From 053eace154cafde7f5eaba06585adae6cf45f333 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Thu, 21 May 2020 16:27:04 +0400
Subject: [PATCH] Prepare overview layouts for media clearing.

---
 Telegram/CMakeLists.txt                       |  1 +
 .../info/media/info_media_list_widget.cpp     | 85 ++++++++++++++-----
 .../info/media/info_media_list_widget.h       | 45 +++++-----
 .../SourceFiles/overview/overview_layout.cpp  | 27 ++++--
 .../SourceFiles/overview/overview_layout.h    | 29 +++++--
 .../overview/overview_layout_delegate.h       | 22 +++++
 6 files changed, 152 insertions(+), 57 deletions(-)
 create mode 100644 Telegram/SourceFiles/overview/overview_layout_delegate.h

diff --git a/Telegram/CMakeLists.txt b/Telegram/CMakeLists.txt
index d5e0d70c43..1066d68f0d 100644
--- a/Telegram/CMakeLists.txt
+++ b/Telegram/CMakeLists.txt
@@ -756,6 +756,7 @@ PRIVATE
     mtproto/type_utils.h
     overview/overview_layout.cpp
     overview/overview_layout.h
+    overview/overview_layout_delegate.h
     passport/passport_encryption.cpp
     passport/passport_encryption.h
     passport/passport_form_controller.cpp
diff --git a/Telegram/SourceFiles/info/media/info_media_list_widget.cpp b/Telegram/SourceFiles/info/media/info_media_list_widget.cpp
index 2af34bd183..58714ae4a3 100644
--- a/Telegram/SourceFiles/info/media/info_media_list_widget.cpp
+++ b/Telegram/SourceFiles/info/media/info_media_list_widget.cpp
@@ -112,6 +112,7 @@ public:
 
 	bool removeItem(UniversalMsgId universalId);
 	FoundItem findItemNearId(UniversalMsgId universalId) const;
+	FoundItem findItemDetails(not_null<BaseLayout*> item) const;
 	FoundItem findItemByPoint(QPoint point) const;
 
 	void paint(
@@ -190,6 +191,11 @@ ListWidget::CachedItem::CachedItem(std::unique_ptr<BaseLayout> item)
 : item(std::move(item)) {
 }
 
+ListWidget::CachedItem::CachedItem(CachedItem &&other) = default;
+
+ListWidget::CachedItem &ListWidget::CachedItem::operator=(
+	CachedItem && other) = default;
+
 ListWidget::CachedItem::~CachedItem() = default;
 
 bool ListWidget::Section::addItem(not_null<BaseLayout*> item) {
@@ -306,9 +312,10 @@ auto ListWidget::Section::findItemByPoint(
 	return { item, rect, rect.contains(point) };
 }
 
-auto ListWidget::Section::findItemNearId(
-		UniversalMsgId universalId) const -> FoundItem {
+auto ListWidget::Section::findItemNearId(UniversalMsgId universalId) const
+-> FoundItem {
 	Expects(!_items.empty());
+
 	auto itemIt = ranges::lower_bound(
 		_items,
 		universalId,
@@ -322,6 +329,11 @@ auto ListWidget::Section::findItemNearId(
 	return { item, findItemRect(item), exact };
 }
 
+auto ListWidget::Section::findItemDetails(not_null<BaseLayout*> item) const
+-> FoundItem {
+	return { item, findItemRect(item), true };
+}
+
 auto ListWidget::Section::findItemAfterTop(
 		int top) -> Items::iterator {
 	return ranges::lower_bound(
@@ -621,6 +633,7 @@ void ListWidget::restart() {
 	_overLayout = nullptr;
 	_sections.clear();
 	_layouts.clear();
+	_heavyLayouts.clear();
 
 	_universalAroundId = kDefaultAroundId;
 	_idsLimit = kMinimalIdsLimit;
@@ -631,11 +644,11 @@ void ListWidget::restart() {
 
 void ListWidget::itemRemoved(not_null<const HistoryItem*> item) {
 	if (isMyItem(item)) {
-		auto universalId = GetUniversalId(item);
+		auto id = GetUniversalId(item);
 
-		auto sectionIt = findSectionByItem(universalId);
+		auto sectionIt = findSectionByItem(id);
 		if (sectionIt != _sections.end()) {
-			if (sectionIt->removeItem(universalId)) {
+			if (sectionIt->removeItem(id)) {
 				auto top = sectionIt->top();
 				if (sectionIt->empty()) {
 					_sections.erase(sectionIt);
@@ -648,11 +661,13 @@ void ListWidget::itemRemoved(not_null<const HistoryItem*> item) {
 			_overLayout = nullptr;
 		}
 
-		_layouts.erase(universalId);
-		_dragSelected.remove(universalId);
+		if (const auto i = _layouts.find(id); i != _layouts.end()) {
+			_heavyLayouts.remove(i->second.item.get());
+			_layouts.erase(i);
+		}
+		_dragSelected.remove(id);
 
-		auto i = _selected.find(universalId);
-		if (i != _selected.cend()) {
+		if (const auto i = _selected.find(id); i != _selected.cend()) {
 			removeItemSelection(i);
 		}
 
@@ -789,6 +804,10 @@ void ListWidget::invalidatePaletteCache() {
 	}
 }
 
+void ListWidget::registerHeavyItem(not_null<BaseLayout*> item) {
+	_heavyLayouts.emplace(item);
+}
+
 SparseIdsMergedSlice::Key ListWidget::sliceKey(
 		UniversalMsgId universalId) const {
 	using Key = SparseIdsMergedSlice::Key;
@@ -871,31 +890,31 @@ std::unique_ptr<BaseLayout> ListWidget::createLayout(
 	switch (type) {
 	case Type::Photo:
 		if (const auto photo = getPhoto()) {
-			return std::make_unique<Photo>(item, photo);
+			return std::make_unique<Photo>(this, item, photo);
 		}
 		return nullptr;
 	case Type::Video:
 		if (const auto file = getFile()) {
-			return std::make_unique<Video>(item, file);
+			return std::make_unique<Video>(this, item, file);
 		}
 		return nullptr;
 	case Type::File:
 		if (const auto file = getFile()) {
-			return std::make_unique<Document>(item, file, songSt);
+			return std::make_unique<Document>(this, item, file, songSt);
 		}
 		return nullptr;
 	case Type::MusicFile:
 		if (const auto file = getFile()) {
-			return std::make_unique<Document>(item, file, songSt);
+			return std::make_unique<Document>(this, item, file, songSt);
 		}
 		return nullptr;
 	case Type::RoundVoiceFile:
 		if (const auto file = getFile()) {
-			return std::make_unique<Voice>(item, file, songSt);
+			return std::make_unique<Voice>(this, item, file, songSt);
 		}
 		return nullptr;
 	case Type::Link:
-		return std::make_unique<Link>(item, item->media());
+		return std::make_unique<Link>(this, item, item->media());
 	case Type::RoundFile:
 		return nullptr;
 	}
@@ -1005,16 +1024,17 @@ auto ListWidget::findItemById(
 	return std::nullopt;
 }
 
-auto ListWidget::findItemDetails(
-		BaseLayout *item) -> std::optional<FoundItem> {
-	return item
-		? findItemById(GetUniversalId(item))
-		: std::nullopt;
+auto ListWidget::findItemDetails(not_null<BaseLayout*> item)
+-> FoundItem {
+	const auto sectionIt = findSectionByItem(GetUniversalId(item));
+	Assert(sectionIt != _sections.end());
+	return foundItemInSection(sectionIt->findItemDetails(item), *sectionIt);
 }
 
 auto ListWidget::foundItemInSection(
-		const FoundItem &item,
-		const Section &section) const -> FoundItem {
+	const FoundItem &item,
+	const Section &section) const
+-> FoundItem {
 	return {
 		item.layout,
 		item.geometry.translated(0, section.top()),
@@ -1028,6 +1048,7 @@ void ListWidget::visibleTopBottomUpdated(
 	_visibleBottom = visibleBottom;
 
 	checkMoveToOtherViewer();
+	clearHeavyItems();
 }
 
 void ListWidget::checkMoveToOtherViewer() {
@@ -1088,6 +1109,25 @@ void ListWidget::checkMoveToOtherViewer() {
 	}
 }
 
+void ListWidget::clearHeavyItems() {
+	const auto visibleHeight = _visibleBottom - _visibleTop;
+	if (!visibleHeight) {
+		return;
+	}
+	const auto above = _visibleTop - visibleHeight;
+	const auto below = _visibleBottom + visibleHeight;
+	for (auto i = _heavyLayouts.begin(); i != _heavyLayouts.end();) {
+		const auto item = *i;
+		const auto rect = findItemDetails(item).geometry;
+		if (rect.top() + rect.height() <= above || rect.top() >= below) {
+			i = _heavyLayouts.erase(i);
+			item->clearHeavyPart();
+		} else {
+			++i;
+		}
+	}
+}
+
 auto ListWidget::countScrollState() const -> ScrollTopState {
 	if (_sections.empty()) {
 		return { 0, 0 };
@@ -2105,6 +2145,7 @@ void ListWidget::clearStaleLayouts() {
 			if (i->second.item.get() == _overLayout) {
 				_overLayout = nullptr;
 			}
+			_heavyLayouts.erase(i->second.item.get());
 			i = _layouts.erase(i);
 		} else {
 			++i;
diff --git a/Telegram/SourceFiles/info/media/info_media_list_widget.h b/Telegram/SourceFiles/info/media/info_media_list_widget.h
index c1d4722c33..2bee7b61ea 100644
--- a/Telegram/SourceFiles/info/media/info_media_list_widget.h
+++ b/Telegram/SourceFiles/info/media/info_media_list_widget.h
@@ -10,6 +10,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "ui/rp_widget.h"
 #include "info/media/info_media_widget.h"
 #include "data/data_shared_media.h"
+#include "overview/overview_layout_delegate.h"
 
 class DeleteMessagesBox;
 
@@ -47,11 +48,14 @@ namespace Media {
 using BaseLayout = Overview::Layout::ItemBase;
 using UniversalMsgId = int32;
 
-class ListWidget : public Ui::RpWidget {
+class ListWidget final
+	: public Ui::RpWidget
+	, public Overview::Layout::Delegate {
 public:
 	ListWidget(
 		QWidget *parent,
 		not_null<AbstractController*> controller);
+	~ListWidget();
 
 	Main::Session &session() const;
 
@@ -72,22 +76,7 @@ public:
 	void saveState(not_null<Memento*> memento);
 	void restoreState(not_null<Memento*> memento);
 
-	~ListWidget();
-
-protected:
-	int resizeGetHeight(int newWidth) override;
-	void visibleTopBottomUpdated(
-		int visibleTop,
-		int visibleBottom) override;
-
-	void paintEvent(QPaintEvent *e) override;
-	void mouseMoveEvent(QMouseEvent *e) override;
-	void mousePressEvent(QMouseEvent *e) override;
-	void mouseReleaseEvent(QMouseEvent *e) override;
-	void mouseDoubleClickEvent(QMouseEvent *e) override;
-	void contextMenuEvent(QContextMenuEvent *e) override;
-	void enterEventHook(QEvent *e) override;
-	void leaveEventHook(QEvent *e) override;
+	void registerHeavyItem(not_null<BaseLayout*> item) override;
 
 private:
 	struct Context;
@@ -104,6 +93,8 @@ private:
 	};
 	struct CachedItem {
 		CachedItem(std::unique_ptr<BaseLayout> item);
+		CachedItem(CachedItem &&other);
+		CachedItem &operator=(CachedItem &&other);
 		~CachedItem();
 
 		std::unique_ptr<BaseLayout> item;
@@ -156,6 +147,20 @@ private:
 		int shift = 0;
 	};
 
+	int resizeGetHeight(int newWidth) override;
+	void visibleTopBottomUpdated(
+		int visibleTop,
+		int visibleBottom) override;
+
+	void paintEvent(QPaintEvent *e) override;
+	void mouseMoveEvent(QMouseEvent *e) override;
+	void mousePressEvent(QMouseEvent *e) override;
+	void mouseReleaseEvent(QMouseEvent *e) override;
+	void mouseDoubleClickEvent(QMouseEvent *e) override;
+	void contextMenuEvent(QContextMenuEvent *e) override;
+	void enterEventHook(QEvent *e) override;
+	void leaveEventHook(QEvent *e) override;
+
 	void start();
 	int recountHeight();
 	void refreshHeight();
@@ -237,7 +242,7 @@ private:
 		int bottom) const;
 	FoundItem findItemByPoint(QPoint point) const;
 	std::optional<FoundItem> findItemById(UniversalMsgId universalId);
-	std::optional<FoundItem> findItemDetails(BaseLayout *item);
+	FoundItem findItemDetails(not_null<BaseLayout*> item);
 	FoundItem foundItemInSection(
 		const FoundItem &item,
 		const Section &section) const;
@@ -269,6 +274,7 @@ private:
 	void switchToWordSelection();
 	void validateTrippleClickStartTime();
 	void checkMoveToOtherViewer();
+	void clearHeavyItems();
 
 	void setActionBoxWeak(QPointer<Ui::RpWidget> box);
 
@@ -283,7 +289,8 @@ private:
 	int _idsLimit = kMinimalIdsLimit;
 	SparseIdsMergedSlice _slice;
 
-	std::map<UniversalMsgId, CachedItem> _layouts;
+	base::flat_map<UniversalMsgId, CachedItem> _layouts;
+	base::flat_set<not_null<BaseLayout*>> _heavyLayouts;
 	std::vector<Section> _sections;
 
 	int _visibleTop = 0;
diff --git a/Telegram/SourceFiles/overview/overview_layout.cpp b/Telegram/SourceFiles/overview/overview_layout.cpp
index a1a58c0570..bea248d03d 100644
--- a/Telegram/SourceFiles/overview/overview_layout.cpp
+++ b/Telegram/SourceFiles/overview/overview_layout.cpp
@@ -7,6 +7,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
 #include "overview/overview_layout.h"
 
+#include "overview/overview_layout_delegate.h"
 #include "data/data_document.h"
 #include "data/data_session.h"
 #include "data/data_web_page.h"
@@ -144,11 +145,16 @@ MsgId AbstractItem::msgId() const {
 	return item ? item->id : 0;
 }
 
-ItemBase::ItemBase(not_null<HistoryItem*> parent)
-: _parent(parent)
+ItemBase::ItemBase(
+	not_null<Delegate*> delegate,
+	not_null<HistoryItem*> parent)
+: _delegate(delegate)
+, _parent(parent)
 , _dateTime(ItemDateTime(parent)) {
 }
 
+ItemBase::~ItemBase() = default;
+
 QDateTime ItemBase::dateTime() const {
 	return _dateTime;
 }
@@ -204,8 +210,6 @@ void ItemBase::ensureCheckboxCreated() {
 	_check = std::make_unique<Checkbox>(repaint, checkboxStyle());
 }
 
-ItemBase::~ItemBase() = default;
-
 void RadialProgressItem::setDocumentLinks(
 		not_null<DocumentData*> document) {
 	const auto context = parent()->fullId();
@@ -311,9 +315,10 @@ void Date::paint(Painter &p, const QRect &clip, TextSelection selection, const P
 }
 
 Photo::Photo(
+	not_null<Delegate*> delegate,
 	not_null<HistoryItem*> parent,
 	not_null<PhotoData*> photo)
-: ItemBase(parent)
+: ItemBase(delegate, parent)
 , _data(photo)
 , _link(std::make_shared<PhotoOpenClickHandler>(photo, parent->fullId())) {
 	if (!_data->thumbnailInline()) {
@@ -413,9 +418,10 @@ TextState Photo::getState(
 }
 
 Video::Video(
+	not_null<Delegate*> delegate,
 	not_null<HistoryItem*> parent,
 	not_null<DocumentData*> video)
-: RadialProgressItem(parent)
+: RadialProgressItem(delegate, parent)
 , _data(video)
 , _duration(formatDurationText(_data->getDuration())) {
 	setDocumentLinks(_data);
@@ -610,10 +616,11 @@ void Video::updateStatusText() {
 }
 
 Voice::Voice(
+	not_null<Delegate*> delegate,
 	not_null<HistoryItem*> parent,
 	not_null<DocumentData*> voice,
 	const style::OverviewFileLayout &st)
-: RadialProgressItem(parent)
+: RadialProgressItem(delegate, parent)
 , _data(voice)
 , _namel(std::make_shared<DocumentOpenClickHandler>(_data, parent->fullId()))
 , _st(st) {
@@ -914,10 +921,11 @@ bool Voice::updateStatusText() {
 }
 
 Document::Document(
+	not_null<Delegate*> delegate,
 	not_null<HistoryItem*> parent,
 	not_null<DocumentData*> document,
 	const style::OverviewFileLayout &st)
-: RadialProgressItem(parent)
+: RadialProgressItem(delegate, parent)
 , _data(document)
 , _msgl(goToMessageClickHandler(parent))
 , _namel(std::make_shared<DocumentOpenClickHandler>(_data, parent->fullId()))
@@ -1377,9 +1385,10 @@ bool Document::updateStatusText() {
 }
 
 Link::Link(
+	not_null<Delegate*> delegate,
 	not_null<HistoryItem*> parent,
 	Data::Media *media)
-: ItemBase(parent) {
+: ItemBase(delegate, parent) {
 	AddComponents(Info::Bit());
 
 	auto textWithEntities = parent->originalText();
diff --git a/Telegram/SourceFiles/overview/overview_layout.h b/Telegram/SourceFiles/overview/overview_layout.h
index 94eea33690..d7b5a78f36 100644
--- a/Telegram/SourceFiles/overview/overview_layout.h
+++ b/Telegram/SourceFiles/overview/overview_layout.h
@@ -26,6 +26,8 @@ namespace Overview {
 namespace Layout {
 
 class Checkbox;
+class ItemBase;
+class Delegate;
 
 class PaintContext : public PaintContextBase {
 public:
@@ -35,7 +37,6 @@ public:
 
 };
 
-class ItemBase;
 class AbstractItem : public LayoutItemBase {
 public:
 	virtual void paint(Painter &p, const QRect &clip, TextSelection selection, const PaintContext *context) = 0;
@@ -62,7 +63,8 @@ public:
 
 class ItemBase : public AbstractItem {
 public:
-	ItemBase(not_null<HistoryItem*> parent);
+	ItemBase(not_null<Delegate*> delegate, not_null<HistoryItem*> parent);
+	~ItemBase();
 
 	QDateTime dateTime() const;
 
@@ -88,12 +90,16 @@ public:
 
 	void invalidateCache() override;
 
-	~ItemBase();
+	virtual void clearHeavyPart() {
+	}
 
 protected:
-	not_null<HistoryItem*> parent() const {
+	[[nodiscard]] not_null<HistoryItem*> parent() const {
 		return _parent;
 	}
+	[[nodiscard]] not_null<Delegate*> delegate() const {
+		return _delegate;
+	}
 	void paintCheckbox(
 		Painter &p,
 		QPoint position,
@@ -104,16 +110,20 @@ protected:
 private:
 	void ensureCheckboxCreated();
 
-	int _position = 0;
+	const not_null<Delegate*> _delegate;
 	const not_null<HistoryItem*> _parent;
 	const QDateTime _dateTime;
 	std::unique_ptr<Checkbox> _check;
+	int _position = 0;
 
 };
 
 class RadialProgressItem : public ItemBase {
 public:
-	RadialProgressItem(not_null<HistoryItem*> parent) : ItemBase(parent) {
+	RadialProgressItem(
+		not_null<Delegate*> delegate,
+		not_null<HistoryItem*> parent)
+	: ItemBase(delegate, parent) {
 	}
 	RadialProgressItem(const RadialProgressItem &other) = delete;
 
@@ -197,9 +207,10 @@ private:
 
 };
 
-class Photo : public ItemBase {
+class Photo final : public ItemBase {
 public:
 	Photo(
+		not_null<Delegate*> delegate,
 		not_null<HistoryItem*> parent,
 		not_null<PhotoData*> photo);
 
@@ -224,6 +235,7 @@ private:
 class Video final : public RadialProgressItem {
 public:
 	Video(
+		not_null<Delegate*> delegate,
 		not_null<HistoryItem*> parent,
 		not_null<DocumentData*> video);
 	~Video();
@@ -258,6 +270,7 @@ private:
 class Voice final : public RadialProgressItem {
 public:
 	Voice(
+		not_null<Delegate*> delegate,
 		not_null<HistoryItem*> parent,
 		not_null<DocumentData*> voice,
 		const style::OverviewFileLayout &st);
@@ -297,6 +310,7 @@ private:
 class Document final : public RadialProgressItem {
 public:
 	Document(
+		not_null<Delegate*> delegate,
 		not_null<HistoryItem*> parent,
 		not_null<DocumentData*> document,
 		const style::OverviewFileLayout &st);
@@ -350,6 +364,7 @@ private:
 class Link final : public ItemBase {
 public:
 	Link(
+		not_null<Delegate*> delegate,
 		not_null<HistoryItem*> parent,
 		Data::Media *media);
 
diff --git a/Telegram/SourceFiles/overview/overview_layout_delegate.h b/Telegram/SourceFiles/overview/overview_layout_delegate.h
new file mode 100644
index 0000000000..addd844302
--- /dev/null
+++ b/Telegram/SourceFiles/overview/overview_layout_delegate.h
@@ -0,0 +1,22 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#pragma once
+
+namespace Overview {
+namespace Layout {
+
+class ItemBase;
+
+class Delegate {
+public:
+	virtual void registerHeavyItem(not_null<ItemBase*> item) = 0;
+
+};
+
+} // namespace Layout
+} // namespace Overview