernohannink/2713579416/
111. And More Audio XML WebKit SQLite / Core Data Networking Bonjour Bluetooth / GameKit AirPrint iCal (EventKit) AirPlay Compass Gyroscope Gestures Core Text
113. Other languages? Cross-platform?
114. http://akosma.com/2009/10/29/iphone-apps-without-objective-c/
116. The App Store in 5 steps
117. 1. Register
118. http://developer.apple.com/programs/iphone/
119. 2. Develop
121. 3. Publish
123. Requirements Free apps: nothing Paying apps: EIN Number, via IRS Bank account
124. 4. Approval
126. 4.1 Rejection
127. “Your application cannot be posted to the App Store at this time because it does not adhere to the iPhone Human Interface Guidelines as outlined in iPhone SDK Agreement section x.x.x. When the device is in this or that condition, the application does not do this or that. This behavior might lead to user confusion. It would be appropriate to display either a notification or an alert stating that such or such condition is required. In order for your application to be reconsidered for the App Store, please resolve this issue and upload your new binary to iTunes Connect.”
128. 5. Sales
129. https://itunesconnect.apple.com/
132. Honor the Mobile Human Interface Guidelines
133. http://developer.apple.com/iphone/library/documentation/ userexperience/conceptual/mobilehig/
135. avoid this
136. http://www.flickr.com/photos/gruber/2635257578/
137. and this
138. http://smokingapples.com/iphone/app-store-iphone/the-worst-twitter-client-ever/
139. “ I can’t find one redeeming quality about this app. It’s slow to start [on a 3GS], doesn’t respond to taps while it’s trying to load other things, and crashes if you try to change modes a lot. It’s limited to only timeline, replies, and messages. It has no other functionality. Oh wait… I forgot its killer feature, you can have custom backgrounds and choose the color of your tweets. That totally makes up for its lack of useful features and sluggish performance. I’m not sure why someone would bother building such an inferior app other than that they wanted to find some suckers and score a quick buck. It seems even more insane to me that they’d be actively seeking out reviewers to cover this. I was given a promo code for ChillTwit, and even for free I didn’t want it on my phone. I was sad just from looking at screenshots. Actually seeing it running confirmed all of my fears. If it was a free app, I might forgive the developer, but the fact that he’s trying to get $0.99 out of people pisses me off to no end. Go buy Tweetie. If you somehow weren’t scared away by all my bitching and whinning, you can see ChillTwit on the app store here. But seriously, if you buy this, we’re not friends anymore.
141. Books
151. Thanks!
152. Questions?
153. Created and edited on Keynote for iPad Copyright 2011 (c) akosma software All Rights Reserved.