Configuration of custom views

[Dixisss]

Could you please help me to find out better solutions to configurate custom views? I have 20 different features on one screen. Each feature has its own view. The app has a dynamic theme. Each view has one input/state. I need to set theme settings for each view. I hope that anybody has some ideas or any examples of how to do it in the best way.

[ShikaSD]

Hi @Dixisss

If you are using Android theme (xml defined), I am not sure there's a solution better than reinflate your views.

In case the theme is some configuration object (e.g. Kotlin data class), you can try representing your theme as a feature state and try to use it to get some reactivity on its updates

Imagining existing setup:

data class Theme(
    val bgColor: Int = Color.BLACK
)

Feature for theme can look like this:

class ThemeFeature : ReducerFeature<Wish, Theme, Nothing>(...) {
    sealed class Wish {
        object SwitchToDark : Wish()
        object SwitchToLight : Wish()
    }
}

When the feature is set up, you can combine it in the following way:

class ThemedWrapper<T>(
    val theme: Theme,
    val viewModel: T
)

class ThemedTransformer<T, R>(val stateToViewModel: (T) -> R): (Pair<Theme, T>) -> ThemedWrapper<R> {
    override fun invoke(pair: Pair<Theme, T>): ThemedWrapper<R> =
        ThemedWrapper(it.first, stateToViewModel(it.second))
}

val featureWithTheme = Observable.combineLatest(
    wrap(themeFeature),
    wrap(feature),
    ::Pair
)

object StateToViewModel: (State) -> ViewModel // your existing transformer

Binder().apply {
    bind(featureWithTheme to view using ThemedTransformer(StateToViewModel))
}

This way you will guarantee atomicity of the theme updates and make sure the view has received the update. Note that your view has to be able to accept ThemedWrapper<ViewModel> to make this work.

I am pretty sure there is a more elegant way to push these updates, so try to test it and see what is working best for you.