Compute lazy list keys from the list the lazy block renders

wolfskin-design/src/main/java/org/justinvisser/wolfskin/design/ComingInSheet.kt

@@ -97,10 +97,9 @@ fun ComingInSheet(shell: ShellState, modifier: Modifier = Modifier) {
                 val visibleRows = remember(data, start, state.windowSize) {
                     data.ordered.subList(start, (start + state.windowSize).coerceAtMost(data.ordered.size))
                 }
-                val rowKeys = remember(visibleRows) { visibleRows.map { it.id }.uniqueKeys() }
                 LazyColumn(Modifier.clipToBounds().then(if (data.status == ComingInStatus.Unavailable) Modifier.weight(1f, fill = false) else Modifier), verticalArrangement = Arrangement.spacedBy(T.listGap)) {
-                    itemsIndexed(visibleRows,
-                        key = { index, _ -> rowKeys[index] }, contentType = { _, _ -> "request" }) { _, item ->
+                    val keys = visibleRows.map { it.id }.uniqueKeys()
+                    itemsIndexed(visibleRows, key = { index, _ -> keys[index] }, contentType = { _, _ -> "request" }) { _, item ->
                         ComingInRow(item, shell.person, !state.recoveryFocused && item.id == state.focusedId, state.expanded && item.id == state.focusedId,
                             state.ratingsVisible && data.signedIn && item.id == state.focusedId,
                             onFocus = { state.focus(item.id) }, onClick = { state.focus(item.id); shell.activateRequest() })

wolfskin-design/src/main/java/org/justinvisser/wolfskin/design/HomeShelf.kt

@@ -48,9 +48,9 @@ fun HomeShelf(row: HomeRow, memory: HomeViewMemory, focused: Boolean, column: In
     Box(Modifier.fillMaxWidth().height(L.rowHeadingBand + height + caption + L.rowGapAfter)) {
         if (!row.skeleton) Text(row.title, color = C.fg, style = T.rowHeading, maxLines = 1, modifier = Modifier.offset(x = L.safeSide))
         val cards = if (row.skeleton) List(if (row.cardKind == HomeCardKind.Poster) 8 else 5) { null } else row.cards + if (row.hasSeeAll) listOf(null) else emptyList()
-        val cardKeys = remember(row.cards, row.skeleton, row.hasSeeAll, row.id) { cards.mapIndexed { index, title -> title?.id ?: "${row.id}:tail:$index" }.uniqueKeys() }
         LazyRow(state = track, modifier = Modifier.fillMaxWidth().offset(y = L.rowHeadingBand - L.rowGapAfter).height(height + caption + L.rowGapAfter * 2).skeletonPulse(row.skeleton).rowReveal(row.id, !row.skeleton), contentPadding = PaddingValues(horizontal = L.safeSide, vertical = L.rowGapAfter), horizontalArrangement = Arrangement.spacedBy(K.posterGap), userScrollEnabled = !row.skeleton) {
-            itemsIndexed(cards, key = { index, _ -> cardKeys[index] }, contentType = { _, title -> if (row.skeleton) "skeleton" else if (title == null) "seeAll" else row.cardKind.name.lowercase() }) { index, title ->
+            val keys = cards.mapIndexed { index, title -> title?.id ?: "${row.id}:tail:$index" }.uniqueKeys()
+            itemsIndexed(cards, key = { index, _ -> keys[index] }, contentType = { _, title -> if (row.skeleton) "skeleton" else if (title == null) "seeAll" else row.cardKind.name.lowercase() }) { index, title ->
                 val selected = !row.skeleton && focused && column == index
                 val cardModifier = Modifier.zIndex(if (selected) 2f else 0f).testTag("home-card:${row.id}:$index")
                     .then(if (!row.skeleton) Modifier.focusOnPointerEnter { onHover(index) } else Modifier)

wolfskin-design/src/main/java/org/justinvisser/wolfskin/design/LibraryScreen.kt

@@ -98,12 +98,6 @@ fun LibraryScreen(
             animateLibraryScroll(view, headerCount, target, density)
         }
     }
-    val rowKeys = remember(items, grid.columns, grid.catalogue) {
-        (0 until (items.size + grid.columns - 1) / grid.columns).map { row ->
-            val title = items[row * grid.columns]
-            "grid-${if (grid.catalogue) title.catalogueKey else title.id}"
-        }.uniqueKeys()
-    }
     Box(modifier.semantics { stateDescription = "${grid.title}:${if (grid.toolbar) "tool-${grid.tool}" else if (grid.inRail) "rail-${grid.railLetter}" else focused?.id ?: "recovery"}" }.testTag("library-grid")) {
         LazyColumn(state = view.listState, modifier = Modifier.fillMaxSize().pointerInput(grid, headerCount) {
             awaitPointerEventScope {
@@ -134,7 +128,13 @@ fun LibraryScreen(
                 LibraryStatus.Unavailable -> item(key = "unavailable", contentType = "state") { LibraryRecovery(grid, active) }
                 LibraryStatus.Ready -> if (items.isEmpty()) item(key = "empty", contentType = "state") { LibraryRecovery(grid, active && !grid.toolbar) }
                 else {
-                    items((items.size + grid.columns - 1) / grid.columns, key = { rowKeys[it] }, contentType = { "grid" }) { row ->
+                    val rowCount = (items.size + grid.columns - 1) / grid.columns
+                    // Keys come from the same items and column count as the row count, never from an earlier composition.
+                    val rowKeys = (0 until rowCount).map { row ->
+                        val title = items[row * grid.columns]
+                        "grid-${if (grid.catalogue) title.catalogueKey else title.id}"
+                    }.uniqueKeys()
+                    items(rowCount, key = { rowKeys[it] }, contentType = { "grid" }) { row ->
                         Box(Modifier.fillMaxWidth().height(rowHeight)) {
                             Row(Modifier.padding(start = L.safeSide).rowReveal("grid-$row"), horizontalArrangement = Arrangement.spacedBy(K.posterGap)) {
                                 for (column in 0 until grid.columns) {

wolfskin-design/src/main/java/org/justinvisser/wolfskin/design/PersonPage.kt

@@ -128,7 +128,6 @@ private fun PersonPage(state: PersonState, shell: ShellState, modifier: Modifier
             }
             key?.let { state.key(it, event.type == KeyEventType.KeyDown, event.nativeKeyEvent.repeatCount, shell) } ?: false
         }.focusable()) {
-        val rowKeys = androidx.compose.runtime.remember(state.credits, columns) { state.credits.chunked(columns).map { it.first().id }.uniqueKeys() }
         LazyColumn(state = list, modifier = Modifier.fillMaxSize()) {
             item(key = "person-header", contentType = "header") {
                 Box(Modifier.height(L.row_phead)) {
@@ -145,7 +144,9 @@ private fun PersonPage(state: PersonState, shell: ShellState, modifier: Modifier
             item(key = "filmography", contentType = "header") {
                 Text("Filmography", color = C.fg, style = TitleTextStyles.rowHeading, modifier = Modifier.height(L.row_gh).padding(start = L.safeSide, top = D.gridHeadingTop))
             }
-            itemsIndexed(state.credits.chunked(columns), key = { index, _ -> rowKeys[index] }, contentType = { _, _ -> "grid" }) { rowIndex, row ->
+            val rowsOfCredits = state.credits.chunked(columns)
+            val rowKeys = rowsOfCredits.map { it.first().id }.uniqueKeys()
+            itemsIndexed(rowsOfCredits, key = { index, _ -> rowKeys[index] }, contentType = { _, _ -> "grid" }) { rowIndex, row ->
                 Row(Modifier.height(D.gridHeight).padding(start = L.safeSide), horizontalArrangement = Arrangement.spacedBy(WolfskinTokens.Card.posterGap)) {
                     row.forEachIndexed { column, item ->
                         val index = rowIndex * columns + column

wolfskin-design/src/main/java/org/justinvisser/wolfskin/design/TitlePage.kt

@@ -203,10 +203,11 @@ private fun TitleSeasons(state: TitleState, active: Boolean) {
             if (NetworkArtTransition.reduced) list.scrollToItem(visibleChip) else list.animateScrollToItem(visibleChip)
         }
     }
-    val seasonKeys = remember(state.data.seasonNumbers) { state.data.seasonNumbers.map { "season-$it" }.uniqueKeys() }
     androidx.compose.foundation.lazy.LazyRow(Modifier.height(L.row_chips).padding(top = D.chipTop), state = list, contentPadding = androidx.compose.foundation.layout.PaddingValues(horizontal = L.safeSide), horizontalArrangement = Arrangement.spacedBy(D.chipGap)) {
-        items(state.data.seasonNumbers.size, key = { seasonKeys[it] }, contentType = { "chip" }) { index ->
-            val number = state.data.seasonNumbers[index]
+        val seasonNumbers = state.data.seasonNumbers
+        val keys = seasonNumbers.map { "season-$it" }.uniqueKeys()
+        items(seasonNumbers.size, key = { keys[it] }, contentType = { "chip" }) { index ->
+            val number = seasonNumbers[index]
             val focused = active && state.column == index
             val selected = state.season == number
             val shape = RoundedCornerShape(WolfskinTokens.Radius.chip)

wolfskin-design/src/main/java/org/justinvisser/wolfskin/design/TitleShelf.kt

@@ -51,8 +51,6 @@ fun TitleCast(state: TitleState, active: Boolean) {
     LaunchedEffect(state.column, active, state.data.cast.size) {
         if (active) track.keepColumnInWindow(state.column, WolfskinTokens.Card.personSlots, pitch, state.data.cast.size)
     }
-    // The same person is credited once per role, so the person id alone repeats.
-    val castKeys = androidx.compose.runtime.remember(state.data.cast) { state.data.cast.map { it.id }.uniqueKeys() }
     Box(Modifier.height(D.castHeight).testTag("title-cast")) {
         Text("Cast", color = C.fg, style = WolfskinTokens.Type.rowHeading, modifier = Modifier.padding(start = L.safeSide).height(L.rowHeadingBand))
         LazyRow(state = track, modifier = Modifier.fillMaxWidth().offset(y = L.rowHeadingBand - L.rowGapAfter).height(WolfskinTokens.Card.personH + L.rowGapAfter * 2).skeletonPulse(state.data.castStatus == TitleReadStatus.Loading),
@@ -61,7 +59,9 @@ fun TitleCast(state: TitleState, active: Boolean) {
                 items(WolfskinTokens.Card.personSlots, key = { "cast-skeleton-$it" }, contentType = { "skeleton" }) {
                     Box(Modifier.size(L.castCircle).background(C.surface2, CircleShape))
                 }
-            } else itemsIndexed(state.data.cast, key = { index, _ -> castKeys[index] }, contentType = { _, _ -> "person" }) { index, person ->
+            } else {
+                val keys = state.data.cast.map { it.id }.uniqueKeys()
+                itemsIndexed(state.data.cast, key = { index, _ -> keys[index] }, contentType = { _, _ -> "person" }) { index, person ->
                 val focused = active && state.column == index
                 Box(Modifier.size(WolfskinTokens.Card.personW, WolfskinTokens.Card.personH).zIndex(if (focused) 1f else 0f)
                     .onGloballyPositioned { state.recordCenter("cast", index, it.boundsInRoot().center.x) }
@@ -73,6 +73,7 @@ fun TitleCast(state: TitleState, active: Boolean) {
                     }
                 }
             }
+            }
         }
     }
 }
@@ -90,7 +91,6 @@ fun TitleMediaShelf(state: TitleState, episodes: Boolean, active: Boolean) {
     LaunchedEffect(state.column, active, titles.size) {
         if (active) track.keepColumnInWindow(state.column, visible, pitch, titles.size)
     }
-    val titleKeys = androidx.compose.runtime.remember(titles) { titles.map { it.id }.uniqueKeys() }
     Box(Modifier.height(L.rowHeadingBand + height + L.rowGapAfter + if (episodes) WolfskinTokens.Shell.zero else WolfskinTokens.Card.posterCaptionBand).testTag("title-shelf:$id")) {
         Text(if (episodes) "Season ${state.season}" else "More like this", color = C.fg, style = WolfskinTokens.Type.rowHeading, modifier = Modifier.padding(start = L.safeSide).height(L.rowHeadingBand))
         LazyRow(state = track, modifier = Modifier.fillMaxWidth().offset(y = L.rowHeadingBand - L.rowGapAfter)
@@ -100,11 +100,14 @@ fun TitleMediaShelf(state: TitleState, episodes: Boolean, active: Boolean) {
                 items(visible, key = { "episode-skeleton-$it" }, contentType = { "skeleton" }) { index ->
                     Box(Modifier.size(width, height).testTag("title-episode-slot-$index").background(C.surface2, RoundedCornerShape(WolfskinTokens.Radius.card)))
                 }
-            } else itemsIndexed(titles, key = { index, _ -> titleKeys[index] }, contentType = { _, _ -> if (episodes) "tile" else "poster" }) { index, item ->
+            } else {
+                val keys = titles.map { it.id }.uniqueKeys()
+                itemsIndexed(titles, key = { index, _ -> keys[index] }, contentType = { _, _ -> if (episodes) "tile" else "poster" }) { index, item ->
                 TitlePoster(item, active && state.column == index, Modifier.width(width).then(if (episodes) Modifier.testTag("title-episode-slot-$index") else Modifier)
                     .onGloballyPositioned { state.recordCenter(id, index, it.boundsInRoot().center.x) },
                     episodes, state.data.connection != TitleConnection.SignedOut, onFocus = { state.focus(id, index) }) { state.click(id, index) }
             }
+            }
         }
     }
 }