Ios – Is it possible to opt-out of dark mode on iOS 13

iosios-darkmodeios13

A large part of my app consists of web views to provide functionality not yet available through native implementations. The web team has no plans to implement a dark theme for the website. As such, my app will look a bit half/half with Dark Mode support on iOS 13.

Is it possible to opt out of Dark Mode support such that our app always shows light mode to match the website theme?

Best Answer

First, here is Apple's entry related to opting out of dark mode. The content at this link is written for Xcode 11 & iOS 13:

Entire app via info.plist file (Xcode 12)

Use the following key in your info.plist file:

UIUserInterfaceStyle

And assign it a value of Light.

The XML for the UIUserInterfaceStyle assignment:

<key>UIUserInterfaceStyle</key>
<string>Light</string>

Apple documentation for UIUserInterfaceStyle

Entire app via info.plist in build settings (Xcode 13)

Entire app window via window property

You can set overrideUserInterfaceStyle against the app's window variable. This will apply to all views that appear within the window. This became available with iOS 13, so for apps that support previous versions, you must include an availability check.

Depending on how your project was created, this may be in the AppDelegate or SceneDelegate file.

if #available(iOS 13.0, *) {
    window?.overrideUserInterfaceStyle = .light
}

Individual UIViewController or UIView

You can set overrideUserInterfaceStyle against the UIViewControllers or UIView's overrideUserInterfaceStyle variable. This became available with iOS 13, so for apps that support previous versions, you must include an availability check.

Swift

override func viewDidLoad() {
    super.viewDidLoad()
    // overrideUserInterfaceStyle is available with iOS 13
    if #available(iOS 13.0, *) {
        // Always adopt a light interface style.
        overrideUserInterfaceStyle = .light
    }
}

For those poor souls in Objective-C

if (@available(iOS 13.0, *)) {
        self.overrideUserInterfaceStyle = UIUserInterfaceStyleLight;
}

When set against the UIViewController, the view controller and its children adopt the defined mode.

When set against the UIView, the view and its children adopt the defined mode.

Apple documentation for overrideUserInterfaceStyle

Individual views via SwiftUI View

You can set preferredColorScheme to be either light or dark. The provided value will set the color scheme for the presentation.

import SwiftUI

struct ContentView: View {
    var body: some View {
        Text("Light Only")
            .preferredColorScheme(.light)
    }
}

Apple documentation for preferredColorScheme

Credit to @Aron Nelson, @Raimundas Sakalauskas, @NSLeader and @rmaddy for improving this answer with their feedback.

Related Solutions

Ios – Design for Facebook authentication in an iOS app that also accesses a secured web service

I just dealt with this myself, and here's the part that bit me:

In your step 5... It's possible for a user to register for an account with you entirely separate from their Facebook ID, right? Then some other time they log in with Facebook.... And you just created them a second account and lost their first one.

There needs to be a way to be logged in to your web service, then log in to facebook, and capture the association between the facebook ID and the local account.

Apart from that, your plan sounds solid.

Update: Facebook has added a doc outlining such a scenario HERE

Swift – Detecting iOS Dark Mode Change

Swift 5:

traitCollectionDidChange also gets called a few times. This is how I detect DarkMode runtime change and setColors().

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

        setColors()
    }

In setColors() func I update the colors. Detecting current colorScheme:

extension UIViewController {
    var isDarkMode: Bool {
        if #available(iOS 13.0, *) {
            return self.traitCollection.userInterfaceStyle == .dark
        }
        else {
            return false
        }
    }

}

I have colors defined like this (for iOS < 13):

enum ColorCompatibility {
    static var myOlderiOSCompatibleColorName: UIColor {
        if UIViewController().isDarkMode {
            return UIColor(red: 33, green: 35, blue: 37, alpha: 0.85)
        }
        else {
            return UIColor(hexString: "#F3F3F3", alpha: 0.85)
        }
    }
}

Example:

private func setColors() {
  myView.backgroundColor = ColorCompatibility.myOlderiOSCompatibleColorName
}

Also you might need to call setColors in ViewDidLoad/Will/DidAppear depending on your case like this:

viewDidLoad() {
...
setColors()
...
}

For iOS11+ you could use "named Colors", defined in Assets and much easier to use in IB.

Cheers