Fix opening Replies section on unread bar.

Telegram/SourceFiles/data/data_messages.cpp

@@ -479,9 +479,15 @@ void MessagesSliceBuilder::requestMessagesCount() {
 MessagesSlice MessagesSliceBuilder::snapshot() const {
 	auto result = MessagesSlice();
 	result.ids.reserve(_ids.size());
+	auto nearestToAround = std::optional<FullMsgId>();
 	for (const auto &position : _ids) {
 		result.ids.push_back(position.fullId);
+		if (!nearestToAround && position >= _key) {
+			nearestToAround = position.fullId;
+		}
 	}
+	result.nearestToAround = nearestToAround.value_or(
+		_ids.empty() ? FullMsgId() : _ids.back().fullId);
 	result.skippedBefore = _skippedBefore;
 	result.skippedAfter = _skippedAfter;
 	result.fullCount = _fullCount;

Telegram/SourceFiles/data/data_messages.h

@@ -93,10 +93,10 @@ constexpr auto UnreadMessagePosition = MessagePosition(
 
 struct MessagesSlice {
 	std::vector<FullMsgId> ids;
+	FullMsgId nearestToAround;
 	std::optional<int> skippedBefore;
 	std::optional<int> skippedAfter;
 	std::optional<int> fullCount;
-
 };
 
 struct MessagesQuery {
@@ -112,7 +112,6 @@ struct MessagesQuery {
 	MessagePosition aroundId;
 	int limitBefore = 0;
 	int limitAfter = 0;
-
 };
 
 struct MessagesResult {

Telegram/SourceFiles/data/data_replies_list.cpp

@@ -227,6 +227,7 @@ void RepliesList::injectRootDivider(
 bool RepliesList::buildFromData(not_null<Viewer*> viewer) {
 	if (_list.empty() && _skippedBefore == 0 && _skippedAfter == 0) {
 		viewer->slice.ids.clear();
+		viewer->slice.nearestToAround = FullMsgId();
 		viewer->slice.fullCount
 			= viewer->slice.skippedBefore
 			= viewer->slice.skippedAfter
@@ -268,10 +269,20 @@ bool RepliesList::buildFromData(not_null<Viewer*> viewer) {
 
 	const auto channelId = _history->channelId();
 	slice->ids.clear();
+	auto nearestToAround = std::optional<MsgId>();
 	slice->ids.reserve(useAfter + useBefore);
 	for (auto j = i - useAfter, e = i + useBefore; j != e; ++j) {
+		if (!nearestToAround && *j < around) {
+			nearestToAround = (j == i - useAfter)
+				? *j
+				: *(j - 1);
+		}
 		slice->ids.emplace_back(channelId, *j);
 	}
+	slice->nearestToAround = FullMsgId(
+		channelId,
+		nearestToAround.value_or(
+			slice->ids.empty() ? 0 : slice->ids.back().msg));
 	slice->fullCount = _fullCount.current();
 
 	injectRootMessageAndReverse(slice);

Telegram/SourceFiles/history/view/history_view_list_widget.cpp

@@ -336,12 +336,16 @@ void ListWidget::refreshRows() {
 
 	_items.clear();
 	_items.reserve(_slice.ids.size());
+	auto nearestIndex = -1;
 	for (const auto &fullId : _slice.ids) {
 		if (const auto item = session().data().message(fullId)) {
+			if (_slice.nearestToAround == fullId) {
+				nearestIndex = int(_items.size());
+			}
 			_items.push_back(enforceViewForItem(item));
 		}
 	}
-	updateAroundPositionFromRows();
+	updateAroundPositionFromNearest(nearestIndex);
 
 	updateItemsGeometry();
 	checkUnreadBarCreation();
@@ -573,8 +577,7 @@ not_null<Element*> ListWidget::enforceViewForItem(
 	return i->second.get();
 }
 
-void ListWidget::updateAroundPositionFromRows() {
-	const auto nearestIndex = findNearestItem(_aroundPosition);
+void ListWidget::updateAroundPositionFromNearest(int nearestIndex) {
 	if (nearestIndex < 0) {
 		_aroundIndex = -1;
 		return;

Telegram/SourceFiles/history/view/history_view_list_widget.h

@@ -305,7 +305,7 @@ private:
 	using CursorState = HistoryView::CursorState;
 
 	void refreshViewer();
-	void updateAroundPositionFromRows();
+	void updateAroundPositionFromNearest(int nearestIndex);
 	void refreshRows();
 	ScrollTopState countScrollState() const;
 	void saveScrollState();

Telegram/SourceFiles/history/view/history_view_replies_section.cpp

@@ -1519,7 +1519,7 @@ void RepliesWidget::updateControlsGeometry() {
 
 	const auto bottom = height();
 	const auto controlsHeight = _composeControls->heightCurrent();
-	const auto scrollY = _topBar->height() + _rootView->height();
+	const auto scrollY = _topBar->height() + _rootViewHeight;
 	const auto scrollHeight = bottom - scrollY - controlsHeight;
 	const auto scrollSize = QSize(contentWidth, scrollHeight);
 	if (_scroll->size() != scrollSize) {
@@ -1585,13 +1585,28 @@ void RepliesWidget::updatePinnedVisibility() {
 		return _root;
 	}();
 	const auto view = _inner->viewByPosition(item->position());
-	setPinnedVisibility(!view
-		|| (view->y() + view->height() <= _scroll->scrollTop()));
+	const auto visible = !view
+		|| (view->y() + view->height() <= _scroll->scrollTop());
+	setPinnedVisibility(visible);
 }
 
 void RepliesWidget::setPinnedVisibility(bool shown) {
 	if (!animating()) {
-		_rootView->toggle(shown, anim::type::normal);
+		if (!_rootViewInited) {
+			const auto height = shown ? st::historyReplyHeight : 0;
+			if (const auto delta = height - _rootViewHeight) {
+				_rootViewHeight = height;
+				if (_scroll->scrollTop() == _scroll->scrollTopMax()) {
+					setGeometryWithTopMoved(geometry(), delta);
+				} else {
+					updateControlsGeometry();
+				}
+			}
+			_rootView->toggle(shown, anim::type::instant);
+			_rootViewInited = true;
+		} else {
+			_rootView->toggle(shown, anim::type::normal);
+		}
 	}
 }
 

Telegram/SourceFiles/history/view/history_view_replies_section.h

@@ -255,6 +255,7 @@ private:
 	object_ptr<Ui::SlideWrap<Ui::RpWidget>> _rootView;
 	int _rootViewHeight = 0;
 	object_ptr<Ui::PlainShadow> _rootShadow;
+	bool _rootViewInited = false;
 
 	std::unique_ptr<Ui::ScrollArea> _scroll;