SECOND EDITION Programming iOS 5 Matt Neuburg Beijing • Cambridge • Farnham • Köln • Sebastopol • Tokyo www.it-ebooks.info Programming iOS 5, Second Edition by Matt Neuburg Revision History for the : Dec 23, 2011 See http://oreilly.com/catalog/errata.csp?isbn=9781449319342 for release details. ISBN: 978-1-449-31934-2 1326317995 www.it-ebooks.info Table of Contents Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii Part I. Language 1. Just Enough C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Compilation, Statements, and Comments 4 Variable Declaration, Initialization, and Data Types 6 Structs 8 Pointers 10 Arrays 12 Operators 13 Flow Control and Conditions 15 Functions 20 Pointer Parameters and the Address Operator 22 Files 24 The Standard Library 27 More Preprocessor Directives 28 Data Type Qualifiers 29 2. Object-Based Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Objects 31 Messages and Methods 32 Classes and Instances 33 Class Methods 36 Instance Variables 37 The Object-Based Philosophy 38 3. Objective-C Objects and Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 An Instance Reference Is a Pointer 43 Instance References, Initialization, and nil 44 iii www.it-ebooks.info Instance References and Assignment 47 Instance References and Memory Management 48 Messages and Methods 50 Sending a Message 50 Declaring a Method 51 Nesting Method Calls 52 No Overloading 53 Parameter Lists 54 Unrecognized Selectors 54 Typecasting and the id Type 56 Messages as Data Type 60 C Functions 61 C Struct Pointers 62 Blocks 63 4. Objective-C Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Class and Superclass 67 Interface and Implementation 69 Header File and Implementation File 71 Class Methods 73 The Secret Life of Classes 74 5. Objective-C Instances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 How Instances Are Created 77 Ready-Made Instances 77 Instantiation from Scratch 78 Nib-Based Instantiation 81 Polymorphism 82 The Keyword self 84 The Keyword super 87 Instance Variables and Accessors 89 Key–Value Coding 91 Properties 92 How to Write an Initializer 94 Part II. IDE 6. Anatomy of an Xcode Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 New Project 99 The Project Window 101 The Navigator Pane 103 The Utilities Pane 107 iv | Table of Contents www.it-ebooks.info The Editor 109 The Project File and Its Dependents 111 The Target 114 Build Phases 114 Build Settings 115 Configurations 117 Schemes and Destinations 118 From Project to App 120 Build Settings 122 Property List Settings 122 Nib Files and Storyboard Files 123 Other Resources 124 Code 126 Frameworks and SDKs 128 7. Nib Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 A Tour of the Nib-Editing Interface 134 The Dock 135 Canvas 136 Inspectors and Libraries 138 Nib Loading and File’s Owner 140 Making and Loading a Nib 142 Outlet Connections 143 More Ways to Create Outlets 148 More About Outlets 150 Action Connections 151 Additional Initialization of Nib-Based Instances 155 8. Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 The Documentation Window 158 Class Documentation Pages 159 Sample Code 163 Other Resources 164 Quick Help 164 Symbols 165 Header Files 165 Internet Resources 166 9. Life Cycle of a Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 Choosing a Device Architecture 169 Localization 173 Editing Your Code 174 Autocompletion 175 Table of Contents | v www.it-ebooks.info Snippets 176 Live Syntax Checking and Fix-it 177 Navigating Your Code 178 Debugging 180 Caveman Debugging 180 The Xcode Debugger 183 Static Analyzer 188 Clean 189 Running in the Simulator 190 Running on a Device 191 Device Management 195 Version Control 196 Instruments 198 Distribution 202 Ad Hoc Distribution 204 Final App Preparations 205 Icons in the App 206 Other Icons 207 Launch Images 207 Screenshots 208 Property List Settings 209 Submission to the App Store 210 Part III. Cocoa 10. Cocoa Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 Subclassing 215 Categories 218 Splitting a Class 219 Private Method Declarations 220 Protocols 221 Optional Methods 226 Some Foundation Classes 227 Useful Structs and Constants 227 NSString and Friends 228 NSDate and Friends 230 NSNumber 230 NSValue 231 NSData 231 Equality and Comparison 232 NSIndexSet 232 NSArray and NSMutableArray 233 vi | Table of Contents www.it-ebooks.info NSSet and Friends 234 NSDictionary and NSMutableDictionary 235 NSNull 237 Immutable and Mutable 237 Property Lists 238 The Secret Life of NSObject 238 11. Cocoa Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243 Reasons for Events 244 Subclassing 244 Notifications 246 Receiving a Built-In Notification 247 Unregistering 249 NSTimer 251 Delegation 251 Data Sources 255 Actions 256 The Responder Chain 261 Deferring Responsibility 261 Nil-Targeted Actions 262 Application Lifetime Events 263 Swamped by Events 268 12. Accessors and Memory Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 Accessors 273 Key–Value Coding 275 Memory Management 279 Principles of Cocoa Memory Management 279 The Golden Rules of Memory Management 281 What ARC Is and What It Does 283 How Cocoa Objects Manage Memory 286 Autorelease 288 Memory Management of Instance Variables (Non-ARC) 291 Memory Management of Instance Variables (ARC) 295 Retain Cycles and Weak References 297 Nib Loading and Memory Management 303 Memory Management of Global Variables 305 Memory Management of Pointer-to-Void Context Info 306 Memory Management of CFTypeRefs 308 Properties 310 13. Data Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317 Model–View–Controller 317 Table of Contents | vii www.it-ebooks.info Instance Visibility 319 Visibility by Instantiation 320 Visibility by Relationship 321 Global Visibility 322 Notifications 323 Key–Value Observing 324 Part IV. Views 14. Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 The Window 333 Subview and Superview 336 Frame 339 Bounds and Center 341 Layout 344 Transform 347 Visibility and Opacity 351 15. Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353 UIImage and UIImageView 353 Graphics Contexts 357 UIImage Drawing 361 CGImage Drawing 362 CIFilter and CIImage 365 Drawing a UIView 368 Graphics Context Settings 370 Paths and Drawing 371 Clipping 375 Gradients 376 Colors and Patterns 378 Graphics Context Transforms 380 Shadows 382 Points and Pixels 383 Content Mode 383 16. Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387 View and Layer 388 Layers and Sublayers 390 Manipulating the Layer Hierarchy 391 Positioning a Sublayer 392 CAScrollLayer 393 Layout of Sublayers 394 viii | Table of Contents www.it-ebooks.info Drawing in a Layer 394 Content Resizing and Positioning 397 Layers that Draw Themselves 399 Transforms 400 Depth 404 Shadows, Borders, and More 406 Layers and Key–Value Coding 409 17. Animation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411 Drawing, Animation, and Threading 412 UIImageView and UIImage Animation 415 View Animation 417 Animation Blocks 417 Modifying an Animation Block 418 Transition Animations 422 Block-Based View Animation 423 Implicit Layer Animation 428 Animation Transactions 429 Media Timing Functions 430 Core Animation 432 CABasicAnimation and Its Inheritance 432 Using a CABasicAnimation 434 Keyframe Animation 437 Making a Property Animatable 438 Grouped Animations 439 Transitions 443 The Animations List 445 Actions 447 What an Action Is 447 The Action Search 448 Hooking Into the Action Search 449 Nonproperty Actions 452 Emitter Layers 453 18. Touches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461 Touch Events and Views 462 Receiving Touches 464 Restricting Touches 465 Interpreting Touches 466 Gesture Recognizers 471 Gesture Recognizer Classes 471 Multiple Gesture Recognizers 476 Subclassing Gesture Recognizers 477 Table of Contents | ix www.it-ebooks.info Gesture Recognizer Delegate 479 Touch Delivery 481 Hit-Testing 482 Initial Touch Event Delivery 487 Gesture Recognizer and View 488 Touch Exclusion Logic 489 Recognition 490 Touches and the Responder Chain 491 Part V. Interface 19. View Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495 The View Controller Hierarchy 498 View Controller and View Creation 502 Manual View 505 Generic Automatic View 507 View in a Separate Nib 509 Nib-Instantiated View Controller 512 Storyboard-Instantiated View Controller 515 Rotation 517 Initial Orientation 519 Rotation Events 522 Presented View Controller 523 Presented View Animation 528 Presentation Styles 529 Presented Views and Rotation 532 Tab Bar Controllers 534 Tab Bar Items 535 Configuring a Tab Bar Controller 536 Navigation Controllers 538 Bar Button Items 542 Navigation Items 544 Toolbar Items 546 Configuring a Navigation Controller 547 Page View Controller 549 Container View Controllers 552 Storyboards 554 View Controller Lifetime Events 560 View Controller Memory Management 562 20. Scroll Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 567 Creating a Scroll View 568 x | Table of Contents www.it-ebooks.info [...]...Scrolling Paging Tiling Zooming Zooming Programmatically Zooming with Detail Scroll View Delegate Scroll View Touches Scroll View Performance 57 1 57 4 57 5 57 7 57 9 57 9 58 2 58 4 58 9 21 Table Views 59 1 Table View Cells Built-In Cell Styles Custom Cells Table View Data The Three Big Questions Table View Sections Refreshing Table View Data Variable... the book up to date for iOS 5 You, the reader, might be coming to iOS programming for the first time, so this edition assumes no prior knowledge of iOS 4 or any previous version On the other hand, you, like me, could be making the transition from iOS 4 to iOS 5, so this edition lays some special emphasis on features that are new in iOS 5 This emphasis could also be useful to new iOS programmers who are... development process However, for iOS programming, I recommend adoption of Xcode 4, and the first edition of this book assumed that the reader had adopted it Such was the situation in May 2011, when the first edition was formally released, describing how to program iOS 4 Less than five months later, in October 2011, Apple released iOS 5 Some of the features that are new in iOS 5 are dramatic and pervasive,... Rearranging Table Items Dynamic Table Content Table View Menus 59 4 59 5 601 609 610 614 618 619 621 627 628 634 637 638 640 642 643 644 22 Popovers and Split Views 647 Configuring and Displaying a Popover Managing a Popover Dismissing a Popover Popover Segues Automatic Popovers Split Views 649 654 654 658 659 661 23 Text ... before iOS 4.2 have been excised from this edition Here is a case in point, showing my attitude and pedagogical approach with regard to new iOS 5 features in this edition iOS 5 introduces ARC (automatic reference counting), which changes the way in which Objective-C programmers manage object memory so profoundly as to render Objective-C a different language Use of ARC is optional in programming iOS, ... useful to new iOS programmers who are thinking of writing apps that can also run under iOS 4 My goal, however, is not to burden the reader with outdated information The vast majority of devices that could run iOS 4 have probably been updated to iOS 5, and you will probably be right in assuming that there will plenty of iOS 5 users out there, without your having to bother to target earlier systems And from... Reading Files User Defaults File Sharing Document Types Handing Off a Document XML SQLite Image File Formats 8 45 846 847 849 851 851 853 856 862 863 37 Basic Networking 867 HTTP Requests Bonjour Push Notifications Beyond Basic Networking 867 873 8 75 876 38 Threads 877 The Main Thread Why Threading... fundamentals of iOS I love Cocoa and have long wished to write about it, but it is iOS and its popularity that has given me a proximate excuse to do so Indeed, my working title was “Fundamentals of Cocoa Touch Programming. ” Here I have attempted to marshal and expound, in what I hope is a pedagogically helpful and instructive yet ruthlessly Euclidean and logical order, the principles on which sound iOS programming. .. program for iOS, you need some knowledge of the C programming language, for two reasons: • Most of your iOS programming will be in the Objective-C language, and ObjectiveC is a superset of C This means that Objective-C presupposes C; everything that is true of C trickles up to Objective-C A common mistake is to forget that “Objective-C is C” and to neglect a basic understanding of C • Some of the iOS API... 743 Alert View Action Sheet Dialog Alternatives Local Notifications 744 746 750 751 Part VI Some Frameworks 27 Audio 759 System Sounds Audio Session Audio Player Remote Control of Your Sound xii | Table of Contents www.it-ebooks.info 759 760 764 766 Playing Sound in the Background Further Topics in Sound 768 769 28 Video . . . 56 7 Creating a Scroll View 56 8 x | Table of Contents www.it-ebooks.info Scrolling 57 1 Paging 57 4 Tiling 57 5 Zooming 57 7 Zooming Programmatically 57 9 Zooming. Controller 51 2 Storyboard-Instantiated View Controller 51 5 Rotation 51 7 Initial Orientation 51 9 Rotation Events 52 2 Presented View Controller 52 3 Presented