Minimal Compose iOS app, Hello World

main.uikit.kt

import androidx.compose.material.Text
import androidx.compose.ui.window.Application
import kotlinx.cinterop.ObjCObjectBase
import kotlinx.cinterop.autoreleasepool
import kotlinx.cinterop.cstr
import kotlinx.cinterop.memScoped
import kotlinx.cinterop.toCValues
import platform.Foundation.NSStringFromClass
import platform.UIKit.UIApplication
import platform.UIKit.UIApplicationDelegateProtocol
import platform.UIKit.UIApplicationDelegateProtocolMeta
import platform.UIKit.UIApplicationMain
import platform.UIKit.UIResponder
import platform.UIKit.UIResponderMeta
import platform.UIKit.UIScreen
import platform.UIKit.UIWindow

fun main() {
    val args = emptyArray<String>()
    memScoped {
        val argc = args.size + 1
        val argv = (arrayOf("skikoApp") + args).map { it.cstr.ptr }.toCValues()
        autoreleasepool {
            UIApplicationMain(argc, argv, null, NSStringFromClass(SkikoAppDelegate))
        }
    }
}

class SkikoAppDelegate : UIResponder, UIApplicationDelegateProtocol {
    companion object : UIResponderMeta(), UIApplicationDelegateProtocolMeta

    @ObjCObjectBase.OverrideInit
    constructor() : super()

    private var _window: UIWindow? = null
    override fun window() = _window
    override fun setWindow(window: UIWindow?) {
        _window = window
    }

    override fun application(application: UIApplication, didFinishLaunchingWithOptions: Map<Any?, *>?): Boolean {
        window = UIWindow(frame = UIScreen.mainScreen.bounds)
        window!!.rootViewController = Application("Your Application") {
            Text("Helo World, from Compose iOS app!!!")
        }
        window!!.makeKeyAndVisible()
        return true
    }
}