Fixes overscrolling on recommended tabs (#881)

## Description
If the continue watching row is empty on recommended pages, it would
scroll to the first successfully loaded row even if previous ones are
still pending.

This PR fixes that so the page waits until the right first row is ready.

### Related issues
Fixes #839

### Testing
Emulator & shield 2019

## Screenshots
N/A

## AI or LLM usage
None

app/src/main/java/com/github/damontecres/wholphin/ui/components/RecommendedContent.kt

@@ -37,9 +37,10 @@ import com.github.damontecres.wholphin.ui.nav.Destination
 import com.github.damontecres.wholphin.util.ApiRequestPager
 import com.github.damontecres.wholphin.util.HomeRowLoadingState
 import com.github.damontecres.wholphin.util.LoadingState
+import kotlinx.coroutines.Deferred
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.async
 import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.launch
 import org.jellyfin.sdk.model.api.MediaType
 import java.util.UUID
 
@@ -99,13 +100,13 @@ abstract class RecommendedViewModel(
     abstract fun update(
         @StringRes title: Int,
         row: HomeRowLoadingState,
-    )
+    ): HomeRowLoadingState
 
     fun update(
         @StringRes title: Int,
         block: suspend () -> List<BaseItem>,
-    ) {
-        viewModelScope.launch(Dispatchers.IO) {
+    ): Deferred<HomeRowLoadingState> =
+        viewModelScope.async(Dispatchers.IO) {
             val titleStr = context.getString(title)
             val row =
                 try {
@@ -115,7 +116,6 @@ abstract class RecommendedViewModel(
                 }
             update(title, row)
         }
-    }
 }
 
 @Composable

app/src/main/java/com/github/damontecres/wholphin/ui/components/RecommendedMovie.kt

@@ -32,6 +32,7 @@ import dagger.assisted.AssistedFactory
 import dagger.assisted.AssistedInject
 import dagger.hilt.android.lifecycle.HiltViewModel
 import dagger.hilt.android.qualifiers.ApplicationContext
+import kotlinx.coroutines.Deferred
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.firstOrNull
@@ -123,6 +124,8 @@ class RecommendedMovieViewModel
                     }
                 }
 
+                val jobs = mutableListOf<Deferred<HomeRowLoadingState>>()
+
                 update(R.string.recently_released) {
                     val request =
                         GetItemsRequest(
@@ -138,7 +141,7 @@ class RecommendedMovieViewModel
                             enableTotalRecordCount = false,
                         )
                     GetItemsRequestHandler.execute(api, request).toBaseItems(api, false)
-                }
+                }.also(jobs::add)
 
                 update(R.string.recently_added) {
                     val request =
@@ -155,7 +158,7 @@ class RecommendedMovieViewModel
                             enableTotalRecordCount = false,
                         )
                     GetItemsRequestHandler.execute(api, request).toBaseItems(api, false)
-                }
+                }.also(jobs::add)
 
                 update(R.string.top_unwatched) {
                     val request =
@@ -173,7 +176,7 @@ class RecommendedMovieViewModel
                             enableTotalRecordCount = false,
                         )
                     GetItemsRequestHandler.execute(api, request).toBaseItems(api, false)
-                }
+                }.also(jobs::add)
 
                 viewModelScope.launch(Dispatchers.IO) {
                     try {
@@ -216,8 +219,17 @@ class RecommendedMovieViewModel
                     }
                 }
 
+                // If the continue watching row is empty, then wait until the first successful row
+                // is loaded before telling the UI that the page is loaded
                 if (loading.value == LoadingState.Loading || loading.value == LoadingState.Pending) {
-                    loading.setValueOnMain(LoadingState.Success)
+                    for (i in 0..<jobs.size) {
+                        val result = jobs[i].await()
+                        if (result.completed) {
+                            Timber.v("First success")
+                            loading.setValueOnMain(LoadingState.Success)
+                        }
+                        break
+                    }
                 }
             }
         }
@@ -225,10 +237,11 @@ class RecommendedMovieViewModel
         override fun update(
             @StringRes title: Int,
             row: HomeRowLoadingState,
-        ) {
+        ): HomeRowLoadingState {
             rows.update { current ->
                 current.toMutableList().apply { set(rowTitles[title]!!, row) }
             }
+            return row
         }
 
         companion object {

app/src/main/java/com/github/damontecres/wholphin/ui/components/RecommendedTvShow.kt

@@ -33,6 +33,7 @@ import dagger.assisted.AssistedFactory
 import dagger.assisted.AssistedInject
 import dagger.hilt.android.lifecycle.HiltViewModel
 import dagger.hilt.android.qualifiers.ApplicationContext
+import kotlinx.coroutines.Deferred
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.async
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -170,6 +171,8 @@ class RecommendedTvShowViewModel
                     }
                 }
 
+                val jobs = mutableListOf<Deferred<HomeRowLoadingState>>()
+
                 update(R.string.recently_released) {
                     val request =
                         GetItemsRequest(
@@ -185,7 +188,7 @@ class RecommendedTvShowViewModel
                             enableTotalRecordCount = false,
                         )
                     GetItemsRequestHandler.execute(api, request).toBaseItems(api, true)
-                }
+                }.also(jobs::add)
 
                 update(R.string.recently_added) {
                     val request =
@@ -202,7 +205,7 @@ class RecommendedTvShowViewModel
                             enableTotalRecordCount = false,
                         )
                     GetItemsRequestHandler.execute(api, request).toBaseItems(api, true)
-                }
+                }.also(jobs::add)
 
                 update(R.string.top_unwatched) {
                     val request =
@@ -220,7 +223,7 @@ class RecommendedTvShowViewModel
                             enableTotalRecordCount = false,
                         )
                     GetItemsRequestHandler.execute(api, request).toBaseItems(api, true)
-                }
+                }.also(jobs::add)
 
                 viewModelScope.launch(Dispatchers.IO) {
                     try {
@@ -264,7 +267,14 @@ class RecommendedTvShowViewModel
                 }
 
                 if (loading.value == LoadingState.Loading || loading.value == LoadingState.Pending) {
-                    loading.setValueOnMain(LoadingState.Success)
+                    for (i in 0..<jobs.size) {
+                        val result = jobs[i].await()
+                        if (result is HomeRowLoadingState.Success) {
+                            Timber.v("First success")
+                            loading.setValueOnMain(LoadingState.Success)
+                        }
+                        break
+                    }
                 }
             }
         }
@@ -272,10 +282,11 @@ class RecommendedTvShowViewModel
         override fun update(
             @StringRes title: Int,
             row: HomeRowLoadingState,
-        ) {
+        ): HomeRowLoadingState {
             rows.update { current ->
                 current.toMutableList().apply { set(rowTitles[title]!!, row) }
             }
+            return row
         }
 
         companion object {

app/src/main/java/com/github/damontecres/wholphin/util/LoadingState.kt

@@ -48,6 +48,9 @@ sealed interface RowLoadingState {
 sealed interface HomeRowLoadingState {
     val title: String
 
+    val completed: Boolean
+        get() = this is Success || this is Error
+
     data class Pending(
         override val title: String,
     ) : HomeRowLoadingState