Add SharedMediaSliceWithLast for chat photos.

Telegram/SourceFiles/history/history_shared_media.cpp

@@ -24,6 +24,7 @@ Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
 #include "apiwrap.h"
 #include "storage/storage_facade.h"
 #include "storage/storage_shared_media.h"
+#include "history/history_media_types.h"
 
 namespace {
 
@@ -78,6 +79,45 @@ void SharedMediaShowOverview(
 	}
 }
 
+SharedMediaSlice::SharedMediaSlice(Key key) : SharedMediaSlice(key, base::none) {
+}
+
+SharedMediaSlice::SharedMediaSlice(
+	Key key,
+	base::optional<int> fullCount)
+	: _key(key)
+	, _fullCount(fullCount) {
+}
+
+base::optional<int> SharedMediaSlice::indexOf(MsgId msgId) const {
+	auto it = _ids.find(msgId);
+	if (it != _ids.end()) {
+		return (it - _ids.begin());
+	}
+	return base::none;
+}
+
+MsgId SharedMediaSlice::operator[](int index) const {
+	Expects(index >= 0 && index < size());
+
+	return *(_ids.begin() + index);
+}
+
+base::optional<int> SharedMediaSlice::distance(const Key &a, const Key &b) const {
+	if (a.type != _key.type
+		|| b.type != _key.type
+		|| a.peerId != _key.peerId
+		|| b.peerId != _key.peerId) {
+		return base::none;
+	}
+	if (auto i = indexOf(a.messageId)) {
+		if (auto j = indexOf(b.messageId)) {
+			return *j - *i;
+		}
+	}
+	return base::none;
+}
+
 QString SharedMediaSlice::debug() const {
 	auto before = _skippedBefore
 		? (*_skippedBefore
@@ -97,7 +137,6 @@ QString SharedMediaSlice::debug() const {
 	return before + middle + after;
 }
 
-
 SharedMediaViewer::SharedMediaViewer(
 	Key key,
 	int limitBefore,
@@ -312,6 +351,93 @@ void SharedMediaViewer::requestMessages(RequestDirection direction) {
 		requestAroundData.second);
 }
 
+SharedMediaSliceMerged::SharedMediaSliceMerged(Key key) : SharedMediaSliceMerged(
+	key,
+	SharedMediaSlice(PartKey(key)),
+	MigratedSlice(key)) {
+}
+
+SharedMediaSliceMerged::SharedMediaSliceMerged(
+	Key key,
+	SharedMediaSlice part,
+	base::optional<SharedMediaSlice> migrated)
+	: _key(key)
+	, _part(std::move(part))
+	, _migrated(std::move(migrated)) {
+}
+
+base::optional<int> SharedMediaSliceMerged::fullCount() const {
+	return Add(
+		_part.fullCount(),
+		_migrated ? _migrated->fullCount() : 0);
+}
+
+base::optional<int> SharedMediaSliceMerged::skippedBefore() const {
+	return Add(
+		isolatedInMigrated() ? 0 : _part.skippedBefore(),
+		_migrated
+			? (isolatedInPart()
+				? _migrated->fullCount()
+				: _migrated->skippedBefore())
+			: 0
+	);
+}
+
+base::optional<int> SharedMediaSliceMerged::skippedAfter() const {
+	return Add(
+		isolatedInMigrated() ? _part.fullCount() : _part.skippedAfter(),
+		isolatedInPart() ? 0 : _migrated->skippedAfter()
+	);
+}
+
+base::optional<int> SharedMediaSliceMerged::indexOf(FullMsgId fullId) const {
+	return isFromPart(fullId)
+		? (_part.indexOf(fullId.msg) | func::add(migratedSize()))
+		: isolatedInPart()
+			? base::none
+			: isFromMigrated(fullId)
+				? _migrated->indexOf(fullId.msg)
+				: base::none;
+}
+
+int SharedMediaSliceMerged::size() const {
+	return (isolatedInPart() ? 0 : migratedSize())
+		+ (isolatedInMigrated() ? 0 : _part.size());
+}
+
+FullMsgId SharedMediaSliceMerged::operator[](int index) const {
+	Expects(index >= 0 && index < size());
+
+	if (auto size = migratedSize()) {
+		if (index < size) {
+			return ComputeId(*_migrated, index);
+		}
+		index -= size;
+	}
+	return ComputeId(_part, index);
+}
+
+base::optional<int> SharedMediaSliceMerged::distance(const Key &a, const Key &b) const {
+	if (a.type != _key.type
+		|| b.type != _key.type
+		|| a.peerId != _key.peerId
+		|| b.peerId != _key.peerId
+		|| a.migratedPeerId != _key.migratedPeerId
+		|| b.migratedPeerId != _key.migratedPeerId) {
+		return base::none;
+	}
+	if (auto i = indexOf(ComputeId(a))) {
+		if (auto j = indexOf(ComputeId(b))) {
+			return *j - *i;
+		}
+	}
+	return base::none;
+}
+
+QString SharedMediaSliceMerged::debug() const {
+	return (_migrated ? (_migrated->debug() + '|') : QString()) + _part.debug();
+}
+
 SharedMediaViewerMerged::SharedMediaViewerMerged(
 	Key key,
 	int limitBefore,
@@ -319,59 +445,35 @@ SharedMediaViewerMerged::SharedMediaViewerMerged(
 	: _key(key)
 	, _limitBefore(limitBefore)
 	, _limitAfter(limitAfter)
-	, _part(PartKey(_key), _limitBefore, _limitAfter)
+	, _part(SharedMediaSliceMerged::PartKey(_key), _limitBefore, _limitAfter)
 	, _migrated(MigratedViewer(_key, _limitBefore, _limitAfter))
-	, _data(_key, SharedMediaSlice(PartKey(_key)), MigratedSlice(_key)) {
+	, _data(_key) {
 	Expects(IsServerMsgId(key.universalId)
 		|| (key.universalId == 0)
 		|| (IsServerMsgId(-key.universalId) && key.migratedPeerId != 0));
 	Expects((key.universalId != 0) || (limitBefore == 0 && limitAfter == 0));
 }
 
-SharedMediaSlice::Key SharedMediaViewerMerged::PartKey(const Key &key) {
-	return {
-		key.peerId,
-		key.type,
-		(key.universalId < 0) ? 1 : key.universalId
-	};
-}
-
-SharedMediaSlice::Key SharedMediaViewerMerged::MigratedKey(const Key &key) {
-	return {
-		key.migratedPeerId,
-		key.type,
-		(key.universalId <= 0) ? (-key.universalId) : (ServerMaxMsgId - 1)
-	};
-}
-
 std::unique_ptr<SharedMediaViewer> SharedMediaViewerMerged::MigratedViewer(
 		const Key &key,
 		int limitBefore,
 		int limitAfter) {
 	return key.migratedPeerId
 		? std::make_unique<SharedMediaViewer>(
-			MigratedKey(key),
+			SharedMediaSliceMerged::MigratedKey(key),
 			limitBefore,
 			limitAfter)
 		: nullptr;
 }
 
-base::optional<SharedMediaSlice> SharedMediaViewerMerged::MigratedSlice(
-		const Key &key) {
-	if (!key.migratedPeerId) {
-		return base::none;
-	}
-	return SharedMediaSlice(MigratedKey(key));
-}
-
 void SharedMediaViewerMerged::start() {
 	subscribe(_part.updated, [this](const SharedMediaSlice &update) {
-		_data = SharedMediaSliceMerged(_key, update, _data._migrated);
+		_data = SharedMediaSliceMerged(_key, update, std::move(_data._migrated));
 		updated.notify(_data);
 	});
 	if (_migrated) {
 		subscribe(_migrated->updated, [this](const SharedMediaSlice &update) {
-			_data = SharedMediaSliceMerged(_key, _data._part, update);
+			_data = SharedMediaSliceMerged(_key, std::move(_data._part), update);
 			updated.notify(_data);
 		});
 	}
@@ -380,3 +482,164 @@ void SharedMediaViewerMerged::start() {
 		_migrated->start();
 	}
 }
+
+SharedMediaSliceWithLast::SharedMediaSliceWithLast(Key key) : SharedMediaSliceWithLast(
+	key,
+	SharedMediaSliceMerged(ViewerKey(key)),
+	EndingSlice(key)) {
+}
+
+SharedMediaSliceWithLast::SharedMediaSliceWithLast(
+	Key key,
+	SharedMediaSliceMerged slice,
+	base::optional<SharedMediaSliceMerged> ending)
+	: _key(key)
+	, _slice(std::move(slice))
+	, _ending(std::move(ending))
+	, _lastPhotoId(LastPeerPhotoId(key.peerId))
+	, _isolatedLastPhoto(_key.type == Type::ChatPhoto
+		? IsLastIsolated(_slice, _ending, _lastPhotoId)
+		: false) {
+}
+
+base::optional<int> SharedMediaSliceWithLast::fullCount() const {
+	return Add(
+		_slice.fullCount(),
+		_isolatedLastPhoto | [](bool isolated) { return isolated ? 1 : 0; });
+}
+
+base::optional<int> SharedMediaSliceWithLast::skippedBefore() const {
+	return _slice.skippedBefore();
+}
+
+base::optional<int> SharedMediaSliceWithLast::skippedAfter() const {
+	return isolatedInSlice()
+		? Add(
+			_slice.skippedAfter(),
+			lastPhotoSkip())
+		: (lastPhotoSkip() | [](int) { return 0; });
+}
+
+base::optional<int> SharedMediaSliceWithLast::indexOf(Value value) const {
+	return base::get_if<FullMsgId>(&value)
+		? _slice.indexOf(*base::get_if<FullMsgId>(&value))
+		: (isolatedInSlice()
+			|| (*base::get_if<not_null<PhotoData*>>(&value))->id != _lastPhotoId)
+			? base::none
+			: Add(_slice.size() - 1, lastPhotoSkip());
+}
+
+int SharedMediaSliceWithLast::size() const {
+	return _slice.size()
+		+ ((!isolatedInSlice() && lastPhotoSkip() == 1) ? 1 : 0);
+}
+
+SharedMediaSliceWithLast::Value SharedMediaSliceWithLast::operator[](int index) const {
+	Expects(index >= 0 && index < size());
+
+	return (index < _slice.size())
+		? Value(_slice[index])
+		: Value(App::photo(_lastPhotoId));
+}
+
+base::optional<int> SharedMediaSliceWithLast::distance(const Key &a, const Key &b) const {
+	if (a.type != _key.type
+		|| b.type != _key.type
+		|| a.peerId != _key.peerId
+		|| b.peerId != _key.peerId
+		|| a.migratedPeerId != _key.migratedPeerId
+		|| b.migratedPeerId != _key.migratedPeerId) {
+		return base::none;
+	}
+	if (auto i = indexOf(ComputeId(a))) {
+		if (auto j = indexOf(ComputeId(b))) {
+			return *j - *i;
+		}
+	}
+	return base::none;
+}
+
+QString SharedMediaSliceWithLast::debug() const {
+	return _slice.debug() + (_isolatedLastPhoto
+		? (*_isolatedLastPhoto ? "@" : "")
+		: "?");
+}
+
+PhotoId SharedMediaSliceWithLast::LastPeerPhotoId(PeerId peerId) {
+	if (auto peer = App::peerLoaded(peerId)) {
+		return peer->photoId;
+	}
+	return UnknownPeerPhotoId;
+}
+
+base::optional<bool> SharedMediaSliceWithLast::IsLastIsolated(
+		const SharedMediaSliceMerged &slice,
+		const base::optional<SharedMediaSliceMerged> &ending,
+		PhotoId lastPeerPhotoId) {
+	if (lastPeerPhotoId == UnknownPeerPhotoId) {
+		return base::none;
+	} else if (!lastPeerPhotoId) {
+		return false;
+	}
+	return LastFullMsgId(ending ? *ending : slice)
+		| [](FullMsgId msgId) {	return App::histItemById(msgId); }
+		| [](HistoryItem *item) { return item ? item->getMedia() : nullptr; }
+		| [](HistoryMedia *media) {
+			return (media && media->type() == MediaTypePhoto)
+				? static_cast<HistoryPhoto*>(media)->photo()
+				: nullptr;
+		}
+		| [](PhotoData *photo) { return photo ? photo->id : 0; }
+		| [&](PhotoId photoId) { return lastPeerPhotoId != photoId; };
+}
+
+base::optional<FullMsgId> SharedMediaSliceWithLast::LastFullMsgId(
+		const SharedMediaSliceMerged &slice) {
+	if (slice.fullCount() == 0) {
+		return FullMsgId();
+	} else if (slice.size() == 0 || slice.skippedAfter() != 0) {
+		return base::none;
+	}
+	return slice[slice.size() - 1];
+}
+
+SharedMediaViewerWithLast::SharedMediaViewerWithLast(
+	Key key,
+	int limitBefore,
+	int limitAfter)
+	: _key(key)
+	, _limitBefore(limitBefore)
+	, _limitAfter(limitAfter)
+	, _viewer(SharedMediaSliceWithLast::ViewerKey(_key), _limitBefore, _limitAfter)
+	, _ending(EndingViewer(_key, _limitBefore, _limitAfter))
+	, _data(_key) {
+}
+
+std::unique_ptr<SharedMediaViewerMerged> SharedMediaViewerWithLast::EndingViewer(
+		const Key &key,
+		int limitBefore,
+		int limitAfter) {
+	return base::get_if<SharedMediaSliceWithLast::MessageId>(&key.universalId)
+		? std::make_unique<SharedMediaViewerMerged>(
+			SharedMediaSliceWithLast::EndingKey(key),
+			1,
+			1)
+		: nullptr;
+}
+
+void SharedMediaViewerWithLast::start() {
+	subscribe(_viewer.updated, [this](const SharedMediaSliceMerged &update) {
+		_data = SharedMediaSliceWithLast(_key, update, std::move(_data._ending));
+		updated.notify(_data);
+	});
+	if (_ending) {
+		subscribe(_ending->updated, [this](const SharedMediaSliceMerged &update) {
+			_data = SharedMediaSliceWithLast(_key, std::move(_data._slice), update);
+			updated.notify(_data);
+		});
+	}
+	_viewer.start();
+	if (_ending) {
+		_ending->start();
+	}
+}

Telegram/SourceFiles/history/history_shared_media.h

@@ -35,57 +35,18 @@ class SharedMediaSlice {
 public:
 	using Key = Storage::SharedMediaKey;
 
-	SharedMediaSlice(
+	SharedMediaSlice(Key key);
-		Key key,
+	SharedMediaSlice(Key key, base::optional<int> fullCount);
-		base::optional<int> fullCount = base::none)
-		: _key(key)
-		, _fullCount(fullCount) {
-	}
 
-	const Key &key() const {
+	const Key &key() const { return _key; }
-		return _key;
-	}
 
-	base::optional<int> fullCount() const {
+	base::optional<int> fullCount() const { return _fullCount; }
-		return _fullCount;
+	base::optional<int> skippedBefore() const { return _skippedBefore; }
-	}
+	base::optional<int> skippedAfter() const { return _skippedAfter; }
-	base::optional<int> skippedBefore() const {
+	base::optional<int> indexOf(MsgId msgId) const;
-		return _skippedBefore;
+	int size() const { return _ids.size(); }
-	}
+	MsgId operator[](int index) const;
-	base::optional<int> skippedAfter() const {
+	base::optional<int> distance(const Key &a, const Key &b) const;
-		return _skippedAfter;
-	}
-	base::optional<int> indexOf(MsgId msgId) const {
-		auto it = _ids.find(msgId);
-		if (it != _ids.end()) {
-			return (it - _ids.begin());
-		}
-		return base::none;
-	}
-	int size() const {
-		return _ids.size();
-	}
-
-	MsgId operator[](int index) const {
-		Expects(index >= 0 && index < size());
-
-		return *(_ids.begin() + index);
-	}
-
-	base::optional<int> distance(const Key &a, const Key &b) const {
-		if (a.type != _key.type
-			|| b.type != _key.type
-			|| a.peerId != _key.peerId
-			|| b.peerId != _key.peerId) {
-			return base::none;
-		}
-		if (auto i = indexOf(a.messageId)) {
-			if (auto j = indexOf(b.messageId)) {
-				return *j - *i;
-			}
-		}
-		return base::none;
-	}
 
 	QString debug() const;
 
@@ -108,12 +69,7 @@ public:
 	using Type = Storage::SharedMediaType;
 	using Key = Storage::SharedMediaKey;
 
-	SharedMediaViewer(
+	SharedMediaViewer(Key key, int limitBefore, int limitAfter);
-		Key key,
-		int limitBefore,
-		int limitAfter);
-	SharedMediaViewer(const SharedMediaViewer &other) = delete;
-	SharedMediaViewer(SharedMediaViewer &&other) = default;
 
 	void start();
 
@@ -182,84 +138,46 @@ public:
 		UniversalMsgId universalId = 0;
 
 	};
+
+	SharedMediaSliceMerged(Key key);
 	SharedMediaSliceMerged(
 		Key key,
 		SharedMediaSlice part,
-		base::optional<SharedMediaSlice> migrated)
+		base::optional<SharedMediaSlice> migrated);
-		: _key(key)
-		, _part(part)
-		, _migrated(migrated) {
-	}
 
-	base::optional<int> fullCount() const {
+	const Key &key() const { return _key; }
-		return Add(
-			_part.fullCount(),
-			_migrated ? _migrated->fullCount() : 0);
-	}
-	base::optional<int> skippedBefore() const {
-		return Add(
-			isolatedInMigrated() ? 0 : _part.skippedBefore(),
-			_migrated
-				? (isolatedInPart()
-					? _migrated->fullCount()
-					: _migrated->skippedBefore())
-				: 0
-		);
-	}
-	base::optional<int> skippedAfter() const {
-		return Add(
-			isolatedInMigrated() ? _part.fullCount() : _part.skippedAfter(),
-			isolatedInPart() ? 0 : _migrated->skippedAfter()
-		);
-	}
-	base::optional<int> indexOf(FullMsgId fullId) const {
-		return isFromPart(fullId)
-			? (_part.indexOf(fullId.msg) | func::add(migratedSize()))
-			: isolatedInPart()
-				? base::none
-				: isFromMigrated(fullId)
-					? _migrated->indexOf(fullId.msg)
-					: base::none;
-	}
-	int size() const {
-		return (isolatedInPart() ? 0 : migratedSize())
-			+ (isolatedInMigrated() ? 0 : _part.size());
-	}
 
-	FullMsgId operator[](int index) const {
+	base::optional<int> fullCount() const;
-		Expects(index >= 0 && index < size());
+	base::optional<int> skippedBefore() const;
+	base::optional<int> skippedAfter() const;
+	base::optional<int> indexOf(FullMsgId fullId) const;
+	int size() const;
+	FullMsgId operator[](int index) const;
+	base::optional<int> distance(const Key &a, const Key &b) const;
 
-		if (auto size = migratedSize()) {
+	QString debug() const;
-			if (index < size) {
-				return ComputeId(*_migrated, index);
-			}
-			index -= size;
-		}
-		return ComputeId(_part, index);
-	}
-
-	base::optional<int> distance(const Key &a, const Key &b) const {
-		if (a.type != _key.type
-			|| b.type != _key.type
-			|| a.peerId != _key.peerId
-			|| b.peerId != _key.peerId
-			|| a.migratedPeerId != _key.migratedPeerId
-			|| b.migratedPeerId != _key.migratedPeerId) {
-			return base::none;
-		}
-		if (auto i = indexOf(ComputeId(a))) {
-			if (auto j = indexOf(ComputeId(b))) {
-				return *j - *i;
-			}
-		}
-		return base::none;
-	}
-
-	QString debug() const {
-		return (_migrated ? (_migrated->debug() + '|') : QString()) + _part.debug();
-	}
 
 private:
+	static SharedMediaSlice::Key PartKey(const Key &key) {
+		return {
+			key.peerId,
+			key.type,
+			(key.universalId < 0) ? 1 : key.universalId
+		};
+	}
+	static SharedMediaSlice::Key MigratedKey(const Key &key) {
+		return {
+			key.migratedPeerId,
+			key.type,
+			(key.universalId <= 0) ? (-key.universalId) : (ServerMaxMsgId - 1)
+		};
+	}
+	static base::optional<SharedMediaSlice> MigratedSlice(const Key &key) {
+		return key.migratedPeerId
+			? base::make_optional(SharedMediaSlice(MigratedKey(key)))
+			: base::none;
+	}
+
 	static bool IsFromSlice(const SharedMediaSlice &slice, FullMsgId fullId) {
 		auto peer = slice.key().peerId;
 		return peerIsChannel(peer)
@@ -320,21 +238,16 @@ public:
 		Key key,
 		int limitBefore,
 		int limitAfter);
-	SharedMediaViewerMerged(const SharedMediaViewerMerged &other) = delete;
-	SharedMediaViewerMerged(SharedMediaViewerMerged &&other) = default;
 
 	void start();
 
 	base::Observable<SharedMediaSliceMerged> updated;
 
 private:
-	static SharedMediaSlice::Key PartKey(const Key &key);
-	static SharedMediaSlice::Key MigratedKey(const Key &key);
 	static std::unique_ptr<SharedMediaViewer> MigratedViewer(
 		const Key &key,
 		int limitBefore,
 		int limitAfter);
-	static base::optional<SharedMediaSlice> MigratedSlice(const Key &key);
 
 	Key _key;
 	int _limitBefore = 0;
@@ -344,3 +257,157 @@ private:
 	SharedMediaSliceMerged _data;
 
 };
+
+class SharedMediaViewerWithLast;
+class SharedMediaSliceWithLast {
+public:
+	using Type = Storage::SharedMediaType;
+
+	// base::none in those mean CurrentPeerPhoto.
+	using Value = base::variant<FullMsgId, not_null<PhotoData*>>;
+	using MessageId = SharedMediaSliceMerged::UniversalMsgId;
+	using UniversalMsgId = base::variant<
+		MessageId,
+		not_null<PhotoData*>>;
+
+	struct Key {
+		Key(
+			PeerId peerId,
+			PeerId migratedPeerId,
+			Type type,
+			UniversalMsgId universalId)
+			: peerId(peerId)
+			, migratedPeerId(migratedPeerId)
+			, type(type)
+			, universalId(universalId) {
+			Expects(base::get_if<MessageId>(&universalId) != nullptr
+				|| type == Type::ChatPhoto);
+		}
+
+		bool operator==(const Key &other) const {
+			return (peerId == other.peerId)
+				&& (migratedPeerId == other.migratedPeerId)
+				&& (type == other.type)
+				&& (universalId == other.universalId);
+		}
+
+		PeerId peerId = 0;
+		PeerId migratedPeerId = 0;
+		Type type = Type::kCount;
+		UniversalMsgId universalId;
+
+	};
+
+	SharedMediaSliceWithLast(Key key);
+	SharedMediaSliceWithLast(
+		Key key,
+		SharedMediaSliceMerged slice,
+		base::optional<SharedMediaSliceMerged> ending);
+
+	base::optional<int> fullCount() const;
+	base::optional<int> skippedBefore() const;
+	base::optional<int> skippedAfter() const;
+	base::optional<int> indexOf(Value fullId) const;
+	int size() const;
+	Value operator[](int index) const;
+	base::optional<int> distance(const Key &a, const Key &b) const;
+
+	QString debug() const;
+
+private:
+	static SharedMediaSliceMerged::Key ViewerKey(const Key &key) {
+		return {
+			key.peerId,
+			key.migratedPeerId,
+			key.type,
+			base::get_if<MessageId>(&key.universalId)
+				? (*base::get_if<MessageId>(&key.universalId))
+				: ServerMaxMsgId - 1
+		};
+	}
+	static SharedMediaSliceMerged::Key EndingKey(const Key &key) {
+		return {
+			key.peerId,
+			key.migratedPeerId,
+			key.type,
+			ServerMaxMsgId - 1
+		};
+	}
+	static base::optional<SharedMediaSliceMerged> EndingSlice(const Key &key) {
+		return base::get_if<MessageId>(&key.universalId)
+			? base::make_optional(SharedMediaSliceMerged(EndingKey(key)))
+			: base::none;
+	}
+
+	static PhotoId LastPeerPhotoId(PeerId peerId);
+	static base::optional<bool> IsLastIsolated(
+		const SharedMediaSliceMerged &slice,
+		const base::optional<SharedMediaSliceMerged> &ending,
+		PhotoId lastPeerPhotoId);
+	static base::optional<FullMsgId> LastFullMsgId(
+		const SharedMediaSliceMerged &slice);
+	static base::optional<int> Add(
+			const base::optional<int> &a,
+			const base::optional<int> &b) {
+		return (a && b) ? base::make_optional(*a + *b) : base::none;
+	}
+	static Value ComputeId(PeerId peerId, MsgId msgId) {
+		return FullMsgId(
+			peerIsChannel(peerId) ? peerToBareInt(peerId) : 0,
+			msgId);
+	}
+	static Value ComputeId(const Key &key) {
+		if (auto messageId = base::get_if<MessageId>(&key.universalId)) {
+			return (*messageId > 0)
+				? ComputeId(key.peerId, *messageId)
+				: ComputeId(key.migratedPeerId, -*messageId);
+		}
+		return *base::get_if<not_null<PhotoData*>>(&key.universalId);
+	}
+
+	bool isolatedInSlice() const {
+		return (_slice.skippedAfter() != 0);
+	}
+	base::optional<int> lastPhotoSkip() const {
+		return _isolatedLastPhoto
+			| [](bool isolated) { return isolated ? 1 : 0; };
+	}
+
+	Key _key;
+	SharedMediaSliceMerged _slice;
+	base::optional<SharedMediaSliceMerged> _ending;
+	PhotoId _lastPhotoId = 0;
+	base::optional<bool> _isolatedLastPhoto;
+
+	friend class SharedMediaViewerWithLast;
+
+};
+
+class SharedMediaViewerWithLast : private base::Subscriber {
+public:
+	using Type = SharedMediaSliceWithLast::Type;
+	using Key = SharedMediaSliceWithLast::Key;
+
+	SharedMediaViewerWithLast(
+		Key key,
+		int limitBefore,
+		int limitAfter);
+
+	void start();
+
+	base::Observable<SharedMediaSliceWithLast> updated;
+
+private:
+	static std::unique_ptr<SharedMediaViewerMerged> EndingViewer(
+		const Key &key,
+		int limitBefore,
+		int limitAfter);
+
+	Key _key;
+	int _limitBefore = 0;
+	int _limitAfter = 0;
+	SharedMediaViewerMerged _viewer;
+	std::unique_ptr<SharedMediaViewerMerged> _ending;
+	SharedMediaSliceWithLast _data;
+
+};

Telegram/SourceFiles/mediaview.cpp

@@ -68,13 +68,13 @@ constexpr auto kIdsPreloadAfter = 28;
 } // namespace
 
 struct MediaView::SharedMedia {
-	SharedMedia(SharedMediaViewerMerged::Key key)
+	SharedMedia(SharedMediaViewerWithLast::Key key)
 		: key(key)
 		, slice(key, kIdsLimit, kIdsLimit) {
 	}
 
-	SharedMediaViewerMerged::Key key;
+	SharedMediaViewerWithLast::Key key;
-	SharedMediaViewerMerged slice;
+	SharedMediaViewerWithLast slice;
 };
 
 MediaView::MediaView() : TWidget(nullptr)
@@ -192,21 +192,11 @@ void MediaView::moveToScreen() {
 	_saveMsg.moveTo((width() - _saveMsg.width()) / 2, (height() - _saveMsg.height()) / 2);
 }
 
-void MediaView::handleSharedMediaUpdate(const SharedMediaSliceMerged &update) {
+void MediaView::handleSharedMediaUpdate(const SharedMediaSliceWithLast &update) {
 	if (isHidden() || (!_photo && !_doc) || !_sharedMedia) {
 		_index = _fullIndex = _fullCount = base::none;
 		return;
 	}
-	//if (_photo && _overview == OverviewChatPhotos && _history && !_history->peer->isUser()) { // TODO chat
-	//	auto lastChatPhoto = computeLastOverviewChatPhoto();
-	//	if (_index < 0 && _photo == lastChatPhoto.photo && _photo == _additionalChatPhoto) {
-	//		auto firstOpened = _firstOpenedPeerPhoto;
-	//		showPhoto(_photo, lastChatPhoto.item);
-	//		_firstOpenedPeerPhoto = firstOpened;
-	//		return;
-	//	}
-	//	computeAdditionalChatPhoto(_history->peer, lastChatPhoto.photo);
-	//}
 
 	_sharedMediaData = update;
 
@@ -628,10 +618,9 @@ void MediaView::clearData() {
 	stopGif();
 	delete _menu;
 	_menu = nullptr;
-	_history = _migrated = nullptr;
+	setContext(base::none);
-	_peer = _from = nullptr;
+	_from = nullptr;
-	_user = nullptr;
+	_photo = nullptr;
-	_photo = _additionalChatPhoto = nullptr;
 	_doc = nullptr;
 	_fullScreenVideo = false;
 	_caption.clear();
@@ -962,8 +951,7 @@ void MediaView::onDelete() {
 	auto deletingPeerPhoto = [this]() {
 		if (!_msgid) return true;
 		if (_photo && _history) {
-			auto lastPhoto = computeLastOverviewChatPhoto();
+			if (_history->peer->photoId == _photo->id) {
-			if (lastPhoto.photo == _photo && _history->peer->photoId == _photo->id) {
 				return _firstOpenedPeerPhoto;
 			}
 		}
@@ -1025,6 +1013,14 @@ base::optional<MediaView::SharedMediaType> MediaView::sharedMediaType() const {
 }
 
 base::optional<MediaView::SharedMediaKey> MediaView::sharedMediaKey() const {
+	if (!_msgid && _peer && !_user && _photo && _peer->photoId == _photo->id) {
+		return SharedMediaKey {
+			_history->peer->id,
+			_migrated ? _migrated->peer->id : 0,
+			SharedMediaType::ChatPhoto,
+			_peer->photoId
+		};
+	}
 	if (!IsServerMsgId(_msgid.msg)) {
 		return base::none;
 	}
@@ -1046,7 +1042,7 @@ bool MediaView::validSharedMedia() const {
 			return false;
 		}
 		auto countDistanceInData = [](const auto &a, const auto &b) {
-			return [&](const SharedMediaSliceMerged &data) {
+			return [&](const SharedMediaSliceWithLast &data) {
 				return data.distance(a, b);
 			};
 		};
@@ -1065,7 +1061,7 @@ bool MediaView::validSharedMedia() const {
 void MediaView::validateSharedMedia() {
 	if (auto key = sharedMediaKey()) {
 		_sharedMedia = std::make_unique<SharedMedia>(*key);
-		subscribe(_sharedMedia->slice.updated, [this](const SharedMediaSliceMerged &data) {
+		subscribe(_sharedMedia->slice.updated, [this](const SharedMediaSliceWithLast &data) {
 			handleSharedMediaUpdate(data);
 		});
 		_sharedMedia->slice.start();
@@ -1085,20 +1081,9 @@ void MediaView::refreshSharedMedia() {
 }
 
 void MediaView::showPhoto(not_null<PhotoData*> photo, HistoryItem *context) {
-	_history = context ? context->history().get() : nullptr;
+	setContext(context);
-	_migrated = nullptr;
+
-	if (_history) {
-		if (_history->peer->migrateFrom()) {
-			_migrated = App::history(_history->peer->migrateFrom()->id);
-		} else if (_history->peer->migrateTo()) {
-			_migrated = _history;
-			_history = App::history(_history->peer->migrateTo()->id);
-		}
-	}
-	_additionalChatPhoto = nullptr;
 	_firstOpenedPeerPhoto = false;
-	_peer = 0;
-	_user = 0;
 	_saveMsgStarted = 0;
 	_loadRequest = 0;
 	_over = OverNone;
@@ -1111,31 +1096,19 @@ void MediaView::showPhoto(not_null<PhotoData*> photo, HistoryItem *context) {
 	}
 	if (!_animOpacities.isEmpty()) _animOpacities.clear();
 
-	_msgid = context ? context->fullId() : FullMsgId();
-	_canForward = context ? context->canForward() : false;
-	_canDelete = context ? context->canDelete() : false;
 	_photo = photo;
 
 	refreshSharedMedia();
-	if (_history) {
-		if (context && !context->toHistoryMessage()) {
-			if (!_history->peer->isUser()) {
-				computeAdditionalChatPhoto(_history->peer, computeLastOverviewChatPhoto().photo);
-			}
-		}
-	}
 
 	displayPhoto(photo, context);
 	preloadData(0);
 	activateControls();
 }
 
-void MediaView::showPhoto(not_null<PhotoData*> photo, PeerData *context) {
+void MediaView::showPhoto(not_null<PhotoData*> photo, not_null<PeerData*> context) {
-	_history = _migrated = nullptr;
+	setContext(context);
-	_additionalChatPhoto = nullptr;
+
 	_firstOpenedPeerPhoto = true;
-	_peer = context;
-	_user = context->asUser();
 	_saveMsgStarted = 0;
 	_loadRequest = 0;
 	_over = OverNone;
@@ -1146,8 +1119,6 @@ void MediaView::showPhoto(not_null<PhotoData*> photo, PeerData *context) {
 	}
 	if (!_animOpacities.isEmpty()) _animOpacities.clear();
 
-	_msgid = {};
-	_canForward = _canDelete = false;
 	_photo = photo;
 
 	refreshSharedMedia();
@@ -1165,29 +1136,6 @@ void MediaView::showPhoto(not_null<PhotoData*> photo, PeerData *context) {
 		//if (_user->photosCount < 0) {
 		//	loadBack();
 		//} // TODO user
-	} else if ((_history = App::historyLoaded(_peer))) {
-		if (_history->peer->migrateFrom()) {
-			_migrated = App::history(_history->peer->migrateFrom()->id);
-		} else if (_history->peer->migrateTo()) {
-			_migrated = _history;
-			_history = App::history(_history->peer->migrateTo()->id);
-		}
-
-		auto lastChatPhoto = computeLastOverviewChatPhoto();
-		if (_photo == lastChatPhoto.photo) {
-			showPhoto(_photo, lastChatPhoto.item);
-			_firstOpenedPeerPhoto = true;
-			return;
-		}
-
-		computeAdditionalChatPhoto(_history->peer, lastChatPhoto.photo);
-		//if (_additionalChatPhoto == _photo) { // TODO chat
-		//	_overview = OverviewChatPhotos;
-		//	findCurrent();
-		//} else {
-			_additionalChatPhoto = nullptr;
-			_history = _migrated = nullptr;
-		//}
 	}
 	displayPhoto(photo, 0);
 	preloadData(0);
@@ -1195,21 +1143,14 @@ void MediaView::showPhoto(not_null<PhotoData*> photo, PeerData *context) {
 }
 
 void MediaView::showDocument(not_null<DocumentData*> document, HistoryItem *context) {
-	_photo = 0;
+	if (context) {
-	_history = context ? context->history().get() : nullptr;
+		setContext(context);
-	_migrated = nullptr;
+	} else {
-	if (_history) {
+		setContext(base::none);
-		if (_history->peer->migrateFrom()) {
-			_migrated = App::history(_history->peer->migrateFrom()->id);
-		} else if (_history->peer->migrateTo()) {
-			_migrated = _history;
-			_history = App::history(_history->peer->migrateTo()->id);
-		}
 	}
-	_additionalChatPhoto = nullptr;
+
+	_photo = nullptr;
 	_saveMsgStarted = 0;
-	_peer = 0;
-	_user = 0;
 	_loadRequest = 0;
 	_down = OverNone;
 	_pressed = false;
@@ -1221,10 +1162,6 @@ void MediaView::showDocument(not_null<DocumentData*> document, HistoryItem *cont
 	}
 	if (!_animOpacities.isEmpty()) _animOpacities.clear();
 
-	_msgid = context ? context->fullId() : FullMsgId();
-	_canForward = context ? context->canForward() : false;
-	_canDelete = context ? context->canDelete() : false;
-
 	if (document->isVideo() || document->isRoundVideo()) {
 		_autoplayVideoDocument = document;
 	}
@@ -2209,6 +2146,63 @@ void MediaView::setZoomLevel(int newZoom) {
 	update();
 }
 
+MediaView::Entity MediaView::entityForSharedMediaValue(
+		SharedMediaSliceWithLast::Value value) const {
+	if (auto photo = base::get_if<not_null<PhotoData*>>(&value)) {
+		// Last peer photo.
+		return { *photo, nullptr };
+	} else if (auto itemId = base::get_if<FullMsgId>(&value)) {
+		if (auto item = App::histItemById(*itemId)) {
+			if (auto media = item->getMedia()) {
+				switch (media->type()) {
+				case MediaTypePhoto: return {
+					static_cast<HistoryPhoto*>(item->getMedia())->photo(),
+					item
+				};
+				case MediaTypeFile:
+				case MediaTypeVideo:
+				case MediaTypeGif:
+				case MediaTypeSticker: return { media->getDocument(), item };
+				}
+			}
+			return { base::none, item };
+		}
+	}
+	return { base::none, nullptr };
+}
+
+void MediaView::setContext(base::optional_variant<
+		not_null<HistoryItem*>,
+		not_null<PeerData*>> context) {
+	if (auto item = base::get_if<not_null<HistoryItem*>>(&context)) {
+		_msgid = (*item)->fullId();
+		_canForward = (*item)->canForward();
+		_canDelete = (*item)->canDelete();
+		_history = (*item)->history();
+		_peer = _history->peer;
+	} else if (auto peer = base::get_if<not_null<PeerData*>>(&context)) {
+		_msgid = FullMsgId();
+		_canForward = _canDelete = false;
+		_history = App::history(*peer);
+		_peer = *peer;
+	} else {
+		_msgid = FullMsgId();
+		_canForward = _canDelete = false;
+		_history = nullptr;
+		_peer = nullptr;
+	}
+	_migrated = nullptr;
+	if (_history) {
+		if (_history->peer->migrateFrom()) {
+			_migrated = App::history(_history->peer->migrateFrom()->id);
+		} else if (_history->peer->migrateTo()) {
+			_migrated = _history;
+			_history = App::history(_history->peer->migrateTo()->id);
+		}
+	}
+	_user = _peer ? _peer->asUser() : nullptr;
+}
+
 bool MediaView::moveToNext(int32 delta) {
 	if (!_index) {
 		return false;
@@ -2217,27 +2211,28 @@ bool MediaView::moveToNext(int32 delta) {
 	if (newIndex < 0 || newIndex >= _sharedMediaData->size()) {
 		return false;
 	}
-	if (auto item = App::histItemById((*_sharedMediaData)[newIndex])) {
+	auto entity = entityForSharedMediaValue((*_sharedMediaData)[newIndex]);
-		_index = newIndex;
+	if (!entity.data && !entity.item) {
-		_msgid = item->fullId();
+		return false;
-		_canForward = item->canForward();
-		_canDelete = item->canDelete();
-		stopGif();
-		if (auto media = item->getMedia()) {
-			switch (media->type()) {
-			case MediaTypePhoto: displayPhoto(static_cast<HistoryPhoto*>(item->getMedia())->photo(), item); preloadData(delta); break;
-			case MediaTypeFile:
-			case MediaTypeVideo:
-			case MediaTypeGif:
-			case MediaTypeSticker: displayDocument(media->getDocument(), item); preloadData(delta); break;
-			}
-		} else {
-			displayDocument(nullptr, item);
-			preloadData(delta);
-		}
-		return true;
 	}
-	return false;
+	_index = newIndex;
+	if (auto item = entity.item) {
+		setContext(item);
+	} else if (_peer) {
+		setContext(_peer);
+	} else {
+		setContext(base::none);
+	}
+	stopGif();
+	if (auto photo = base::get_if<not_null<PhotoData*>>(&entity.data)) {
+		displayPhoto(*photo, entity.item);
+	} else if (auto document = base::get_if<not_null<DocumentData*>>(&entity.data)) {
+		displayDocument(*document, entity.item);
+	} else {
+		displayDocument(nullptr, entity.item);
+	}
+	preloadData(delta);
+	return true;
 
 	//if (_index < 0) { // TODO chat
 	//	if (delta == -1 && _photo == _additionalChatPhoto) {
@@ -2338,34 +2333,25 @@ void MediaView::preloadData(int32 delta) {
 
 	auto forgetIndex = *_index - delta * 2;
 	if (forgetIndex >= 0 && forgetIndex < _sharedMediaData->size()) {
-		if (auto item = App::histItemById((*_sharedMediaData)[forgetIndex])) {
+		auto entity = entityForSharedMediaValue((*_sharedMediaData)[forgetIndex]);
-			if (auto media = item->getMedia()) {
+		if (auto photo = base::get_if<not_null<PhotoData*>>(&entity.data)) {
-				switch (media->type()) {
+			(*photo)->forget();
-				case MediaTypePhoto: static_cast<HistoryPhoto*>(media)->photo()->forget(); break;
+		} else if (auto document = base::get_if<not_null<DocumentData*>>(&entity.data)) {
-				case MediaTypeFile:
+			(*document)->forget();
-				case MediaTypeVideo:
-				case MediaTypeGif:
-				case MediaTypeSticker: media->getDocument()->forget(); break;
-				}
-			}
 		}
 	}
 
 	for (auto index = from; index != till; ++index) {
 		if (index >= 0 && index < _sharedMediaData->size()) {
-			if (auto item = App::histItemById((*_sharedMediaData)[index])) {
+			auto entity = entityForSharedMediaValue((*_sharedMediaData)[index]);
-				if (auto media = item->getMedia()) {
+			if (auto photo = base::get_if<not_null<PhotoData*>>(&entity.data)) {
-					switch (media->type()) {
+				(*photo)->download();
-					case MediaTypePhoto: static_cast<HistoryPhoto*>(media)->photo()->download(); break;
+			} else if (auto document = base::get_if<not_null<DocumentData*>>(&entity.data)) {
-					case MediaTypeFile:
+				if (auto sticker = (*document)->sticker()) {
-					case MediaTypeVideo:
+					sticker->img->load();
-					case MediaTypeGif: {
+				} else {
-						auto doc = media->getDocument();
+					(*document)->thumb->load();
-						doc->thumb->load();
+					(*document)->automaticLoad(entity.item);
-						doc->automaticLoad(item);
-					} break;
-					case MediaTypeSticker: media->getDocument()->sticker()->img->load(); break;
-					}
 				}
 			}
 		}
@@ -2820,7 +2806,9 @@ void MediaView::findCurrent() {
 		_index = _fullIndex = _fullCount = base::none;
 		return;
 	}
-	_index = _sharedMediaData->indexOf(_msgid);
+	_index = _msgid
+		? _sharedMediaData->indexOf(_msgid)
+		: _photo ? _sharedMediaData->indexOf(_photo) : base::none;
 	if (_index && _sharedMediaData->skippedBefore()) {
 		_fullIndex = (*_index + *_sharedMediaData->skippedBefore());
 	} else {
@@ -2893,44 +2881,6 @@ void MediaView::loadBack() {
 	//} // TODO user
 }
 
-MediaView::LastChatPhoto MediaView::computeLastOverviewChatPhoto() {
-	LastChatPhoto emptyResult = { nullptr, nullptr };
-	auto lastPhotoInOverview = [&emptyResult](auto history, auto list) -> LastChatPhoto {
-		auto end = list.end();
-		if (auto item = App::histItemById(history->channelId(), *--end)) {
-			if (auto media = item->getMedia()) {
-				if (media->type() == MediaTypePhoto && !item->toHistoryMessage()) {
-					return { item, static_cast<HistoryPhoto*>(media)->photo() };
-				}
-			}
-		}
-		return emptyResult;
-	};
-
-	if (!_history) return emptyResult;
-	auto &list = _history->overview(OverviewChatPhotos);
-	if (!list.isEmpty()) {
-		return lastPhotoInOverview(_history, list);
-	}
-
-	if (!_migrated || !_history->overviewLoaded(OverviewChatPhotos)) return emptyResult;
-	auto &migratedList = _migrated->overview(OverviewChatPhotos);
-	if (!migratedList.isEmpty()) {
-		return lastPhotoInOverview(_migrated, migratedList);
-	}
-	return emptyResult;
-}
-
-void MediaView::computeAdditionalChatPhoto(PeerData *peer, PhotoData *lastOverviewPhoto) {
-	if (!peer->photoId || peer->photoId == UnknownPeerPhotoId) {
-		_additionalChatPhoto = nullptr;
-	} else if (lastOverviewPhoto && lastOverviewPhoto->id == peer->photoId) {
-		_additionalChatPhoto = nullptr;
-	} else {
-		_additionalChatPhoto = App::photo(peer->photoId);
-	}
-}
-
 void MediaView::userPhotosLoaded(UserData *u, const MTPphotos_Photos &photos, mtpRequestId req) {
 	if (req == _loadRequest) {
 		_loadRequest = 0;

Telegram/SourceFiles/mediaview.h

@@ -57,14 +57,9 @@ public:
 
 	void setVisible(bool visible) override;
 
-	void updateOver(QPoint mpos);
-
 	void showPhoto(not_null<PhotoData*> photo, HistoryItem *context);
-	void showPhoto(not_null<PhotoData*> photo, PeerData *context);
+	void showPhoto(not_null<PhotoData*> photo, not_null<PeerData*> context);
 	void showDocument(not_null<DocumentData*> document, HistoryItem *context);
-	void moveToScreen();
-	bool moveToNext(int32 delta);
-	void preloadData(int32 delta);
 
 	void leaveToChildEvent(QEvent *e, QWidget *child) override { // e -- from enterEvent() of child TWidget
 		updateOverState(OverNone);
@@ -151,20 +146,35 @@ private:
 		OverVideo,
 	};
 
+	void updateOver(QPoint mpos);
+	void moveToScreen();
+	bool moveToNext(int32 delta);
+	void preloadData(int32 delta);
+	struct Entity {
+		base::optional_variant<
+			not_null<PhotoData*>,
+			not_null<DocumentData*>> data;
+		HistoryItem *item;
+	};
+	Entity entityForSharedMediaValue(SharedMediaSliceWithLast::Value value) const;
+	void setContext(base::optional_variant<
+		not_null<HistoryItem*>,
+		not_null<PeerData*>> context);
+
 	void refreshLang();
 	void showSaveMsgFile();
 	void updateMixerVideoVolume() const;
 
 	struct SharedMedia;
-	using SharedMediaType = SharedMediaViewerMerged::Type;
+	using SharedMediaType = SharedMediaViewerWithLast::Type;
-	using SharedMediaKey = SharedMediaViewerMerged::Key;
+	using SharedMediaKey = SharedMediaViewerWithLast::Key;
 	base::optional<SharedMediaType> sharedMediaType() const;
 	base::optional<SharedMediaKey> sharedMediaKey() const;
 	void validateSharedMedia();
 	bool validSharedMedia() const;
 	std::unique_ptr<SharedMedia> createSharedMedia() const;
 	void refreshSharedMedia();
-	void handleSharedMediaUpdate(const SharedMediaSliceMerged &update);
+	void handleSharedMediaUpdate(const SharedMediaSliceWithLast &update);
 	void refreshNavVisibility();
 
 	void dropdownHidden();
@@ -206,14 +216,6 @@ private:
 	void radialStart();
 	TimeMs radialTimeShift() const;
 
-	// Computes the last OverviewChatPhotos PhotoData* from _history or _migrated.
-	struct LastChatPhoto {
-		HistoryItem *item;
-		PhotoData *photo;
-	};
-	LastChatPhoto computeLastOverviewChatPhoto();
-	void computeAdditionalChatPhoto(PeerData *peer, PhotoData *lastOverviewPhoto);
-
 	void userPhotosLoaded(UserData *u, const MTPphotos_Photos &photos, mtpRequestId req);
 
 	void deletePhotosDone(const MTPVector<MTPlong> &result);
@@ -244,7 +246,7 @@ private:
 	PhotoData *_photo = nullptr;
 	DocumentData *_doc = nullptr;
 	std::unique_ptr<SharedMedia> _sharedMedia;
-	base::optional<SharedMediaSliceMerged> _sharedMediaData;
+	base::optional<SharedMediaSliceWithLast> _sharedMediaData;
 
 	QRect _closeNav, _closeNavIcon;
 	QRect _leftNav, _leftNavIcon, _rightNav, _rightNavIcon;
@@ -310,10 +312,6 @@ private:
 	PeerData *_peer = nullptr;
 	UserData *_user = nullptr; // if user profile photos overview
 
-	// There can be additional first photo in chat photos overview, that is not
-	// in the _history->overview(OverviewChatPhotos) (if the item was deleted).
-	PhotoData *_additionalChatPhoto = nullptr;
-
 	// We save the information about the reason of the current mediaview show:
 	// did we open a peer profile photo or a photo from some message.
 	// We use it when trying to delete a photo: if we've opened a peer photo,