Use Text to display empty group state.

Telegram/SourceFiles/history/history_inner_widget.cpp

@@ -180,7 +180,7 @@ HistoryInner::HistoryInner(
 void HistoryInner::messagesReceived(
 		PeerData *peer,
 		const QVector<MTPMessage> &messages) {
-	if (_history && _history->peer == peer) {
+	if (_history->peer == peer) {
 		_history->addOlderSlice(messages);
 	} else if (_migrated && _migrated->peer == peer) {
 		const auto newLoaded = _migrated
@@ -194,7 +194,7 @@ void HistoryInner::messagesReceived(
 }
 
 void HistoryInner::messagesReceivedDown(PeerData *peer, const QVector<MTPMessage> &messages) {
-	if (_history && _history->peer == peer) {
+	if (_history->peer == peer) {
 		const auto oldLoaded = _migrated
 			&& _history->isEmpty()
 			&& !_migrated->isEmpty();
@@ -523,6 +523,14 @@ TextSelection HistoryInner::itemRenderSelection(
 	return TextSelection();
 }
 
+void HistoryInner::paintEmpty(Painter &p, int width, int height) {
+	if (!_emptyPainter) {
+		_emptyPainter = std::make_unique<HistoryView::EmptyPainter>(
+			_history);
+	}
+	_emptyPainter->paint(p, width, height);
+}
+
 void HistoryInner::paintEvent(QPaintEvent *e) {
 	if (Ui::skipPaintEvent(this, e)) {
 		return;
@@ -552,7 +560,7 @@ void HistoryInner::paintEvent(QPaintEvent *e) {
 			p.restoreTextPalette();
 		}
 	} else if (historyDisplayedEmpty) {
-		HistoryView::paintEmpty(p, _history, width(), height());
+		paintEmpty(p, width(), height());
 	}
 	if (!noHistoryDisplayed) {
 		auto readMentions = base::flat_set<not_null<HistoryItem*>>();
@@ -1371,8 +1379,6 @@ void HistoryInner::mouseReleaseEvent(QMouseEvent *e) {
 }
 
 void HistoryInner::mouseDoubleClickEvent(QMouseEvent *e) {
-	if (!_history) return;
-
 	mouseActionStart(e->globalPos(), e->button());
 
 	const auto mouseActionView = _mouseActionItem
@@ -2101,8 +2107,6 @@ bool HistoryInner::displayScrollDate() const {
 }
 
 void HistoryInner::scrollDateCheck() {
-	if (!_history) return;
-
 	auto newScrollDateItem = _history->scrollTopItem ? _history->scrollTopItem : (_migrated ? _migrated->scrollTopItem : nullptr);
 	auto newScrollDateItemTop = _history->scrollTopItem ? _history->scrollTopOffset : (_migrated ? _migrated->scrollTopOffset : 0);
 	//if (newScrollDateItem && !displayScrollDate()) {
@@ -2282,7 +2286,6 @@ auto HistoryInner::nextItem(Element *view) -> Element* {
 	} else if (const auto result = view->nextInBlocks()) {
 		return result;
 	} else if (view->data()->history() == _migrated
-		&& _history
 		&& _migrated->loadedAtBottom()
 		&& _history->loadedAtTop()
 		&& !_history->isEmpty()) {
@@ -2380,7 +2383,7 @@ void HistoryInner::onTouchSelect() {
 }
 
 void HistoryInner::mouseActionUpdate() {
-	if (!_history || hasPendingResizedItems()) {
+	if (hasPendingResizedItems()) {
 		return;
 	}
 
@@ -2553,7 +2556,6 @@ void HistoryInner::mouseActionUpdate() {
 		}
 	} else if (item) {
 		if (_mouseAction == MouseAction::Selecting) {
-			auto canSelectMany = (_history != nullptr);
 			if (selectingText) {
 				uint16 second = dragState.symbol;
 				if (dragState.afterSymbol && _mouseSelectType == TextSelectType::Letters) {
@@ -2573,8 +2575,8 @@ void HistoryInner::mouseActionUpdate() {
 					_wasSelectedText = true;
 					setFocus();
 				}
-				updateDragSelection(0, 0, false);
+				updateDragSelection(nullptr, nullptr, false);
-			} else if (canSelectMany) {
+			} else {
 				auto selectingDown = (itemTop(_mouseActionItem) < itemTop(item)) || (_mouseActionItem == item && _dragStartPosition.y() < m.y());
 				auto dragSelFrom = _mouseActionItem->mainView();
 				auto dragSelTo = view;
@@ -2680,7 +2682,7 @@ void HistoryInner::updateDragSelection(Element *dragSelFrom, Element *dragSelTo,
 
 int HistoryInner::historyHeight() const {
 	int result = 0;
-	if (!_history || _history->isEmpty()) {
+	if (_history->isEmpty()) {
 		result += _migrated ? _migrated->height() : 0;
 	} else {
 		result += _history->height() - _historySkipHeight + (_migrated ? _migrated->height() : 0);
@@ -2706,7 +2708,11 @@ int HistoryInner::migratedTop() const {
 
 int HistoryInner::historyTop() const {
 	int mig = migratedTop();
-	return (_history && !_history->isEmpty()) ? (mig >= 0 ? (mig + _migrated->height() - _historySkipHeight) : _historyPaddingTop) : -1;
+	return !_history->isEmpty()
+		? (mig >= 0
+			? (mig + _migrated->height() - _historySkipHeight)
+			: _historyPaddingTop)
+		: -1;
 }
 
 int HistoryInner::historyDrawTop() const {
@@ -2736,7 +2742,7 @@ int HistoryInner::itemTop(const Element *view) const {
 }
 
 void HistoryInner::notifyIsBotChanged() {
-	const auto newinfo = (_peer && _peer->isUser())
+	const auto newinfo = _peer->isUser()
 		? _peer->asUser()->botInfo.get()
 		: nullptr;
 	if ((!newinfo && !_botAbout)
@@ -2918,7 +2924,7 @@ void HistoryInner::deleteItem(not_null<HistoryItem*> item) {
 }
 
 bool HistoryInner::hasPendingResizedItems() const {
-	return (_history && _history->hasPendingResizedItems())
+	return _history->hasPendingResizedItems()
 		|| (_migrated && _migrated->hasPendingResizedItems());
 }
 
@@ -3007,12 +3013,12 @@ void HistoryInner::applyDragSelection(
 		addSelectionRange(toItems, _history, fromblock, fromitem, toblock, toitem);
 	} else {
 		auto toRemove = std::vector<not_null<HistoryItem*>>();
-		for (auto i = toItems->begin(); i != toItems->cend(); ++i) {
+		for (const auto &item : *toItems) {
-			auto iy = itemTop(i->first);
+			auto iy = itemTop(item.first);
 			if (iy < -1) {
-				toRemove.push_back(i->first);
+				toRemove.emplace_back(item.first);
 			} else if (iy >= 0 && iy >= selfromy && iy < seltoy) {
-				toRemove.push_back(i->first);
+				toRemove.emplace_back(item.first);
 			}
 		}
 		for (const auto item : toRemove) {

Telegram/SourceFiles/history/history_inner_widget.h

@@ -23,6 +23,7 @@ struct TextState;
 struct StateRequest;
 enum class CursorState : char;
 enum class PointState : char;
+class EmptyPainter;
 } // namespace HistoryView
 
 namespace Window {
@@ -54,6 +55,7 @@ public:
 	void messagesReceivedDown(PeerData *peer, const QVector<MTPMessage> &messages);
 
 	TextWithEntities getSelectedText() const;
+	void paintEmpty(Painter &p, int width, int height);
 
 	void touchScrollUpdated(const QPoint &screenPos);
 
@@ -292,8 +294,8 @@ private:
 
 	not_null<Window::Controller*> _controller;
 
-	not_null<PeerData*> _peer;
+	const not_null<PeerData*> _peer;
-	not_null<History*> _history;
+	const not_null<History*> _history;
 	History *_migrated = nullptr;
 	int _contentWidth = 0;
 	int _historyPaddingTop = 0;
@@ -303,6 +305,7 @@ private:
 	int _historySkipHeight = 0;
 
 	std::unique_ptr<BotAbout> _botAbout;
+	std::unique_ptr<HistoryView::EmptyPainter> _emptyPainter;
 
 	HistoryWidget *_widget = nullptr;
 	Ui::ScrollArea *_scroll = nullptr;

Telegram/SourceFiles/history/history_item.h

@@ -298,7 +298,7 @@ protected:
 
 	void setGroupId(MessageGroupId groupId);
 
-	Text _text = { int(st::msgMinWidth) };
+	Text _text = { st::msgMinWidth };
 	int _textWidth = -1;
 	int _textHeight = 0;
 

Telegram/SourceFiles/history/history_widget.cpp

@@ -6557,7 +6557,10 @@ void HistoryWidget::paintEvent(QPaintEvent *e) {
 		}
 		if (_scroll->isHidden() && _history) {
 			p.setClipRect(_scroll->geometry());
-			HistoryView::paintEmpty(p, _history, width(), height() - _field->height() - 2 * st::historySendPadding);
+			_list->paintEmpty(
+				p,
+				width(),
+				height() - _field->height() - 2 * st::historySendPadding);
 		}
 	} else {
 		const auto w = st::msgServiceFont->width(lang(lng_willbe_history))

Telegram/SourceFiles/history/view/history_view_service_message.cpp

@@ -15,10 +15,11 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "data/data_abstract_structure.h"
 #include "data/data_chat.h"
 #include "data/data_channel.h"
-#include "styles/style_history.h"
+#include "ui/text_options.h"
 #include "mainwidget.h"
 #include "layout.h"
 #include "lang/lang_keys.h"
+#include "styles/style_history.h"
 
 namespace HistoryView {
 namespace {
@@ -175,81 +176,13 @@ void paintPreparedDate(Painter &p, const QString &dateText, int dateTextWidth, i
 	p.drawText(left + st::msgServicePadding.left(), y + st::msgServiceMargin.top() + st::msgServicePadding.top() + st::msgServiceFont->ascent, dateText);
 }
 
-void PaintAboutGroup(Painter &p, int width, int height) {
+bool NeedAboutGroup(not_null<History*> history) {
-	constexpr auto kPhrasesCount = 4;
+	if (const auto chat = history->peer->asChat()) {
-	const auto header = lang(lng_group_about_header);
+		return chat->amCreator();
-	const auto text = lang(lng_group_about_text);
+	} else if (const auto channel = history->peer->asMegagroup()) {
-	const auto phrases = std::array<QString, kPhrasesCount>{
+		return channel->amCreator();
-		lang(lng_group_about1),
-		lang(lng_group_about2),
-		lang(lng_group_about3),
-		lang(lng_group_about4),
-	};
-
-	const auto &font = st::msgServiceFont;
-	const auto headerWidth = font->width(header);
-	const auto textWidth = font->width(text);
-	const auto phraseWidths = ranges::view::all(
-		phrases
-	) | ranges::view::transform([&](const QString &text) {
-		return font->width(text);
-	}) | ranges::to_vector;
-
-	const auto maxPhraseWidth = *ranges::max_element(phraseWidths);
-
-	const auto margin = st::msgMargin.left();
-	const auto maxBubbleWidth = width - 2 * st::historyGroupAboutMargin;
-	const auto padding = st::historyGroupAboutPadding;
-	const auto bubbleWidth = std::min(
-		maxBubbleWidth,
-		std::max({
-			maxPhraseWidth + st::historyGroupAboutBulletSkip,
-			headerWidth,
-			textWidth }) + padding.left() + padding.right());
-	const auto bubbleHeight = padding.top()
-		+ font->height
-		+ st::historyGroupAboutHeaderSkip
-		+ font->height
-		+ st::historyGroupAboutTextSkip
-		+ font->height * kPhrasesCount
-		+ st::historyGroupAboutSkip * (kPhrasesCount - 1)
-		+ padding.bottom();
-	const auto bubbleLeft = (width - bubbleWidth) / 2;
-	const auto bubbleTop = (height - bubbleHeight) / 3;
-
-	ServiceMessagePainter::paintBubble(
-		p,
-		bubbleLeft,
-		bubbleTop,
-		bubbleWidth,
-		bubbleHeight);
-
-	p.setFont(font);
-	p.setPen(st::msgServiceFg);
-	const auto left = bubbleLeft + padding.left();
-	auto top = bubbleTop + padding.top();
-
-	p.drawTextLeft(bubbleLeft + (bubbleWidth - headerWidth) / 2, top, width, header);
-	top += font->height + st::historyGroupAboutHeaderSkip;
-
-	p.drawTextLeft(left, top, width, text);
-	top += font->height + st::historyGroupAboutTextSkip;
-
-	p.setBrush(st::msgServiceFg);
-	for (const auto &text : phrases) {
-		p.setPen(st::msgServiceFg);
-		p.drawTextLeft(left + st::historyGroupAboutBulletSkip, top, width, text);
-		{
-			PainterHighQualityEnabler hq(p);
-			p.setPen(Qt::NoPen);
-			p.drawEllipse(
-				left,
-				top + (font->height - st::mediaUnreadSize) / 2,
-				st::mediaUnreadSize,
-				st::mediaUnreadSize);
-		}
-		top += font->height + st::historyGroupAboutSkip;
 	}
+	return false;
 }
 
 } // namepsace
@@ -360,24 +293,6 @@ QVector<int> ServiceMessagePainter::countLineWidths(const Text &text, const QRec
 	return lineWidths;
 }
 
-void paintEmpty(
-		Painter &p,
-		not_null<History*> history,
-		int width,
-		int height) {
-	const auto needAboutGroup = [&] {
-		if (const auto chat = history->peer->asChat()) {
-			return chat->amCreator();
-		} else if (const auto channel = history->peer->asMegagroup()) {
-			return channel->amCreator();
-		}
-		return false;
-	}();
-	if (needAboutGroup) {
-		PaintAboutGroup(p, width, height);
-	}
-}
-
 void serviceColorsUpdated() {
 	if (serviceMessageStyle) {
 		for (auto &corner : serviceMessageStyle->corners) {
@@ -625,4 +540,119 @@ TextSelection Service::adjustSelection(
 	return message()->_text.adjustSelection(selection, type);
 }
 
+EmptyPainter::EmptyPainter(not_null<History*> history) : _history(history) {
+	if (NeedAboutGroup(_history)) {
+		fillAboutGroup();
+	}
+}
+
+void EmptyPainter::fillAboutGroup() {
+	const auto phrases = {
+		lang(lng_group_about1),
+		lang(lng_group_about2),
+		lang(lng_group_about3),
+		lang(lng_group_about4),
+	};
+	const auto setText = [](Text &text, const QString &content) {
+		text.setText(
+			st::serviceTextStyle,
+			content,
+			Ui::ItemTextServiceOptions());
+	};
+	setText(_header, lang(lng_group_about_header));
+	setText(_text, lang(lng_group_about_header));
+	for (const auto &text : phrases) {
+		_phrases.emplace_back(st::msgMinWidth);
+		setText(_phrases.back(), text);
+	}
+}
+
+void EmptyPainter::paint(Painter &p, int width, int height) {
+	if (_phrases.empty()) {
+		return;
+	}
+	constexpr auto kMaxTextLines = 3;
+	const auto maxPhraseWidth = ranges::max_element(
+		_phrases,
+		ranges::less(),
+		&Text::maxWidth
+	)->maxWidth();
+
+	const auto &font = st::serviceTextStyle.font;
+	const auto margin = st::msgMargin.left();
+	const auto maxBubbleWidth = width - 2 * st::historyGroupAboutMargin;
+	const auto padding = st::historyGroupAboutPadding;
+	const auto bubbleWidth = std::min(
+		maxBubbleWidth,
+		std::max({
+			maxPhraseWidth + st::historyGroupAboutBulletSkip,
+			_header.maxWidth(),
+			_text.maxWidth() }) + padding.left() + padding.right());
+	const auto innerWidth = bubbleWidth - padding.left() - padding.right();
+	const auto textHeight = [&](const Text &text) {
+		return std::min(
+			text.countHeight(innerWidth),
+			kMaxTextLines * font->height);
+	};
+	const auto bubbleHeight = padding.top()
+		+ textHeight(_header)
+		+ st::historyGroupAboutHeaderSkip
+		+ textHeight(_text)
+		+ st::historyGroupAboutTextSkip
+		+ ranges::accumulate(_phrases, 0, ranges::plus(), textHeight)
+		+ st::historyGroupAboutSkip * int(_phrases.size() - 1)
+		+ padding.bottom();
+	const auto bubbleLeft = (width - bubbleWidth) / 2;
+	const auto bubbleTop = (height - bubbleHeight) / 3;
+
+	ServiceMessagePainter::paintBubble(
+		p,
+		bubbleLeft,
+		bubbleTop,
+		bubbleWidth,
+		bubbleHeight);
+
+	p.setPen(st::msgServiceFg);
+	p.setBrush(st::msgServiceFg);
+
+	const auto left = bubbleLeft + padding.left();
+	auto top = bubbleTop + padding.top();
+
+	_header.drawElided(
+		p,
+		left,
+		top,
+		innerWidth,
+		kMaxTextLines,
+		style::al_top);
+	top += textHeight(_header) + st::historyGroupAboutHeaderSkip;
+
+	_text.drawElided(
+		p,
+		left,
+		top,
+		innerWidth,
+		kMaxTextLines);
+	top += textHeight(_text) + st::historyGroupAboutTextSkip;
+
+	for (const auto &text : _phrases) {
+		p.setPen(st::msgServiceFg);
+		text.drawElided(
+			p,
+			left + st::historyGroupAboutBulletSkip,
+			top,
+			innerWidth,
+			kMaxTextLines);
+
+		PainterHighQualityEnabler hq(p);
+		p.setPen(Qt::NoPen);
+		p.drawEllipse(
+			left,
+			top + (font->height - st::mediaUnreadSize) / 2,
+			st::mediaUnreadSize,
+			st::mediaUnreadSize);
+		top += textHeight(text) + st::historyGroupAboutSkip;
+	}
+}
+
 } // namespace HistoryView

Telegram/SourceFiles/history/view/history_view_service_message.h

@@ -74,11 +74,21 @@ private:
 
 };
 
-void paintEmpty(
+class EmptyPainter {
-	Painter &p,
+public:
-	not_null<History*> history,
+	explicit EmptyPainter(not_null<History*> history);
-	int width,
+
-	int height);
+	void paint(Painter &p, int width, int height);
+
+private:
+	void fillAboutGroup();
+
+	not_null<History*> _history;
+	Text _header = { st::msgMinWidth };
+	Text _text = { st::msgMinWidth };
+	std::vector<Text> _phrases;
+
+};
 
 void serviceColorsUpdated();
 

Telegram/SourceFiles/overview/overview_layout.h

@@ -352,7 +352,7 @@ private:
 	WebPageData *_page = nullptr;
 	int _pixw = 0;
 	int _pixh = 0;
-	Text _text = { int(st::msgMinWidth) };
+	Text _text = { st::msgMinWidth };
 
 	struct LinkEntry {
 		LinkEntry() : width(0) {