chenzhang2006

private val _loginState = MutableStateFlow<Boolean>(false)
val loginStateFlow: StateFlow<Boolean> = _loginState.asStateFlow()

fun loggedIn() {
  _loginState.value = true
 }
 
 fun loggedOut() {
   _loginState.value = false
 }  

chenzhang2006

private val lock = Mutex() // #1
private var cachedAccount: Account? = null

suspend fun getAccount(): Account? {
        return cachedAccount ?: mutex.withLock { // #2, #3, #6
            cachedAccount ?: withContext(Dispatchers.IO) { // #4, #5, #6
                val networkModel = ... // perform network query and response parsing
                cachedAccout = networkModel.mapToAccountDomain()
                cachedAccount
        }

chenzhang2006

val backdropState = rememberBackdropScaffoldState(Revealed)
var offset by (backdropState.offset as MutableState)

// Optional conditions: ex. should-bounce flag, data-loading finished, etc.
if (backdropState.isRevealed) { 
  // remember the original offset position to go back to
  val revealedOffset = remember { backdropState.offset.value }
  // value holder Animatable for the actual offset
  val offsetAnimatable = remember { Animatable(revealedOffset) }
  

chenzhang2006

@Composable
fun FunctionName(input: T) {
  ...
}

chenzhang2006

val items: List<Room> = rooms
val listState = rememberLazyListState()

LazyColumn(state = listState) { 
  items(items = items) { item -> RoomItem(item) }
}

@Composable
fun RoomItem(item: Room) {
  Text(...)

chenzhang2006

val rooms: List<Room> = rooms
val recyclerViewAdapter = CustomAdapter(rooms)

val recyclerView: RecyclerView = findViewById(R.id.recycler_view)
recyclerView.layoutManager = LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false)
recyclerView.adapter = recyclerViewAdapter

chenzhang2006

class CustomAdapter(private val dataSet: Array<String>) : RecyclerView.Adapter<CustomAdapter.ViewHolder>() {
    class ViewHolder(view: View) : RecyclerView.ViewHolder(view) {
        val textView: TextView
        init {
            textView = view.findViewById(R.id.textView)
        }
    }
    override fun onCreateViewHolder(viewGroup: ViewGroup, viewType: Int): ViewHolder {
        val view = LayoutInflater.from(viewGroup.context)

chenzhang2006

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    ...>
    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/element_text"/>
</FrameLayout>

chenzhang2006

<android.support.v7.widget.RecyclerView
    android:id="@+id/recyclerView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

chenzhang2006

// Horizontle RecyclerView
val horizontalRecyclerView: RecyclerView = findViewById(R.id.horizontal_recycler_view)
val horizontalLayoutManager: LinearLayoutManager = LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false)
horizontalRecyclerView.layoutManager = horizontalLayoutManager

// Vertical RecyclerView
val verticalRecyclerView: RecyclerView = findViewById(R.id.vertical_recycler_view)
val verticalLayoutManager: LinearLayoutManager = LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false)
verticalRecyclerView.layoutManager = verticalLayoutManager