Perseus Dark Mode

Integration Capabilities

Demo Apps and Others

In Brief

This library lets a developer being awared of Dark Mode via a variable DarkMode.style. Also, with this library it is possible to change the value of Dark Mode in runtime easily.

Reqirements

Xcode 10.1+
Swift 4.2+
iOS: 9.3+, UIKit SDK
macOS: 10.9+, AppKit SDK

Third-party software

SwiftLint Shell Script Runner

Installation

Step 1: Add PerseusDarkMode to a host project tree

Standalone

Make a copy of the file PerseusDarkModeSingle.swift then put it into a place required of a host project.

CocoaPods

Podfile should contain:

target "ProjectTarget" do
  use_frameworks!
  pod 'PerseusDarkMode', '1.1.3'
end

Carthage

Cartfile should contain:

github "perseusrealdeal/PerseusDarkMode" == 1.1.4

Some Carthage usage tips placed here.

Swift Package Manager

As a package dependency so Package.swift should contain the following statements:

dependencies: [
        .package(url: "https://github.com/perseusrealdeal/PerseusDarkMode.git",
            .exact("1.1.4"))
    ],

As an Xcode project dependency:

Project in the Navigator > Package Dependencies > Add Package Dependency

Using “Exact” with the Version field is strongly recommended.

Step 2: Make DarkMode ready for using

iOS

Override the following method of the first screen to let Perseus know that system’s appearance changed:

class MainViewController: UIViewController {
    override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
        super.traitCollectionDidChange(previousTraitCollection)

        if #available(iOS 13.0, *) {
            AppearanceService.processTraitCollectionDidChange(previousTraitCollection)
        }
    }
}

Also, if Dark Mode is released with Settings bundle put the statements into the app’s delegate:

extension AppDelegate: UIApplicationDelegate {

    func applicationDidBecomeActive(_ application: UIApplication) {

        // Update Dark Mode from Settings
        if let choice = isDarkModeSettingsChanged() {
            // Change Dark Mode value in Perseus Dark Mode library
            AppearanceService.DarkModeUserChoice = choice
            // Update appearance in accoring with changed Dark Mode Style
            AppearanceService.makeUp()
        }
    }
}

Used functions are distributed via standalone file DarkModeSwitching.swift.

iOS and macOS

Call the method AppearanceService.makeUp() with the app’s delegate if appearance changing is going to take place:

extension AppDelegate: UIApplicationDelegate {

    func application(_ application: UIApplication, didFinishLaunchingWithOptions
        launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        
        // ... code
        
        // Call AppearanceService.makeUp() method if AppearanceService.register(:, :)
        // is taken into account
        AppearanceService.makeUp()

        // ... otherwise call AppearanceService.recalculateStyleIfNeeded()
        // to load DarkMode.style from user defaults
        // AppearanceService.recalculateStyleIfNeeded()
    }
}

Copy the file DarkModeSwitching.swift into a host project for having fun with manual changing Dark Mode value.

Usage

Each time if Dark Mode changed the mentioned method #selector(makeUp) called, but registering is required:

class MainViewController: UIViewController {

    // At any view controller where changing is required

    override func viewDidLoad() {
        super.viewDidLoad()

        AppearanceService.register(stakeholder: self, selector: #selector(makeUp))
    }

    @objc private func makeUp() {
        print("^_^ \(AppearanceService.DarkModeUserChoice)"

        switch DarkMode.style {
        case .light:
            // make drawings for light mode
            break
        case .dark:
            // make drawings for dark mode
            break
        }
    }
}

There is another way to be notified of Dark Mode—KVO. To learn have a look at sample directly.

License MIT

The year starts from the creation of the world according to a Slavic calendar.
September, the 1st of Slavic year.

Have a look at LICENSE for details.

Author and Acknowledgments

PerseusDarkMode was written at Novosibirsk by Mikhail Zhigulin i.e. me, mzhigulin@gmail.com.

Mostly I’d like thank my lovely parents for supporting me in all my ways.