Make ExtensionFilterViewModel collect languages only while subscribed (#3718)

Assisted-by: Claude:claude-opus-5

app/src/main/java/eu/kanade/tachiyomi/ui/browse/extension/ExtensionFilterScreen.kt

@@ -2,9 +2,9 @@ package eu.kanade.tachiyomi.ui.browse.extension
 
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
-import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.ui.platform.LocalContext
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
 import cafe.adriel.voyager.navigator.LocalNavigator
 import cafe.adriel.voyager.navigator.currentOrThrow
@@ -22,7 +22,7 @@ class ExtensionFilterScreen : Screen() {
         val context = LocalContext.current
         val navigator = LocalNavigator.currentOrThrow
         val viewModel = viewModel<ExtensionFilterViewModel>()
-        val state by viewModel.state.collectAsState()
+        val state by viewModel.state.collectAsStateWithLifecycle()
 
         if (state is ExtensionFilterState.Loading) {
             LoadingScreen()

app/src/main/java/eu/kanade/tachiyomi/ui/browse/extension/ExtensionFilterViewModel.kt

@@ -1,53 +1,49 @@
 package eu.kanade.tachiyomi.ui.browse.extension
 
 import androidx.compose.runtime.Immutable
+import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import eu.kanade.domain.extension.interactor.GetExtensionLanguages
 import eu.kanade.domain.source.interactor.ToggleLanguage
 import eu.kanade.domain.source.service.SourcePreferences
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.WhileSubscribed
 import kotlinx.coroutines.flow.catch
-import kotlinx.coroutines.flow.collectLatest
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.receiveAsFlow
-import kotlinx.coroutines.flow.update
-import kotlinx.coroutines.launch
+import kotlinx.coroutines.flow.stateIn
 import logcat.LogPriority
-import mihon.core.viewmodel.StateViewModel
 import tachiyomi.core.common.util.system.logcat
 import uy.kohesive.injekt.Injekt
 import uy.kohesive.injekt.api.get
+import kotlin.time.Duration.Companion.seconds
 
 class ExtensionFilterViewModel(
     private val preferences: SourcePreferences = Injekt.get(),
     private val getExtensionLanguages: GetExtensionLanguages = Injekt.get(),
     private val toggleLanguage: ToggleLanguage = Injekt.get(),
-) : StateViewModel<ExtensionFilterState>(ExtensionFilterState.Loading) {
+) : ViewModel() {
 
     private val _events: Channel<ExtensionFilterEvent> = Channel()
     val events: Flow<ExtensionFilterEvent> = _events.receiveAsFlow()
 
-    init {
-        viewModelScope.launch {
-            combine(
-                getExtensionLanguages.subscribe(),
-                preferences.enabledLanguages.changes(),
-            ) { a, b -> a to b }
-                .catch { throwable ->
-                    logcat(LogPriority.ERROR, throwable)
-                    _events.send(ExtensionFilterEvent.FailedFetchingLanguages)
-                }
-                .collectLatest { (extensionLanguages, enabledLanguages) ->
-                    mutableState.update {
-                        ExtensionFilterState.Success(
-                            languages = extensionLanguages,
-                            enabledLanguages = enabledLanguages,
-                        )
-                    }
-                }
-        }
+    val state: StateFlow<ExtensionFilterState> = combine(
+        getExtensionLanguages.subscribe(),
+        preferences.enabledLanguages.changes(),
+    ) { extensionLanguages, enabledLanguages ->
+        ExtensionFilterState.Success(
+            languages = extensionLanguages,
+            enabledLanguages = enabledLanguages,
+        )
     }
+        .catch { throwable ->
+            logcat(LogPriority.ERROR, throwable)
+            _events.send(ExtensionFilterEvent.FailedFetchingLanguages)
+        }
+        .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5.seconds), ExtensionFilterState.Loading)
 
     fun toggle(language: String) {
         toggleLanguage.await(language)