The iOS 5 Developer's Cookbook

Key-Value Coding 78 Key-Value Observing 79 MRR and High Retain Counts 79 Other Ways to Create Objects 80 Deallocating Objects 82 Using Blocks 84 Defining Blocks in Your Code 85 Assigning Block References 85 Blocks and Local Variables 87 Blocks and typedef 87 Blocks and Memory Management with MRR 88 Other Uses for Blocks 88 Getting Up to Speed with ARC 88 Property and Variable Qualifiers 89 Reference Cycles 92 Autorelease Pools 94 Opting into and out of ARC 95 Migrating to ARC 95 Disabling ARC across a Target 96 Disabling ARC on a File-by-File Basis 97 Creating an ARC-less Project from Xcode Templates 97 ARC Rules 98 Using ARC with Core Foundation and Toll Free Bridging 99 Casting between Objective-C and Core Foundation 99 Choosing a Bridging Approach 101 Runtime Workarounds 102 Tips and Tricks for Working with ARC 103 Crafting Singletons 103 Categories (Extending Classes) 104 Protocols 106 Defining a Protocol 106 Incorporating a Protocol 107 Adding Callbacks 107 Declaring Optional Callbacks 107 Implementing Optional Callbacks 108 Conforming to a Protocol 108 Foundation Classes 109 Strings 110 Numbers and Dates 115 Collections 117 One More Thing: Message Forwarding 123 Implementing Message Forwarding 123 House Cleaning 125 Super-easy Forwarding 126 Summary 126 3 Building Your First Project 127 Creating New Projects 127 Building Hello World the Template Way 129 Create a New Project 129 Introducing the Xcode Workspace 132 Review the Project 137 Open the iPhone Storyboard 138 Edit the View 140 Run Your Application 141 Using the Simulator 142 Simulator: Behind the Scenes 144 Sharing Simulator Applications 146 The Minimalist Hello World 146 Browsing the SDK APIs 149 Converting Interface Builder Files to Their Objective-C Equivalents 151 Using the Debugger 153 Set a Breakpoint 153 Open the Debugger 154 Inspect the Label 155 Set Another Breakpoint 156 Backtraces 157 Console 158 Add Simple Debug Tracing 158 Memory Management 158 Recipe: Using Instruments to Detect Leaks 159 Recipe: Using Instruments to Monitor Cached Object Allocations 162 Simulating Low-Memory Conditions 163 Analyzing Your Code 165 From Xcode to Device: The Organizer Interface 165 Devices 165 Summary 167 Provisioning Profiles 168 Device Logs 168 Applications 169 Console 169 Screenshots 170 Building for the iOS Device 170 Using a Development Provision 170 Enable a Device 171 Inspect Your Application Identifier 172 Set Your Device and Code Signing Identity 172 Set Your Base and Deployment SDK Targets 173 Compile and Run the Hello World Application 174 Signing Compiled Applications 175 Detecting Simulator Builds with Compile-Time Checks 175 Performing Runtime Compatibility Checks 175 Pragma Marks 177 Collapsing Methods 178 Preparing for Distribution 178 Locating and Cleaning Builds 178 Using Schemes and Actions 179 Adding Build Configurations 181 About Ad Hoc Distribution 182 Building Ad Hoc Packages 183 Over-the-Air Ad Hoc Distribution 184 Building a Manifest 184 Submitting to the App Store 186 Summary 188 4 Designing Interfaces 191 UIView and UIWindow 191 Views That Display Data 192 Views for Making Choices 193 Controls 193 Tables and Pickers 195 Bars 195 Progress and Activity 196 View Controllers 196 UIViewController 197 UINavigationController 197 UITabBarController 198 Split View Controllers 198 Page View Controller 199 Popover Controllers 199 Table Controllers 199 Address Book Controllers 200 Image Picker 200 Mail Composition 200 Document Interaction Controller 200 GameKit Peer Picker 201 Media Player Controllers 201 View Design Geometry 201 Status Bar 202 Navigation Bars, Toolbars, and Tab Bars 203 Keyboards and Pickers 205 Text Fields 207 The UIScreen Class 207 Building Interfaces 207 Walkthrough: Building Storyboard Interfaces 208 Create a New Project 208 Add More View Controllers 208 Organize Your Views 209 Update Classes 210 Name Your Scenes 211 Edit View Attributes 211 Add Navigation Buttons 211 Add Another Navigation Controller 213 Name the Controllers 213 Tint the Navigation Bars 214 Add a Button 214 Change the Entry Point 215 Add Dismiss Code 215 Run the App 216 Popover Walkthrough 216 Add a Navigation Controller 216 Change the View Controller Class 217 Customize the Popover View 217 Make the Connections 218 Edit the Code 218 Walkthrough: Building an iOS-based Temperature Converter with IB 220 Create a New Project 220 Add Media 221 Interface Builder 221 Add Labels and Views 222 Enable Reorientation 223 Test the Interface 223 Add Outlets and an Action 223 Add the Conversion Method 225 Update the Keyboard Type 225 Connecting the iPad Interface 226 Walkthrough: Building a Converter Interface by Hand 227 Putting the Project Together 230 Walkthrough: Creating, Loading, and Using Hybrid Interfaces 230 Create a New XIB Interface File 231 Add a View and Populate It 231 Tag Your Views 231 Edit the Code 232 Designing for Rotation 233 Enabling Reorientation 233 Autosizing 235 Autosizing Example 237 Evaluating the Autosize Option 238 Moving Views 239 Recipe: Moving Views by Mimicking Templates 240 One More Thing: A Few Great Interface Builder Tips 243 Summary 245 5 Working with View Controllers 247 Developing with Navigation Controllers and Split Views 247 Using Navigation Controllers and Stacks 249 Pushing and Popping View Controllers 249 The Navigation Item Class 250 Modal Presentation 251 Recipe: Building a Simple Two-Item Menu 252 Recipe: Adding a Segmented Control 253 Recipe: Navigating Between View Controllers 255 Recipe: Presenting a Custom Modal Information View 258 Recipe: Page View Controllers 262 Book Properties 262 Wrapping the Implementation 263 Exploring the Recipe 264 Recipe: Scrubbing Pages in a Page View Controller 269 Recipe: Tab Bars 271 Recipe: Remembering Tab State 275 Recipe: Building Split View Controllers 278 Recipe: Creating Universal Split View/Navigation Apps 282 Recipe: Custom Containers and Segues 284 Transitioning Between View Controllers 290 One More Thing: Interface Builder and Tab Bar Controllers 291 Summary 292 6 Assembling Views and Animations 295 View Hierarchies 295 Recipe: Recovering a View Hierarchy Tree 297 Recipe: Querying Subviews 298 Managing Subviews 300 Adding Subviews 300 Reordering and Removing Subviews 300 View Callbacks 301 Recipe: Tagging and Retrieving Views 301 Using Tags to Find Views 302 Recipe: Naming Views 303 Associated Objects 304 Using a Name Dictionary 305 View Geometry 308 Frames 309 Transforms 310 Coordinate Systems 310 Recipe: Working with View Frames 311 Adjusting Sizes 312 CGRects and Centers 313 Other Utility Methods 314 Recipe: Randomly Moving a Bounded View 318 Recipe: Transforming Views 319 Display and Interaction Traits 320 UIView Animations 321 Building UIView Animation Transactions 322 Building Animations with Blocks 323 Conditional Animation 324 Recipe: Fading a View In and Out 324 Recipe: Swapping Views 326 Recipe: Flipping Views 327 Recipe: Using Core Animation Transitions 328 Recipe: Bouncing Views as They Appear 329 Recipe: Image View Animations 331 One More Thing: Adding Reflections to Views 332 Summary 335 7 Working with Images 337 Finding and Loading Images 337 Reading Image Data 339 Recipe: Accessing Photos from the iOS Photo Album 342 Working with the Image Picker 342 Recovering Image Edit Information 344 Recipe: Retrieving Images from Asset URLs 347 Recipe: Snapping Photos and Writing Them to the Photo Album 349 Choosing Between Cameras 351 Saving Pictures to the Documents Folder 353 Recipe: E-mailing Pictures 354 Creating Message Contents 354 Presenting the Composition Controller 356 Automating Camera Shots 358 Using a Custom Camera Overlay 358 Recipe: Accessing the AVFoundation Camera 359 Requiring Cameras 360 Querying and Retrieving Cameras 360 Establishing a Camera Session 361 Switching Cameras 363 Camera Previews 364 Laying Out a Camera Preview 364 EXIF 365 Image Geometry 365 Building Camera Helper 367 Recipe: Adding a Core Image Filter 368 Recipe: Core Image Face Detection 370 Extracting Faces 376 Recipe: Working with Bitmap Representations 377 Drawing into a Bitmap Context 378 Applying Image Processing 380 Image Processing Realities 382 Recipe: Sampling a Live Feed 384 Converting to HSB 386 Recipe: Building Thumbnails from Images 387 Taking View-based Screenshots 390 Drawing into PDF Files 390 Creating New Images from Scratch 391 Recipe: Displaying Images in a Scrollable View 392 Creating a Multi-Image Paged Scroll 395 Summary 396 8 Gestures and Touches 397 Touches 397 Phases 398 Touches and Responder Methods 399 Touching Views 399 Multitouch 400 Gesture Recognizers 400 Recipe: Adding a Simple Direct Manipulation Interface 401 Recipe: Adding Pan Gesture Recognizers 402 Recipe: Using Multiple Gesture Recognizers at Once 404 Resolving Gesture Conflicts 407 Recipe: Constraining Movement 408 Recipe: Testing Touches 409 Recipe: Testing Against a Bitmap 411 Recipe: Adding Persistence to Direct Manipulation Interfaces 413 Storing State 413 Recovering State 415 Recipe: Persistence Through Archiving 416 Recipe: Adding Undo Support 418 Creating an Undo Manager 418 Child-View Undo Support 418 Working with Navigation Bars 419 Registering Undos 420 Adding Shake-Controlled Undo Support 422 Add an Action Name for Undo and Redo (Optional) 422 Provide Shake-To-Edit Support 423 Force First Responder 423 Recipe: Drawing Touches Onscreen 424 Recipe: Smoothing Drawings 426 Recipe: Detecting Circles 429 Creating a Custom Gesture Recognizer 433 Recipe: Using Multitouch 435 Retaining Touch Paths 438 One More Thing: Dragging from a Scroll View 440 Summary 443 9 Building and Using Controls 445 The UIControl Class 445 Kinds of Controls 445 Control Events 446 Buttons 448 Adding Buttons in Interface Builder 449 Art 450 Connecting Buttons to Actions 451 Buttons That Are Not Buttons 452 Building Custom Buttons in Xcode 453 Multiline Button Text 455 Adding Animated Elements to Buttons 456 Recipe: Animating Button Responses 456 Recipe: Adding a Slider With a Custom Thumb 458 Customizing UISlider 459 Adding Efficiency 460 Appearance Proxies 460 Recipe: Creating a Twice-Tappable Segmented Control 465 Recipe: Subclassing UIControl 467 Creating UIControls 468 Tracking Touches 468 Dispatching Events 468 Working with Switches and Steppers 471 Recipe: Building a Star Slider 472 Recipe: Building a Touch Wheel 476 Adding a Page Indicator Control 478 Recipe: Creating a Customizable Paged Scroller 481 Building a Toolbar 486 Building Toolbars in Code 487 iOS 5 Toolbar Tips 489 Summary 489 10 Working with Text 491 Recipe: Dismissing a UITextField Keyboard 491 Text Trait Properties 492 Other Text Field Properties 493 Recipe: Adjusting Views Around Keyboards 495 Recipe: Dismissing Text Views with Custom Accessory Views 498 Recipe: Resizing Views with Hardware Keyboards 500 Recipe: Creating a Custom Input View 503 Recipe: Making Text-Input-Aware Views 508 Recipe: Adding Custom Input Views to Non-Text Views 511 Adding Input Clicks 511 Recipe: Building a Better Text Editor 513 Recipe: Text Entry Filtering 516 Recipe: Detecting Text Patterns 518 Rolling Your Own Expressions 518 Enumerating Regular Expressions 519 Data Detectors 520 Adding Built-in Type Detectors 520 Recipe: Detecting Misspelling in a UITextView 522 Searching for Text Strings 523 Recipe: Dumping Fonts 524 Recipe: Adding Custom Fonts to Your App 525 Recipe: Basic Core Text and Attributed Strings 526 Using Pseudo-HTML to Create Attributed Text 532 Recipe: Splitting Core Text into Pages 536 Recipe: Drawing Core Text into PDF 537 Recipe: Drawing into Nonrectangular Paths 539 Recipe: Drawing Text onto Paths 542 Drawing Text onto Bezier Paths 543 Drawing Proportionately 544 Drawing the Glyph 545 One More Thing: Big Phone Text 551 Summary 554 11 Creating and Managing Table Views 555 Introducing UITableView and UITableView Controller 555 Creating the Table 556 Recipe: Implementing a Basic Table 558 Populating a Table 558 Data Source Methods 559 Reusing Cells 560 Responding to User Touches 560 Selection Color 561 Changing a Table's Background Color 561 Cell Types 562 Recipe: Building Custom Cells in Interface Builder 563 Adding in Custom Selection Traits 565 Alternating Cell Colors 565 Removing Selection Highlights from Cells 566 Creating Grouped Tables 567 Recipe: Remembering Control State for Custom Cells 567 Visualizing Cell Reuse 570 Creating Checked Table Cells 571 Working with Disclosure Accessories 572 Recipe: Table Edits 574 Displaying Remove Controls 575 Dismissing Remove Controls 575 Handling Delete Requests 576 Supporting Undo 576 Swiping Cells 576 Adding Cells 576 Reordering Cells 579 Sorting Tables Algorithmically 580 Recipe: Working with Sections 581 Building Sections 582 Counting Sections and Rows 583 Returning Cells 583 Creating Header Titles 584 Creating a Section Index 584 Delegation with Sections 585 Recipe: Searching Through a Table 586 Creating a Search Display Controller 586 Building the Searchable Data Source Methods 587 Delegate Methods 589 Using a Search-Aware Index 589 Customizing Headers and Footers 591 Recipe: Adding "Pull-to-Refresh" to Your Table 592 Coding a Custom Group Table 595 Creating Grouped Preferences Tables 595 Recipe: Building a Multiwheel Table 597 Creating the UIPickerView 598 Recipe: Using a View-based Picker 601 Recipe: Using the UIDatePicker 603 Creating the Date Picker 603 One More Thing: Formatting Dates 606 Summary 608 12 A Taste of Core Data 611 Introducing Core Data 611 Creating and Editing Model Files 612 Generating Class Files 614 Creating a Core Data Context 615 Adding Objects 616 Querying the Database 618 Detecting Changes 619 Removing Objects 619 Recipe: Using Core Data for a Table Data Source 620 Recipe: Search Tables and Core Data 623 Recipe: Integrating Core Data Table Views with Live Data Edits 625 Recipe: Implementing Undo/Redo Support with Core Data 628 Summary 632 13 Alerting the User 633 Talking Directly to Your User Through Alerts 633 Building Simple Alerts 633 Alert Delegates 634 Displaying the Alert 636 Kinds of Alerts 636 "Please Wait": Showing Progress to Your User 637 Using UIActivityIndicatorView 638 Using UIProgressView 639 Recipe: No-Button Alerts 639 Building a Floating Progress Monitor 642 Recipe: Creating Modal Alerts with Run Loops 642 Recipe: Using Variadic Arguments with Alert Views 645 Presenting Simple Menus 646 Scrolling Menus 648 Displaying Text in Action Sheets 648 Recipe: Building Custom Overlays 649 Tappable Overlays 650 Recipe: Basic Popovers 650 Recipe: Local Notifications 652 Alert Indicators 654 Badging Applications 654 Recipe: Simple Audio Alerts 654 System Sounds 655 Vibration 656 Alerts 656 Delays 656 One More Thing: Showing the Volume Alert 658 Summary 659 14 Device Capabilities 661 Accessing Basic Device Information 661 Adding Device Capability Restrictions 662 Recipe: Recovering Additional Device Information 664 Monitoring the iPhone Battery State 666 Enabling and Disabling the Proximity Sensor 667 Recipe: Using Acceleration to Locate "Up" 668 Retrieving the Current Accelerometer Angle Synchronously 670 Calculate a Relative Angle 671 Working with Basic Orientation 671 Recipe: Using Acceleration to Move Onscreen Objects 672 Adding a Little Sparkle 675 Recipe: Core Motion Basics 676 Testing for Sensors 677 Handler Blocks 677 Recipe: Retrieving and Using Device Attitude 680 Detecting Shakes Using Motion Events 681 Recipe: Detecting Shakes via the Accelerometer 683 Recipe: Using External Screens 686 Detecting Screens 687 Retrieving Screen Resolutions 687 Setting Up Video Out 688 Adding a Display Link 688 Overscanning Compensation 688 VIDEOkit 688 One More Thing: Checking for Available Disk Space 692 Summary 693 15 Networking 695 Checking Your Network Status 695 Recipe: Extending the UIDevice Class for Reachability 697 Scanning for Connectivity Changes 700 Recovering IP and Host Information 702 Using Queues for Blocking Checks 705 Checking Site Availability 707 Synchronous Downloads 709 Asynchronous Downloads in Theory 713 Recipe: Asynchronous Downloads 715 Handling Authentication Challenges 721 Storing Credentials 722 Recipe: Storing and Retrieving Keychain Credentials 725 Recipe: Uploading Data 728 NSOperationQueue 728 Twitter 732 Recipe: Converting XML into Trees 733 Trees 733 Building a Parse Tree 734 Using the Tree Results 736 Recipe: Building a Simple Web-based Server 738 One More Thing: Using JSON Serialization 742 Summary 742 Index 745