Using custom font for entire iOS app swift

Question

I know that to set a custom font of an element on the screen I can simply dosomeLabel.font=UIFont(name: "Exo 2.0", size: 15).

I was wondering how one could set it for an entire app using swift. (A hack would be to do what I know for every single element of the app but that is just going to be a maintainability nightmare)

I see that this question has already been asked with an objective-C tag, How to set a custom font for entire iOS app without specifying size but I'm not familiar enough with objective-C enough to port the code to swift

Answer 1

You can set the appearance of the UILabel and other UIViews:

UILabel.appearance().font = UIFont(name: "yourFont", size: yourSize)

More General:

AnyUIView.appearance().font = UIFont(name: "yourFont", size: yourSize)

Answer 2

As a more detailed answer and with these benefits I recommend using extensions:

• No size override (whatever you set in designer will be used)
• No style override (Bold, Light, Medium, UltraLight is implemented in my code but you can customize it as you need)

import UIKit

extension UILabel {
    @objc var substituteFontName : String {
        get {
            return self.font.fontName;
        }
        set {
            let fontNameToTest = self.font.fontName.lowercased();
            var fontName = newValue;
            if fontNameToTest.range(of: "bold") != nil {
                fontName += "-Bold";
            } else if fontNameToTest.range(of: "medium") != nil {
                fontName += "-Medium";
            } else if fontNameToTest.range(of: "light") != nil {
                fontName += "-Light";
            } else if fontNameToTest.range(of: "ultralight") != nil {
                fontName += "-UltraLight";
            }
            self.font = UIFont(name: fontName, size: self.font.pointSize)
        }
    }
}

extension UITextView {
    @objc var substituteFontName : String {
        get {
            return self.font?.fontName ?? "";
        }
        set {
            let fontNameToTest = self.font?.fontName.lowercased() ?? "";
            var fontName = newValue;
            if fontNameToTest.range(of: "bold") != nil {
                fontName += "-Bold";
            } else if fontNameToTest.range(of: "medium") != nil {
                fontName += "-Medium";
            } else if fontNameToTest.range(of: "light") != nil {
                fontName += "-Light";
            } else if fontNameToTest.range(of: "ultralight") != nil {
                fontName += "-UltraLight";
            }
            self.font = UIFont(name: fontName, size: self.font?.pointSize ?? 17)
        }
    }
}

extension UITextField {
    @objc var substituteFontName : String {
        get {
            return self.font?.fontName ?? "";
        }
        set {
            let fontNameToTest = self.font?.fontName.lowercased() ?? "";
            var fontName = newValue;
            if fontNameToTest.range(of: "bold") != nil {
                fontName += "-Bold";
            } else if fontNameToTest.range(of: "medium") != nil {
                fontName += "-Medium";
            } else if fontNameToTest.range(of: "light") != nil {
                fontName += "-Light";
            } else if fontNameToTest.range(of: "ultralight") != nil {
                fontName += "-UltraLight";
            }
            self.font = UIFont(name: fontName, size: self.font?.pointSize ?? 17)
        }
    }
}

Samples for using Extensions:

e.g. put these lines in your starting controller viewDidLoad

UILabel.appearance().substituteFontName = "IRANSans"; // USE YOUR FONT NAME INSTEAD
UITextView.appearance().substituteFontName = "IRANSans"; // USE YOUR FONT NAME INSTEAD
UITextField.appearance().substituteFontName = "IRANSans"; // USE YOUR FONT NAME INSTEAD

P.S. as @Christian mentioned, you can write your own extensions for almost AnyUIView

Answer 3

FINALLY figured this out. Cleanest way I could find. (Swift 4) Solution doesn't require you to set font sizes and won't override all font sizes.

  UILabel.appearance().font = UIFont.preferredFont(forTextStyle: UIFontTextStyle(rawValue: "Roboto"))

For those looking for where to place this code. I put it in my AppDelegate.swift file inside of

 func application(_ application: UIApplication, 
 didFinishLaunchingWithOptions...

Swift 4.2

 UILabel.appearance().font = UIFont.preferredFont(forTextStyle: UIFont.TextStyle(rawValue: "Roboto"))

Answer 4

I found out a way to do same in Swift 4 with iOS 11

Only need to add @objc keyword before variable name. So variable declaration will be like this

@objc public var substituteFontName : String {
    get {}
    set {}
}

Hope this helps others who are facing this issue.