SwiftUI For Dummies

Wei-Meng Lee (Singapore) is founder of Developer Learning Solutions, a firm specializing in hands-on training for software developers. He teaches courses in mobile development, blockchain, machine learning, and AI. He is author of a number of books, including Beginning Swift Programming (Wiley).

• Introduction 1About This Book 1Foolish Assumptions 2Icons Used in This Book 2Beyond the Book 3Where to Go from Here 3Part 1: Getting Started with Swift and SwiftUI 5Chapter 1: Introducing SwiftUI 7Understanding What SwiftUI Is 7Getting the Tools 11Hello, SwiftUI 12Automatically previewing your user interface using the canvas 14Working with Live Preview 18Generating different previews 19The Gory Details 21Info plist 22AppDelegate swift 22SceneDelegate swift 23Chapter 2: Basics of the Swift Programming Language 25Basic Swift Syntax 26Constants 26Variables 27Strings 27Comments 27Basic Data Types 28Integers 28Floating-point numbers 29Booleans 29Tuples 30Arrays 30Retrieving elements from an array 31Inserting elements into an array 31Modifying elements in an array 31Appending elements to an array 31Removing elements from an array 32Dictionaries 32Retrieving elements from a dictionary 32Modifying an item in a dictionary 33Removing an item from a dictionary 33Optional Types 33Working with implicitly unwrapped optionals 35Using optional binding 36Unwrapping optionals using “?” 36Using the nil coalescing operator 37Functions 38Understanding input parameters 38Returning a value 39Flow Control 39If-Else statement 40Ternary conditional operator 40Switch statement 40Looping 41For-In loop 42While loop 42Repeat-While loop 42Control transfer statements 42Range operators 43Structures 43Memberwise initializers 44Structures as value types 45Classes 47Defining a class 47Understanding properties 47Using methods in classes 49Trying out the self property 50Closures 51Understanding closures 51Using functions as closures 52Assigning closures to variables 52Writing closures inline 53Understanding type inference 53Using shorthand argument names 54Working with the operator function 54Using trailing closures 55Protocols 55Defining and using a protocol 56Conforming to a protocol 56Using the Codable protocol 57Using the some keyword 59Part 2: Understanding the Basics of SwiftUI 61Chapter 3: Getting Started with the Basics of SwiftUI 63Taking a Look at SwiftUI Views 63Conforming to the View protocol 64Using modifiers 66Stacking modifiers 66Using the Inspector 67Displaying an Image 70Using modifiers on the Image view 72Resizing images 73Displaying a Button 75Customizing the button 76Adding actions 77Stacking the Views 78VStack 79HStack 80Putting on the Finishing Touches 85Chapter 4: Handling User Inputs and Custom Views 87Looking at Input Views 87TextField 88SecureField 92Toggle 93Slider 94Stepper 98Picker 100Composing Custom Views 103Composing the custom view 104Using the custom view 111Chapter 5: Displaying Lists of Items 113Using the List View to Display Items 113Customizing the rows 114Adding rows programmatically 116Alternative way to generate rows in a List view 119Displaying the List within a NavigationView 120Making the items tappable 121Adding rows 123Using the Identifiable protocol 125Deleting rows 126Editing rows 128Moving rows 130Displaying Sections 133Displaying sections from a dictionary 134Changing the style of the List view 136Previewing in Light and Dark Modes 138During runtime 138During design time 139Chapter 6: Creating Navigation and Tabbed Applications 143Creating Navigation Apps 144Working with the two key views in navigation-style apps 145Navigating to a page 148Navigating programmatically 149Creating a news reader application 151Creating Tabbed Applications 167Using the TabView 168Selecting TabViews programmatically 169Chapter 7: Formatting Your User Interface 173Laying Out Views Using Stacks 173VStack 174HStack 186ZStack 190Using Container Views 195Form and Section 198Group 200Divider 203Part 3: Exploring with SwiftUI in More Detail 205Chapter 8: Understanding State Management in SwiftUI 207Using a Property Wrapper 207Maintaining State Using State Variables 209Binding State Variables 213Managing State from External Objects 218Using the ObservableObject protocol and @Published 219Using the @ObservedObject 221Sharing Objects 223Accessing Built-in Environment Variables 228Defining your own environment keys 230Using your own environment keys 231Chapter 9: Using Legacy UIKit Views and View Controllers in SwiftUI 235Using UIKit in SwiftUI 236Understanding the UIKit View Controller life cycle 237Understanding the SwiftUI view life cycle 239Using the UIViewRepresentable Protocol for UIKit Views 247ActivityIndicator 248WebView 251Using the UIViewControllerRepresentable Protocol for UIKit View Controllers 253Creating the ImagePickerViewController 254Handling events using coordinators 256Defining the methods in the Coordinator class 258Using the updated ImagePickerViewController 260Part 4: Performing Animations and Drawings 263Chapter 10: Drawings and Special Effects 265Drawing Using the Five Built-in Shapes 266Rectangles 266Rounded rectangles 270Circles 273Capsules 274Ellipses 275Clipping with the Basic Shapes 277Drawing Custom Shapes 281Drawing lines 283Filling the shape 284Drawing a border 286Drawing an arc 287Combining fill and stroke 289Using Special Effects in SwiftUI 292Blend modes 292Blurs 297Saturation 298Chapter 11: Performing Animations in SwiftUI 299Understanding How to Animate 299Specifying the type of animation 303Repeating the animation 303Stopping the animation 304Performing Your Own Animation 307Rotating in 2D 307Rotating in 3D 309Creating a Custom Progress Indicator 314Indeterminate progress indicator 314Determinate progress indicator 318Chapter 12: Creating a Complete Project 323Understanding What the App Does 323Building the Project 325Creating the layouts 325Defining the news sources and observable objects 328Fetching the data 330Displaying the news headlines 331Displaying the images 334Displaying the news 336Creating the share sheet 338Creating the preferences view 339Persisting the user’s preferences 344Deploying the App 346Part 5: The Part of Tens 351Chapter 13: Ten SwiftUI Tips and Tricks 353Resuming Live Preview 353Implementing Localization 354Combining Text Views 358Creating Custom Modifiers 360Displaying Multiple Alerts 362Enabling Debug Preview 363Previewing Using Different Devices 364Dark Mode Only Works On NavigationView 368Extracting Subviews 370Displaying a Context Menu 373Chapter 14: Ten Great SwiftUI Resources 375Apple 375SwiftUI by Example 376100 Days of SwiftUI 376Gosh Darn SwiftUI 376SwiftUI Hub 376Awesome SwiftUI 377raywenderlich com 377Swift Talk 377About SwiftUI 377Stack Overflow 378Appendix: Code Snippets for Common Swiftui Views 379Index 387