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Code Issues 29 Pull requests Releases Activity

refactor chatview to have two sliver lists

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Co-authored-by: Erwan Leboucher <erwanleboucher@gmail.com>
This commit is contained in:
Henry Hiles 2026-09-24 20:02:23 -04:00
commit 110caff170
Signed by: Henry-Hiles
SSH key fingerprint: SHA256:VKQUdS31Q90KvX7EkKMHMBpUspcmItAh86a+v7PGiIs
4 changed files with 161 additions and 152 deletions
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194
lib/helpers/hooks/chat_scroll.dart
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@ -4,126 +4,148 @@ import "package:hooks_riverpod/hooks_riverpod.dart";
import "package:material_ui/material_ui.dart";
import "package:super_sliver_list/super_sliver_list.dart";
final class ChatScroll({
required final ListController listController,
final class ChatScroll<T>({
required final IList<T> historyItems,
required final IList<T> liveItems,
required final GlobalKey centerKey,
required final ListController historyListController,
required final ListController liveListController,
required final ScrollController scrollController,
required final bool hasMore,
required final bool isLoadingOlder,
required final Future<void> Function() loadOlder,
required final Future<void> Function(String id) jumpToId,
}) {
static ChatScroll use<T>({
static ChatScroll<T> use<T>({
required AsyncValue<IList<T>?> controllerData,
required String Function(T item) id,
required Future<bool> Function() loadOlder,
required bool Function() shouldLoadOlder,
required Future<void> Function() onReachedBottom,
}) {
final listController = useRef(ListController());
final historyListController = useRef(ListController());
final liveListController = useRef(ListController());
final scrollController = useScrollController();
final centerKey = useMemoized(GlobalKey.new);
final anchorId = useState<String?>(null);
final hasMore = useState(true);
final topItemBeforeLoad = useState<String?>(null);
final loadingOlder = useRef(false);
final initialized = useRef(false);
final isLoadingOlder = useState(false);
Future<void> loadOlderItems() async {
if (loadingOlder.value || !hasMore.value) return;
if (controllerData case AsyncData(:final value?)) {
loadingOlder.value = true;
topItemBeforeLoad.value = value.firstOrNull == null
? null
: id(value.first);
try {
hasMore.value = await loadOlder();
} finally {
loadingOlder.value = false;
}
}
}
Future<void> jumpToId(String itemId) async {
final index =
controllerData.value?.indexWhere((item) => id(item) == itemId) ?? -1;
if (index == -1) return;
listController.value.animateToItem(
index: index,
scrollController: scrollController,
alignment: 0.5,
duration: (_) => .new(milliseconds: 700),
curve: (_) => Curves.easeInOut,
);
}
final anchorIdValue = anchorId.value;
useEffect(() {
if (controllerData case AsyncData(:final value?)) {
WidgetsBinding.instance.addPostFrameCallback((_) {
if (!scrollController.hasClients) return;
if (!initialized.value) {
initialized.value = true;
if (value.isNotEmpty) {
listController.value.jumpToItem(
index: value.length - 1,
scrollController: scrollController,
alignment: 1,
);
}
return;
}
final topItem = topItemBeforeLoad.value;
if (topItem != null) {
final index = value.indexWhere((item) => id(item) == topItem);
if (index != -1) {
listController.value.jumpToItem(
index: index,
scrollController: scrollController,
alignment: 0,
);
}
topItemBeforeLoad.value = null;
} else if (scrollController.position.atEdge &&
scrollController.position.pixels != 0) {
scrollController.jumpTo(scrollController.position.maxScrollExtent);
}
});
if (anchorId.value == null) {
if (controllerData case AsyncData(:final value?)
when value.isNotEmpty) {
anchorId.value = id(value.last);
}
}
return null;
}, [controllerData]);
final ({IList<T> history, IList<T> live}) split = useMemoized(() {
final items = controllerData.value;
final anchor = anchorIdValue;
if (items == null || anchor == null) {
return (history: const .empty(), live: const .empty());
}
final anchorIndex = items.indexWhere((item) => id(item) == anchor);
if (anchorIndex == -1) {
return (history: const .empty(), live: items);
}
return (
history: items.take(anchorIndex).toIList().reversed.toIList(),
live: items.skip(anchorIndex).toIList(),
);
}, [controllerData, anchorIdValue]);
Future<void> loadOlderItems() async {
if (!hasMore.value || isLoadingOlder.value) return;
isLoadingOlder.value = true;
try {
hasMore.value = await loadOlder();
} finally {
isLoadingOlder.value = false;
}
}
Future<void> jumpToId(String itemId) async {
if (!scrollController.hasClients) return;
final historyIndex = split.history.indexWhere(
(item) => id(item) == itemId,
);
if (historyIndex != -1) {
historyListController.value.animateToItem(
index: historyIndex,
scrollController: scrollController,
alignment: 0.5,
duration: (_) => .new(milliseconds: 700),
curve: (_) => Curves.easeInOut,
);
return;
}
final liveIndex = split.live.indexWhere((item) => id(item) == itemId);
if (liveIndex != -1) {
liveListController.value.animateToItem(
index: liveIndex,
scrollController: scrollController,
alignment: 0.5,
duration: (_) => .new(milliseconds: 700),
curve: (_) => Curves.easeInOut,
);
}
}
useEffect(() {
Future<void> listener() async {
if (!scrollController.hasClients || !scrollController.position.atEdge) {
const loadThreshold = 500.0;
const bottomThreshold = 50.0;
void checkPosition() {
if (!scrollController.hasClients) {
return;
}
if (scrollController.position.pixels == 0) {
if (shouldLoadOlder()) {
await loadOlderItems();
final position = scrollController.position;
if (position.extentAfter <= loadThreshold) {
if (hasMore.value && !isLoadingOlder.value) {
loadOlderItems();
}
} else {
await onReachedBottom();
}
if (position.extentBefore <= bottomThreshold) {
onReachedBottom();
}
}
scrollController.addListener(listener);
scrollController.addListener(checkPosition);
return () => scrollController.removeListener(listener);
}, [controllerData]);
WidgetsBinding.instance.addPostFrameCallback((_) => checkPosition());
return () => scrollController.removeListener(checkPosition);
}, [scrollController, onReachedBottom]);
return .new(
listController: listController.value,
historyItems: split.history,
liveItems: split.live,
centerKey: centerKey,
historyListController: historyListController.value,
liveListController: liveListController.value,
scrollController: scrollController,
hasMore: hasMore.value,
isLoadingOlder: isLoadingOlder.value,
loadOlder: loadOlderItems,
jumpToId: jumpToId,
);