Support floating topic bars in forums.

Telegram/SourceFiles/boxes/peers/edit_forum_topic_box.cpp

@@ -77,7 +77,9 @@ DefaultIconEmoji::DefaultIconEmoji(
 	std::move(value) | rpl::start_with_next([=](DefaultIcon value) {
 		_icon = value;
 		_image = QImage();
-		repaint();
+		if (repaint) {
+			repaint();
+		}
 	}, _lifetime);
 }
 

Telegram/SourceFiles/data/data_channel.cpp

@@ -235,7 +235,8 @@ void ChannelData::setFlags(ChannelDataFlags which) {
 		| Flag::CallNotEmpty
 		| Flag::SimilarExpanded
 		| Flag::Signatures
-		| Flag::SignatureProfiles)) {
+		| Flag::SignatureProfiles
+		| Flag::ForumTabs)) {
 		if (const auto history = this->owner().historyLoaded(this)) {
 			if (diff & Flag::CallNotEmpty) {
 				history->updateChatListEntry();
@@ -262,6 +263,9 @@ void ChannelData::setFlags(ChannelDataFlags which) {
 			if (diff & (Flag::Signatures | Flag::SignatureProfiles)) {
 				session().changes().peerUpdated(this, UpdateFlag::Rights);
 			}
+			if (diff & Flag::ForumTabs) {
+				history->forumTabsChanged(which & Flag::ForumTabs);
+			}
 		}
 	}
 	if (const auto raw = takenForum.get()) {

Telegram/SourceFiles/data/data_forum_topic.cpp

@@ -32,6 +32,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "ui/painter.h"
 #include "ui/color_int_conversion.h"
 #include "ui/text/text_custom_emoji.h"
+#include "ui/text/text_utilities.h"
 #include "styles/style_dialogs.h"
 #include "styles/style_chat_helpers.h"
 
@@ -756,6 +757,16 @@ TextWithEntities ForumTopic::titleWithIcon() const {
 	return ForumTopicIconWithTitle(_rootId, _iconId, _title);
 }
 
+TextWithEntities ForumTopic::titleWithIconOrLogo() const {
+	if (_iconId || isGeneral()) {
+		return titleWithIcon();
+	}
+	return Ui::Text::SingleCustomEmoji(Data::TopicIconEmojiEntity({
+		.title = _title,
+		.colorId = _colorId,
+	})).append(' ').append(_title);
+}
+
 int ForumTopic::titleVersion() const {
 	return _titleVersion;
 }

Telegram/SourceFiles/data/data_forum_topic.h

@@ -148,6 +148,7 @@ public:
 
 	[[nodiscard]] QString title() const;
 	[[nodiscard]] TextWithEntities titleWithIcon() const;
+	[[nodiscard]] TextWithEntities titleWithIconOrLogo() const;
 	[[nodiscard]] int titleVersion() const;
 	void applyTitle(const QString &title);
 	[[nodiscard]] DocumentId iconId() const;

Telegram/SourceFiles/history/history.cpp

@@ -3464,6 +3464,26 @@ bool History::suggestDraftAllowed() const {
 	return peer->isMonoforum() && !peer->amMonoforumAdmin();
 }
 
+bool History::hasForumThreadBars() const {
+	if (amMonoforumAdmin()) {
+		return true;
+	} else if (const auto channel = peer->asChannel()) {
+		return channel->forum() && channel->useSubsectionTabs();
+	}
+	return false;
+}
+
+void History::forumTabsChanged(bool forumTabs) {
+	for (auto &block : blocks) {
+		for (auto &view : block->messages) {
+			view->setPendingResize();
+			if (forumTabs || view->Has<HistoryView::ForumThreadBar>()) {
+				view->previousInBlocksChanged();
+			}
+		}
+	}
+}
+
 not_null<History*> History::migrateToOrMe() const {
 	if (const auto to = peer->migrateTo()) {
 		return owner().history(to);

Telegram/SourceFiles/history/history.h

@@ -80,6 +80,8 @@ public:
 	void monoforumChanged(Data::SavedMessages *old);
 	[[nodiscard]] bool amMonoforumAdmin() const;
 	[[nodiscard]] bool suggestDraftAllowed() const;
+	[[nodiscard]] bool hasForumThreadBars() const;
+	void forumTabsChanged(bool forumTabs);
 
 	[[nodiscard]] not_null<History*> migrateToOrMe() const;
 	[[nodiscard]] History *migrateFrom() const;

Telegram/SourceFiles/history/history_inner_widget.cpp

@@ -928,8 +928,8 @@ void HistoryInner::enumerateDates(Method method) {
 }
 
 template <typename Method>
-void HistoryInner::enumerateMonoforumSenders(Method method) {
-	if (!_history->amMonoforumAdmin()) {
+void HistoryInner::enumerateForumThreadBars(Method method) {
+	if (!_history->hasForumThreadBars()) {
 		return;
 	}
 
@@ -946,28 +946,28 @@ void HistoryInner::enumerateMonoforumSenders(Method method) {
 	// -1 means we didn't find a same-day with previous message yet.
 	auto lowestInOneBunchItemBottom = -1;
 
-	auto senderCallback = [&](not_null<Element*> view, int itemtop, int itembottom) {
+	auto barCallback = [&](not_null<Element*> view, int itemtop, int itembottom) {
 		const auto item = view->data();
 		if (lowestInOneBunchItemBottom < 0 && view->isInOneBunchWithPrevious()) {
 			lowestInOneBunchItemBottom = itembottom - view->marginBottom();
 		}
 
-		// Call method on a sender for all messages that have it and for those who are not showing it
+		// Call method on a bar for all messages that have it and for those who are not showing it
 		// because they are in a one day together with the previous message if they are top-most visible.
-		if (view->displayMonoforumSender() || (!item->isEmpty() && itemtop <= _visibleAreaTop)) {
+		if (view->displayForumThreadBar() || (!item->isEmpty() && itemtop <= _visibleAreaTop)) {
 			if (lowestInOneBunchItemBottom < 0) {
 				lowestInOneBunchItemBottom = itembottom - view->marginBottom();
 			}
-			// Attach sender to the top of the visible area with the same margin as it has in service message.
-			int senderTop = qMax(itemtop + view->displayedDateHeight(), _visibleAreaTop + skip) + st::msgServiceMargin.top();
+			// Attach bar to the top of the visible area with the same margin as it has in service message.
+			int barTop = qMax(itemtop + view->displayedDateHeight(), _visibleAreaTop + skip) + st::msgServiceMargin.top();
 
-			// Do not let the sender go below the single-sender messages pack bottom line.
-			int senderHeight = st::msgServicePadding.bottom() + st::msgServiceFont->height + st::msgServicePadding.top();
-			senderTop = qMin(senderTop, lowestInOneBunchItemBottom - senderHeight);
+			// Do not let the bar go below the single-bar messages pack bottom line.
+			int barHeight = st::msgServicePadding.bottom() + st::msgServiceFont->height + st::msgServicePadding.top();
+			barTop = qMin(barTop, lowestInOneBunchItemBottom - barHeight);
 
 			// Call the template callback function that was passed
 			// and return if it finished everything it needed.
-			if (!method(view, itemtop, senderTop)) {
+			if (!method(view, itemtop, barTop)) {
 				return false;
 			}
 		}
@@ -980,7 +980,7 @@ void HistoryInner::enumerateMonoforumSenders(Method method) {
 		return true;
 	};
 
-	enumerateItems<EnumItemsDirection::BottomToTop>(senderCallback);
+	enumerateItems<EnumItemsDirection::BottomToTop>(barCallback);
 }
 
 TextSelection HistoryInner::computeRenderSelection(
@@ -1395,31 +1395,31 @@ void HistoryInner::paintEvent(QPaintEvent *e) {
 	});
 	p.setOpacity(1.);
 
-	enumerateMonoforumSenders([&](not_null<Element*> view, int itemtop, int senderTop) {
-		// stop the enumeration if the sender is above the painted rect
-		if (senderTop + dateHeight <= clip.top()) {
+	enumerateForumThreadBars([&](not_null<Element*> view, int itemtop, int barTop) {
+		// stop the enumeration if the bar is above the painted rect
+		if (barTop + dateHeight <= clip.top()) {
 			return false;
 		}
 
-		const auto displaySender = view->displayMonoforumSender();
-		auto senderInPlace = displaySender;
-		if (senderInPlace) {
-			const auto correctSenderTop = itemtop + view->displayedDateHeight() + st::msgServiceMargin.top();
-			senderInPlace = (senderTop < correctSenderTop + st::msgServiceMargin.top());
+		const auto displayBar = view->displayForumThreadBar();
+		auto barInPlace = displayBar;
+		if (barInPlace) {
+			const auto correctBarTop = itemtop + view->displayedDateHeight() + st::msgServiceMargin.top();
+			barInPlace = (barTop < correctBarTop + st::msgServiceMargin.top());
 		}
 
-		// paint the sender if it intersects the painted rect
-		if (senderTop < clip.top() + clip.height()) {
-			const auto senderY = senderTop - st::msgServiceMargin.top();
-			if (const auto sender = view->Get<HistoryView::MonoforumSenderBar>()) {
-				sender->paint(p, context.st, senderY, _contentWidth, _isChatWide, !senderInPlace);
+		// paint the bar if it intersects the painted rect
+		if (barTop < clip.top() + clip.height()) {
+			const auto barY = barTop - st::msgServiceMargin.top();
+			if (const auto bar = view->Get<HistoryView::ForumThreadBar>()) {
+				bar->paint(p, context.st, barY, _contentWidth, _isChatWide, !barInPlace);
 			} else {
-				HistoryView::MonoforumSenderBar::PaintFor(
+				_forumThreadBarWidth = HistoryView::ForumThreadBar::PaintForGetWidth(
 					p,
 					context.st,
 					view,
-					_monoforumSenderUserpicView,
-					senderY,
+					_forumThreadBarUserpicView,
+					barY,
 					_contentWidth,
 					_isChatWide);
 			}
@@ -3698,7 +3698,7 @@ void HistoryInner::toggleScrollDateShown() {
 void HistoryInner::repaintScrollDateCallback() {
 	int updateTop = _visibleAreaTop;
 	int updateHeight = st::msgServiceMargin.top() + st::msgServicePadding.top() + st::msgServiceFont->height + st::msgServicePadding.bottom();
-	if (_history->amMonoforumAdmin()) {
+	if (_history->hasForumThreadBars()) {
 		updateHeight *= 2;
 	}
 	update(0, updateTop, width(), updateHeight);
@@ -4261,6 +4261,54 @@ void HistoryInner::mouseActionUpdate() {
 			}
 			return true;
 		});
+		if (!dragState.link) {
+			enumerateForumThreadBars([&](not_null<Element*> view, int itemtop, int barTop) {
+				// stop the enumeration if the bar is above our point
+				if (barTop + dateHeight <= point.y()) {
+					return false;
+				}
+
+				const auto displayBar = view->displayForumThreadBar();
+				auto barInPlace = displayBar;
+				if (barInPlace) {
+					const auto correctBarTop = itemtop + view->displayedDateHeight() + st::msgServiceMargin.top();
+					barInPlace = (barTop < correctBarTop + st::msgServiceMargin.top());
+				}
+
+				// stop enumeration if we've found a bar under the cursor
+				if (barTop <= point.y()) {
+					const auto item = view->data();
+					auto barWidth = 0;
+					if (const auto bar = view->Get<HistoryView::ForumThreadBar>()) {
+						barWidth = bar->width;
+					} else {
+						barWidth = _forumThreadBarWidth;
+					}
+					auto barLeft = st::msgServiceMargin.left();
+					auto maxwidth = _contentWidth;
+					if (_isChatWide) {
+						maxwidth = qMin(maxwidth, int32(st::msgMaxWidth + 2 * st::msgPhotoSkip + 2 * st::msgMargin.left()));
+					}
+					auto widthForBar = maxwidth - st::msgServiceMargin.left() - st::msgServiceMargin.left();
+
+					barLeft += (widthForBar - barWidth) / 2;
+
+					if (point.x() >= barLeft && point.x() < barLeft + barWidth) {
+						if (!_forumThreadBarLink) {
+							_forumThreadBarLink = std::make_shared<Window::ForumThreadClickHandler>(item);
+						} else {
+							static_cast<Window::ForumThreadClickHandler*>(_forumThreadBarLink.get())->update(item);
+						}
+						dragState = TextState(
+							nullptr,
+							_forumThreadBarLink);
+						_dragStateItem = session().data().message(dragState.itemId);
+						lnkhost = view;
+					}
+				}
+				return true;
+			});
+		}
 		if (!dragState.link) {
 			StateRequest request;
 			if (_mouseAction == MouseAction::Selecting) {

Telegram/SourceFiles/history/history_inner_widget.h

@@ -315,13 +315,13 @@ private:
 	template <typename Method>
 	void enumerateDates(Method method);
 
-	// This function finds all monoforum sender elements that are displayed and calls template method
+	// This function finds all forum thread bar elements that are displayed and calls template method
 	// for each found date element (from the bottom to the top) using enumerateItems() method.
 	//
 	// Method has "bool (*Method)(not_null<Element*> view, int itemtop, int dateTop)" signature
 	// if it returns false the enumeration stops immediately.
 	template <typename Method>
-	void enumerateMonoforumSenders(Method method);
+	void enumerateForumThreadBars(Method method);
 
 	void scrollDateCheck();
 	void scrollDateHideByTimer();
@@ -470,7 +470,8 @@ private:
 	int _contentWidth = 0;
 	int _historyPaddingTop = 0;
 	int _revealHeight = 0;
-	Ui::PeerUserpicView _monoforumSenderUserpicView;
+	int _forumThreadBarWidth = 0;
+	Ui::PeerUserpicView _forumThreadBarUserpicView;
 
 	// Save visible area coords for painting / pressing userpics.
 	int _visibleAreaTop = 0;
@@ -572,6 +573,7 @@ private:
 	Element *_scrollDateLastItem = nullptr;
 	int _scrollDateLastItemTop = 0;
 	ClickHandlerPtr _scrollDateLink;
+	ClickHandlerPtr _forumThreadBarLink;
 
 };
 

Telegram/SourceFiles/history/view/history_view_element.cpp

@@ -427,20 +427,37 @@ void DateBadge::paint(
 	ServiceMessagePainter::PaintDate(p, st, text, width, y, w, chatWide);
 }
 
-void MonoforumSenderBar::init(
+void ForumThreadBar::init(
 		not_null<PeerData*> parentChat,
-		not_null<PeerData*> peer) {
-	sender = peer;
-	text.setText(st::semiboldTextStyle, peer->name());
+		not_null<Data::Thread*> thread) {
+	this->thread = thread;
+	const auto sublist = thread->asSublist();
+	if (sublist) {
+		text.setText(st::semiboldTextStyle, sublist->sublistPeer()->name());
+	} else if (const auto topic = thread->asTopic()) {
+		text.setMarkedText(
+			st::semiboldTextStyle,
+			topic->titleWithIconOrLogo(),
+			kMarkupTextOptions,
+			Core::TextContext({ .session = &topic->session() }));
+	}
 	const auto skip = st::monoforumBarUserpicSkip;
-	const auto userpic = st::msgServicePadding.top()
-		+ st::msgServiceFont->height
-		+ st::msgServicePadding.bottom()
-		- 2 * skip;
-	width = skip + userpic + skip * 2 + text.maxWidth() + st::msgServicePadding.right();
+	const auto userpic = sublist
+		? (st::msgServicePadding.top()
+			+ st::msgServiceFont->height
+			+ st::msgServicePadding.bottom()
+			- 2 * skip)
+		: (st::msgServicePadding.left() - 3 * skip);
+
+	width = skip
+		+ userpic
+		+ skip * 2
+		+ text.maxWidth()
+		+ st::topicButtonArrowSkip
+		+ st::msgServicePadding.right();
 }
 
-int MonoforumSenderBar::height() const {
+int ForumThreadBar::height() const {
 	return st::msgServiceMargin.top()
 		+ st::msgServicePadding.top()
 		+ st::msgServiceFont->height
@@ -448,17 +465,29 @@ int MonoforumSenderBar::height() const {
 		+ st::msgServiceMargin.bottom();
 }
 
-void MonoforumSenderBar::paint(
+void ForumThreadBar::paint(
 		Painter &p,
 		not_null<const Ui::ChatStyle*> st,
 		int y,
 		int w,
 		bool chatWide,
 		bool skipPatternLine) const {
-	Paint(p, st, sender, text, width, view, y, w, chatWide, skipPatternLine);
+	if (const auto strong = thread.get()) {
+		Paint(
+			p,
+			st,
+			strong,
+			text,
+			width,
+			view,
+			y,
+			w,
+			chatWide,
+			skipPatternLine);
+	}
 }
 
-void MonoforumSenderBar::PaintFor(
+int ForumThreadBar::PaintForGetWidth(
 		Painter &p,
 		not_null<const Ui::ChatStyle*> st,
 		not_null<Element*> itemView,
@@ -466,31 +495,49 @@ void MonoforumSenderBar::PaintFor(
 		int y,
 		int w,
 		bool chatWide) {
-	const auto sublist = itemView->data()->savedSublist();
-	const auto sender = (sublist && sublist->parentChat())
-		? sublist->sublistPeer().get()
+	const auto item = itemView->data();
+	const auto topic = item->topic();
+	const auto sublist = item->savedSublist();
+	const auto sender = topic
+		? (Data::Thread*)topic
+		: (sublist && sublist->parentChat())
+		? (Data::Thread*)sublist
 		: nullptr;
-	if (!sender || sender->isMonoforum()) {
-		return;
+	auto text = Ui::Text::String();
+	if (!sender
+		|| !topic
+		|| (sublist && sublist->sublistPeer()->isMonoforum())) {
+		return 0;
+	} else if (topic) {
+		text.setMarkedText(
+			st::semiboldTextStyle,
+			topic->titleWithIconOrLogo(),
+			kMarkupTextOptions,
+			Core::TextContext({ .session = &topic->session() }));
+	} else {
+		text.setText(st::semiboldTextStyle, sublist->sublistPeer()->name());
 	}
-	auto text = Ui::Text::String(st::semiboldTextStyle, sender->name());
 	const auto skip = st::monoforumBarUserpicSkip;
-	const auto userpic = st::msgServicePadding.top()
-		+ st::msgServiceFont->height
-		+ st::msgServicePadding.bottom()
-		- 2 * skip;
+	const auto userpic = sublist
+		? (st::msgServicePadding.top()
+			+ st::msgServiceFont->height
+			+ st::msgServicePadding.bottom()
+			- 2 * skip)
+		: (st::msgServicePadding.left() - 3 * skip);
 	const auto width = skip
 		+ userpic
 		+ skip * 2
 		+ text.maxWidth()
+		+ st::topicButtonArrowSkip
 		+ st::msgServicePadding.right();
 	Paint(p, st, sender, text, width, userpicView, y, w, chatWide, true);
+	return width;
 }
 
-void MonoforumSenderBar::Paint(
+void ForumThreadBar::Paint(
 		Painter &p,
 		not_null<const Ui::ChatStyle*> st,
-		not_null<PeerData*> sender,
+		not_null<Data::Thread*> thread,
 		const Ui::Text::String &text,
 		int width,
 		Ui::PeerUserpicView &view,
@@ -498,8 +545,6 @@ void MonoforumSenderBar::Paint(
 		int w,
 		bool chatWide,
 		bool skipPatternLine) {
-	Expects(sender != nullptr);
-
 	int left = st::msgServiceMargin.left();
 	const auto maxwidth = chatWide
 		? std::min(w, WideChatWidth())
@@ -528,24 +573,47 @@ void MonoforumSenderBar::Paint(
 		p.drawLine(left + use, top, 2 * w, top);
 	}
 
-	const auto userpic = st::msgServicePadding.top()
-		+ st::msgServiceFont->height
-		+ st::msgServicePadding.bottom()
-		- 2 * skip;
-	const auto available = use - (skip + userpic + skip * 2 + st::msgServicePadding.right());
+	const auto sublist = thread->asSublist();
+	const auto userpic = sublist
+		? (st::msgServicePadding.top()
+			+ st::msgServiceFont->height
+			+ st::msgServicePadding.bottom()
+			- 2 * skip)
+		: (st::msgServicePadding.left() - 3 * skip);
+	const auto available = use
+		- (skip
+			+ userpic
+			+ skip * 2
+			+ st::topicButtonArrowSkip
+			+ st::msgServicePadding.right());
 
-	sender->paintUserpic(p, view, left + skip, y + st::msgServiceMargin.top() + skip, userpic);
+	if (sublist) {
+		sublist->sublistPeer()->paintUserpic(
+			p,
+			view,
+			left + skip,
+			y + st::msgServiceMargin.top() + skip,
+			userpic);
+	}
 
+	const auto textLeft = left + skip + userpic + skip * 2;
+	const auto textTop = y
+		+ st::msgServiceMargin.top()
+		+ st::msgServicePadding.top();
 	p.setFont(st::msgServiceFont);
 	p.setPen(st->msgServiceFg());
 	text.draw(p, {
-		.position = {
-			left + skip + userpic + skip * 2,
-			y + st::msgServiceMargin.top() + st::msgServicePadding.top(),
-		},
+		.position = { textLeft, textTop },
 		.availableWidth = available,
 		.elisionLines = 1,
 	});
+
+	st::topicButtonArrow.paint(
+		p,
+		textLeft + available + st::topicButtonArrowPosition.x(),
+		textTop + st::topicButtonArrowPosition.y(),
+		w,
+		st->msgServiceFg()->c);
 }
 
 void ServicePreMessage::init(
@@ -1367,7 +1435,7 @@ void Element::validateTextSkipBlock(bool has, int width, int height) {
 }
 
 void Element::previousInBlocksChanged() {
-	recountMonoforumSenderBarInBlocks();
+	recountThreadBarInBlocks();
 	recountDisplayDateInBlocks();
 	recountAttachToPreviousInBlocks();
 }
@@ -1404,7 +1472,7 @@ bool Element::computeIsAttachToPrevious(not_null<Element*> previous) {
 	if (!Has<DateBadge>()
 		&& !Has<UnreadBar>()
 		&& !Has<ServicePreMessage>()
-		&& !Has<MonoforumSenderBar>()) {
+		&& !Has<ForumThreadBar>()) {
 		const auto prev = previous->data();
 		const auto previousMarkup = prev->inlineReplyMarkup();
 		const auto possible = (std::abs(prev->date() - item->date())
@@ -1516,12 +1584,12 @@ bool Element::isInOneDayWithPrevious() const {
 	return !data()->isEmpty() && !displayDate();
 }
 
-bool Element::displayMonoforumSender() const {
-	return Has<MonoforumSenderBar>();
+bool Element::displayForumThreadBar() const {
+	return Has<ForumThreadBar>();
 }
 
 bool Element::isInOneBunchWithPrevious() const {
-	return !data()->isEmpty() && !displayMonoforumSender();
+	return !data()->isEmpty() && !displayForumThreadBar();
 }
 
 void Element::recountAttachToPreviousInBlocks() {
@@ -1542,34 +1610,49 @@ void Element::recountAttachToPreviousInBlocks() {
 	setAttachToPrevious(attachToPrevious, previous);
 }
 
-void Element::recountMonoforumSenderBarInBlocks() {
+void Element::recountThreadBarInBlocks() {
 	const auto item = data();
+	const auto topic = item->topic();
 	const auto sublist = item->savedSublist();
-	const auto parentChat = sublist ? sublist->parentChat() : nullptr;
-	const auto barPeer = [&]() -> PeerData* {
+	const auto parentChat = (topic && topic->channel()->useSubsectionTabs())
+		? topic->channel().get()
+		: sublist
+		? sublist->parentChat()
+		: nullptr;
+	const auto barThread = [&]() -> Data::Thread* {
 		if (!parentChat
 			|| isHidden()
 			|| item->isEmpty()
 			|| item->isSponsored()) {
 			return nullptr;
 		}
-		const auto sublistPeer = sublist->sublistPeer();
 		if (const auto previous = previousDisplayedInBlocks()) {
 			const auto prev = previous->data();
-			if (const auto prevSublist = prev->savedSublist()) {
+			if (const auto prevTopic = prev->topic()) {
+				Assert(prevTopic->channel() == parentChat);
+				const auto topicRootId = topic->rootId();
+				if (prevTopic->rootId() == topicRootId) {
+					return nullptr;
+				}
+			} else if (const auto prevSublist = prev->savedSublist()) {
 				Assert(prevSublist->parentChat() == parentChat);
+				const auto sublistPeer = sublist->sublistPeer();
 				if (prevSublist->sublistPeer() == sublistPeer) {
 					return nullptr;
 				}
 			}
 		}
-		return (sublistPeer == parentChat) ? nullptr : sublistPeer.get();
+		return topic
+			? (Data::Thread*)topic
+			: (sublist && sublist->sublistPeer() != parentChat)
+			? (Data::Thread*)sublist
+			: nullptr;
 	}();
-	if (barPeer && !Has<MonoforumSenderBar>()) {
-		AddComponents(MonoforumSenderBar::Bit());
-		Get<MonoforumSenderBar>()->init(parentChat, barPeer);
-	} else if (!barPeer && Has<MonoforumSenderBar>()) {
-		RemoveComponents(MonoforumSenderBar::Bit());
+	if (barThread && !Has<ForumThreadBar>()) {
+		AddComponents(ForumThreadBar::Bit());
+		Get<ForumThreadBar>()->init(parentChat, barThread);
+	} else if (!barThread && Has<ForumThreadBar>()) {
+		RemoveComponents(ForumThreadBar::Bit());
 	}
 }
 

Telegram/SourceFiles/history/view/history_view_element.h

@@ -20,6 +20,7 @@ struct HistoryMessageReply;
 struct PreparedServiceText;
 
 namespace Data {
+class Thread;
 struct Reaction;
 struct ReactionId;
 } // namespace Data
@@ -265,8 +266,10 @@ struct DateBadge : RuntimeComponent<DateBadge, Element> {
 
 };
 
-struct MonoforumSenderBar : RuntimeComponent<MonoforumSenderBar, Element> {
-	void init(not_null<PeerData*> parentChat, not_null<PeerData*> peer);
+struct ForumThreadBar : RuntimeComponent<ForumThreadBar, Element> {
+	void init(
+		not_null<PeerData*> parentChat,
+		not_null<Data::Thread*> thread);
 
 	int height() const;
 	void paint(
@@ -276,7 +279,7 @@ struct MonoforumSenderBar : RuntimeComponent<MonoforumSenderBar, Element> {
 		int w,
 		bool chatWide,
 		bool skipPatternLine) const;
-	static void PaintFor(
+	static int PaintForGetWidth(
 		Painter &p,
 		not_null<const Ui::ChatStyle*> st,
 		not_null<Element*> itemView,
@@ -285,9 +288,8 @@ struct MonoforumSenderBar : RuntimeComponent<MonoforumSenderBar, Element> {
 		int w,
 		bool chatWide);
 
-	PeerData *sender = nullptr;
+	base::weak_ptr<Data::Thread> thread;
 	Ui::Text::String text;
-	ClickHandlerPtr link;
 	mutable Ui::PeerUserpicView view;
 	int width = 0;
 
@@ -295,7 +297,7 @@ private:
 	static void Paint(
 		Painter &p,
 		not_null<const Ui::ChatStyle*> st,
-		not_null<PeerData*> sender,
+		not_null<Data::Thread*> thread,
 		const Ui::Text::String &text,
 		int width,
 		Ui::PeerUserpicView &view,
@@ -475,7 +477,7 @@ public:
 	[[nodiscard]] bool displayDate() const;
 	[[nodiscard]] bool isInOneDayWithPrevious() const;
 
-	[[nodiscard]] bool displayMonoforumSender() const;
+	[[nodiscard]] bool displayForumThreadBar() const;
 	[[nodiscard]] bool isInOneBunchWithPrevious() const;
 
 	virtual void draw(Painter &p, const PaintContext &context) const = 0;
@@ -688,7 +690,7 @@ protected:
 	std::unique_ptr<Reactions::InlineList> _reactions;
 
 private:
-	void recountMonoforumSenderBarInBlocks();
+	void recountThreadBarInBlocks();
 
 	// This should be called only from previousInBlocksChanged()
 	// to add required bits to the Composer mask

Telegram/SourceFiles/history/view/history_view_message.cpp

@@ -1092,10 +1092,13 @@ QSize Message::performCountOptimalSize() {
 
 void Message::refreshTopicButton() {
 	const auto item = data();
-	if (isAttachedToPrevious()
-		|| delegate()->elementHideTopicButton(this)) {
+	if (isAttachedToPrevious() || delegate()->elementHideTopicButton(this)) {
 		_topicButton = nullptr;
 	} else if (const auto topic = item->topic()) {
+		if (topic->channel()->useSubsectionTabs()) {
+			_topicButton = nullptr;
+			return;
+		}
 		if (!_topicButton) {
 			_topicButton = std::make_unique<TopicButton>();
 		}
@@ -1132,8 +1135,8 @@ int Message::marginTop() const {
 	if (const auto bar = Get<UnreadBar>()) {
 		result += bar->height();
 	}
-	if (const auto monoforumBar = Get<MonoforumSenderBar>()) {
-		result += monoforumBar->height();
+	if (const auto bar = Get<ForumThreadBar>()) {
+		result += bar->height();
 	}
 	if (const auto service = Get<ServicePreMessage>()) {
 		result += service->height;
@@ -1181,8 +1184,8 @@ void Message::draw(Painter &p, const PaintContext &context) const {
 		if (const auto date = Get<DateBadge>()) {
 			aboveh += date->height();
 		}
-		if (const auto sender = Get<MonoforumSenderBar>()) {
-			aboveh += sender->height();
+		if (const auto bar = Get<ForumThreadBar>()) {
+			aboveh += bar->height();
 		}
 		if (context.clip.intersects(QRect(0, aboveh, width(), unreadbarh))) {
 			p.translate(0, aboveh);

Telegram/SourceFiles/history/view/history_view_service_message.cpp

@@ -527,8 +527,8 @@ int Service::marginTop() const {
 	if (const auto bar = Get<UnreadBar>()) {
 		result += bar->height();
 	}
-	if (const auto monoforumBar = Get<MonoforumSenderBar>()) {
-		result += monoforumBar->height();
+	if (const auto bar = Get<ForumThreadBar>()) {
+		result += bar->height();
 	}
 	if (const auto service = Get<ServicePreMessage>()) {
 		result += service->height;
@@ -553,8 +553,8 @@ void Service::draw(Painter &p, const PaintContext &context) const {
 		if (const auto date = Get<DateBadge>()) {
 			aboveh += date->height();
 		}
-		if (const auto sender = Get<MonoforumSenderBar>()) {
-			aboveh += sender->height();
+		if (const auto bar = Get<ForumThreadBar>()) {
+			aboveh += bar->height();
 		}
 		if (context.clip.intersects(QRect(0, aboveh, width(), unreadbarh))) {
 			p.translate(0, aboveh);

Telegram/SourceFiles/window/window_session_controller.cpp

@@ -348,6 +348,33 @@ void DateClickHandler::onClick(ClickContext context) const {
 	}
 }
 
+ForumThreadClickHandler::ForumThreadClickHandler(not_null<HistoryItem*> item)
+: _thread(resolveThread(item)) {
+}
+
+void ForumThreadClickHandler::update(not_null<HistoryItem*> item) {
+	_thread = resolveThread(item);
+}
+
+void ForumThreadClickHandler::onClick(ClickContext context) const {
+	const auto my = context.other.value<ClickHandlerContext>();
+	if (const auto window = my.sessionWindow.get()) {
+		if (const auto strong = _thread.get()) {
+			window->showThread(strong, 0, SectionShow::Way::ClearStack);
+		}
+	}
+}
+
+base::weak_ptr<Data::Thread> ForumThreadClickHandler::resolveThread(
+		not_null<HistoryItem*> item) const {
+	if (const auto sublist = item->savedSublist()) {
+		return sublist;
+	} else if (const auto topic = item->topic()) {
+		return topic;
+	}
+	return nullptr;
+}
+
 MessageHighlightId SearchHighlightId(const QString &query) {
 	auto result = MessageHighlightId{ .quote = { query } };
 	if (!result.quote.empty()) {

Telegram/SourceFiles/window/window_session_controller.h

@@ -126,6 +126,21 @@ private:
 
 };
 
+class ForumThreadClickHandler : public ClickHandler {
+public:
+	explicit ForumThreadClickHandler(not_null<HistoryItem*> item);
+
+	void update(not_null<HistoryItem*> item);
+	void onClick(ClickContext context) const override;
+
+private:
+	[[nodiscard]] base::weak_ptr<Data::Thread> resolveThread(
+		not_null<HistoryItem*> item) const;
+
+	base::weak_ptr<Data::Thread> _thread;
+
+};
+
 struct SectionShow {
 	enum class Way {
 		Forward,