Add short-polling of stories.

Telegram/SourceFiles/data/data_stories.cpp

@@ -38,6 +38,8 @@ constexpr auto kSavedPerPage = 100;
 constexpr auto kMaxPreloadSources = 10;
 constexpr auto kStillPreloadFromFirst = 3;
 constexpr auto kMaxSegmentsCount = 180;
+constexpr auto kPollingIntervalChat = 5 * TimeId(60);
+constexpr auto kPollingIntervalViewer = 1 * TimeId(60);
 
 using UpdateFlag = StoryUpdate::Flag;
 
@@ -98,10 +100,12 @@ Stories::Stories(not_null<Session*> owner)
 : _owner(owner)
 , _expireTimer([=] { processExpired(); })
 , _markReadTimer([=] { sendMarkAsReadRequests(); })
-, _incrementViewsTimer([=] { sendIncrementViewsRequests(); }) {
+, _incrementViewsTimer([=] { sendIncrementViewsRequests(); })
+, _pollingTimer([=] { sendPollingRequests(); }) {
 }
 
 Stories::~Stories() {
+	Expects(_pollingSettings.empty());
 }
 
 Session &Stories::owner() const {
@@ -348,7 +352,7 @@ Story *Stories::parseAndApply(
 		const auto result = i->second.get();
 		const auto pinned = result->pinned();
 		const auto mediaChanged = (result->media() != *media);
-		if (result->applyChanges(*media, data)) {
+		if (result->applyChanges(*media, data, now)) {
 			if (result->pinned() != pinned) {
 				savedStateUpdated(result);
 			}
@@ -358,6 +362,11 @@ Story *Stories::parseAndApply(
 			if (const auto item = lookupItem(result)) {
 				item->applyChanges(result);
 			}
+			_owner->refreshStoryItemViews(fullId);
+		}
+		const auto j = _pollingSettings.find(result);
+		if (j != end(_pollingSettings)) {
+			maybeSchedulePolling(result, j->second, now);
 		}
 		if (mediaChanged) {
 			_preloaded.remove(fullId);
@@ -378,7 +387,7 @@ Story *Stories::parseAndApply(
 		StoryMedia{ *media },
 		data.vdate().v,
 		data.vexpire_date().v)).first->second.get();
-	result->applyChanges(*media, data);
+	result->applyChanges(*media, data, now);
 	if (result->pinned()) {
 		savedStateUpdated(result);
 	}
@@ -656,6 +665,7 @@ void Stories::applyDeleted(FullStoryId id) {
 				preloadFinished(id);
 			}
 			_owner->refreshStoryItemViews(id);
+			Assert(!_pollingSettings.contains(story.get()));
 			if (i->second.empty()) {
 				_stories.erase(i);
 			}
@@ -818,13 +828,15 @@ base::expected<not_null<Story*>, NoStory> Stories::lookup(
 		_deleted.contains(id) ? NoStory::Deleted : NoStory::Unknown);
 }
 
-void Stories::resolve(FullStoryId id, Fn<void()> done) {
+void Stories::resolve(FullStoryId id, Fn<void()> done, bool force) {
-	const auto already = lookup(id);
+	if (!force) {
-	if (already.has_value() || already.error() != NoStory::Unknown) {
+		const auto already = lookup(id);
-		if (done) {
+		if (already.has_value() || already.error() != NoStory::Unknown) {
-			done();
+			if (done) {
+				done();
+			}
+			return;
 		}
-		return;
 	}
 	if (const auto i = _resolveSent.find(id.peer); i != end(_resolveSent)) {
 		if (const auto j = i->second.find(id.story); j != end(i->second)) {
@@ -1493,6 +1505,84 @@ bool Stories::isUnread(not_null<Story*> story) {
 	return (story->id() > readTill);
 }
 
+void Stories::registerPolling(not_null<Story*> story, Polling polling) {
+	auto &settings = _pollingSettings[story];
+	switch (polling) {
+	case Polling::Chat: ++settings.chat; break;
+	case Polling::Viewer: ++settings.viewer; break;
+	}
+	maybeSchedulePolling(story, settings, base::unixtime::now());
+}
+
+void Stories::unregisterPolling(not_null<Story*> story, Polling polling) {
+	const auto i = _pollingSettings.find(story);
+	Assert(i != end(_pollingSettings));
+
+	switch (polling) {
+	case Polling::Chat:
+		Assert(i->second.chat > 0);
+		--i->second.chat;
+		break;
+	case Polling::Viewer:
+		Assert(i->second.viewer > 0);
+		--i->second.viewer;
+		break;
+	}
+	if (!i->second.chat && !i->second.viewer) {
+		_pollingSettings.erase(i);
+	}
+}
+
+bool Stories::registerPolling(FullStoryId id, Polling polling) {
+	if (const auto maybeStory = lookup(id)) {
+		registerPolling(*maybeStory, polling);
+		return true;
+	}
+	return false;
+}
+
+void Stories::unregisterPolling(FullStoryId id, Polling polling) {
+	const auto maybeStory = lookup(id);
+	Assert(maybeStory.has_value());
+	unregisterPolling(*maybeStory, polling);
+}
+
+int Stories::pollingInterval(const PollingSettings &settings) const {
+	return settings.viewer ? kPollingIntervalViewer : kPollingIntervalChat;
+}
+
+void Stories::maybeSchedulePolling(
+		not_null<Story*> story,
+		const PollingSettings &settings,
+		TimeId now) {
+	const auto last = story->lastUpdateTime();
+	const auto next = last + pollingInterval(settings);
+	const auto left = std::max(next - now, 0) * crl::time(1000) + 1;
+	if (!_pollingTimer.isActive() || _pollingTimer.remainingTime() > left) {
+		_pollingTimer.callOnce(left);
+	}
+}
+
+void Stories::sendPollingRequests() {
+	auto min = 0;
+	const auto now = base::unixtime::now();
+	for (const auto &[story, settings] : _pollingSettings) {
+		const auto last = story->lastUpdateTime();
+		const auto next = last + pollingInterval(settings);
+		if (now >= next) {
+			resolve(story->fullId(), nullptr, true);
+		} else {
+			const auto left = (next - now) * crl::time(1000) + 1;
+			if (!min || left < min) {
+				min = left;
+			}
+		}
+	}
+	if (min > 0) {
+		_pollingTimer.callOnce(min);
+	}
+}
+
 void Stories::updateUserStoriesState(not_null<PeerData*> peer) {
 	const auto till = _readTill.find(peer->id);
 	const auto readTill = (till != end(_readTill)) ? till->second : 0;

Telegram/SourceFiles/data/data_stories.h

@@ -153,7 +153,7 @@ public:
 
 	[[nodiscard]] base::expected<not_null<Story*>, NoStory> lookup(
 		FullStoryId id) const;
-	void resolve(FullStoryId id, Fn<void()> done);
+	void resolve(FullStoryId id, Fn<void()> done, bool force = false);
 	[[nodiscard]] std::shared_ptr<HistoryItem> resolveItem(FullStoryId id);
 	[[nodiscard]] std::shared_ptr<HistoryItem> resolveItem(
 		not_null<Story*> story);
@@ -209,6 +209,16 @@ public:
 		StoryId storyMaxId);
 	[[nodiscard]] bool isUnread(not_null<Story*> story);
 
+	enum class Polling {
+		Chat,
+		Viewer,
+	};
+	void registerPolling(not_null<Story*> story, Polling polling);
+	void unregisterPolling(not_null<Story*> story, Polling polling);
+
+	bool registerPolling(FullStoryId id, Polling polling);
+	void unregisterPolling(FullStoryId id, Polling polling);
+
 private:
 	struct Saved {
 		StoriesIds ids;
@@ -217,6 +227,10 @@ private:
 		bool loaded = false;
 		mtpRequestId requestId = 0;
 	};
+	struct PollingSettings {
+		int chat = 0;
+		int viewer = 0;
+	};
 
 	void parseAndApply(const MTPUserStories &stories);
 	[[nodiscard]] Story *parseAndApply(
@@ -265,6 +279,14 @@ private:
 	void startPreloading(not_null<Story*> story);
 	void preloadFinished(FullStoryId id, bool markAsPreloaded = false);
 
+	[[nodiscard]] int pollingInterval(
+		const PollingSettings &settings) const;
+	void maybeSchedulePolling(
+		not_null<Story*> story,
+		const PollingSettings &settings,
+		TimeId now);
+	void sendPollingRequests();
+
 	const not_null<Session*> _owner;
 	std::unordered_map<
 		PeerId,
@@ -336,6 +358,9 @@ private:
 	mtpRequestId _readTillsRequestId = 0;
 	bool _readTillReceived = false;
 
+	base::flat_map<not_null<Story*>, PollingSettings> _pollingSettings;
+	base::Timer _pollingTimer;
+
 };
 
 } // namespace Data

Telegram/SourceFiles/data/data_story.cpp

@@ -371,7 +371,12 @@ void Story::applyViewsSlice(
 	}
 }
 
-bool Story::applyChanges(StoryMedia media, const MTPDstoryItem &data) {
+bool Story::applyChanges(
+		StoryMedia media,
+		const MTPDstoryItem &data,
+		TimeId now) {
+	_lastUpdateTime = now;
+
 	const auto pinned = data.is_pinned();
 	const auto edited = data.is_edited();
 	const auto isPublic = data.is_public();
@@ -424,6 +429,10 @@ bool Story::applyChanges(StoryMedia media, const MTPDstoryItem &data) {
 	return true;
 }
 
+TimeId Story::lastUpdateTime() const {
+	return _lastUpdateTime;
+}
+
 StoryPreload::StoryPreload(not_null<Story*> story, Fn<void()> done)
 : _story(story)
 , _done(std::move(done)) {

Telegram/SourceFiles/data/data_story.h

@@ -113,7 +113,11 @@ public:
 		const std::vector<StoryView> &slice,
 		int total);
 
-	bool applyChanges(StoryMedia media, const MTPDstoryItem &data);
+	bool applyChanges(
+		StoryMedia media,
+		const MTPDstoryItem &data,
+		TimeId now);
+	[[nodiscard]] TimeId lastUpdateTime() const;
 
 private:
 	const StoryId _id = 0;
@@ -125,6 +129,7 @@ private:
 	int _views = 0;
 	const TimeId _date = 0;
 	const TimeId _expires = 0;
+	TimeId _lastUpdateTime = 0;
 	bool _pinned : 1 = false;
 	bool _isPublic : 1 = false;
 	bool _closeFriends : 1 = false;

Telegram/SourceFiles/history/view/media/history_view_gif.cpp

@@ -42,6 +42,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "ui/effects/path_shift_gradient.h"
 #include "ui/effects/spoiler_mess.h"
 #include "data/data_session.h"
+#include "data/data_stories.h"
 #include "data/data_streaming.h"
 #include "data/data_document.h"
 #include "data/data_file_click_handler.h"
@@ -134,6 +135,7 @@ Gif::~Gif() {
 			_parent->checkHeavyPart();
 		}
 	}
+	togglePollingStory(false);
 }
 
 bool Gif::CanPlayInline(not_null<DocumentData*> document) {
@@ -1432,6 +1434,22 @@ void Gif::dataMediaCreated() const {
 		_dataMedia->videoThumbnailWanted(_realParent->fullId());
 	}
 	history()->owner().registerHeavyViewPart(_parent);
+	togglePollingStory(true);
+}
+
+void Gif::togglePollingStory(bool enabled) const {
+	if (!_story || _pollingStory == enabled) {
+		return;
+	}
+	const auto polling = Data::Stories::Polling::Chat;
+	const auto media = _parent->data()->media();
+	const auto id = media ? media->storyId() : FullStoryId();
+	if (!enabled) {
+		_data->owner().stories().unregisterPolling(id, polling);
+	} else if (!_data->owner().stories().registerPolling(id, polling)) {
+		return;
+	}
+	_pollingStory = enabled;
 }
 
 bool Gif::uploading() const {
@@ -1686,6 +1704,7 @@ void Gif::unloadHeavyPart() {
 	_thumbCache = QImage();
 	_videoThumbnailFrame = nullptr;
 	_caption.unloadPersistentAnimation();
+	togglePollingStory(false);
 }
 
 void Gif::refreshParentId(not_null<HistoryItem*> realParent) {
@@ -1815,6 +1834,7 @@ void Gif::setStreamed(std::unique_ptr<Streamed> value) {
 	_streamed = std::move(value);
 	if (set) {
 		history()->owner().registerHeavyViewPart(_parent);
+		togglePollingStory(true);
 	} else if (removed) {
 		_parent->checkHeavyPart();
 	}

Telegram/SourceFiles/history/view/media/history_view_gif.h

@@ -208,6 +208,8 @@ private:
 		StateRequest request,
 		QPoint position) const;
 
+	void togglePollingStory(bool enabled) const;
+
 	const not_null<DocumentData*> _data;
 	Ui::Text::String _caption;
 	std::unique_ptr<Streamed> _streamed;
@@ -222,6 +224,7 @@ private:
 	mutable bool _thumbCacheBlurred : 1 = false;
 	mutable bool _thumbIsEllipse : 1 = false;
 	mutable bool _story : 1 = false;
+	mutable bool _pollingStory : 1 = false;
 
 };
 

Telegram/SourceFiles/history/view/media/history_view_photo.cpp

@@ -28,6 +28,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "ui/painter.h"
 #include "ui/power_saving.h"
 #include "data/data_session.h"
+#include "data/data_stories.h"
 #include "data/data_streaming.h"
 #include "data/data_photo.h"
 #include "data/data_photo_media.h"
@@ -101,6 +102,7 @@ Photo::~Photo() {
 			_parent->checkHeavyPart();
 		}
 	}
+	togglePollingStory(false);
 }
 
 void Photo::create(FullMsgId contextId, PeerData *chat) {
@@ -145,6 +147,7 @@ void Photo::dataMediaCreated() const {
 		_dataMedia->wanted(PhotoSize::Small, _realParent->fullId());
 	}
 	history()->owner().registerHeavyViewPart(_parent);
+	togglePollingStory(true);
 }
 
 bool Photo::hasHeavyPart() const {
@@ -160,6 +163,23 @@ void Photo::unloadHeavyPart() {
 	}
 	_imageCache = QImage();
 	_caption.unloadPersistentAnimation();
+	togglePollingStory(false);
+}
+
+void Photo::togglePollingStory(bool enabled) const {
+	const auto pollingStory = (enabled ? 1 : 0);
+	if (!_story || _pollingStory == pollingStory) {
+		return;
+	}
+	const auto polling = Data::Stories::Polling::Chat;
+	const auto media = _parent->data()->media();
+	const auto id = media ? media->storyId() : FullStoryId();
+	if (!enabled) {
+		_data->owner().stories().unregisterPolling(id, polling);
+	} else if (!_data->owner().stories().registerPolling(id, polling)) {
+		return;
+	}
+	_pollingStory = pollingStory;
 }
 
 QSize Photo::countOptimalSize() {
@@ -926,6 +946,7 @@ void Photo::setStreamed(std::unique_ptr<Streamed> value) {
 	_streamed = std::move(value);
 	if (set) {
 		history()->owner().registerHeavyViewPart(_parent);
+		togglePollingStory(true);
 	} else if (removed) {
 		_parent->checkHeavyPart();
 	}

Telegram/SourceFiles/history/view/media/history_view_photo.h

@@ -160,6 +160,8 @@ private:
 
 	[[nodiscard]] QSize photoSize() const;
 
+	void togglePollingStory(bool enabled) const;
+
 	const not_null<PhotoData*> _data;
 	Ui::Text::String _caption;
 	mutable std::shared_ptr<Data::PhotoMedia> _dataMedia;
@@ -167,10 +169,11 @@ private:
 	const std::unique_ptr<MediaSpoiler> _spoiler;
 	mutable QImage _imageCache;
 	mutable std::optional<Ui::BubbleRounding> _imageCacheRounding;
-	uint32 _serviceWidth : 29 = 0;
+	uint32 _serviceWidth : 28 = 0;
 	mutable uint32 _imageCacheForum : 1 = 0;
 	mutable uint32 _imageCacheBlurred : 1 = 0;
 	mutable uint32 _story : 1 = 0;
+	mutable uint32 _pollingStory : 1 = 0;
 
 };
 

Telegram/SourceFiles/history/view/media/history_view_story_mention.cpp

@@ -52,7 +52,9 @@ StoryMention::StoryMention(
 , _unread(story->owner().stories().isUnread(story) ? 1 : 0) {
 }
 
-StoryMention::~StoryMention() = default;
+StoryMention::~StoryMention() {
+	changeSubscribedTo(0);
+}
 
 int StoryMention::top() {
 	return st::msgServiceGiftBoxButtonMargins.top();
@@ -105,13 +107,12 @@ void StoryMention::draw(
 				? history->session().user()
 				: history->peer);
 		_thumbnailFromStory = showStory;
-		_subscribed = 0;
+		changeSubscribedTo(0);
 	}
-	if (!_subscribed) {
+	if (changeSubscribedTo(1)) {
 		_thumbnail->subscribeToUpdates([=] {
 			_parent->data()->history()->owner().requestViewRepaint(_parent);
 		});
-		_subscribed = 1;
 	}
 
 	const auto padding = (geometry.width() - st::storyMentionSize) / 2;
@@ -164,10 +165,26 @@ bool StoryMention::hasHeavyPart() {
 }
 
 void StoryMention::unloadHeavyPart() {
-	if (_subscribed) {
+	if (changeSubscribedTo(0)) {
-		_subscribed = 0;
 		_thumbnail->subscribeToUpdates(nullptr);
 	}
 }
 
+bool StoryMention::changeSubscribedTo(uint32 value) {
+	Expects(value == 0 || value == 1);
+
+	if (_subscribed == value) {
+		return false;
+	}
+	_subscribed = value;
+	const auto stories = &_parent->history()->owner().stories();
+	if (value) {
+		_parent->history()->owner().registerHeavyViewPart(_parent);
+		stories->registerPolling(_story, Data::Stories::Polling::Chat);
+	} else {
+		stories->unregisterPolling(_story, Data::Stories::Polling::Chat);
+	}
+	return true;
+}
+
 } // namespace HistoryView

Telegram/SourceFiles/history/view/media/history_view_story_mention.h

@@ -55,6 +55,8 @@ public:
 private:
 	using Thumbnail = Dialogs::Stories::Thumbnail;
 
+	bool changeSubscribedTo(uint32 value);
+
 	const not_null<Element*> _parent;
 	const not_null<Data::Story*> _story;
 	std::shared_ptr<Thumbnail> _thumbnail;

Telegram/SourceFiles/info/stories/info_stories_provider.cpp

@@ -56,6 +56,10 @@ Provider::Provider(not_null<AbstractController*> controller)
 	}, _lifetime);
 }
 
+Provider::~Provider() {
+	clear();
+}
+
 Type Provider::type() {
 	return Type::PhotoVideo;
 }
@@ -90,11 +94,20 @@ std::optional<int> Provider::fullCount() {
 	return _slice.fullCount();
 }
 
-void Provider::restart() {
+void Provider::clear() {
+	for (const auto &[storyId, _] : _layouts) {
+		_peer->owner().stories().unregisterPolling(
+			{ _peer->id, storyId },
+			Data::Stories::Polling::Chat);
+	}
 	_layouts.clear();
 	_aroundId = kDefaultAroundId;
 	_idsLimit = kMinimalIdsLimit;
 	_slice = Data::StoriesIdsSlice();
+}
+
+void Provider::restart() {
+	clear();
 	refreshViewer();
 }
 
@@ -210,6 +223,9 @@ void Provider::markLayoutsStale() {
 void Provider::clearStaleLayouts() {
 	for (auto i = _layouts.begin(); i != _layouts.end();) {
 		if (i->second.stale) {
+			_peer->owner().stories().unregisterPolling(
+				{ _peer->id, i->first },
+				Data::Stories::Polling::Chat);
 			_layoutRemoved.fire(i->second.item.get());
 			const auto taken = _items.take(i->first);
 			i = _layouts.erase(i);
@@ -240,6 +256,9 @@ bool Provider::isAfter(
 void Provider::itemRemoved(not_null<const HistoryItem*> item) {
 	const auto id = StoryIdFromMsgId(item->id);
 	if (const auto i = _layouts.find(id); i != end(_layouts)) {
+		_peer->owner().stories().unregisterPolling(
+			{ _peer->id, id },
+			Data::Stories::Polling::Chat);
 		_layoutRemoved.fire(i->second.item.get());
 		_layouts.erase(i);
 	}
@@ -253,6 +272,9 @@ BaseLayout *Provider::getLayout(
 		if (auto layout = createLayout(id, delegate)) {
 			layout->initDimensions();
 			it = _layouts.emplace(id, std::move(layout)).first;
+			_peer->owner().stories().registerPolling(
+				{ _peer->id, id },
+				Data::Stories::Polling::Chat);
 		} else {
 			return nullptr;
 		}

Telegram/SourceFiles/info/stories/info_stories_provider.h

@@ -30,6 +30,7 @@ class Provider final
 	, public base::has_weak_ptr {
 public:
 	explicit Provider(not_null<AbstractController*> controller);
+	~Provider();
 
 	Media::Type type() override;
 	bool hasSelectRestriction() override;
@@ -99,6 +100,7 @@ private:
 	void itemRemoved(not_null<const HistoryItem*> item);
 	void markLayoutsStale();
 	void clearStaleLayouts();
+	void clear();
 
 	[[nodiscard]] HistoryItem *ensureItem(StoryId id);
 	[[nodiscard]] Media::BaseLayout *getLayout(

Telegram/SourceFiles/media/stories/media_stories_controller.cpp

@@ -302,7 +302,9 @@ Controller::Controller(not_null<Delegate*> delegate)
 	_contentFadeAnimation.stop();
 }
 
-Controller::~Controller() = default;
+Controller::~Controller() {
+	changeShown(nullptr);
+}
 
 void Controller::updateContentFaded() {
 	if (_contentFaded == _replyActive) {
@@ -480,6 +482,9 @@ void Controller::initLayout() {
 }
 
 Data::Story *Controller::story() const {
+	if (!_session) {
+		return nullptr;
+	}
 	const auto maybeStory = _session->data().stories().lookup(_shown);
 	return maybeStory ? maybeStory->get() : nullptr;
 }
@@ -748,10 +753,9 @@ void Controller::show(
 		.date = story->date(),
 		.edited = story->edited(),
 	});
-	if (_shown == storyId && _session == &story->session()) {
+	if (!changeShown(story)) {
 		return;
 	}
-	_shown = storyId;
 	_viewed = false;
 	invalidate_weak_ptrs(&_viewsLoadGuard);
 	_reactions->hide();
@@ -769,41 +773,72 @@ void Controller::show(
 		.valid = user->isSelf(),
 	});
 
-	const auto session = &story->session();
-	if (_session != session) {
-		_session = session;
-		_sessionLifetime = session->changes().storyUpdates(
-			Data::StoryUpdate::Flag::Destroyed
-		) | rpl::start_with_next([=](Data::StoryUpdate update) {
-			if (update.story->fullId() == _shown) {
-				_delegate->storiesClose();
-			}
-		});
-		session->data().stories().itemsChanged(
-		) | rpl::start_with_next([=](PeerId peerId) {
-			if (_waitingForId.peer == peerId) {
-				checkWaitingFor();
-			}
-		}, _sessionLifetime);
-		session->changes().storyUpdates(
-			Data::StoryUpdate::Flag::Edited
-		) | rpl::filter([=](const Data::StoryUpdate &update) {
-			return (update.story == this->story());
-		}) | rpl::start_with_next([=](const Data::StoryUpdate &update) {
-			show(update.story, _context);
-			_delegate->storiesRedisplay(update.story);
-		}, _sessionLifetime);
-		_sessionLifetime.add([=] {
-			session->data().stories().setPreloadingInViewer({});
-		});
-	}
-
 	stories.loadAround(storyId, context);
 
 	updatePlayingAllowed();
 	user->updateFull();
 }
 
+bool Controller::changeShown(Data::Story *story) {
+	const auto id = story ? story->fullId() : FullStoryId();
+	const auto session = story ? &story->session() : nullptr;
+	const auto sessionChanged = (_session != session);
+	if (_shown == id && !sessionChanged) {
+		return false;
+	}
+	if (const auto now = this->story()) {
+		now->owner().stories().unregisterPolling(
+			now,
+			Data::Stories::Polling::Viewer);
+	}
+	if (sessionChanged) {
+		_sessionLifetime.destroy();
+	}
+	_shown = id;
+	_session = session;
+	if (sessionChanged) {
+		subscribeToSession();
+	}
+	if (story) {
+		story->owner().stories().registerPolling(
+			story,
+			Data::Stories::Polling::Viewer);
+	}
+	return true;
+}
+
+void Controller::subscribeToSession() {
+	Expects(!_sessionLifetime);
+
+	if (!_session) {
+		return;
+	}
+	_session->changes().storyUpdates(
+		Data::StoryUpdate::Flag::Destroyed
+	) | rpl::start_with_next([=](Data::StoryUpdate update) {
+		if (update.story->fullId() == _shown) {
+			_delegate->storiesClose();
+		}
+	}, _sessionLifetime);
+	_session->data().stories().itemsChanged(
+	) | rpl::start_with_next([=](PeerId peerId) {
+		if (_waitingForId.peer == peerId) {
+			checkWaitingFor();
+		}
+	}, _sessionLifetime);
+	_session->changes().storyUpdates(
+		Data::StoryUpdate::Flag::Edited
+	) | rpl::filter([=](const Data::StoryUpdate &update) {
+		return (update.story == this->story());
+	}) | rpl::start_with_next([=](const Data::StoryUpdate &update) {
+		show(update.story, _context);
+		_delegate->storiesRedisplay(update.story);
+	}, _sessionLifetime);
+	_sessionLifetime.add([=] {
+		_session->data().stories().setPreloadingInViewer({});
+	});
+}
+
 void Controller::updatePlayingAllowed() {
 	if (!_shown) {
 		return;

Telegram/SourceFiles/media/stories/media_stories_controller.h

@@ -164,6 +164,8 @@ private:
 	class Unsupported;
 
 	void initLayout();
+	bool changeShown(Data::Story *story);
+	void subscribeToSession();
 	void updatePhotoPlayback(const Player::TrackState &state);
 	void updatePlayback(const Player::TrackState &state);
 	void updatePowerSaveBlocker(const Player::TrackState &state);