takahirom

class HogeActivity {
  val featureFlags = FeatureFlags()

  @OptIn(AmazingFeature::class)
  fun onClick() {
    if (featureFlags.isAmazingFeaturesEnabled()) {
      brokenAmazingFeatures()
    }
  }
}

takahirom

@RequiresOptIn(message = "AmazingFeature should be checked")
@Retention(AnnotationRetention.BINARY)
@Target(AnnotationTarget.CLASS, AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY)
annotation class AmazingFeature
  
@AmazingFeature
fun brokenAmazingFeature() {
  TODO("aaaaa")
}
  

takahirom

class HogeActivity {
  fun onClick() {
    brokenAmazingFeature() // Crash when clicked!!!
  }
}

fun brokenAmazingFeature() {
  TODO("aaaaa")
}

takahirom

@Composable
fun SettingScreen(
    settingScreenState: SettingScreenState = rememberSettingScreenState()
) {
    SettingScreen(
        scaffoldState = settingScreenState.scaffoldState,
        isDarkModeSetting = settingScreenState.isDarkMode,
        onDarkModeSettingChanged = {
            settingScreenState.onDarkModeChange(it)
        }

takahirom

@Composable
fun SettingScreen(
    settingViewModel: SettingViewModel = viewModel(),
    scaffoldState: ScaffoldState = rememberScaffoldState(),
    coroutinesScope: CoroutineScope = rememberCoroutineScope(),
) {
    val isDarkMode by settingViewModel.isDarkMode.collectAsState()
    SettingScreen(
        scaffoldState = scaffoldState,
        isDarkModeSetting = isDarkMode,

takahirom

class SettingViewModel(
    val scaffoldState: ScaffoldState
) : ViewModel()

@Composable
fun SettingScreen() {
  val scaffoldState = rememberScaffoldState()
  val settingViewModel = viewModes(factory = { SettingViewModel.Factory.create(scaffoldState) })
}

takahirom

@Composable
fun SettingScreen(
    settingViewModel: SettingViewModel = viewModel()
) {
    val isDarkMode by settingViewModel.isDarkMode.collectAsState()
    MySwitch(checked = isDarkMode, onCheckChanged = {
        settingViewModel.onDarkModeChange(it)
    })
}

takahirom

// stateful
@Composable
fun SettingScreen(
    settingViewModel: SettingViewModel = viewModel()
) {
    val isDarkMode by settingViewModel.isDarkMode.collectAsState()
    SettingScreen(isDarkModeSetting = isDarkMode, onDarkModeSettingChanged = {
        settingViewModel.onDarkModeChange(it)
    })
}

takahirom

@Composable
fun Screen() {
    // I have a state in both Screen and MySwitch.
    var checked by remember { mutableStateOf(false) }
    Row {
        MySwitch(initialChecked = false, onCheckChanged = {checked = it})
        Text(
            text = if(checked) "on" else "false",
            Modifier.clickable {
                checked = !checked

takahirom

@Composable
fun Screen() {
    // State has only on Screen
    var checked by remember { mutableStateOf(false) }
    Row {
        MySwitch(checked = checked, onCheckChanged = { checked = it })
        Text(
            text = if (checked) "on" else "false",
            Modifier.clickable {
                checked = !checked