El Arsenal de Android – Preferencias

object UserSettingsModel : SettingsModel(DataStoreStorage(name = "user")) {

  // Basic
  val name by stringPref("User")
  val alive by boolPref(true)
  val hairColor by intPref(Color.parseColor("#A52A2A"))
  val age by intPref(40)
  val income by floatPref(50000f)
  val dayOfBirth by longPref(0L)
  
  // Sets
  val childrenAges by intSetPref(setOf(20, 18, 16))
  val childrenIncomes by floatSetPref(setOf(30000f, 10000f, 0f))
  val childrenDaysOfBirth by longSetPref(setOf(0L, 0L, 0L))
  
  // Enum
  val car by enumPref(Car.Tesla)
  
  // custom class - provide a custom converter (String <=> Class)
  val testClass by anyPref(TestClass.CONVERTER, TestClass())
}

// 1) simply observe a setting
UserSettingsModel.name.observe(lifecycleScope) {
 L.d { "name = $it"}
}

// 2) direct read (not recommended if not necessary but may be useful in many cases => simply returns flow.first() in a blocking way)
val name = UserSettingsModel.name.value

// 3) observe a setting once
UserSettingsModel.name.observeOnce(lifecycleScope) {
 L.d { "name = $it"}
}

// 4) observe ALL settings
UserSettingsModel.changes.onEach {
 L.d { "[ALL SETTINGS OBSERVER] Setting '${it.setting.key}' changed its value to ${it.value}" }
}.launchIn(lifecycleScope)

// 5) observe SOME settings
UserSettingsModel.changes´
 .filter {
  it.setting == UserSettingsModel.name ||
  it.setting == UserSettingsModel.age
 }.onEach {
  // we know that either the name or the age changes
  L.d { "[SOME SETTINGS OBSERVER] Setting '${it.setting.key}' changed its value to ${it.value}" }
 }.launchIn(lifecycleScope)
 
// 6) read multiple settings in a suspending way
lifecycleScope.launch(Dispatchers.IO) {
  val name = UserSettingsModel.childName1.flow.first()
  val alive = DemoSettingsModel.alive.flow.first()
  val hairColor = DemoSettingsModel.hairColor.flow.first()
  withContext(Dispatchers.Main) {
 textView.text = "Informations: $name, $alive, $hairColor"
  }
}

val lifedata = UserSettingsModel.name.flow.asLiveData()

lifecycleScope.launch(Dispatchers.IO)  {
  UserSettingsModel.name.update("Some new name")
  UserSettingsModel.age.update(30)
}