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)

Creating context menus

A context menu is a pop-up menu used to display actions that the developer anticipates the user might want to take. SwiftUI context menus are triggered using 3D Touch on iOS and a right-click on macOS.

Context menus consist of a collection of buttons displayed horizontally in an implicit HStack.

In this recipe, we will create a context menu to change the color of an SF symbol.

Getting ready

Create a new SwiftUI project named DisplayingContextMenus.

How to do it

We will display a light bulb in our view and change its color using a context menu. To achieve this, we'll need to create an @State variable to hold the current color of the bulb and change its value within the context menu. The steps are as follows:

  1. Just above the body variable in ContentView.swift, add an @State variable to hold the color of the bulb. Initialize it to red:
    @State private var bulbColor = Color.red
  2. Within the body variable, change the Text struct to an...