Book Image

SwiftUI Cookbook - Second Edition

By : Giordano Scalzo, Edgar Nzokwe
Book Image

SwiftUI Cookbook - Second Edition

By: Giordano Scalzo, Edgar Nzokwe

Overview of this book

SwiftUI provides an innovative and simple way to build beautiful user interfaces (UIs) for all Apple platforms, from iOS and macOS through to watchOS and tvOS, using the Swift programming language. In this recipe-based cookbook, you’ll cover the foundations of SwiftUI as well as the new SwiftUI 3 features introduced in iOS 15 and explore a range of essential techniques and concepts that will help you through the development process. The cookbook begins by explaining how to use basic SwiftUI components. Once you’ve learned the core concepts of UI development, such as Views, Controls, Lists, and ScrollViews, using practical implementations in Swift, you'll advance to adding useful features to SwiftUI using drawings, built-in shapes, animations, and transitions. You’ll understand how to integrate SwiftUI with exciting new components in the Apple development ecosystem, such as Combine for managing events and Core Data for managing app data. Finally, you’ll write iOS, macOS, and watchOS apps by sharing the same SwiftUI codebase. By the end of this SwiftUI book, you'll have discovered a range of simple, direct solutions to common problems encountered when building SwiftUI apps.
Table of Contents (17 chapters)

Applying groups of styles using ViewModifier

SwiftUI comes with built-in modifiers such as background() and fontWeight(), among others. It also gives you the ability to create your own custom modifiers. You can use custom modifiers to combine multiple existing modifiers into one.

In this section, we will create a custom modifier that adds rounded corners and a background to a Text view.

Getting ready

Create a new SwiftUI project named UsingViewModifiers.

How to do it…

Let's create a view modifier and use a single line of code to apply it to a Text view. The steps are given here:

  1. Change the string in the ContentView view to "Perfect":
    Text("Perfect")
  2. In the ContentView.swift file, create a struct that conforms to the ViewModifier protocol, accepts a parameter of type Color, and applies styles to the view's body:
    struct BackgroundStyle: ViewModifier {
        var bgColor: Color
        func...