How to change screen brightness in Kotlin Multiplatform Mobile using Compose

I am trying to code up a way to set screen brightness to max after clicking a button in Kotlin Multiplatform Compose.

I have created an actual function that looks like this:

expect fun setBrightness(brightness: Float)

And then have implemented actual classes on both Android and iOS sides in commonMain module.

Android:

actual fun setBrightness(brightness: Float) {
    val window = requireActivity().window
    val layoutParams = window.attributes
    layoutParams.screenBrightness = brightness // set the brightness value between 0 and 1
    window.attributes = layoutParams
}

iOS:

actual fun setBrightness(brightness: Float) {
    UIScreen.main.brightness = brightness
}

The problem is that requireActivity() is unresolved in androidMain module in shared directory. How do I go around this? I guess this is because it is only available on the native Android side.

How do I set the brightness on both platforms using KMM so that is works in Compose?

You should consider this approach:

1. Create an interface in the commonMain

   interface BrightnessController{
        fun setBrightness(value: Float)
    }

2. Then create expect class in the commonMain

    expect class BrightnessControllerImpl: BrightnessController

3. Then create actual class for Android

    actual class BrightnessControllerImpl(val context: Context): BrightnessController {
        ...
    }

4. Then you just need to inject the context(in Koin you can use androidContext())

First, create expected variable for the module

    expect val brightnessModule: Module

Then create actual for all platforms (example for the Android)

    actual val brightnessModule = module {
        single<BrightnessController> { BrightnessControllerImpl(androidContext()) }
    }

Then to add the module in the App class (any name you have for class that extends Application)

    override fun onCreate(){
        super.onCreate()
        startKoin {
            androidContext(this@App)
            brightnessModule
        }
    }

Note:
You can also create separated modules without the expect/actual. For example call them androidModule and iosModule. Then you can add only the module you need into the platform.