Fix preview list not recomposing on detail refresh

app/src/main/kotlin/com/hippo/ehviewer/ui/screen/GalleryDetailContent.kt

@@ -145,6 +145,7 @@ import kotlinx.coroutines.CoroutineStart
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.async
+import kotlinx.coroutines.flow.emptyFlow
 import kotlinx.coroutines.launch
 import moe.tarsin.coroutines.runSuspendCatching
 import moe.tarsin.coroutines.runSwallowingWithUI
@@ -240,7 +241,7 @@ fun GalleryDetailContent(
         }
     }
 
-    val previews = galleryDetail?.let { collectPreviewItems(it, thumbColumns) }
+    val previews = galleryDetail.collectPreviewItems(thumbColumns)
     when (windowSizeClass.windowWidthSizeClass) {
         WindowWidthSizeClass.MEDIUM, WindowWidthSizeClass.COMPACT -> FastScrollLazyVerticalGrid(
             columns = GridCells.Fixed(thumbColumns),
@@ -298,8 +299,8 @@ fun GalleryDetailContent(
                     }
                 }
             }
-            if (previews != null) {
-                galleryPreview(previews) { navToReader(galleryDetail.galleryInfo, it) }
+            if (galleryDetail != null) {
+                galleryPreview(galleryDetail, previews) { navToReader(galleryDetail.galleryInfo, it) }
             }
         }
 
@@ -366,8 +367,8 @@ fun GalleryDetailContent(
                     }
                 }
             }
-            if (previews != null) {
-                galleryPreview(previews) { navToReader(galleryDetail.galleryInfo, it) }
+            if (galleryDetail != null) {
+                galleryPreview(galleryDetail, previews) { navToReader(galleryDetail.galleryInfo, it) }
             }
         }
     }
@@ -735,10 +736,10 @@ private fun List<GalleryTagGroup>.getArtistTag(): String? {
     return null
 }
 
-typealias Previews = Pair<GalleryDetail, LazyPagingItems<GalleryPreview>>
-
+context(Context)
 @Composable
-private fun Context.collectPreviewItems(detail: GalleryDetail, prefetchDistance: Int) = rememberInVM(detail) {
+private fun GalleryDetail?.collectPreviewItems(prefetchDistance: Int) = rememberInVM(this) {
+    val detail = this@collectPreviewItems ?: return@rememberInVM emptyFlow()
     val pageSize = detail.previewList.size
     val pages = detail.pages
     val previewPagesMap = detail.previewList.associateBy { it.position } as MutableMap
@@ -777,10 +778,13 @@ private fun Context.collectPreviewItems(detail: GalleryDetail, prefetchDistance:
             override val jumpingSupported = true
         }
     }.flow.cachedIn(viewModelScope)
-}.collectAsLazyPagingItems().let { remember(detail, it) { detail to it } }
+}.collectAsLazyPagingItems()
 
-private fun LazyGridScope.galleryPreview(previews: Previews, onClick: (Int) -> Unit) {
-    val (detail, data) = previews
+private fun LazyGridScope.galleryPreview(
+    detail: GalleryDetail,
+    data: LazyPagingItems<GalleryPreview>,
+    onClick: (Int) -> Unit,
+) {
     items(
         count = data.itemCount,
         key = data.itemKey(key = { item -> item.position }),