MangaScreen: Improve chapter list scrolling performance (#7491)

* MangaScreen: Improve chapter list scrolling performance

Process chapter title, date and read progress string ahead of time

* Use enum for contentType and add key

(cherry picked from commit 1551891c15eb5d323cb1d425794876a753316091)

# Conflicts:
#	app/src/main/java/eu/kanade/presentation/manga/MangaScreen.kt
#	app/src/main/java/eu/kanade/tachiyomi/ui/manga/MangaPresenter.kt

app/src/main/java/eu/kanade/presentation/manga/MangaScreen.kt

@@ -44,7 +44,6 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.hapticfeedback.HapticFeedbackType
 import androidx.compose.ui.layout.onSizeChanged
-import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.platform.LocalHapticFeedback
 import androidx.compose.ui.platform.LocalLayoutDirection
@@ -52,7 +51,6 @@ import androidx.compose.ui.res.stringResource
 import com.google.accompanist.swiperefresh.SwipeRefresh
 import com.google.accompanist.swiperefresh.rememberSwipeRefreshState
 import eu.kanade.domain.chapter.model.Chapter
-import eu.kanade.domain.manga.model.Manga.Companion.CHAPTER_DISPLAY_NUMBER
 import eu.kanade.presentation.components.ExtendedFloatingActionButton
 import eu.kanade.presentation.components.Scaffold
 import eu.kanade.presentation.components.SwipeRefreshIndicator
@@ -76,18 +74,8 @@ import eu.kanade.tachiyomi.source.getNameForMangaInfo
 import eu.kanade.tachiyomi.source.online.MetadataSource
 import eu.kanade.tachiyomi.ui.manga.ChapterItem
 import eu.kanade.tachiyomi.ui.manga.MangaScreenState
-import eu.kanade.tachiyomi.util.lang.toRelativeString
 import exh.source.MERGED_SOURCE_ID
 import exh.source.getMainSource
-import java.text.DecimalFormat
-import java.text.DecimalFormatSymbols
-import java.util.Date
-
-private val chapterDecimalFormat = DecimalFormat(
-    "#.###",
-    DecimalFormatSymbols()
-        .apply { decimalSeparator = '.' },
-)
 
 @Composable
 fun MangaScreen(
@@ -361,7 +349,10 @@ private fun MangaScreenSmallImpl(
                     state = chapterListState,
                     contentPadding = noTopContentPadding,
                 ) {
-                    item(contentType = "info_box") {
+                    item(
+                        key = MangaScreenItem.INFO_BOX,
+                        contentType = MangaScreenItem.INFO_BOX,
+                    ) {
                         MangaInfoBox(
                             windowWidthSizeClass = WindowWidthSizeClass.Compact,
                             appBarPadding = topPadding,
@@ -377,7 +368,10 @@ private fun MangaScreenSmallImpl(
                         )
                     }
 
-                    item(contentType = "action_row") {
+                    item(
+                        key = MangaScreenItem.ACTION_ROW,
+                        contentType = MangaScreenItem.ACTION_ROW,
+                    ) {
                         MangaActionRow(
                             favorite = state.manga.favorite,
                             trackingCount = state.trackingCount,
@@ -393,7 +387,10 @@ private fun MangaScreenSmallImpl(
 
                     // SY -->
                     if (metadataSource != null) {
-                        item(contentType = "metadata_info") {
+                        item(
+                            key = MangaScreenItem.METADATA_INFO,
+                            contentType = MangaScreenItem.METADATA_INFO,
+                        ) {
                             metadataSource.DescriptionComposable(
                                 state = state,
                                 openMetadataViewer = onMetadataViewerClicked,
@@ -403,7 +400,10 @@ private fun MangaScreenSmallImpl(
                     }
                     // SY <--
 
-                    item(contentType = "desc") {
+                    item(
+                        key = MangaScreenItem.DESCRIPTION_WITH_TAG,
+                        contentType = MangaScreenItem.DESCRIPTION_WITH_TAG,
+                    ) {
                         ExpandableMangaDescription(
                             defaultExpandState = state.isFromSource,
                             description = state.manga.description,
@@ -420,7 +420,10 @@ private fun MangaScreenSmallImpl(
 
                     // SY -->
                     if (!state.showRecommendationsInOverflow || state.showMergeWithAnother) {
-                        item(contentType = "info_buttons") {
+                        item(
+                            key = MangaScreenItem.INFO_BUTTONS,
+                            contentType = MangaScreenItem.INFO_BUTTONS,
+                        ) {
                             MangaInfoButtons(
                                 showRecommendsButton = !state.showRecommendationsInOverflow,
                                 showMergeWithAnotherButton = state.showMergeWithAnother,
@@ -431,7 +434,10 @@ private fun MangaScreenSmallImpl(
                     }
                     // SY <--
 
-                    item(contentType = "header") {
+                    item(
+                        key = MangaScreenItem.CHAPTER_HEADER,
+                        contentType = MangaScreenItem.CHAPTER_HEADER,
+                    ) {
                         ChapterHeader(
                             chapterCount = chapters.size,
                             isChapterFiltered = state.manga.chaptersFiltered(),
@@ -441,7 +447,6 @@ private fun MangaScreenSmallImpl(
 
                     sharedChapterItems(
                         chapters = chapters,
-                        state = state,
                         selected = selected,
                         selectedPositions = selectedPositions,
                         onChapterClicked = onChapterClicked,
@@ -680,7 +685,10 @@ fun MangaScreenLargeImpl(
                         state = chapterListState,
                         contentPadding = withNavBarContentPadding,
                     ) {
-                        item(contentType = "header") {
+                        item(
+                            key = MangaScreenItem.CHAPTER_HEADER,
+                            contentType = MangaScreenItem.CHAPTER_HEADER,
+                        ) {
                             ChapterHeader(
                                 chapterCount = chapters.size,
                                 isChapterFiltered = state.manga.chaptersFiltered(),
@@ -690,7 +698,6 @@ fun MangaScreenLargeImpl(
 
                         sharedChapterItems(
                             chapters = chapters,
-                            state = state,
                             selected = selected,
                             selectedPositions = selectedPositions,
                             onChapterClicked = onChapterClicked,
@@ -753,56 +760,27 @@ private fun SharedMangaBottomActionMenu(
 
 private fun LazyListScope.sharedChapterItems(
     chapters: List<ChapterItem>,
-    state: MangaScreenState.Success,
     selected: SnapshotStateList<ChapterItem>,
     selectedPositions: Array<Int>,
     onChapterClicked: (Chapter) -> Unit,
     onDownloadChapter: ((List<ChapterItem>, ChapterDownloadAction) -> Unit)?,
 ) {
-    items(items = chapters) { chapterItem ->
+    items(
-        val context = LocalContext.current
+        items = chapters,
+        key = { it.chapter.id },
+        contentType = { MangaScreenItem.CHAPTER },
+    ) { chapterItem ->
         val haptic = LocalHapticFeedback.current
-
-        val (chapter, downloadState, downloadProgress) = chapterItem
-        val chapterTitle = if (state.manga.displayMode == CHAPTER_DISPLAY_NUMBER) {
-            stringResource(
-                id = R.string.display_mode_chapter,
-                chapterDecimalFormat.format(chapter.chapterNumber.toDouble()),
-            )
-        } else {
-            chapter.name
-        }
-        val date = remember(chapter.dateUpload) {
-            chapter.dateUpload
-                .takeIf { it > 0 }
-                ?.let {
-                    Date(it).toRelativeString(
-                        context,
-                        state.dateRelativeTime,
-                        state.dateFormat,
-                    )
-                }
-        }
-        val lastPageRead = remember(chapter.lastPageRead) {
-            chapter.lastPageRead.takeIf { /* SY --> */(!chapter.read || state.alwaysShowPageProgress)/* SY <-- */ && it > 0 }
-        }
-        val scanlator = remember(chapter.scanlator) { chapter.scanlator.takeIf { !it.isNullOrBlank() } }
-
         MangaChapterListItem(
-            title = chapterTitle,
+            title = chapterItem.chapterTitleString,
-            date = date,
+            date = chapterItem.dateUploadString,
-            readProgress = lastPageRead?.let {
+            readProgress = chapterItem.readProgressString,
-                stringResource(
+            scanlator = chapterItem.chapter.scanlator.takeIf { !it.isNullOrBlank() },
-                    id = R.string.chapter_progress,
+            read = chapterItem.chapter.read,
-                    it + 1,
+            bookmark = chapterItem.chapter.bookmark,
-                )
-            },
-            scanlator = scanlator,
-            read = chapter.read,
-            bookmark = chapter.bookmark,
             selected = selected.contains(chapterItem),
-            downloadStateProvider = { downloadState },
+            downloadStateProvider = { chapterItem.downloadState },
-            downloadProgressProvider = { downloadProgress },
+            downloadProgressProvider = { chapterItem.downloadProgress },
             onLongClick = {
                 val dispatched = onChapterItemLongClick(
                     chapterItem = chapterItem,

app/src/main/java/eu/kanade/presentation/manga/MangaScreenConstants.kt

@@ -20,3 +20,21 @@ enum class EditCoverAction {
     EDIT,
     DELETE,
 }
+
+enum class MangaScreenItem {
+    INFO_BOX,
+    ACTION_ROW,
+
+    // SY -->
+    METADATA_INFO,
+
+    // SY <--
+    DESCRIPTION_WITH_TAG,
+
+    // SY -->
+    INFO_BUTTONS,
+
+    // SY <--
+    CHAPTER_HEADER,
+    CHAPTER,
+}

app/src/main/java/eu/kanade/presentation/manga/components/MangaChapterListItem.kt

@@ -81,8 +81,8 @@ fun MangaChapterListItem(
                 }
                 Text(
                     text = title,
-                    style = MaterialTheme.typography.bodyMedium
+                    color = textColor,
-                        .copy(color = textColor),
+                    style = MaterialTheme.typography.bodyMedium,
                     maxLines = 1,
                     overflow = TextOverflow.Ellipsis,
                     onTextLayout = { textHeight = it.size.height },

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

@@ -1,5 +1,6 @@
 package eu.kanade.tachiyomi.ui.manga
 
+import android.app.Application
 import android.content.Context
 import android.os.Bundle
 import androidx.compose.runtime.Immutable
@@ -60,6 +61,7 @@ import eu.kanade.tachiyomi.util.chapter.ChapterSettingsHelper
 import eu.kanade.tachiyomi.util.chapter.getChapterSort
 import eu.kanade.tachiyomi.util.lang.launchIO
 import eu.kanade.tachiyomi.util.lang.launchUI
+import eu.kanade.tachiyomi.util.lang.toRelativeString
 import eu.kanade.tachiyomi.util.lang.withUIContext
 import eu.kanade.tachiyomi.util.preference.asImmediateFlow
 import eu.kanade.tachiyomi.util.removeCovers
@@ -80,7 +82,6 @@ import exh.metadata.metadata.base.RaisedSearchMetadata
 import exh.source.MERGED_SOURCE_ID
 import exh.source.getMainSource
 import exh.source.isEhBasedManga
-import exh.source.isEhBasedSource
 import exh.source.mangaDexSourceIds
 import exh.util.nullIfEmpty
 import exh.util.trimOrNull
@@ -110,6 +111,9 @@ import uy.kohesive.injekt.Injekt
 import uy.kohesive.injekt.api.get
 import uy.kohesive.injekt.injectLazy
 import java.text.DateFormat
+import java.text.DecimalFormat
+import java.text.DecimalFormatSymbols
+import java.util.Date
 import eu.kanade.domain.chapter.model.Chapter as DomainChapter
 import eu.kanade.domain.manga.model.Manga as DomainManga
 import eu.kanade.tachiyomi.data.database.models.Manga.Companion as DbManga
@@ -284,7 +288,20 @@ class MangaPresenter(
                 }
                 // SY <--
                 .collectLatest { (manga, chapters, flatMetadata, mergedData) ->
-                    val chapterItems = chapters.toChapterItems(manga, mergedData)
+                    val chapterItems = chapters.toChapterItems(
+                        context = view?.activity ?: Injekt.get<Application>(),
+                        manga = manga,
+                        // SY -->
+                        dateRelativeTime = if (manga.isEhBasedManga()) 0 else preferences.relativeTime().get(),
+                        dateFormat = if (manga.isEhBasedManga()) {
+                            MetadataUtil.EX_DATE_FORMAT
+                        } else {
+                            preferences.dateFormat()
+                        },
+                        mergedData = mergedData,
+                        alwaysShowReadingProgress = preferences.preserveReadingPosition().get() && manga.isEhBasedManga(),
+                        // SY <--
+                    )
                     _state.update { currentState ->
                         when (currentState) {
                             // Initialize success state
@@ -293,12 +310,6 @@ class MangaPresenter(
                                 MangaScreenState.Success(
                                     manga = manga,
                                     source = source,
-                                    dateRelativeTime = if (source.isEhBasedSource()) 0 else preferences.relativeTime().get(),
-                                    dateFormat = if (source.isEhBasedSource()) {
-                                        MetadataUtil.EX_DATE_FORMAT
-                                    } else {
-                                        preferences.dateFormat()
-                                    },
                                     isFromSource = isFromSource,
                                     trackingAvailable = trackManager.hasLoggedServices(),
                                     chapters = chapterItems,
@@ -306,7 +317,6 @@ class MangaPresenter(
                                     mergedData = mergedData,
                                     showRecommendationsInOverflow = preferences.recommendsInOverflow().get(),
                                     showMergeWithAnother = smartSearched,
-                                    alwaysShowPageProgress = preferences.preserveReadingPosition().get() && manga.isEhBasedManga(),
                                 )
                             }
 
@@ -818,7 +828,14 @@ class MangaPresenter(
         }
     }
 
-    private fun List<DomainChapter>.toChapterItems(manga: DomainManga, mergedData: MergedMangaData?): List<ChapterItem> {
+    private fun List<DomainChapter>.toChapterItems(
+        context: Context,
+        manga: DomainManga,
+        dateRelativeTime: Int,
+        dateFormat: DateFormat,
+        mergedData: MergedMangaData?,
+        alwaysShowReadingProgress: Boolean,
+    ): List<ChapterItem> {
         return map { chapter ->
             val activeDownload = downloadManager.queue.find { chapter.id == it.chapter.id }
             val chapter = chapter.let { if (mergedData != null) it.toMergedDownloadedChapter() else it }
@@ -840,6 +857,29 @@ class MangaPresenter(
                 chapter = chapter,
                 downloadState = downloadState,
                 downloadProgress = activeDownload?.progress ?: 0,
+                chapterTitleString = if (manga.displayMode == DomainManga.CHAPTER_DISPLAY_NUMBER) {
+                    context.getString(
+                        R.string.display_mode_chapter,
+                        chapterDecimalFormat.format(chapter.chapterNumber.toDouble()),
+                    )
+                } else {
+                    chapter.name
+                },
+                dateUploadString = chapter.dateUpload
+                    .takeIf { it > 0 }
+                    ?.let {
+                        Date(it).toRelativeString(
+                            context,
+                            dateRelativeTime,
+                            dateFormat,
+                        )
+                    },
+                readProgressString = chapter.lastPageRead.takeIf { /* SY --> */(!chapter.read || alwaysShowReadingProgress)/* SY <-- */ && it > 0 }?.let {
+                    context.getString(
+                        R.string.chapter_progress,
+                        it + 1,
+                    )
+                },
             )
         }
     }
@@ -1319,8 +1359,6 @@ sealed class MangaScreenState {
     data class Success(
         val manga: DomainManga,
         val source: Source,
-        val dateRelativeTime: Int,
-        val dateFormat: DateFormat,
         val isFromSource: Boolean,
         val chapters: List<ChapterItem>,
         val trackingAvailable: Boolean = false,
@@ -1334,7 +1372,6 @@ sealed class MangaScreenState {
         val mergedData: MergedMangaData?,
         val showRecommendationsInOverflow: Boolean,
         val showMergeWithAnother: Boolean,
-        val alwaysShowPageProgress: Boolean,
         // SY <--
     ) : MangaScreenState() {
 
@@ -1386,6 +1423,16 @@ data class ChapterItem(
     val chapter: DomainChapter,
     val downloadState: Download.State,
     val downloadProgress: Int,
+
+    val chapterTitleString: String,
+    val dateUploadString: String?,
+    val readProgressString: String?,
 ) {
     val isDownloaded = downloadState == Download.State.DOWNLOADED
 }
+
+private val chapterDecimalFormat = DecimalFormat(
+    "#.###",
+    DecimalFormatSymbols()
+        .apply { decimalSeparator = '.' },
+)