Book Image

SwiftUI Cookbook

By : Giordano Scalzo, Edgar Nzokwe
Book Image

SwiftUI Cookbook

By: Giordano Scalzo, Edgar Nzokwe

Overview of this book

SwiftUI is an innovative and simple way to build beautiful user interfaces (UIs) for all Apple platforms, right from iOS and macOS through to watchOS and tvOS, using the Swift programming language. In this recipe-based book, you’ll work with SwiftUI and explore a range of essential techniques and concepts that will help you through the development process. The recipes cover the foundations of SwiftUI as well as the new SwiftUI 2.0 features introduced in iOS 14. Other recipes will help you to make some of the new SwiftUI 2.0 components backward-compatible with iOS 13, such as the Map View or the Sign in with Apple View. The cookbook begins by explaining how to use basic SwiftUI components. Then, you’ll learn the core concepts of UI development such as Views, Controls, Lists, and ScrollViews using practical implementation in Swift. By learning drawings, built-in shapes, and adding animations and transitions, you’ll discover how to add useful features to the SwiftUI. When you’re ready, 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 while 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 found in building SwiftUI apps.
Table of Contents (15 chapters)

Implementing a progress ring

Admit it – since you bought your Apple Watch, you are getting fitter, aren't you?

I bet it is because of the activity rings you want to close every day – am I right?

In this recipe, we'll implement a progress ring similar to those on the Apple Watch, and we'll drive them via some sliders.

Getting ready

There's nothing in particular that needs preparing for this recipe; just create a SwiftUI project called ProgressRingApp.

How to do it...

We are going to implement two components:

  • A single ProgressRing View
  • A composite RingsView

We'll add the latter to ContentView, and we'll simulate the progress using three sliders:

  1. Implement a ring view using a Shape object and an arc:
    struct ProgressRing: Shape {
        private let startAngle = Angle.radians(1.5 * .pi)
        var progress: Double