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iOS 14
Dive Deep into Views, View Controllers,
and Frameworks
Matt Neuburg
ELEVENTH EDITION
Programming iOS 14
Dive Deep into Views, View Controllers,
and Frameworks
Matt Neuburg
Boston
Programming iOS 14, Eleventh Edition
by Matt Neuburg
Copyright © 2021 Matt Neuburg. All rights reserved.
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November 2015: Sixth Edition
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December 2017: Eighth Edition
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October 2020: Eleventh Edition
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2020-10-08: First release
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978-1-492-09217-9
[MBP]
Table of Contents
Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxi
Part I. Views
1. Views. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Window and Root View 4
Window Scene Architecture 4
How an App Launches 6
App Without a Storyboard 7
Referring to the Window 8
Experimenting with Views 9
Subview and Superview 10
Color 13
Visibility and Opacity 14
Frame 15
Bounds and Center 17
Transform 21
Transform3D 25
Window Coordinates and Screen Coordinates 27
Trait Collections 28
Interface Style 29
Size Classes 31
Overriding Trait Collections 32
Layout 32
Autoresizing 34
Autolayout and Constraints 36
Implicit Autoresizing Constraints 39
Creating Constraints in Code 40
Constraints as Objects 46
iii
Margins and Guides 48
Intrinsic Content Size 54
Self-Sizing Views 56
Stack Views 57
Internationalization 60
Mistakes with Constraints 61
Configuring Layout in the Nib 64
Autoresizing in the Nib 65
Creating a Constraint 65
Viewing and Editing Constraints 67
Problems with Nib Constraints 69
Varying the Screen Size 71
Conditional Interface Design 72
Xcode View Features 75
View Debugger 75
Previewing Your Interface 76
Designable Views and Inspectable Properties 76
Layout Events 79
2. Drawing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Images and Image Views 81
Image Files 82
Image Views 88
Resizable Images 90
Transparency Masks 93
Reversible Images 95
Graphics Contexts 96
Drawing on Demand 98
Drawing a UIImage 99
UIImage Drawing 100
CGImage Drawing 103
Snapshots 105
CIFilter and CIImage 106
Blur and Vibrancy Views 111
Drawing a UIView 113
Graphics Context Commands 115
Graphics Context Settings 115
Paths and Shapes 116
Clipping 120
Gradients 121
Colors and Patterns 123
Graphics Context Transforms 125
iv | Table of Contents
Shadows 127
Erasing 128
Points and Pixels 129
Content Mode 130
3. Layers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
View and Layer 134
Layers and Sublayers 135
Manipulating the Layer Hierarchy 138
Positioning a Sublayer 139
CAScrollLayer 140
Layer and Delegate 141
Layout of Layers 141
Drawing in a Layer 142
Drawing-Related Layer Properties 144
Content Resizing and Positioning 145
Layers that Draw Themselves 148
Transforms 148
Affine Transforms 149
3D Transforms 151
Depth 151
Further Layer Features 155
Shadows 155
Borders and Rounded Corners 156
Masks 157
Layer Efficiency 158
Layers and Key–Value Coding 159
4. Animation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Drawing, Animation, and Threading 164
Image View and Image Animation 166
View Animation 168
A Brief History of View Animation 168
Property Animator Basics 169
View Animation Basics 172
View Animation Configuration 175
Timing Curves 180
Cancelling a View Animation 183
Frozen View Animation 186
Custom Animatable View Properties 187
Keyframe View Animation 188
Transitions 191
Table of Contents | v
Implicit Layer Animation 194
Animatable Layer Properties 194
Animating a Custom Layer Subclass 195
Animation Transactions 196
Media Timing Functions 198
Core Animation 198
CABasicAnimation and Its Inheritance 199
Using a CABasicAnimation 201
Springing Animation 204
Keyframe Animation 204
Making a Property Animatable 206
Grouped Animations 207
Animating Multiple Layers 211
Freezing an Animation 212
Transitions 213
Animations List 214
Actions 216
What an Action Is 217
Action Search 217
Hooking Into the Action Search 219
Making a Custom Property Implicitly Animatable 222
Nonproperty Actions 223
Emitter Layers 224
CIFilter Transitions 230
UIKit Dynamics 232
The Dynamics Stack 232
Custom Behaviors 236
Animator and Behaviors 238
Motion Effects 245
Animation and Layout 246
5. Touches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
Touch Events and Views 250
Receiving Touches 252
Restricting Touches 254
Interpreting Touches 255
Gesture Recognizers 259
Gesture Recognizer Classes 260
Gesture Recognizer States 263
Gesture Recognizer Examples 263
Gesture Recognizer Conflicts 266
Gesture Recognizer Delegate 268
vi | Table of Contents
Subclassing Gesture Recognizers 270
Gesture Recognizers in the Nib 273
Touch Delivery 273
Hit-Testing 274
Performing Hit-Testing 275
Hit-Test Munging 276
Hit-Testing for Layers 277
Hit-Testing for Drawings 278
Hit-Testing During Animation 279
Initial Touch Event Delivery 281
Gesture Recognizer and View 282
Touch Exclusion Logic 283
Gesture Recognition Logic 284
Part II. Interface
6. View Controllers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
View Controller Responsibilities 290
View Controller Hierarchy 291
Automatic Child View Placement 294
Manual Child View Placement 295
Presented View Placement 297
Ensuring a Coherent Hierarchy 299
View Controller Creation 300
How a View Controller Obtains Its View 301
Manual View 303
Generic Automatic View 304
View in a Separate Nib 305
Summary 308
How Storyboards Work 308
How a Storyboard View Controller Nib is Loaded 309
How a Storyboard View Nib is Loaded 311
View Resizing 311
View Size in the Nib Editor 312
Bars and Underlapping 312
Resizing and Layout Events 316
Rotation 318
Uses of Rotation 318
Permitting Compensatory Rotation 319
Initial Orientation 321
Detecting Rotation 321
Table of Contents | vii
View Controller Manual Layout 322
Initial Manual Layout 322
Manual Layout During Rotation 323
Presented View Controller 325
Presentation and Dismissal 325
Configuring a Presentation 328
Communication with a Presented View Controller 334
Adaptive Presentation 336
Presentation, Rotation, and the Status Bar 338
Tab Bar Controller 339
Tab Bar Items 339
Configuring a Tab Bar Controller 341
Navigation Controller 343
Bar Button Items 345
Navigation Items and Toolbar Items 347
Configuring a Navigation Controller 350
Custom Transition 354
Noninteractive Custom Transition Animation 355
Interactive Custom Transition Animation 360
Custom Presented View Controller Transition 365
Transition Coordinator 371
Page View Controller 372
Preparing a Page View Controller 373
Page View Controller Navigation 375
Other Page View Controller Configurations 378
Container View Controllers 379
Adding and Removing Children 380
Status Bar, Traits, and Resizing 384
Previews and Context Menus 386
Context Menu Interaction and Configuration 386
Configuring the Preview 388
Configuring the Menu 390
Storyboards 391
Triggered Segues 396
Container Views and Embed Segues 401
Storyboard References 402
Unwind Segues 403
View Controller Lifetime Events 407
Order of Events 409
Appear and Disappear Events 410
Event Forwarding to a Child View Controller 410
View Controller Memory Management 412
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