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Update the LaunchedEffect snippet #285

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Merged
merged 1 commit into from
Jun 25, 2024
Merged

Update the LaunchedEffect snippet #285

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52 changes: 16 additions & 36 deletions ...se/snippets/src/main/java/com/example/compose/snippets/sideeffects/SideEffectsSnippets.kt
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Original file line number Diff line number Diff line change
Expand Up @@ -18,12 +18,13 @@ package com.example.compose.snippets.sideeffects

import android.media.Image
import androidx.compose.animation.AnimatedVisibility
import androidx.compose.animation.core.Animatable
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.foundation.lazy.rememberLazyListState
import androidx.compose.material.Button
import androidx.compose.material3.Button
import androidx.compose.material3.Scaffold
import androidx.compose.material3.SnackbarHost
import androidx.compose.material3.SnackbarHostState
Expand All @@ -50,53 +51,32 @@ import com.example.compose.snippets.interop.FirebaseAnalytics
import com.example.compose.snippets.interop.User
import com.example.compose.snippets.kotlin.Message
import kotlinx.coroutines.delay
import kotlinx.coroutines.isActive
import kotlinx.coroutines.launch

// [START android_compose_side_effects_launchedeffect]
@Composable
fun MyScreen(
state: UiState<List<Movie>>,
snackbarHostState: SnackbarHostState
) {

// If the UI state contains an error, show snackbar
if (state.hasError) {

// `LaunchedEffect` will cancel and re-launch if
// `scaffoldState.snackbarHostState` changes
LaunchedEffect(snackbarHostState) {
// Show snackbar using a coroutine, when the coroutine is cancelled the
// snackbar will automatically dismiss. This coroutine will cancel whenever
// `state.hasError` is false, and only start when `state.hasError` is true
// (due to the above if-check), or if `scaffoldState.snackbarHostState` changes.
snackbarHostState.showSnackbar(
message = "Error message",
actionLabel = "Retry message"
)
}
}

Scaffold(
snackbarHost = {
SnackbarHost(hostState = snackbarHostState)
fun MyScreen() {
// [START android_compose_side_effects_launchedeffect]
// Allow the pulse rate to be configured, so it can be sped up if the user is running
// out of time
var pulseRateMs by remember { mutableStateOf(3000L) }
val alpha = remember { Animatable(1f) }
LaunchedEffect(pulseRateMs) { // Restart the effect when the pulse rate changes
while (isActive) {
delay(pulseRateMs) // Pulse the alpha every pulseRateMs to alert the user
alpha.animateTo(0f)
alpha.animateTo(1f)
}
) { contentPadding ->
// [START_EXCLUDE]
Box(Modifier.padding(contentPadding))
// [END_EXCLUDE]
}
// [END android_compose_side_effects_launchedeffect]
}

// [START_EXCLUDE silent]
class Movie {
val url = ""
val id = ""
}
class UiState<T> {
val hasError = true
}
// [END_EXCLUDE]
// [END android_compose_side_effects_launchedeffect]

// [START android_compose_side_effects_remembercoroutinescope]
@Composable
fun MoviesScreen(snackbarHostState: SnackbarHostState) {
Expand Down