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What's new in Android

BubbleApi (0:04)

• api 29
• What's New in the Android Os User Interface thu @ 9: 30

Dark theme (1:35)

• in Q()
• MODE_NIGHT_AUTO_TIME deprecated
• OptionA - use Theme

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// before
class MainViewModel(val view: MainView, val dataStore: DataStore) {

    private var currentItem: Item by Delegates.observable(Item("kotlin", "#FF0000"),
        { _: KProperty<*>, oldItem: Item, newItem: Item ->
            view.onUpdatedItem(oldItem, newItem)
        })

    private var currentState: NetworkState<Item> by Delegates.observable(NetworkState.Init(),
    { _: KProperty<*>, _: NetworkState<Item>, newState: NetworkState<Item> ->

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class MainViewModel(val view: MainView, val dataStore: DataStore) {

    private var currentItem: Item by Delegates.observable(Item("kotlin", "#FF0000"),
        { _: KProperty<*>, oldItem: Item, newItem: Item ->
            view.onUpdatedItem(oldItem, newItem)
        })

    private var currentState: NetworkState<Item> by Delegates.observable(NetworkState.Init(),
    { _: KProperty<*>, _: NetworkState<Item>, newState: NetworkState<Item> ->
        when (newState) {

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// before
sealed class NetworkState {
    class Init : NetworkState()
    class Loading : NetworkState()
    class Success(val item: Item) : NetworkState()
    class Error(val throwable: Throwable?) : NetworkState()
}

// after
sealed class NetworkState<out T> {

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class MainViewModel(val view: MainView, val dataStore: DataStore) {

    private var currentItem: Item by Delegates.observable(Item("kotlin", "#FF0000"),
        { _: KProperty<*>, oldItem: Item, newItem: Item ->
            view.onUpdatedItem(oldItem, newItem)
        })

    private var currentState: NetworkState by Delegates.observable(NetworkState.Init(),
        { _: KProperty<*>, _: NetworkState, newState: NetworkState ->
            when (newState) {

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sealed class NetworkState {
    class Init : NetworkState()
    class Loading : NetworkState()
    class Success(val item: Item) : NetworkState()
    class Error(val throwable: Throwable?) : NetworkState()
}

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// before
class MainViewModel(val view: MainView) {

    private var currentItem: Item by Delegates.observable(Item.ITEM_A,
        { _: KProperty<*>, oldItem: Item, newItem: Item ->
            view.onUpdatedItem(oldItem, newItem)
        })

    fun onClicked(item: Item) {
        currentItem = item

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// before
enum class Item(val titleId: Int, val colorId: Int) {
    ITEM_A(R.string.a, R.color.red),
    ITEM_B(R.string.b, R.color.green),
    ITEM_C(R.string.c, R.color.blue)
} 

// after
data class Item(val title: String, val color: String)

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class MainActivity : AppCompatActivity(), MainView {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val mainViewModel = MainViewModel(this, DataStore())

        bt_a.setOnClickListener {
            mainViewModel.requestItemInfo(ItemType.ITEM_A)

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interface MainView {
    fun onUpdatedItem(oldItem: Item, newItem: Item)

    fun showProgress()

    fun hideProgress()

    fun onError(throwable: Throwable)
}