Sulkta-OSS/element-x-ada
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Make sure Snackbars are only displayed once (#1175)

Browse source 
* Make sure Snackbars are only displayed once

* Use a queue instead

* Fix docs

* Add tests for `SnackbarDispatcher`.
This commit is contained in:
Jorge Martin Espinosa 2023-08-30 10:43:23 +02:00 • committed by GitHub
parent 0b88dac719
commit 36f0bec184
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
4 changed files with 150 additions and 25 deletions
Download patch file Download diff file Expand all files Collapse all files

77
libraries/designsystem/src/main/kotlin/io/element/android/libraries/designsystem/utils/Snackbar.kt
View file

@ -34,33 +34,40 @@ import androidx.compose.ui.unit.dp
import io.element.android.libraries.designsystem.components.button.ButtonVisuals
import io.element.android.libraries.designsystem.theme.components.IconSource
import io.element.android.libraries.designsystem.theme.components.Snackbar
import kotlinx.coroutines.CancellationException
import kotlinx.coroutines.currentCoroutineContext
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.flow.MutableStateFlow
import kotlinx.coroutines.flow.asStateFlow
import kotlinx.coroutines.flow.update
import kotlinx.coroutines.flow.flow
import kotlinx.coroutines.isActive
import kotlinx.coroutines.launch
import kotlinx.coroutines.sync.Mutex
import kotlinx.coroutines.sync.withLock
import java.util.concurrent.atomic.AtomicBoolean
/**
* A global dispatcher of [SnackbarMessage] to be displayed in [Snackbar] via a [SnackbarHostState].
*/
class SnackbarDispatcher {
private val mutex = Mutex()
private val _snackbarMessage = MutableStateFlow<SnackbarMessage?>(null)
val snackbarMessage: Flow<SnackbarMessage?> = _snackbarMessage.asStateFlow()
suspend fun post(message: SnackbarMessage) {
mutex.withLock {
_snackbarMessage.update { message }
private val queueMutex = Mutex()
private val snackBarMessageQueue = ArrayDeque<SnackbarMessage>()
val snackbarMessage: Flow<SnackbarMessage?> = flow {
while (currentCoroutineContext().isActive) {
queueMutex.lock()
emit(snackBarMessageQueue.firstOrNull())
}
}
suspend fun clear() {
mutex.withLock {
_snackbarMessage.update { null }
suspend fun post(message: SnackbarMessage) {
if (snackBarMessageQueue.isEmpty()) {
snackBarMessageQueue.add(message)
if (queueMutex.isLocked) queueMutex.unlock()
} else {
snackBarMessageQueue.add(message)
}
}
fun clear() {
if (snackBarMessageQueue.isNotEmpty()) {
snackBarMessageQueue.removeFirstOrNull()
if (queueMutex.isLocked) queueMutex.unlock()
}
}
}
@ -87,31 +94,51 @@ fun SnackbarHost(hostState: SnackbarHostState, modifier: Modifier = Modifier) {
}
}
/**
* Helper method to display a [SnackbarMessage] in a [SnackbarHostState] handling cancellations.
*/
@Composable
fun rememberSnackbarHostState(snackbarMessage: SnackbarMessage?): SnackbarHostState {
val snackbarHostState = remember { SnackbarHostState() }
val snackbarMessageText = snackbarMessage?.let {
stringResource(id = snackbarMessage.messageResId)
}
} ?: return snackbarHostState
val dispatcher = LocalSnackbarDispatcher.current
LaunchedEffect(snackbarMessage) {
if (snackbarMessageText == null) return@LaunchedEffect
launch {
snackbarHostState.showSnackbar(
message = snackbarMessageText,
duration = snackbarMessage.duration,
)
if (isActive) {
LaunchedEffect(snackbarMessageText) {
// If the message wasn't already displayed, do it now, and mark it as displayed
// This will prevent the message from appearing in any other active SnackbarHosts
if (snackbarMessage.isDisplayed.getAndSet(true) == false) {
try {
snackbarHostState.showSnackbar(
message = snackbarMessageText,
duration = snackbarMessage.duration,
)
// The snackbar item was displayed and dismissed, clear its message
dispatcher.clear()
} catch (e: CancellationException) {
// The snackbar was being displayed when the coroutine was cancelled,
// so we need to clear its message
dispatcher.clear()
throw e
}
}
}
return snackbarHostState
}
/**
* A message to be displayed in a [Snackbar].
* @param messageResId The message to be displayed.
* @param duration The duration of the message. The default value is [SnackbarDuration.Short].
* @param actionResId The action text to be displayed. The default value is `null`.
* @param isDisplayed Used to track if the current message is already displayed or not.
* @param action The action to be performed when the action is clicked.
*/
data class SnackbarMessage(
@StringRes val messageResId: Int,
val duration: SnackbarDuration = SnackbarDuration.Short,
@StringRes val actionResId: Int? = null,
val isDisplayed: AtomicBoolean = AtomicBoolean(false),
val action: () -> Unit = {},
)