//Main.scala
/* imports */
object Main extends SimpleSwingApplication {
lazy val ui = new TabbedPane {
/* contents */
}
def top = new MainFrame {
/* contents */
}
override def startup(args: Array[String]) {
val t = top
val loginStatus = new Login(t).status
if (loginStatus == true) {
if (t.size == new Dimension(0, 0)) t.pack
t.visible = true
} else
quit
}
}
//Login.scala
class Login(owner: Window) extends Dialog(owner) {
import Login._
var status = true
contents = ui
listenTo(login) //login is a Button
reactions += {
case ButtonClicked(login) => {
if (/* login field is empty */)
status = false
else if (/* login info is correct */)
status = true
else /*login info is wrong*/
status = false
}
}
}
How can I have 'Main' to wait for 'Login' before displaying itself?
Use a CountDownLatch:
//Main.scala
/* imports */
object Main extends SimpleSwingApplication {
private val latch = new CountDownLatch(1)
lazy val ui = new TabbedPane {
/* contents */
}
def top = new MainFrame {
/* contents */
}
override def startup(args: Array[String]) {
val t = top
val loginDialog = new Login(t, latch)
latch.await
val loginStatus = loginWindow.status
if (loginStatus == true) {
if (t.size == new Dimension(0, 0)) { t.pack }
t.visible = true
} else
quit
}
}
//Login.scala
class Login(owner: Window, latch: CountDownLatch) extends Dialog(owner) {
import Login._
var status = true
contents = ui
listenTo(login) //login is a Button
reactions += {
case ButtonClicked(login) => {
latch.countdown
if (/* login field is empty */)
status = false
else if (/* login info is correct */)
status = true
else /*login info is wrong*/
status = false
}
}
}
Related
How can a Snackbar be shown above a Dialog or AlertDialog in Jetpack Compose? Everything I have tried has resulted in the snack bar being below the scrim of the dialog not to mention the dialog itself.
According to Can I display material design Snackbar in dialog? it is possible in non-Compose Android by using a custom or special (like getDialog().getWindow().getDecorView()) view, but that isn't accessible from Compose I believe (at least not without a lot of effort).
I came up with a solution that mostly works. It uses the built-in Snackbar() composable for the rendering but handles the role of SnackbarHost() with a new function SnackbarInDialogContainer().
Usage example:
var error by remember { mutableStateOf<String?>(null) }
AlertDialog(
...
text = {
...
if (error !== null) {
SnackbarInDialogContainer(error, dismiss = { error = null }) {
Snackbar(it, Modifier.padding(WindowInsets.ime.asPaddingValues()))
}
}
}
...
)
It has the following limitations:
Has to be used in place within the dialog instead of at the top level
There is no host to queue messages, instead that has to be handled elsewhere if desired
Dismissal is done with a callback (i.e. { error = null} above) instead of automatically
Actions currently do nothing at all, but that could be fixed (I had no use for them, the code do include everything necessary to render the actions I believe, but none of the interaction).
This has built-in support for avoiding the IME (software keyboard), but you may still need to follow https://stackoverflow.com/a/73889690/582298 to make it fully work.
Code for the Composable:
#Composable
fun SnackbarInDialogContainer(
text: String,
actionLabel: String? = null,
duration: SnackbarDuration =
if (actionLabel == null) SnackbarDuration.Short else SnackbarDuration.Indefinite,
dismiss: () -> Unit,
content: #Composable (SnackbarData) -> Unit
) {
val snackbarData = remember {
SnackbarDataImpl(
SnackbarVisualsImpl(text, actionLabel, true, duration),
dismiss
)
}
val dur = getDuration(duration, actionLabel)
if (dur != Long.MAX_VALUE) {
LaunchedEffect(snackbarData) {
delay(dur)
snackbarData.dismiss()
}
}
val popupPosProvider by imeMonitor()
Popup(
popupPositionProvider = popupPosProvider,
properties = PopupProperties(clippingEnabled = false),
) {
content(snackbarData)
}
}
#Composable
private fun getDuration(duration: SnackbarDuration, actionLabel: String?): Long {
val accessibilityManager = LocalAccessibilityManager.current
return remember(duration, actionLabel, accessibilityManager) {
val orig = when (duration) {
SnackbarDuration.Short -> 4000L
SnackbarDuration.Long -> 10000L
SnackbarDuration.Indefinite -> Long.MAX_VALUE
}
accessibilityManager?.calculateRecommendedTimeoutMillis(
orig, containsIcons = true, containsText = true, containsControls = actionLabel != null
) ?: orig
}
}
/**
* Monitors the size of the IME (software keyboard) and provides an updating
* PopupPositionProvider.
*/
#Composable
private fun imeMonitor(): State<PopupPositionProvider> {
val provider = remember { mutableStateOf(ImePopupPositionProvider(0)) }
val context = LocalContext.current
val decorView = remember(context) { context.getActivity()?.window?.decorView }
if (decorView != null) {
val ime = remember { WindowInsetsCompat.Type.ime() }
val bottom = remember { MutableStateFlow(0) }
LaunchedEffect(Unit) {
while (true) {
bottom.value = ViewCompat.getRootWindowInsets(decorView)?.getInsets(ime)?.bottom ?: 0
delay(33)
}
}
LaunchedEffect(Unit) {
bottom.collect { provider.value = ImePopupPositionProvider(it) }
}
}
return provider
}
/**
* Places the popup at the bottom of the screen but above the keyboard.
* This assumes that the anchor for the popup is in the middle of the screen.
*/
private data class ImePopupPositionProvider(val imeSize: Int): PopupPositionProvider {
override fun calculatePosition(
anchorBounds: IntRect, windowSize: IntSize,
layoutDirection: LayoutDirection, popupContentSize: IntSize
) = IntOffset(
anchorBounds.left + (anchorBounds.width - popupContentSize.width) / 2, // centered on screen
anchorBounds.top + (anchorBounds.height - popupContentSize.height) / 2 + // centered on screen
(windowSize.height - imeSize) / 2 // move to the bottom of the screen
)
}
private fun Context.getActivity(): Activity? {
var currentContext = this
while (currentContext is ContextWrapper) {
if (currentContext is Activity) {
return currentContext
}
currentContext = currentContext.baseContext
}
return null
}
private data class SnackbarDataImpl(
override val visuals: SnackbarVisuals,
val onDismiss: () -> Unit,
) : SnackbarData {
override fun performAction() { /* TODO() */ }
override fun dismiss() { onDismiss() }
}
private data class SnackbarVisualsImpl(
override val message: String,
override val actionLabel: String?,
override val withDismissAction: Boolean,
override val duration: SnackbarDuration
) : SnackbarVisuals
I follow MVVM Login API, with Retrofit ,My problem is livedata is observed more than twice and always emitting previous response when observed from activity, But inside Repository its giving correct response
I tried a lot of solutions from stackoverflow and other websites but still no luck, Tried removing observers also but still getting previous data ,so plz suggest a working solution, I will post my code below,
LoginActivity.kt
private lateinit var loginViewModel: LoginViewModel
loginViewModel = ViewModelProvider(this, ViewModelProvider.NewInstanceFactory()).get(
LoginViewModel::class.java
)
loginViewModel.login(userEmail, pwd)
loginViewModel.getLoginRepository().observe(this, Observer {
val loginResult = it ?: return#Observer
val accessToken = loginResult.user?.jwtToken.toString()
})
val statusMsgObserver = Observer<String> { statusMsg ->
showToast(statusMsg)
})
val errorMsgObserver = Observer<String> { errorMsg ->
// Update the UI
showToast(errorMsg)
})
loginViewModel.getStatusMessage()?.observe(this, statusMsgObserver)
loginViewModel.getErrorStatusMessage()?.observe(this, errorMsgObserver)
LoginViewModel.kt:
class LoginViewModel: ViewModel() {
private var loginRepository: LoginRepository? = null
private var _mutableLiveData = MutableLiveData<LoginAPIResponse?>()
val liveData: LiveData<LoginAPIResponse?> get() = _mutableLiveData
private var responseMsgLiveData:MutableLiveData<String>?= null
private var errorResponseMsgLiveData:MutableLiveData<String>?= null
fun login(username: String, password: String) {
loginRepository = LoginRepository.getInstance()!!
/* Query data from Repository */
//val _mutableLiveData: MutableLiveData<Response<LoginAPIResponse?>?>? = loginRepository?.doLogin(username, password)
_mutableLiveData = loginRepository?.doLogin(username, password)!!
responseMsgLiveData = loginRepository?.respMessage!!
errorResponseMsgLiveData = loginRepository?.loginResponseErrorData!!
}
fun getLoginRepository(): LiveData<LoginAPIResponse?> {
return liveData
}
fun getStatusMessage(): LiveData<String>? {
return responseMsgLiveData
}
fun getErrorStatusMessage(): LiveData<String>? {
return errorResponseMsgLiveData
}
}
LoginRepository.kt:
class LoginRepository {
private val loginApi: ApiEndpoints = RetrofitService.createService(ApiEndpoints::class.java)
val responseData = MutableLiveData<LoginAPIResponse?>()
var respMessage = MutableLiveData<String>()
var loginResponseErrorData = MutableLiveData<String>()
fun doLogin(username: String, password: String)
: MutableLiveData<LoginAPIResponse?> {
respMessage.value = null
loginResponseErrorData.value = null
val params = JsonObject()
params.addProperty("email", username)
params.addProperty("password",password)
val jsonParams = JsonObject()
jsonParams.add("user",params)
loginApi.loginToServer(jsonParams).enqueue(object : Callback<LoginAPIResponse?> {
override fun onResponse( call: Call<LoginAPIResponse?>, response: Response<LoginAPIResponse?> ) {
responseData.value = response.body()
respMessage.value = RetrofitService.handleError(response.code())
val error = response.errorBody()
if (!response.isSuccessful) {
val errorMsg = error?.charStream()?.readText()
println("Error Message: $errorMsg")
loginResponseErrorData.value = errorMsg
} else {
println("API Success -> Login, $username, ${response.body()?.user?.email.toString()}")
}
}
override fun onFailure(call: Call<LoginAPIResponse?>, t: Throwable) {
println("onFailure:(message) "+t.message)
loginResponseErrorData.value = t.message
responseData.value = null
}
})
return responseData
}
companion object {
private var loginRepository: LoginRepository? = null
internal fun getInstance(): LoginRepository? {
if (loginRepository == null) {
loginRepository = LoginRepository()
}
return loginRepository
}
}
}
In onDestroy(),I have removed the observers,
override fun onDestroy() {
super.onDestroy()
loginViewModel.getLoginRepository()?.removeObservers(this)
this.viewModelStore.clear()
}
In LoginActivity, when I observe loginResult it gives previous emitted accessToken first and then again called and giving current accessToken, Similarly observer is called more than twice everytime.
But inside repository,its giving recent data, plz check my code and suggest where I have to correct to get correct recent livedata
Finally i found the solution, In LoginRepository, I declared responseData outside doLogin(), It should be declared inside doLogin()
Since it was outside the method, it always gave previous data first and then current data,
Once I declare inside method problem was solved and now it is working Perfect!!!
When using a PublishSubject in conjunction with blockingGet(), there seems to be a race condition where a subscriber does not receive the events.
I attached a basic JUnit test in Kotlin, which has 2 methods.
rxTestBroken() shows the broken behavior with a PublishSubject.
rxTestOk() shows that everything works fine with a BehaviorSubject, because the latter replays the last event in case the subscriber is not subscribed in time.
Where does this race condition come from and is using a BehaviorSubject the correct fix?
import io.reactivex.Single
import io.reactivex.subjects.BehaviorSubject
import io.reactivex.subjects.PublishSubject
import io.reactivex.subjects.Subject
import org.assertj.core.api.Assertions.assertThat
import org.junit.Test
import java.util.concurrent.TimeUnit
class StateMachine(val stateSubject: Subject<Int>) {
companion object {
val STATE_IDLE = 1
val STATE_READY = 2
}
val output = 10L
var currentState = STATE_IDLE
fun scheduleNextState(nextState: Int) {
Thread(Runnable {
currentState = nextState
stateSubject.onNext(currentState)
}).start()
}
fun start() = scheduleNextState(STATE_READY)
fun stop() = scheduleNextState(STATE_IDLE)
}
class RxTest {
fun stateOutput(stateSubject: Subject<Int>): Single<Int> {
val stateMachine = StateMachine(stateSubject)
val waitForIdle = stateSubject
.startWith(stateMachine.currentState)
.doOnNext {
if (it != StateMachine.STATE_IDLE) { stateMachine.stop() }
}
.filter { it == StateMachine.STATE_IDLE }
.firstOrError()
val scanFile = stateSubject
.doOnSubscribe { stateMachine.start() }
.filter {
when (it) {
StateMachine.STATE_READY -> true
StateMachine.STATE_IDLE -> false
else -> throw RuntimeException("Wrong state $it")
}
}
.firstOrError()
.map { stateMachine.output.toInt() }
.doFinally { stateMachine.stop() }
return waitForIdle.flatMap { scanFile }.timeout(1, TimeUnit.SECONDS).onErrorReturnItem(-1)
}
#Test
fun rxTestBroken() {
for (i in 1..10000) {
assertThat(stateOutput(PublishSubject.create<Int>()).blockingGet())
.withFailMessage("worked $i times")
.isEqualTo(10)
}
}
#Test
fun rxTestOk() {
for (i in 1..10000) {
assertThat(stateOutput(BehaviorSubject.createDefault(StateMachine.STATE_IDLE)).blockingGet())
.withFailMessage("worked $i times")
.isEqualTo(10)
}
}
}
I have this simple function that return some Status:
def getStatus : String =
{
//...
}
And i want to wait until this return specific status but still count this number of calls before exit:
def wait =
{
var count = 0
while (getStatus != "smeStatus" && count < 10) {
// some code here
count++
}
}
How can i avoid of using var ?
You can use a recursive method that takes the count-so-far and returns it + 1:
def waitUntilDone(countSoFar: Int): Int = {
if (getStatus != "smeStatus" && countSoFar < 10) {
// some code here
waitUntilDone(countSoFar + 1)
} else {
countSoFar
}
}
// invoke it starting with 0:
val count = waitUntilDone(0)
def status = ""
def waiting: Unit = {
def check(count: Int): Unit = {
if(count < 10 && status != "smeStatus") {
// do something
check(count + 1)
}
}
check(0)
}
I have a login window view, and I want to display a progress bar when I click/press enter button while slick is querying the password. If I change the visible attribute for the progress bar at the button actionEvent it doesn´t appear until after the query is done. Also I don't want the progress bar to be taking space while its invisible. Does anybody know how to do these things?
object SPM extends JFXApp {
/*
* Primary stage: Log in
* */
stage = new PrimaryStage {
// error message hidden label
val errorLabel = new Label()
errorLabel.textFill = Color.Red
errorLabel.font = Font.font("Helvetica", FontWeight.ExtraLight, 12)
val usernameField = new TextField {
promptText = "User"
maxWidth = 250
prefHeight = 35
}
val passwordField = new PasswordField() {
promptText = "Password"
maxWidth = 250
prefHeight = 35
}
val progressBar = new ProgressBar {
maxWidth = 300
visible = false
}
title = "Software Project Management"
scene = new Scene(800, 600) {
root = new VBox {
spacing = 10
padding = Insets(20)
alignment = Pos.Center
children = List(
new ImageView {
image = new Image(
this.getClass.getResourceAsStream("/images/logo.png"))
margin = Insets(0, 0, 20, 0)
},
new Label {
text = "Software Project Management"
font = Font.font("Helvetica", FontWeight.ExtraLight, 32)
},
new Label {
text = "Sign in to get started"
font = Font.font("Helvetica", FontWeight.Thin, 18)
},
errorLabel,
progressBar,
usernameField,
passwordField,
new Button {
text = "Enter"
defaultButton = true
prefHeight = 35
font = Font.font("Helvetica", FontWeight.Thin, 18)
maxWidth = 250
onAction = (ae: ActionEvent) => {
progressBar.visible = true
val password = Users.checkPassword(usernameField.text.value)
if (password != passwordField.text.value)
errorLabel.text = "Please re-enter your password"
else root = chooseProject
}
}
) // children
} // root
} // scene
Your Button.onAction handler is running on JavaFX application thread. The same that is used to update UI. When you run long running task you should run it on a separate thread it will help UI to react properly. The common way to do that is to use JavaFX Task. General pattern is like this:
// Define your task
val task = new javafx.concurrent.Task[T] {
override def call(): T = {
// Do your task and return result
// Executed off JavaFX Application thread
}
override def succeeded(): Unit = {
// Update UI to finish processing
// Executed on JavaFX Application thread
}
override def failed(): Unit = {
// Handle errors, if any
// Executed on JavaFX Application thread
}
}
// Run your task
val t = new Thread(task, "My Task")
t.setDaemon(true)
t.start()
```
Here is how it could look in your code:
root = new VBox { _root =>
...
onAction = (ae: ActionEvent) => {
progressBar.visible = true
_root.disable = true
// progressBar.visible = true
val task = new javafx.concurrent.Task[Boolean] {
override def call(): Boolean = {
println("Checking password... ")
Thread.sleep(3000)
println("Password checked. ")
// Assume password is correct
true
}
override def succeeded(): Unit = {
progressBar.visible = false
_root.disable = false
val passwordOK = get()
if (passwordOK) {
new Alert(AlertType.Information) {
headerText = "Password OK"
}.showAndWait()
} else {
new Alert(AlertType.Warning) {
headerText = "Invalid Password"
}.showAndWait()
}
}
override def failed(): Unit = {
println("failed")
progressBar.visible = false
_root.disable = false
}
}
val t = new Thread(task, "Password Task")
t.setDaemon(true)
t.start()
}