init

Telegram/SourceFiles/layout/abstract_layout_item.cpp

@@ -0,0 +1,57 @@
+/*
+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
+*/
+#include "layout/abstract_layout_item.h"
+
+AbstractLayoutItem::AbstractLayoutItem() {
+}
+
+int AbstractLayoutItem::maxWidth() const {
+	return _maxw;
+}
+int AbstractLayoutItem::minHeight() const {
+	return _minh;
+}
+
+int AbstractLayoutItem::resizeGetHeight(int width) {
+	_width = qMin(width, _maxw);
+	_height = _minh;
+	return _height;
+}
+
+int AbstractLayoutItem::width() const {
+	return _width;
+}
+int AbstractLayoutItem::height() const {
+	return _height;
+}
+
+void AbstractLayoutItem::setPosition(int position) {
+	_position = position;
+}
+int AbstractLayoutItem::position() const {
+	return _position;
+}
+
+void AbstractLayoutItem::setShiftX(int x) {
+	_shiftX = x;
+}
+
+void AbstractLayoutItem::setShiftY(int y) {
+	_shiftY = y;
+}
+
+QPoint AbstractLayoutItem::shift() const {
+	return { _shiftX, _shiftY };
+}
+
+bool AbstractLayoutItem::hasPoint(QPoint point) const {
+	return QRect(0, 0, width(), height()).contains(point);
+}
+
+AbstractLayoutItem::~AbstractLayoutItem() {
+}

Telegram/SourceFiles/layout/abstract_layout_item.h

@@ -0,0 +1,61 @@
+/*
+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
+
+#include "base/runtime_composer.h"
+#include "ui/click_handler.h"
+
+class PaintContextBase {
+public:
+	PaintContextBase(crl::time ms, bool selecting)
+	: ms(ms)
+	, selecting(selecting) {
+	}
+	crl::time ms = 0;
+	bool selecting = false;
+
+};
+
+class AbstractLayoutItem
+	: public RuntimeComposer<AbstractLayoutItem>
+	, public ClickHandlerHost {
+public:
+	AbstractLayoutItem();
+
+	AbstractLayoutItem(const AbstractLayoutItem &other) = delete;
+	AbstractLayoutItem &operator=(
+		const AbstractLayoutItem &other) = delete;
+
+	[[nodiscard]] int maxWidth() const;
+	[[nodiscard]] int minHeight() const;
+	virtual int resizeGetHeight(int width);
+
+	[[nodiscard]] int width() const;
+	[[nodiscard]] int height() const;
+
+	virtual void setPosition(int position);
+	[[nodiscard]] int position() const;
+
+	void setShiftX(int x);
+	void setShiftY(int y);
+	[[nodiscard]] QPoint shift() const;
+
+	[[nodiscard]] bool hasPoint(QPoint point) const;
+
+	virtual ~AbstractLayoutItem();
+
+protected:
+	int _width = 0;
+	int _height = 0;
+	int _maxw = 0;
+	int _minh = 0;
+	int _position = 0; // < 0 means removed from layout
+	int _shiftX = 0;
+	int _shiftY = 0;
+
+};

Telegram/SourceFiles/layout/layout_document_generic_preview.cpp

@@ -0,0 +1,120 @@
+/*
+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
+*/
+#include "layout/layout_document_generic_preview.h"
+
+#include "data/data_document.h"
+#include "lang/lang_keys.h"
+#include "styles/style_media_view.h"
+
+namespace Layout {
+
+const style::icon *DocumentGenericPreview::icon() const {
+	switch (index) {
+	case 0: return &st::mediaviewFileBlue;
+	case 1: return &st::mediaviewFileGreen;
+	case 2: return &st::mediaviewFileRed;
+	case 3: return &st::mediaviewFileYellow;
+	}
+	Unexpected("Color index in DocumentGenericPreview::icon.");
+}
+
+DocumentGenericPreview DocumentGenericPreview::Create(
+		DocumentData *document) {
+	auto colorIndex = 0;
+
+	const auto name = (document
+		? (document->filename().isEmpty()
+			? (document->sticker()
+				? tr::lng_in_dlg_sticker(tr::now)
+				: u"Unknown File"_q)
+			: document->filename())
+		: tr::lng_message_empty(tr::now)).toLower();
+	auto lastDot = name.lastIndexOf('.');
+	const auto mime = document ? document->mimeString() : QString();
+	if (name.endsWith(u".doc"_q) ||
+		name.endsWith(u".docx"_q) ||
+		name.endsWith(u".txt"_q) ||
+		name.endsWith(u".psd"_q) ||
+		mime.startsWith(u"text/"_q)) {
+		colorIndex = 0;
+	} else if (
+		name.endsWith(u".xls"_q) ||
+		name.endsWith(u".xlsx"_q) ||
+		name.endsWith(u".csv"_q)) {
+		colorIndex = 1;
+	} else if (
+		name.endsWith(u".pdf"_q) ||
+		name.endsWith(u".ppt"_q) ||
+		name.endsWith(u".pptx"_q) ||
+		name.endsWith(u".key"_q)) {
+		colorIndex = 2;
+	} else if (
+		name.endsWith(u".zip"_q) ||
+		name.endsWith(u".rar"_q) ||
+		name.endsWith(u".ai"_q) ||
+		name.endsWith(u".mp3"_q) ||
+		name.endsWith(u".mov"_q) ||
+		name.endsWith(u".avi"_q)) {
+		colorIndex = 3;
+	} else {
+		auto ch = (lastDot >= 0 && lastDot + 1 < name.size())
+			? name.at(lastDot + 1)
+			: (name.isEmpty()
+				? (mime.isEmpty() ? '0' : mime.at(0))
+				: name.at(0));
+		colorIndex = (ch.unicode() % 4) & 3;
+	}
+
+	const auto ext = document
+		? ((lastDot < 0 || lastDot + 2 > name.size())
+			? name
+			: name.mid(lastDot + 1))
+		: QString();
+
+	switch (colorIndex) {
+	case 0: return {
+		.index = colorIndex,
+		.color = st::msgFile1Bg,
+		.dark = st::msgFile1BgDark,
+		.over = st::msgFile1BgOver,
+		.selected = st::msgFile1BgSelected,
+		.ext = ext,
+	};
+	case 1: return {
+		.index = colorIndex,
+		.color = st::msgFile2Bg,
+		.dark = st::msgFile2BgDark,
+		.over = st::msgFile2BgOver,
+		.selected = st::msgFile2BgSelected,
+		.ext = ext,
+	};
+	case 2: return {
+		.index = colorIndex,
+		.color = st::msgFile3Bg,
+		.dark = st::msgFile3BgDark,
+		.over = st::msgFile3BgOver,
+		.selected = st::msgFile3BgSelected,
+		.ext = ext,
+	};
+	case 3: return {
+		.index = colorIndex,
+		.color = st::msgFile4Bg,
+		.dark = st::msgFile4BgDark,
+		.over = st::msgFile4BgOver,
+		.selected = st::msgFile4BgSelected,
+		.ext = ext,
+	};
+	}
+	Unexpected("Color index in CreateDocumentGenericPreview.");
+}
+
+// Ui::CachedRoundCorners DocumentCorners(int32 colorIndex) {
+// 	return Ui::CachedRoundCorners(Ui::Doc1Corners + (colorIndex & 3));
+// }
+
+} // namespace Layout

Telegram/SourceFiles/layout/layout_document_generic_preview.h

@@ -0,0 +1,25 @@
+/*
+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 Layout {
+
+struct DocumentGenericPreview final {
+	static DocumentGenericPreview Create(DocumentData *document);
+	const style::icon *icon() const;
+	const int index;
+	const style::color &color;
+	const style::color &dark;
+	const style::color &over;
+	const style::color &selected;
+	const QString ext;
+};
+
+// Ui::CachedRoundCorners DocumentCorners(int colorIndex);
+
+} // namespace Layout

Telegram/SourceFiles/layout/layout_item_base.cpp

@@ -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
+*/
+#include "layout/layout_item_base.h"
+
+#include "history/view/history_view_cursor_state.h"
+
+[[nodiscard]] HistoryView::TextState LayoutItemBase::getState(
+		QPoint point,
+		StateRequest request) const {
+	return {};
+}
+
+[[nodiscard]] TextSelection LayoutItemBase::adjustSelection(
+		TextSelection selection,
+		TextSelectType type) const {
+	return selection;
+}

Telegram/SourceFiles/layout/layout_item_base.h

@@ -0,0 +1,33 @@
+/*
+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
+
+#include "layout/abstract_layout_item.h"
+
+namespace HistoryView {
+struct TextState;
+struct StateRequest;
+} // namespace HistoryView
+
+class LayoutItemBase : public AbstractLayoutItem {
+public:
+	using TextState = HistoryView::TextState;
+	using StateRequest = HistoryView::StateRequest;
+
+	using AbstractLayoutItem::AbstractLayoutItem;
+
+	virtual void initDimensions() = 0;
+
+	[[nodiscard]] virtual TextState getState(
+		QPoint point,
+		StateRequest request) const;
+	[[nodiscard]] virtual TextSelection adjustSelection(
+		TextSelection selection,
+		TextSelectType type) const;
+
+};

Telegram/SourceFiles/layout/layout_mosaic.cpp

@@ -0,0 +1,391 @@
+/*
+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
+*/
+#include "layout/layout_mosaic.h"
+
+#include "styles/style_chat_helpers.h"
+
+namespace Mosaic::Layout {
+
+AbstractMosaicLayout::AbstractMosaicLayout(int bigWidth)
+: _bigWidth(bigWidth) {
+}
+
+int AbstractMosaicLayout::rowHeightAt(int row) const {
+	Expects(row >= 0 && row < _rows.size());
+
+	return _rows[row].height;
+}
+
+int AbstractMosaicLayout::countDesiredHeight(int newWidth) {
+	auto result = 0;
+	for (auto &row : _rows) {
+		layoutRow(row, newWidth ? newWidth : _width);
+		result += row.height;
+	}
+	return _padding.top() + result + _padding.bottom();
+}
+
+FoundItem AbstractMosaicLayout::findByPoint(const QPoint &globalPoint) const {
+	auto sx = globalPoint.x() - _padding.left();
+	auto sy = globalPoint.y() - _padding.top();
+	auto row = -1;
+	auto col = -1;
+	auto sel = -1;
+	bool exact = true;
+	if (sy >= 0) {
+		row = 0;
+		for (auto rows = rowsCount(); row < rows; ++row) {
+			const auto rowHeight = _rows[row].height;
+			if (sy < rowHeight) {
+				break;
+			}
+			sy -= rowHeight;
+		}
+	} else {
+		row = 0;
+		exact = false;
+	}
+	if (row >= rowsCount()) {
+		row = rowsCount() - 1;
+		exact = false;
+	}
+	if (sx < 0) {
+		sx = 0;
+		exact = false;
+	}
+	if (sx >= 0 && row >= 0 && row < rowsCount()) {
+		const auto columnsCount = _rows[row].items.size();
+		col = 0;
+		for (int cols = columnsCount; col < cols; ++col) {
+			const auto item = itemAt(row, col);
+			const auto width = item->width();
+			if (sx < width) {
+				break;
+			}
+			sx -= width;
+			sx -= _rightSkip;
+		}
+		if (col >= columnsCount) {
+			col = columnsCount - 1;
+			exact = false;
+		}
+
+		sel = ::Layout::PositionToIndex(row, + col);
+	} else {
+		row = col = -1;
+	}
+	return { sel, exact, QPoint(sx, sy) };
+}
+
+QRect AbstractMosaicLayout::findRect(int index) const {
+	const auto clip = QRect(0, 0, _width, 100);
+	const auto fromX = style::RightToLeft()
+		? (_width - clip.x() - clip.width())
+		: clip.x();
+	const auto toX = style::RightToLeft()
+		? (_width - clip.x())
+		: (clip.x() + clip.width());
+	const auto rows = _rows.size();
+	auto top = 0;
+	for (auto row = 0; row != rows; ++row) {
+		auto &inlineRow = _rows[row];
+		// if ((top + inlineRow.height) > clip.top()) {
+			auto left = 0;
+			if (row == (rows - 1)) {
+//				context.lastRow = true;
+			}
+			for (const auto &item : inlineRow.items) {
+				if (left >= toX) {
+					break;
+				}
+
+				const auto w = item->width();
+				if ((left + w) > fromX) {
+					if (item->position() == index) {
+						return QRect(
+							left + _padding.left(),
+							top + _padding.top(),
+							item->width(),
+							item->height());
+					}
+				}
+				left += w;
+				left += _rightSkip;
+			}
+		// }
+		top += inlineRow.height;
+	}
+	return QRect();
+}
+
+void AbstractMosaicLayout::addItems(
+		gsl::span<const not_null<AbstractLayoutItem*>> items) {
+	_rows.reserve(items.size());
+	auto row = Row();
+	row.items.reserve(kInlineItemsMaxPerRow);
+	auto sumWidth = 0;
+	for (const auto &item : items) {
+		addItem(item, row, sumWidth);
+	}
+	rowFinalize(row, sumWidth, true);
+}
+
+void AbstractMosaicLayout::setRightSkip(int rightSkip) {
+	_rightSkip = rightSkip;
+}
+
+void AbstractMosaicLayout::setPadding(QMargins padding) {
+	_padding = padding;
+}
+
+void AbstractMosaicLayout::setFullWidth(int w) {
+	_width = w;
+}
+
+bool AbstractMosaicLayout::empty() const {
+	return _rows.empty();
+}
+
+int AbstractMosaicLayout::rowsCount() const {
+	return _rows.size();
+}
+
+not_null<AbstractLayoutItem*> AbstractMosaicLayout::itemAt(
+		int row,
+		int column) const {
+	Expects((row >= 0)
+		&& (row < _rows.size())
+		&& (column >= 0)
+		&& (column < _rows[row].items.size()));
+
+	return _rows[row].items[column];
+}
+
+not_null<AbstractLayoutItem*> AbstractMosaicLayout::itemAt(int index) const {
+	const auto &[row, column] = ::Layout::IndexToPosition(index);
+	return itemAt(row, column);
+}
+
+AbstractLayoutItem *AbstractMosaicLayout::maybeItemAt(
+		int row,
+		int column) const {
+	if ((row >= 0)
+		&& (row < _rows.size())
+		&& (column >= 0)
+		&& (column < _rows[row].items.size())) {
+		return _rows[row].items[column];
+	}
+	return nullptr;
+}
+
+AbstractLayoutItem *AbstractMosaicLayout::maybeItemAt(int index) const {
+	const auto &[row, column] = ::Layout::IndexToPosition(index);
+	return maybeItemAt(row, column);
+}
+
+void AbstractMosaicLayout::clearRows(bool resultsDeleted) {
+	if (!resultsDeleted) {
+		for (const auto &row : _rows) {
+			for (const auto &item : row.items) {
+				item->setPosition(-1);
+			}
+		}
+	}
+	_rows.clear();
+}
+
+void AbstractMosaicLayout::forEach(
+		Fn<void(not_null<const AbstractLayoutItem*>)> callback) {
+	for (const auto &row : _rows) {
+		for (const auto &item : row.items) {
+			callback(item);
+		}
+	}
+}
+
+void AbstractMosaicLayout::paint(
+		Fn<void(not_null<AbstractLayoutItem*>, QPoint)> paintItem,
+		const QRect &clip) const {
+	auto top = _padding.top();
+	const auto fromX = style::RightToLeft()
+		? (_width - clip.x() - clip.width())
+		: clip.x();
+	const auto toX = style::RightToLeft()
+		? (_width - clip.x())
+		: (clip.x() + clip.width());
+	const auto rows = _rows.size();
+	for (auto row = 0; row != rows; ++row) {
+		if (top >= clip.top() + clip.height()) {
+			break;
+		}
+		auto &inlineRow = _rows[row];
+		if ((top + inlineRow.height) > clip.top()) {
+			auto left = _padding.left();
+			if (row == (rows - 1)) {
+//				context.lastRow = true;
+			}
+			for (const auto &item : inlineRow.items) {
+				if (left >= toX) {
+					break;
+				}
+
+				const auto w = item->width();
+				if ((left + w) > fromX) {
+					paintItem(item, QPoint(left, top));
+				}
+				left += w;
+				left += _rightSkip;
+			}
+		}
+		top += inlineRow.height;
+	}
+}
+
+int AbstractMosaicLayout::validateExistingRows(
+		Fn<bool(not_null<const AbstractLayoutItem*>, int)> checkItem,
+		int count) {
+	auto until = 0;
+	auto untilRow = 0;
+	auto untilCol = 0;
+	while (until < count) {
+		if ((untilRow >= _rows.size())
+			|| checkItem(_rows[untilRow].items[untilCol], until)) {
+			break;
+		}
+		++until;
+		if (++untilCol == _rows[untilRow].items.size()) {
+			++untilRow;
+			untilCol = 0;
+		}
+	}
+	if (until == count) { // All items are layed out.
+		if (untilRow == _rows.size()) { // Nothing changed.
+			return until;
+		}
+
+		{
+			const auto rows = _rows.size();
+			auto skip = untilCol;
+			for (auto i = untilRow; i < rows; ++i) {
+				for (const auto &item : _rows[i].items) {
+					if (skip) {
+						--skip;
+					} else {
+						item->setPosition(-1);
+					}
+				}
+			}
+		}
+		if (!untilCol) { // All good rows are filled.
+			_rows.resize(untilRow);
+			return until;
+		}
+		_rows.resize(untilRow + 1);
+		_rows[untilRow].items.resize(untilCol);
+		_rows[untilRow].maxWidth = ranges::accumulate(
+			_rows[untilRow].items,
+			0,
+			[](int w, auto &row) { return w + row->maxWidth(); });
+		layoutRow(_rows[untilRow], _width);
+		return until;
+	}
+	if (untilRow && !untilCol) { // Remove last row, maybe it is not full.
+		--untilRow;
+		untilCol = _rows[untilRow].items.size();
+	}
+	until -= untilCol;
+
+	for (auto i = untilRow; i < _rows.size(); ++i) {
+		for (const auto &item : _rows[i].items) {
+			item->setPosition(-1);
+		}
+	}
+	_rows.resize(untilRow);
+
+	return until;
+}
+
+void AbstractMosaicLayout::addItem(
+		not_null<AbstractLayoutItem*> item,
+		Row &row,
+		int &sumWidth) {
+	// item->preload();
+
+	using namespace ::Layout;
+	item->setPosition(PositionToIndex(_rows.size(), row.items.size()));
+	if (rowFinalize(row, sumWidth, false)) {
+		item->setPosition(PositionToIndex(_rows.size(), 0));
+	}
+
+	sumWidth += item->maxWidth();
+	if (!row.items.empty() && _rightSkip) {
+		sumWidth += _rightSkip;
+	}
+
+	row.items.push_back(item);
+}
+
+bool AbstractMosaicLayout::rowFinalize(Row &row, int &sumWidth, bool force) {
+	if (row.items.empty()) {
+		return false;
+	}
+
+	const auto full = (row.items.size() >= kInlineItemsMaxPerRow);
+	// Currently use the same GIFs layout for all widget sizes.
+	const auto big = (sumWidth >= _bigWidth);
+	if (full || big || force) {
+		row.maxWidth = (full || big) ? sumWidth : 0;
+		layoutRow(row, _width);
+		_rows.push_back(std::move(row));
+		row = Row();
+		row.items.reserve(kInlineItemsMaxPerRow);
+		sumWidth = 0;
+		return true;
+	}
+	return false;
+}
+
+void AbstractMosaicLayout::layoutRow(Row &row, int fullWidth) {
+	const auto count = int(row.items.size());
+	Assert(count <= kInlineItemsMaxPerRow);
+
+	// Enumerate items in the order of growing maxWidth()
+	// for that sort item indices by maxWidth().
+	int indices[kInlineItemsMaxPerRow];
+	for (auto i = 0; i != count; ++i) {
+		indices[i] = i;
+	}
+	std::sort(indices, indices + count, [&](int a, int b) {
+		return row.items[a]->maxWidth() < row.items[b]->maxWidth();
+	});
+
+	auto desiredWidth = row.maxWidth;
+	row.height = 0;
+	auto availableWidth = fullWidth - _padding.left() - _padding.right();
+	for (auto i = 0; i < count; ++i) {
+		const auto index = indices[i];
+		const auto &item = row.items[index];
+		const auto w = desiredWidth
+			? (item->maxWidth() * availableWidth / desiredWidth)
+			: item->maxWidth();
+		const auto actualWidth = std::max(w, st::inlineResultsMinWidth);
+		row.height = std::max(
+			row.height,
+			item->resizeGetHeight(actualWidth));
+		if (desiredWidth) {
+			availableWidth -= actualWidth;
+			desiredWidth -= row.items[index]->maxWidth();
+			if (index > 0 && _rightSkip) {
+				availableWidth -= _rightSkip;
+				desiredWidth -= _rightSkip;
+			}
+		}
+	}
+}
+
+} // namespace Mosaic::Layout

Telegram/SourceFiles/layout/layout_mosaic.h

@@ -0,0 +1,156 @@
+/*
+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
+
+#include "layout/abstract_layout_item.h"
+#include "layout/layout_position.h"
+
+namespace Mosaic::Layout {
+
+struct FoundItem {
+	int index = -1;
+	bool exact = false;
+	QPoint relative;
+};
+
+class AbstractMosaicLayout {
+public:
+	AbstractMosaicLayout(int bigWidth);
+
+	[[nodiscard]] int rowHeightAt(int row) const;
+	[[nodiscard]] int countDesiredHeight(int newWidth);
+
+	[[nodiscard]] FoundItem findByPoint(const QPoint &globalPoint) const;
+
+	[[nodiscard]] QRect findRect(int index) const;
+
+	void setRightSkip(int rightSkip);
+	void setPadding(QMargins padding);
+	void setFullWidth(int w);
+
+	[[nodiscard]] bool empty() const;
+	[[nodiscard]] int rowsCount() const;
+
+	void clearRows(bool resultsDeleted);
+
+protected:
+	void addItems(gsl::span<const not_null<AbstractLayoutItem*>> items);
+
+	[[nodiscard]] not_null<AbstractLayoutItem*> itemAt(int row, int column) const;
+	[[nodiscard]] not_null<AbstractLayoutItem*> itemAt(int index) const;
+
+	[[nodiscard]] AbstractLayoutItem *maybeItemAt(int row, int column) const;
+	[[nodiscard]] AbstractLayoutItem *maybeItemAt(int index) const;
+
+	void forEach(Fn<void(not_null<const AbstractLayoutItem*>)> callback);
+
+	void paint(
+		Fn<void(not_null<AbstractLayoutItem*>, QPoint)> paintItem,
+		const QRect &clip) const;
+	int validateExistingRows(
+		Fn<bool(not_null<const AbstractLayoutItem*>, int)> checkItem,
+		int count);
+
+private:
+	static constexpr auto kInlineItemsMaxPerRow = 5;
+	struct Row {
+		int maxWidth = 0;
+		int height = 0;
+		std::vector<AbstractLayoutItem*> items;
+	};
+
+	void addItem(not_null<AbstractLayoutItem*> item, Row &row, int &sumWidth);
+	bool rowFinalize(Row &row, int &sumWidth, bool force);
+	void layoutRow(Row &row, int fullWidth);
+
+	int _bigWidth;
+	int _width = 0;
+	int _rightSkip = 0;
+	QMargins _padding;
+	std::vector<Row> _rows;
+
+};
+
+template <
+	typename ItemBase,
+	typename = std::enable_if_t<
+		std::is_base_of_v<AbstractLayoutItem, ItemBase>>>
+class MosaicLayout final : public AbstractMosaicLayout {
+	using Parent = AbstractMosaicLayout;
+
+public:
+	using Parent::Parent;
+
+	void addItems(const std::vector<not_null<ItemBase*>> &items) {
+		Parent::addItems({
+			reinterpret_cast<const not_null<AbstractLayoutItem*>*>(
+				items.data()),
+			items.size() });
+	}
+
+	[[nodiscard]] not_null<ItemBase*> itemAt(int row, int column) const {
+		return Downcast(Parent::itemAt(row, column));
+	}
+	[[nodiscard]] not_null<ItemBase*> itemAt(int index) const {
+		return Downcast(Parent::itemAt(index));
+	}
+	[[nodiscard]] ItemBase *maybeItemAt(int row, int column) const {
+		return Downcast(Parent::maybeItemAt(row, column));
+	}
+	[[nodiscard]] ItemBase *maybeItemAt(int index) const {
+		return Downcast(Parent::maybeItemAt(index));
+	}
+
+	void forEach(Fn<void(not_null<const ItemBase*>)> callback) {
+		Parent::forEach([&](
+				not_null<const AbstractLayoutItem*> item) {
+			callback(Downcast(item));
+		});
+	}
+
+	void paint(
+			Fn<void(not_null<ItemBase*>, QPoint)> paintItem,
+			const QRect &clip) const {
+		Parent::paint([&](
+				not_null<AbstractLayoutItem*> item,
+				QPoint point) {
+			paintItem(Downcast(item), point);
+		}, clip);
+	}
+
+	int validateExistingRows(
+			Fn<bool(not_null<const ItemBase*>, int)> checkItem,
+			int count) {
+		return Parent::validateExistingRows([&](
+				not_null<const AbstractLayoutItem*> item,
+				int until) {
+			return checkItem(Downcast(item), until);
+		}, count);
+	}
+
+private:
+	[[nodiscard]] static not_null<ItemBase*> Downcast(
+			not_null<AbstractLayoutItem*> item) {
+		return static_cast<ItemBase*>(item.get());
+	}
+	[[nodiscard]] static ItemBase *Downcast(
+			AbstractLayoutItem *item) {
+		return static_cast<ItemBase*>(item);
+	}
+	[[nodiscard]] static not_null<const ItemBase*> Downcast(
+			not_null<const AbstractLayoutItem*> item) {
+		return static_cast<const ItemBase*>(item.get());
+	}
+	[[nodiscard]] static const ItemBase *Downcast(
+			const AbstractLayoutItem *item) {
+		return static_cast<const ItemBase*>(item);
+	}
+
+};
+
+} // namespace Mosaic::Layout

Telegram/SourceFiles/layout/layout_position.cpp

@@ -0,0 +1,31 @@
+/*
+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
+*/
+#include "layout/layout_position.h"
+
+namespace Layout {
+namespace {
+
+constexpr auto kMatrixRowShift = 40000;
+
+} // namespace
+
+Layout::Position IndexToPosition(int index) {
+	return {
+		(index >= 0) ? (index / kMatrixRowShift) : -1,
+		(index >= 0) ? (index % kMatrixRowShift) : -1 };
+}
+
+int PositionToIndex(int row, int column) {
+	return row * kMatrixRowShift + column;
+}
+
+int PositionToIndex(const Layout::Position &position) {
+	return PositionToIndex(position.row, position.column);
+}
+
+} // namespace Layout

Telegram/SourceFiles/layout/layout_position.h

@@ -0,0 +1,21 @@
+/*
+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 Layout {
+
+struct Position {
+	int row = -1;
+	int column = -1;
+};
+
+[[nodiscard]] Position IndexToPosition(int index);
+[[nodiscard]] int PositionToIndex(int row, int column);
+[[nodiscard]] int PositionToIndex(const Position &position);
+
+} // namespace Layout

Telegram/SourceFiles/layout/layout_selection.cpp

@@ -0,0 +1,42 @@
+/*
+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
+*/
+#include "layout/layout_selection.h"
+
+bool IsSubGroupSelection(TextSelection selection) {
+	return (selection.from == 0xFFFF) && (selection.to != 0xFFFF);
+}
+
+bool IsGroupItemSelection(
+		TextSelection selection,
+		int index) {
+	Expects(index >= 0 && index < 0x0F);
+
+	return IsSubGroupSelection(selection) && (selection.to & (1 << index));
+}
+
+TextSelection AddGroupItemSelection(
+		TextSelection selection,
+		int index) {
+	Expects(index >= 0 && index < 0x0F);
+
+	const auto bit = uint16(1U << index);
+	return TextSelection(
+		0xFFFF,
+		IsSubGroupSelection(selection) ? (selection.to | bit) : bit);
+}
+
+TextSelection RemoveGroupItemSelection(
+		TextSelection selection,
+		int index) {
+	Expects(index >= 0 && index < 0x0F);
+
+	const auto bit = uint16(1U << index);
+	return IsSubGroupSelection(selection)
+		? TextSelection(0xFFFF, selection.to & ~bit)
+		: selection;
+}

Telegram/SourceFiles/layout/layout_selection.h

@@ -0,0 +1,26 @@
+/*
+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
+
+#include "ui/text/text.h"
+
+constexpr auto FullSelection = TextSelection { 0xFFFF, 0xFFFF };
+
+[[nodiscard]] bool IsSubGroupSelection(TextSelection selection);
+
+[[nodiscard]] bool IsGroupItemSelection(
+		TextSelection selection,
+		int index);
+
+[[nodiscard]] TextSelection AddGroupItemSelection(
+		TextSelection selection,
+		int index);
+
+[[nodiscard]] TextSelection RemoveGroupItemSelection(
+		TextSelection selection,
+		int index);