indextrown/scalekit

🚀 Features

• Screen-diagonal-based dynamic scaling
• .scaled extensions for CGFloat, Double, Int, and Float
• Works seamlessly with both SwiftUI and UIKit
• Concurrency-safe using @MainActor

📦 Installation

Swift Package Manager (SPM)

Xcode → File > Add Packages → Enter: https://github.com/indextrown/ScaleKit.git

✅ Usage

SwiftUI

// App.swift
import SwiftUI
import ScaleKit

@main
struct TestApp: App {

    init() {
        // 1. Set screen size once at app launch
        DynamicSize.setScreenSize(UIScreen.main.bounds)

        // 2. Or explicitly set a different base device
        DynamicSize.setScreenSize(UIScreen.main.bounds, baseDevice: .iPhone14ProMax)
    }

    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

// ContentView.swift
import SwiftUI
import ScaleKit

struct ContentView: View {
    var body: some View {
        Text("Start")
            .font(.system(size: 18.scaled))
            .padding(12.0.scaled)
            .frame(width: 100.scaled, height: 50.scaled)
    }
}

UIKit

import UIKit
import ScaleKit

class SceneDelegate: UIResponder, UIWindowSceneDelegate {
    
    var window: UIWindow?
    
    func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
        guard let windowScene = (scene as? UIWindowScene) else { return }
        DynamicSize.setScreenSize(windowScene.screen.bounds)

        let label = UILabel()
        label.font = .systemFont(ofSize: 18.scaled)
        label.layer.cornerRadius = 12.scaled
    }
}

⚠️ Important

Make sure to call the following method once at app launch:

DynamicSize.setScreenSize(UIScreen.main.bounds)

In SwiftUI, call it inside the App struct’s init(). In UIKit, call it in SceneDelegate or AppDelegate.

🧠 Scaling Formula

Default Base Device: iPhone 15 Pro Max (430 x 932pt)

scaleFactor = √(screenWidth² + screenHeight²) / √(430² + 932²)
scaledSize = baseSize × scaleFactor

🔧 Structure

• DynamicSize: Sets screen size and calculates scale factor
• .scaled: Extensions for Int, Double, Float, and CGFloat

📂 Folder Structure

Sources/
└── ScaleKit/
    ├── DynamicSize.swift
    ├── DynamicSize+BaseDevice.swift
    └── Scaled+Extensions.swift

📄 License

MIT License

Copyright (c) 2025 Donghyeon Kim

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction...

Made with 💻 by @donghyeon-kim

Package Metadata

Repository: indextrown/scalekit

Default branch: main

README: README.md