Make MangaCoverViewModel collect manga only while subscribed (#3716)

Assisted-by: Claude:claude-opus-5

app/src/main/java/eu/kanade/tachiyomi/ui/manga/MangaCoverViewModel.kt

@@ -3,6 +3,7 @@ package eu.kanade.tachiyomi.ui.manga
 import android.content.Context
 import android.net.Uri
 import androidx.compose.material3.SnackbarHostState
+import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import androidx.lifecycle.viewmodel.CreationExtras
 import androidx.lifecycle.viewmodel.initializer
@@ -19,10 +20,14 @@ import eu.kanade.tachiyomi.data.saver.Location
 import eu.kanade.tachiyomi.util.editCover
 import eu.kanade.tachiyomi.util.system.getBitmapOrNull
 import eu.kanade.tachiyomi.util.system.toShareIntent
-import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.WhileSubscribed
+import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
 import logcat.LogPriority
-import mihon.core.viewmodel.StateViewModel
 import tachiyomi.core.common.i18n.stringResource
 import tachiyomi.core.common.util.lang.launchIO
 import tachiyomi.core.common.util.lang.withIOContext
@@ -33,6 +38,7 @@ import tachiyomi.domain.manga.model.Manga
 import tachiyomi.i18n.MR
 import uy.kohesive.injekt.Injekt
 import uy.kohesive.injekt.api.get
+import kotlin.time.Duration.Companion.seconds
 
 class MangaCoverViewModel(
     private val mangaId: Long,
@@ -42,7 +48,7 @@ class MangaCoverViewModel(
     private val updateManga: UpdateManga = Injekt.get(),
 
     val snackbarHostState: SnackbarHostState = SnackbarHostState(),
-) : StateViewModel<Manga?>(null) {
+) : ViewModel() {
 
     companion object {
         val MANGA_ID_KEY = CreationExtras.Key<Long>()
@@ -56,12 +62,9 @@ class MangaCoverViewModel(
         }
     }
 
-    init {
-        viewModelScope.launchIO {
-            getManga.subscribe(mangaId)
-                .collect { newManga -> mutableState.update { newManga } }
-        }
-    }
+    val state: StateFlow<Manga?> = getManga.subscribe(mangaId)
+        .flowOn(Dispatchers.IO)
+        .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5.seconds), null)
 
     fun saveCover(context: Context) {
         viewModelScope.launch {
@@ -147,7 +150,6 @@ class MangaCoverViewModel(
     }
 
     fun deleteCustomCover(context: Context) {
-        val mangaId = state.value?.id ?: return
         viewModelScope.launchIO {
             try {
                 coverCache.deleteCustomCover(mangaId)

app/src/main/java/eu/kanade/tachiyomi/ui/manga/MangaScreen.kt

@@ -6,7 +6,6 @@ import androidx.activity.result.contract.ActivityResultContracts
 import androidx.compose.foundation.layout.systemBarsPadding
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
-import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -250,7 +249,7 @@ class MangaScreen(
                         set(MangaCoverViewModel.MANGA_ID_KEY, successState.manga.id)
                     },
                 )
-                val manga by sm.state.collectAsState()
+                val manga by sm.state.collectAsStateWithLifecycle()
                 if (manga != null) {
                     val getContent = rememberLauncherForActivityResult(ActivityResultContracts.GetContent()) {
                         if (it == null) return@rememberLauncherForActivityResult

data/src/main/java/tachiyomi/data/manga/MangaRepositoryImpl.kt

@@ -33,7 +33,7 @@ class MangaRepositoryImpl(
             .awaitAsOne()
     }
 
-    override suspend fun getMangaByIdAsFlow(id: Long): Flow<Manga> {
+    override fun getMangaByIdAsFlow(id: Long): Flow<Manga> {
         return database.mangasQueries
             .getMangaById(id, MangaMapper::mapManga)
             .subscribeToOne()

domain/src/main/java/tachiyomi/domain/manga/interactor/GetManga.kt

@@ -19,7 +19,7 @@ class GetManga(
         }
     }
 
-    suspend fun subscribe(id: Long): Flow<Manga> {
+    fun subscribe(id: Long): Flow<Manga> {
         return mangaRepository.getMangaByIdAsFlow(id)
     }
 

domain/src/main/java/tachiyomi/domain/manga/repository/MangaRepository.kt

@@ -10,7 +10,7 @@ interface MangaRepository {
 
     suspend fun getMangaById(id: Long): Manga
 
-    suspend fun getMangaByIdAsFlow(id: Long): Flow<Manga>
+    fun getMangaByIdAsFlow(id: Long): Flow<Manga>
 
     suspend fun getMangaByUrlAndSourceId(url: String, sourceId: Long): Manga?