// register all themes that you want to use (our just a subset of them, even a single one is enough)
val allThemes: List<ComposeTheme.Theme> =
    DefaultThemes.getAllThemes() +
            MetroThemes.getAllThemes() +
            FlatUIThemes.getAllThemes() +
            Material500Themes.getAllThemes()
ComposeTheme.register(*allThemes.toTypedArray())

// create a state that holds the current theme settings
val baseTheme = rememberSaveable { mutableStateOf(ComposeTheme.BaseTheme.System) }
val contrast = rememberSaveable { mutableStateOf(ComposeTheme.Contrast.Normal) }
val dynamic = rememberSaveable { mutableStateOf(false) }
val theme = rememberSaveable { mutableStateOf(ThemeDefault.Theme.id) } // id of the current theme
val state = ComposeTheme.State(baseTheme, contrast, dynamic, theme)

// use ComposeTheme instead of MaterialTheme
ComposeTheme(state = state) {
    // app content
}

ComposeTheme(
    state = state
) {
    // set the color that you use behind the status bar and navigation bar (e.g. primary toolbar + surface bottom navigation)
    val statusBarColor = ...
    val navigationBarColor = ...

    // UpdateEdgeToEdgeDefault...helper function to easily enable edgeToEdge
    // SystemBarStyle also offers some extensions (statusBar, navigationBar, transparent) that can be used

    // this app draws a bottom navigation behind the navigation bar in portrait only, in landscape mode it doesn't
    val landscape = LocalConfiguration.current.orientation == Configuration.ORIENTATION_LANDSCAPE
    val isDark = state.base.value.isDark()

    UpdateEdgeToEdgeDefault(
        activity = this,
        themeState = state,
        statusBarColor = statusBarColor,
        navigationBarColor = if (landscape) {
            SystemBarStyle.defaultScrim(resources, isDark)
        } else navigationBarColor,
        isNavigationBarContrastEnforced = landscape
    )
}