tdesktop/Telegram/SourceFiles/window/themes/window_theme_preview.cpp

/*
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 "window/themes/window_theme_preview.h"

#include "lang/lang_keys.h"
#include "platform/platform_window_title.h"
#include "ui/text/text_options.h"
#include "ui/text/text_utilities.h"
#include "ui/image/image_prepare.h"
#include "ui/empty_userpic.h"
#include "ui/emoji_config.h"
#include "ui/painter.h"
#include "ui/chat/chat_theme.h"
#include "ui/chat/chat_style.h"
#include "ui/chat/message_bubble.h"
#include "ui/image/image_prepare.h"
#include "styles/style_widgets.h"
#include "styles/style_window.h"
#include "styles/style_media_view.h"
#include "styles/style_chat.h"
#include "styles/style_dialogs.h"
#include "styles/style_info.h"

namespace Window {
namespace Theme {
namespace {

QString fillLetters(const QString &name) {
	QList<QString> letters;
	QList<int> levels;
	auto level = 0;
	auto letterFound = false;
	auto ch = name.constData(), end = ch + name.size();
	while (ch != end) {
		auto emojiLength = 0;
		if (Ui::Emoji::Find(ch, end, &emojiLength)) {
			ch += emojiLength;
		} else if (ch->isHighSurrogate()) {
			++ch;
			if (ch != end && ch->isLowSurrogate()) {
				++ch;
			}
		} else if (!letterFound && ch->isLetterOrNumber()) {
			letterFound = true;
			if (ch + 1 != end && Ui::Text::IsDiac(*(ch + 1))) {
				letters.push_back(QString(ch, 2));
				levels.push_back(level);
				++ch;
			} else {
				letters.push_back(QString(ch, 1));
				levels.push_back(level);
			}
			++ch;
		} else {
			if (*ch == ' ') {
				level = 0;
				letterFound = false;
			} else if (letterFound && *ch == '-') {
				level = 1;
				letterFound = true;
			}
			++ch;
		}
	}

	// We prefer the second letter to be after ' ', but it can also be after '-'.
	auto result = QString();
	if (!letters.isEmpty()) {
		result += letters.front();
		auto bestIndex = 0;
		auto bestLevel = 2;
		for (auto i = letters.size(); i != 1;) {
			if (levels[--i] < bestLevel) {
				bestIndex = i;
				bestLevel = levels[i];
			}
		}
		if (bestIndex > 0) {
			result += letters[bestIndex];
		}
	}
	return result.toUpper();
}

class Generator {
public:
	Generator(
		const Instance &theme,
		CurrentData &&current,
		PreviewType type);

	[[nodiscard]] QImage generate();

private:
	enum class Status {
		None,
		Sent,
		Received
	};
	struct Row {
		Ui::Text::String name;
		QString letters;
		enum class Type {
			User,
			Group,
			Channel
		};
		Type type = Type::User;
		int peerIndex = 0;
		int unreadCounter = 0;
		bool muted = false;
		bool pinned = false;
		QString date;
		Ui::Text::String text;
		Status status = Status::None;
		bool selected = false;
		bool active = false;
	};
	struct Bubble {
		int width = 0;
		int height = 0;
		bool outbg = false;
		Status status = Status::None;
		QString date;
		bool attachToTop = false;
		bool attachToBottom = false;
		bool tail = true;
		Ui::Text::String text = { st::msgMinWidth };
		QVector<int> waveform;
		int waveactive = 0;
		QString wavestatus;
		QImage photo;
		int photoWidth = 0;
		int photoHeight = 0;
		Ui::Text::String replyName = { st::msgMinWidth };
		Ui::Text::String replyText = { st::msgMinWidth };
	};

	[[nodiscard]] bool extended() const;
	void prepare();

	void addRow(
		QString name,
		int peerIndex,
		QString date,
		const TextWithEntities &text);
	void addBubble(Bubble bubble, int width, int height, QString date, Status status);
	void addAudioBubble(QVector<int> waveform, int waveactive, QString wavestatus, QString date, Status status);
	void addTextBubble(QString text, QString date, Status status);
	void addDateBubble(QString date);
	void addPhotoBubble(QString image, QString caption, QString date, Status status);
	QSize computeSkipBlock(Status status, QString date);
	int computeInfoWidth(Status status, QString date);

	void generateData();

	void paintHistoryList();
	void paintHistoryBackground();
	void paintTopBar();
	void paintComposeArea();
	void paintDialogs();
	void paintDialogsList();
	void paintHistoryShadows();
	void paintRow(const Row &row);
	void paintBubble(const Bubble &bubble);
	void paintService(QString text);

	void paintUserpic(int x, int y, Row::Type type, int index, QString letters);

	void setTextPalette(const style::TextPalette &st);
	void restoreTextPalette();

	const Instance &_theme;
	const style::palette &_palette;
	const CurrentData _current;
	const PreviewType _type;
	Ui::ChatStyle _st;
	Painter *_p = nullptr;

	QRect _rect;
	QRect _inner;
	QRect _body;
	QRect _dialogs;
	QRect _dialogsList;
	QRect _topBar;
	QRect _composeArea;
	QRect _history;

	int _rowsTop = 0;
	std::vector<Row> _rows;

	Ui::Text::String _topBarName;
	QString _topBarStatus;
	bool _topBarStatusActive = false;

	int _historyBottom = 0;
	std::vector<Bubble> _bubbles;

	style::TextPalette _textPalette;

};

bool Generator::extended() const {
	return (_type == PreviewType::Extended);
}

void Generator::prepare() {
	const auto size = extended()
		? QRect(
			QPoint(),
			st::themePreviewSize).marginsAdded(st::themePreviewMargin).size()
		: st::themePreviewSize;
	_rect = QRect(QPoint(), size);
	_inner = extended() ? _rect.marginsRemoved(st::themePreviewMargin) : _rect;
	_body = extended() ? _inner.marginsRemoved(QMargins(0, Platform::PreviewTitleHeight(), 0, 0)) : _inner;
	_dialogs = QRect(_body.x(), _body.y(), st::themePreviewDialogsWidth, _body.height());
	_dialogsList = _dialogs.marginsRemoved(QMargins(0, st::dialogsFilterPadding.y() + st::dialogsMenuToggle.height + st::dialogsFilterPadding.y(), 0, st::defaultDialogRow.padding.bottom()));
	_topBar = QRect(_dialogs.x() + _dialogs.width(), _dialogs.y(), _body.width() - _dialogs.width(), st::topBarHeight);
	_composeArea = QRect(_topBar.x(), _body.y() + _body.height() - st::historySendSize.height(), _topBar.width(), st::historySendSize.height());
	_history = QRect(_topBar.x(), _topBar.y() + _topBar.height(), _topBar.width(), _body.height() - _topBar.height() - _composeArea.height());

	generateData();
}

void Generator::addRow(
		QString name,
		int peerIndex,
		QString date,
		const TextWithEntities &text) {
	Row row;
	row.name.setText(st::msgNameStyle, name, Ui::NameTextOptions());

	row.letters = fillLetters(name);

	row.peerIndex = peerIndex;
	row.date = date;
	row.text.setMarkedText(
		st::dialogsTextStyle,
		text,
		Ui::DialogTextOptions());
	_rows.push_back(std::move(row));
}

void Generator::addBubble(Bubble bubble, int width, int height, QString date, Status status) {
	bubble.width = width;
	bubble.height = height;
	bubble.date = date;
	bubble.status = status;
	_bubbles.push_back(std::move(bubble));
}

void Generator::addAudioBubble(QVector<int> waveform, int waveactive, QString wavestatus, QString date, Status status) {
	Bubble bubble;
	bubble.waveform = waveform;
	bubble.waveactive = waveactive;
	bubble.wavestatus = wavestatus;

	auto skipBlock = computeSkipBlock(status, date);

	auto width = st::msgFileMinWidth;
	const auto &st = st::msgFileLayout;
	auto tleft = st.padding.left() + st.thumbSize + st.thumbSkip;
	accumulate_max(width, tleft + st::normalFont->width(wavestatus) + skipBlock.width() + st::msgPadding.right());
	accumulate_min(width, st::msgMaxWidth);

	auto height = st.padding.top() + st.thumbSize + st.padding.bottom();
	addBubble(std::move(bubble), width, height, date, status);
}

QSize Generator::computeSkipBlock(Status status, QString date) {
	auto infoWidth = computeInfoWidth(status, date);
	auto width = st::msgDateSpace + infoWidth - st::msgDateDelta.x();
	auto height = st::msgDateFont->height - st::msgDateDelta.y();
	return QSize(width, height);
}

int Generator::computeInfoWidth(Status status, QString date) {
	auto result = st::msgDateFont->width(date);
	if (status != Status::None) {
		result += st::historySendStateSpace;
	}
	return result;
}

void Generator::addTextBubble(QString text, QString date, Status status) {
	Bubble bubble;
	auto skipBlock = computeSkipBlock(status, date);
	auto marked = TextWithEntities{ std::move(text) };
	bubble.text.setMarkedText(
		st::messageTextStyle,
		std::move(marked),
		Ui::ItemTextDefaultOptions());
	bubble.text.updateSkipBlock(skipBlock.width(), skipBlock.height());

	auto width = _history.width() - st::msgMargin.left() - st::msgMargin.right();
	accumulate_min(width, st::msgPadding.left() + bubble.text.maxWidth() + st::msgPadding.right());
	accumulate_min(width, st::msgMaxWidth);

	auto textWidth = qMax(width - st::msgPadding.left() - st::msgPadding.right(), 1);
	auto textHeight = bubble.text.countHeight(textWidth);

	auto height = st::msgPadding.top() + textHeight + st::msgPadding.bottom();
	addBubble(std::move(bubble), width, height, date, status);
}

void Generator::addDateBubble(QString date) {
	Bubble bubble;
	addBubble(std::move(bubble), 0, 0, date, Status::None);
}

void Generator::addPhotoBubble(QString image, QString caption, QString date, Status status) {
	Bubble bubble;
	bubble.photo.load(image);
	bubble.photoWidth = style::ConvertScale(bubble.photo.width() / 2);
	bubble.photoHeight = style::ConvertScale(bubble.photo.height() / 2);
	auto skipBlock = computeSkipBlock(status, date);
	auto marked = TextWithEntities{ std::move(caption) };
	bubble.text.setMarkedText(
		st::messageTextStyle,
		std::move(marked),
		Ui::ItemTextDefaultOptions());
	bubble.text.updateSkipBlock(skipBlock.width(), skipBlock.height());

	auto width = _history.width() - st::msgMargin.left() - st::msgMargin.right();
	accumulate_min(width, bubble.photoWidth);
	accumulate_min(width, st::msgMaxWidth);

	auto textWidth = qMax(width - st::msgPadding.left() - st::msgPadding.right(), 1);
	auto textHeight = bubble.text.countHeight(textWidth);

	auto height = st::mediaCaptionSkip + textHeight + st::msgPadding.bottom();
	addBubble(std::move(bubble), width, height, date, status);
}

void Generator::generateData() {
	_rows.reserve(9);
	addRow(
		"Eva Summer",
		0,
		"11:00",
		{ .text = "We are too smart for this world. "
			+ QString::fromUtf8("\xf0\x9f\xa4\xa3\xf0\x9f\x98\x82") });
	_rows.back().active = true;
	_rows.back().pinned = true;
	addRow("Alexandra Smith", 7, "10:00", { .text = "This is amazing!" });
	_rows.back().unreadCounter = 2;
	addRow(
		"Mike Apple",
		2,
		"9:00",
		Ui::Text::PlainLink(QChar(55357)
			+ QString()
			+ QChar(56836)
			+ " Sticker"));
	_rows.back().unreadCounter = 2;
	_rows.back().muted = true;
	addRow("Evening Club", 1, "8:00", Ui::Text::PlainLink("Eva: Photo"));
	_rows.back().type = Row::Type::Group;
	addRow(
		"Old Pirates",
		6,
		"7:00",
		Ui::Text::PlainLink("Max:").append(" Yo-ho-ho!"));
	_rows.back().type = Row::Type::Group;
	addRow("Max Bright", 3, "6:00", { .text = "How about some coffee?" });
	_rows.back().status = Status::Received;
	addRow("Natalie Parker", 4, "5:00", { .text = "OK, great)" });
	_rows.back().status = Status::Received;
	addRow("Davy Jones", 5, "4:00", Ui::Text::PlainLink("Keynote.pdf"));

	_topBarName.setText(st::msgNameStyle, "Eva Summer", Ui::NameTextOptions());
	_topBarStatus = "online";
	_topBarStatusActive = true;

	addPhotoBubble(":/gui/art/themeimage.jpg", "To reach a port, we must sail. " + QString::fromUtf8("\xf0\x9f\xa5\xb8"), "7:00", Status::None);
	int wavedata[] = { 0, 0, 0, 0, 27, 31, 4, 1, 0, 0, 23, 30, 18, 9, 7, 19, 4, 2, 2, 2, 0, 0, 15, 15, 15, 15, 3, 15, 19, 3, 2, 0, 0, 0, 0, 0, 3, 12, 16, 6, 4, 6, 14, 12, 2, 12, 12, 11, 3, 0, 7, 5, 7, 4, 7, 5, 2, 4, 0, 9, 5, 7, 6, 2, 2, 0, 0 };
	auto waveform = QVector<int>(base::array_size(wavedata));
	memcpy(waveform.data(), wavedata, sizeof(wavedata));
	addAudioBubble(waveform, 33, "0:07", "8:00", Status::None);
	_bubbles.back().outbg = true;
	_bubbles.back().status = Status::Received;
	addDateBubble("December 26");
	addTextBubble("Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. " + QString::fromUtf8("\xf0\x9f\xa7\x90"), "10:00", Status::Received);
	_bubbles.back().tail = false;
	_bubbles.back().outbg = true;
	_bubbles.back().attachToBottom = true;
	addTextBubble("Mark Twain said that " + QString::fromUtf8("\xe2\x98\x9d\xef\xb8\x8f"), "10:00", Status::Received);
	_bubbles.back().outbg = true;
	_bubbles.back().attachToTop = true;
	_bubbles.back().tail = true;
	addTextBubble("We are too smart for this world. " + QString::fromUtf8("\xf0\x9f\xa4\xa3\xf0\x9f\x98\x82"), "11:00", Status::None);
	_bubbles.back().replyName.setText(st::msgNameStyle, "Alex Cassio", Ui::NameTextOptions());
	_bubbles.back().replyText.setText(st::messageTextStyle, "Mark Twain said that " + QString::fromUtf8("\xe2\x98\x9d\xef\xb8\x8f"), Ui::DialogTextOptions());
}

Generator::Generator(
	const Instance &theme,
	CurrentData &&current,
	PreviewType type)
: _theme(theme)
, _palette(_theme.palette)
, _current(std::move(current))
, _type(type)
, _st(&_palette) {
}

QImage Generator::generate() {
	prepare();

	auto result = QImage(
		_rect.size() * cIntRetinaFactor(),
		QImage::Format_ARGB32_Premultiplied);
	result.setDevicePixelRatio(cRetinaFactor());
	result.fill(st::themePreviewBg->c);

	{
		Painter p(&result);
		PainterHighQualityEnabler hq(p);
		_p = &p;

		_p->fillRect(_body, QColor(0, 0, 0));
		_p->fillRect(_body, st::windowBg[_palette]);

		paintHistoryList();
		paintTopBar();
		paintComposeArea();
		paintDialogs();
		paintHistoryShadows();
	}
	if (extended()) {
		Platform::PreviewWindowFramePaint(result, _palette, _body, _rect.width());
	}

	return result;
}

void Generator::paintHistoryList() {
	paintHistoryBackground();

	_historyBottom = _history.y() + _history.height();
	_historyBottom -= st::historyPaddingBottom;
	_p->setClipping(true);
	for (auto i = _bubbles.size(); i != 0;) {
		auto &bubble = _bubbles[--i];
		if (bubble.width > 0) {
			paintBubble(bubble);
		} else {
			paintService(bubble.date);
		}
	}

	_p->setClipping(false);
}

void Generator::paintHistoryBackground() {
	auto fromy = (-st::topBarHeight);
	auto background = _theme.background;
	auto tiled = _theme.tiled;
	if (background.isNull()) {
		const auto fakePaper = Data::WallPaper(_current.backgroundId);
		if (Data::IsThemeWallPaper(fakePaper)) {
			background = Ui::ReadBackgroundImage(
				u":/gui/art/background.tgv"_q,
				QByteArray(),
				true);
			const auto paper = Data::DefaultWallPaper();
			background = Ui::PreparePatternImage(
				std::move(background),
				paper.backgroundColors(),
				paper.gradientRotation(),
				paper.patternOpacity());
			tiled = false;
		} else {
			background = std::move(_current.backgroundImage);
			tiled = _current.backgroundTiled;
		}
	}
	background = std::move(background).convertToFormat(
		QImage::Format_ARGB32_Premultiplied);
	background.setDevicePixelRatio(cRetinaFactor());
	_p->setClipRect(_history);
	if (tiled) {
		auto width = background.width();
		auto height = background.height();
		auto repeatTimesX = qCeil(_history.width() * cIntRetinaFactor() / float64(width));
		auto repeatTimesY = qCeil((_history.height() - fromy) * cIntRetinaFactor() / float64(height));
		auto imageForTiled = QImage(
			width * repeatTimesX,
			height * repeatTimesY,
			QImage::Format_ARGB32_Premultiplied);
		imageForTiled.setDevicePixelRatio(background.devicePixelRatio());
		auto imageForTiledBytes = imageForTiled.bits();
		auto bytesInLine = width * sizeof(uint32);
		for (auto timesY = 0; timesY != repeatTimesY; ++timesY) {
			auto imageBytes = background.constBits();
			for (auto y = 0; y != height; ++y) {
				for (auto timesX = 0; timesX != repeatTimesX; ++timesX) {
					memcpy(imageForTiledBytes, imageBytes, bytesInLine);
					imageForTiledBytes += bytesInLine;
				}
				imageBytes += background.bytesPerLine();
				imageForTiledBytes += imageForTiled.bytesPerLine()
					- (repeatTimesX * bytesInLine);
			}
		}
		_p->drawImage(_history.x(), _history.y() + fromy, imageForTiled);
	} else {
		PainterHighQualityEnabler hq(*_p);

		auto fill = QSize(_topBar.width(), _body.height());
		const auto rects = Ui::ComputeChatBackgroundRects(
			fill,
			background.size());
		auto to = rects.to;
		to.moveTop(to.top() + fromy);
		to.moveTopLeft(to.topLeft() + _history.topLeft());
		_p->drawImage(to, background, rects.from);
	}
	_p->setClipping(false);
}

void Generator::paintTopBar() {
	_p->fillRect(_topBar, st::topBarBg[_palette]);

	auto right = st::topBarMenuToggle.width;
	st::topBarMenuToggle.icon[_palette].paint(*_p, _topBar.x() + _topBar.width() - right + st::topBarMenuToggle.iconPosition.x(), _topBar.y() + st::topBarMenuToggle.iconPosition.y(), _rect.width());
	right += st::topBarSkip + st::topBarCall.width;
	st::topBarCall.icon[_palette].paint(*_p, _topBar.x() + _topBar.width() - right + st::topBarCall.iconPosition.x(), _topBar.y() + st::topBarCall.iconPosition.y(), _rect.width());
	right += st::topBarSearch.width;
	st::topBarSearch.icon[_palette].paint(*_p, _topBar.x() + _topBar.width() - right + st::topBarSearch.iconPosition.x(), _topBar.y() + st::topBarSearch.iconPosition.y(), _rect.width());

	auto decreaseWidth = st::topBarCall.width + st::topBarCallSkip + st::topBarSearch.width + st::topBarMenuToggle.width;
	auto nameleft = _topBar.x() + st::topBarArrowPadding.right();
	auto nametop = _topBar.y() + st::topBarArrowPadding.top();
	auto statustop = _topBar.y() + st::topBarHeight - st::topBarArrowPadding.bottom() - st::dialogsTextFont->height;
	auto namewidth = _topBar.x() + _topBar.width() - decreaseWidth - nameleft - st::topBarArrowPadding.right();
	_p->setFont(st::dialogsTextFont);
	_p->setPen(_topBarStatusActive ? st::historyStatusFgActive[_palette] : st::historyStatusFg[_palette]);
	_p->drawText(nameleft, statustop + st::dialogsTextFont->ascent, _topBarStatus);

	_p->setPen(st::dialogsNameFg[_palette]);
	_topBarName.drawElided(*_p, nameleft, nametop, namewidth);
}

void Generator::paintComposeArea() {
	_p->fillRect(_composeArea, st::historyReplyBg[_palette]);

	auto controlsTop = _composeArea.y() + _composeArea.height() - st::historySendSize.height();
	const auto attachIconLeft = (st::historyAttach.iconPosition.x() < 0)
		? ((st::historyAttach.width - st::historyAttach.icon.width()) / 2)
		: st::historyAttach.iconPosition.x();
	const auto attachIconTop = (st::historyAttach.iconPosition.y() < 0)
		? ((st::historyAttach.height - st::historyAttach.icon.height()) / 2)
		: st::historyAttach.iconPosition.y();
	st::historyAttach.icon[_palette].paint(*_p, _composeArea.x() + attachIconLeft, controlsTop + attachIconTop, _rect.width());
	auto right = st::historySendRight + st::historySendSize.width();
	st::historyRecordVoice[_palette].paintInCenter(*_p, QRect(_composeArea.x() + _composeArea.width() - right, controlsTop, st::historySendSize.width(), st::historySendSize.height()));

	const auto emojiIconLeft = (st::historyAttachEmoji.iconPosition.x() < 0)
		? ((st::historyAttachEmoji.width - st::historyAttachEmoji.icon.width()) / 2)
		: st::historyAttachEmoji.iconPosition.x();
	const auto emojiIconTop = (st::historyAttachEmoji.iconPosition.y() < 0)
		? ((st::historyAttachEmoji.height - st::historyAttachEmoji.icon.height()) / 2)
		: st::historyAttachEmoji.iconPosition.y();
	const auto &emojiIcon = st::historyAttachEmoji.icon[_palette];
	right += st::historyAttachEmoji.width;
	auto attachEmojiLeft = _composeArea.x() + _composeArea.width() - right;
	_p->fillRect(attachEmojiLeft, controlsTop, st::historyAttachEmoji.width, st::historyAttachEmoji.height, st::historyComposeAreaBg[_palette]);
	emojiIcon.paint(*_p, attachEmojiLeft + emojiIconLeft, controlsTop + emojiIconTop, _rect.width());

	auto pen = st::historyEmojiCircleFg[_palette]->p;
	pen.setWidthF(style::ConvertScaleExact(st::historyEmojiCircleLine));
	pen.setCapStyle(Qt::RoundCap);
	_p->setPen(pen);
	_p->setBrush(Qt::NoBrush);

	PainterHighQualityEnabler hq(*_p);
	const auto skipx = emojiIcon.width() / 4;
	const auto skipy = emojiIcon.height() / 4;
	const auto inner = QRect(
		attachEmojiLeft + emojiIconLeft + skipx,
		controlsTop + emojiIconTop + skipy,
		emojiIcon.width() - 2 * skipx,
		emojiIcon.height() - 2 * skipy);
	_p->drawEllipse(inner);

	auto fieldLeft = _composeArea.x() + st::historyAttach.width;
	auto fieldTop = _composeArea.y() + _composeArea.height() - st::historyAttach.height + st::historySendPadding;
	auto fieldWidth = _composeArea.width() - st::historyAttach.width - st::historySendSize.width() - st::historySendRight - st::historyAttachEmoji.width;
	auto fieldHeight = st::historySendSize.height() - 2 * st::historySendPadding;
	auto field = QRect(fieldLeft, fieldTop, fieldWidth, fieldHeight);
	_p->fillRect(field, st::historyComposeField.textBg[_palette]);

	_p->setClipRect(field);
	_p->save();
	_p->setFont(st::historyComposeField.font);
	_p->setPen(st::historyComposeField.placeholderFg[_palette]);

	auto placeholderRect = QRect(
		field.x() + st::historyComposeField.textMargins.left() + st::historyComposeField.placeholderMargins.left(),
		field.y() + st::historyComposeField.textMargins.top() + st::historyComposeField.placeholderMargins.top(),
		field.width() - st::historyComposeField.textMargins.left() - st::historyComposeField.textMargins.right(),
		field.height() - st::historyComposeField.textMargins.top() - st::historyComposeField.textMargins.bottom());
	_p->drawText(placeholderRect, tr::lng_message_ph(tr::now), QTextOption(st::historyComposeField.placeholderAlign));

	_p->restore();
	_p->setClipping(false);
}

void Generator::paintDialogs() {
	_p->fillRect(_dialogs, st::dialogsBg[_palette]);

	const auto iconLeft = (st::dialogsMenuToggle.iconPosition.x() < 0)
		? (st::dialogsMenuToggle.width - st::dialogsMenuToggle.icon.width()) / 2
		: st::dialogsMenuToggle.iconPosition.x();
	const auto iconTop = (st::dialogsMenuToggle.iconPosition.y() < 0)
		? (st::dialogsMenuToggle.height - st::dialogsMenuToggle.icon.height()) / 2
		: st::dialogsMenuToggle.iconPosition.y();
	st::dialogsMenuToggle.icon[_palette].paint(*_p, _dialogs.x() + st::dialogsFilterPadding.x() + iconLeft, _dialogs.y() + st::dialogsFilterPadding.y() + iconTop, _rect.width());

	auto filterLeft = _dialogs.x() + st::dialogsFilterPadding.x() + st::dialogsMenuToggle.width + st::dialogsFilterPadding.x();
	auto filterRight = st::dialogsFilterSkip + st::dialogsFilterPadding.x();
	auto filterWidth = _dialogs.x() + _dialogs.width() - filterLeft - filterRight;
	auto filterAreaHeight = st::topBarHeight;
	auto filterTop = _dialogs.y() + (filterAreaHeight - st::dialogsFilter.heightMin) / 2;
	auto filter = QRect(filterLeft, filterTop, filterWidth, st::dialogsFilter.heightMin);

	auto pen = st::dialogsFilter.borderFg[_palette]->p;
	pen.setWidth(st::dialogsFilter.border);
	_p->setPen(pen);
	_p->setBrush(st::dialogsFilter.textBg[_palette]);
	{
		PainterHighQualityEnabler hq(*_p);
		const auto radius = st::dialogsFilter.borderRadius
			- (st::dialogsFilter.border / 2.);
		_p->drawRoundedRect(
			QRectF(filter).marginsRemoved(
				QMarginsF(
					st::dialogsFilter.border / 2.,
					st::dialogsFilter.border / 2.,
					st::dialogsFilter.border / 2.,
					st::dialogsFilter.border / 2.)),
			radius,
			radius);
	}

	_p->save();
	_p->setClipRect(filter);
	auto phRect = QRect(filter.x() + st::dialogsFilter.textMargins.left() + st::dialogsFilter.placeholderMargins.left(), filter.y() + st::dialogsFilter.textMargins.top() + st::dialogsFilter.placeholderMargins.top(), filter.width() - st::dialogsFilter.textMargins.left() - st::dialogsFilter.textMargins.right(), filter.height() - st::dialogsFilter.textMargins.top() - st::dialogsFilter.textMargins.bottom());
	_p->setFont(st::dialogsFilter.font);
	_p->setPen(st::dialogsFilter.placeholderFg[_palette]);
	_p->drawText(phRect, tr::lng_dlg_filter(tr::now), QTextOption(st::dialogsFilter.placeholderAlign));
	_p->restore();
	_p->setClipping(false);

	paintDialogsList();
}

void Generator::paintDialogsList() {
	_p->setClipRect(_dialogsList);
	_rowsTop = _dialogsList.y();
	for (auto &row : _rows) {
		paintRow(row);
		_rowsTop += st::dialogsRowHeight;
	}
	_p->setClipping(false);
}

void Generator::paintRow(const Row &row) {
	auto x = _dialogsList.x();
	auto y = _rowsTop;
	auto fullWidth = _dialogsList.width();
	auto fullRect = QRect(x, y, fullWidth, st::dialogsRowHeight);
	if (row.active || row.selected) {
		_p->fillRect(fullRect, row.active ? st::dialogsBgActive[_palette] : st::dialogsBgOver[_palette]);
	}
	const auto &st = st::defaultDialogRow;
	paintUserpic(
		x + st.padding.left(),
		y + st.padding.top(),
		row.type,
		row.peerIndex,
		row.letters);

	auto nameleft = x + st.nameLeft;
	auto namewidth = x + fullWidth - nameleft - st.padding.right();
	auto rectForName = QRect(nameleft, y + st.nameTop, namewidth, st::msgNameFont->height);

	auto chatTypeIcon = ([&row]() -> const style::icon * {
		if (row.type == Row::Type::Group) {
			return &(row.active ? st::dialogsChatIconActive : (row.selected ? st::dialogsChatIconOver : st::dialogsChatIcon));
		} else if (row.type == Row::Type::Channel) {
			return &(row.active ? st::dialogsChannelIconActive : (row.selected ? st::dialogsChannelIconOver : st::dialogsChannelIcon));
		}
		return nullptr;
	})();
	if (chatTypeIcon) {
		(*chatTypeIcon)[_palette].paint(*_p, rectForName.topLeft(), fullWidth);
		rectForName.setLeft(rectForName.left()
			+ chatTypeIcon->width()
			+ st::dialogsChatTypeSkip);
	}

	auto texttop = y + st.textTop;

	auto dateWidth = st::dialogsDateFont->width(row.date);
	rectForName.setWidth(rectForName.width() - dateWidth - st::dialogsDateSkip);
	_p->setFont(st::dialogsDateFont);
	_p->setPen(row.active ? st::dialogsDateFgActive[_palette] : (row.selected ? st::dialogsDateFgOver[_palette] : st::dialogsDateFg[_palette]));
	_p->drawText(rectForName.left() + rectForName.width() + st::dialogsDateSkip, rectForName.top() + st::msgNameFont->height - st::msgDateFont->descent, row.date);

	auto availableWidth = namewidth;
	if (row.unreadCounter) {
		auto counter = QString::number(row.unreadCounter);
		auto unreadRight = x + fullWidth - st.padding.right();
		auto unreadTop = texttop + st::dialogsTextFont->ascent - st::dialogsUnreadFont->ascent - (st::dialogsUnreadHeight - st::dialogsUnreadFont->height) / 2;

		auto unreadWidth = st::dialogsUnreadFont->width(counter);
		auto unreadRectWidth = unreadWidth + 2 * st::dialogsUnreadPadding;
		auto unreadRectHeight = st::dialogsUnreadHeight;
		accumulate_max(unreadRectWidth, unreadRectHeight);

		auto unreadRectLeft = unreadRight - unreadRectWidth;
		auto unreadRectTop = unreadTop;
		availableWidth -= unreadRectWidth + st::dialogsUnreadPadding;

		style::color bg[] = {
			st::dialogsUnreadBg,
			st::dialogsUnreadBgOver,
			st::dialogsUnreadBgActive,
			st::dialogsUnreadBgMuted,
			st::dialogsUnreadBgMutedOver,
			st::dialogsUnreadBgMutedActive
		};

		auto index = (row.active ? 2 : row.selected ? 1 : 0) + (row.muted ? 3 : 0);
		_p->setPen(Qt::NoPen);
		_p->setBrush(bg[index][_palette]);
		_p->drawRoundedRect(QRectF(unreadRectLeft, unreadRectTop, unreadRectWidth, unreadRectHeight), unreadRectHeight / 2., unreadRectHeight / 2.);

		auto textTop = (unreadRectHeight - st::dialogsUnreadFont->height) / 2;
		_p->setFont(st::dialogsUnreadFont);
		_p->setPen(row.active ? st::dialogsUnreadFgActive[_palette] : (row.selected ? st::dialogsUnreadFgOver[_palette] : st::dialogsUnreadFg[_palette]));
		_p->drawText(unreadRectLeft + (unreadRectWidth - unreadWidth) / 2, unreadRectTop + textTop + st::dialogsUnreadFont->ascent, counter);
	} else if (row.pinned) {
		auto icon = (row.active ? st::dialogsPinnedIconActive[_palette] : (row.selected ? st::dialogsPinnedIconOver[_palette] : st::dialogsPinnedIcon[_palette]));
		icon.paint(*_p, x + fullWidth - st.padding.right() - icon.width(), texttop, fullWidth);
		availableWidth -= icon.width() + st::dialogsUnreadPadding;
	}
	auto textRect = QRect(nameleft, texttop, availableWidth, st::dialogsTextFont->height);
	setTextPalette(row.active ? st::dialogsTextPaletteActive : (row.selected ? st::dialogsTextPaletteOver : st::dialogsTextPalette));
	_p->setFont(st::dialogsTextFont);
	_p->setPen(row.active ? st::dialogsTextFgActive[_palette] : (row.selected ? st::dialogsTextFgOver[_palette] : st::dialogsTextFg[_palette]));
	row.text.drawElided(*_p, textRect.left(), textRect.top(), textRect.width(), textRect.height() / st::dialogsTextFont->height);
	restoreTextPalette();

	auto sendStateIcon = ([&row]() -> const style::icon* {
		if (row.status == Status::Sent) {
			return &(row.active ? st::dialogsSentIconActive : (row.selected ? st::dialogsSentIconOver : st::dialogsSentIcon));
		} else if (row.status == Status::Received) {
			return &(row.active ? st::dialogsReceivedIconActive : (row.selected ? st::dialogsReceivedIconOver : st::dialogsReceivedIcon));
		}
		return nullptr;
	})();
	if (sendStateIcon) {
		rectForName.setWidth(rectForName.width() - st::dialogsSendStateSkip);
		(*sendStateIcon)[_palette].paint(*_p, rectForName.topLeft() + QPoint(rectForName.width(), 0), fullWidth);
	}
	_p->setPen(row.active ? st::dialogsNameFgActive[_palette] : (row.selected ? st::dialogsNameFgOver[_palette] : st::dialogsNameFg[_palette]));
	row.name.drawElided(*_p, rectForName.left(), rectForName.top(), rectForName.width());
}

void Generator::paintBubble(const Bubble &bubble) {
	auto height = bubble.height;
	if (!bubble.replyName.isEmpty()) {
		height += st::msgReplyPadding.top() + st::msgReplyBarSize.height() + st::msgReplyPadding.bottom();
	}
	auto isPhoto = !bubble.photo.isNull();

	auto x = _history.x();
	auto y = _historyBottom - st::msgMargin.bottom() - height;
	auto bubbleTop = y;
	auto bubbleHeight = height;
	if (isPhoto) {
		bubbleTop -= Ui::BubbleRadiusLarge() + 1;
		bubbleHeight += Ui::BubbleRadiusLarge() + 1;
	}

	auto left = bubble.outbg ? st::msgMargin.right() : st::msgMargin.left();
	if (bubble.outbg) {
		left += _history.width() - st::msgMargin.left() - st::msgMargin.right() - bubble.width;
	}
	x += left;

	using Corner = Ui::BubbleCornerRounding;
	auto rounding = Ui::BubbleRounding{
		Corner::Large,
		Corner::Large,
		Corner::Large,
		Corner::Large,
	};
	if (bubble.outbg) {
		if (bubble.attachToTop) {
			rounding.topRight = Corner::Small;
		}
		if (bubble.attachToBottom) {
			rounding.bottomRight = Corner::Small;
		} else if (bubble.tail) {
			rounding.bottomRight = Corner::Tail;
		}
	} else {
		if (bubble.attachToTop) {
			rounding.topLeft = Corner::Small;
		}
		if (bubble.attachToBottom) {
			rounding.bottomLeft = Corner::Small;
		} else if (bubble.tail) {
			rounding.bottomLeft = Corner::Tail;
		}
	}
	Ui::PaintBubble(*_p, Ui::SimpleBubble{
		.st = &_st,
		.geometry = QRect(x, bubbleTop, bubble.width, bubbleHeight),
		.outerWidth = _rect.width(),
		.outbg = bubble.outbg,
		.rounding = rounding,
	});

	auto trect = QRect(x, y, bubble.width, bubble.height);
	if (isPhoto) {
		trect = trect.marginsRemoved(QMargins(st::msgPadding.left(), st::mediaCaptionSkip, st::msgPadding.right(), st::msgPadding.bottom()));
	} else {
		trect = trect.marginsRemoved(st::msgPadding);
	}
	if (!bubble.replyName.isEmpty()) {
		auto h = st::msgReplyPadding.top() + st::msgReplyBarSize.height() + st::msgReplyPadding.bottom();

		auto bar = (bubble.outbg ? st::msgOutReplyBarColor[_palette] : st::msgInReplyBarColor[_palette]);
		auto rbar = style::rtlrect(trect.x() + st::msgReplyBarPos.x(), trect.y() + st::msgReplyPadding.top() + st::msgReplyBarPos.y(), st::msgReplyBarSize.width(), st::msgReplyBarSize.height(), _rect.width());
		_p->fillRect(rbar, bar);

		_p->setPen(bubble.outbg ? st::msgOutServiceFg[_palette] : st::msgInServiceFg[_palette]);
		bubble.replyName.drawLeftElided(*_p, trect.x() + st::msgReplyBarSkip, trect.y() + st::msgReplyPadding.top(), bubble.width - st::msgReplyBarSkip, _rect.width());

		_p->setPen(bubble.outbg ? st::historyTextOutFg[_palette] : st::historyTextInFg[_palette]);
		bubble.replyText.drawLeftElided(*_p, trect.x() + st::msgReplyBarSkip, trect.y() + st::msgReplyPadding.top() + st::msgServiceNameFont->height, bubble.width - st::msgReplyBarSkip, _rect.width());

		trect.setY(trect.y() + h);
	}

	if (!bubble.text.isEmpty()) {
		setTextPalette(bubble.outbg ? st::outTextPalette : st::inTextPalette);
		_p->setPen(bubble.outbg ? st::historyTextOutFg[_palette] : st::historyTextInFg[_palette]);
		_p->setFont(st::msgFont);
		bubble.text.draw(*_p, trect.x(), trect.y(), trect.width());
	} else if (!bubble.waveform.isEmpty()) {
		const auto &st = st::msgFileLayout;
		auto nameleft = x + st.padding.left() + st.thumbSize + st.thumbSkip;
		auto nameright = st.padding.right();
		auto statustop = y + st.statusTop;

		auto inner = style::rtlrect(x + st.padding.left(), y + st.padding.top(), st.thumbSize, st.thumbSize, _rect.width());
		_p->setPen(Qt::NoPen);
		_p->setBrush(bubble.outbg ? st::msgFileOutBg[_palette] : st::msgFileInBg[_palette]);

		_p->drawEllipse(inner);

		auto icon = ([&bubble] {
			return &(bubble.outbg ? st::historyFileOutPlay : st::historyFileInPlay);
		})();
		(*icon)[_palette].paintInCenter(*_p, inner);

		auto namewidth = x + bubble.width - nameleft - nameright;

		// rescale waveform by going in waveform.size * bar_count 1D grid
		auto active = bubble.outbg ? st::msgWaveformOutActive[_palette] : st::msgWaveformInActive[_palette];
		auto inactive = bubble.outbg ? st::msgWaveformOutInactive[_palette] : st::msgWaveformInInactive[_palette];
		auto wf_size = bubble.waveform.size();
		auto availw = namewidth + st::msgWaveformSkip;
		auto bar_count = qMin(availw / (st::msgWaveformBar + st::msgWaveformSkip), wf_size);
		auto max_value = 0;
		auto max_delta = st::msgWaveformMax - st::msgWaveformMin;
		auto wave_bottom = y + st::msgFileLayout.padding.top() + st::msgWaveformMax;
		_p->setPen(Qt::NoPen);
		auto norm_value = uchar(31);
		for (auto i = 0, bar_x = 0, sum_i = 0; i < wf_size; ++i) {
			auto value = bubble.waveform[i];
			if (sum_i + bar_count >= wf_size) { // draw bar
				sum_i = sum_i + bar_count - wf_size;
				if (sum_i < (bar_count + 1) / 2) {
					if (max_value < value) max_value = value;
				}
				auto bar_value = ((max_value * max_delta) + ((norm_value + 1) / 2)) / (norm_value + 1);

				if (i >= bubble.waveactive) {
					_p->fillRect(nameleft + bar_x, wave_bottom - bar_value, st::msgWaveformBar, st::msgWaveformMin + bar_value, inactive);
				} else {
					_p->fillRect(nameleft + bar_x, wave_bottom - bar_value, st::msgWaveformBar, st::msgWaveformMin + bar_value, active);
				}
				bar_x += st::msgWaveformBar + st::msgWaveformSkip;

				if (sum_i < (bar_count + 1) / 2) {
					max_value = 0;
				} else {
					max_value = value;
				}
			} else {
				if (max_value < value) max_value = value;

				sum_i += bar_count;
			}
		}

		auto status = bubble.outbg ? st::mediaOutFg[_palette] : st::mediaInFg[_palette];
		_p->setFont(st::normalFont);
		_p->setPen(status);
		_p->drawTextLeft(nameleft, statustop, _rect.width(), bubble.wavestatus);
	}

	_p->setFont(st::msgDateFont);
	auto infoRight = x + bubble.width - st::msgPadding.right() + st::msgDateDelta.x();
	auto infoBottom = y + height - st::msgPadding.bottom() + st::msgDateDelta.y();
	_p->setPen(bubble.outbg ? st::msgOutDateFg[_palette] : st::msgInDateFg[_palette]);
	auto infoWidth = computeInfoWidth(bubble.status, bubble.date);

	auto dateX = infoRight - infoWidth;
	auto dateY = infoBottom - st::msgDateFont->height;
	_p->drawText(dateX, dateY + st::msgDateFont->ascent, bubble.date);
	auto icon = ([&bubble]() -> const style::icon * {
		if (bubble.status == Status::Sent) {
			return &st::historySentIcon;
		} else if (bubble.status == Status::Received) {
			return &st::historyReceivedIcon;
		}
		return nullptr;
	})();
	if (icon) {
		(*icon)[_palette].paint(*_p, QPoint(infoRight, infoBottom) + st::historySendStatePosition, _rect.width());
	}

	_historyBottom = y - (bubble.attachToTop ? st::msgMarginTopAttached : st::msgMargin.top());

	if (isPhoto) {
		auto image = bubble.photo.scaled(bubble.photoWidth * cIntRetinaFactor(), bubble.photoHeight * cIntRetinaFactor(), Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
		image.setDevicePixelRatio(cRetinaFactor());
		_p->drawImage(x, y - bubble.photoHeight, image);
		_historyBottom -= bubble.photoHeight;
	}
}

void Generator::paintService(QString text) {
	auto bubbleHeight = st::msgServicePadding.top() + st::msgServiceFont->height + st::msgServicePadding.bottom();
	auto bubbleTop = _historyBottom - st::msgServiceMargin.bottom() - bubbleHeight;
	auto textWidth = st::msgServiceFont->width(text);
	auto bubbleWidth = st::msgServicePadding.left() + textWidth + st::msgServicePadding.right();
	auto radius = bubbleHeight / 2;
	_p->setPen(Qt::NoPen);
	_p->setBrush(st::msgServiceBg[_palette]);
	auto bubbleLeft = _history.x() + (_history.width() - bubbleWidth) / 2;
	_p->drawRoundedRect(bubbleLeft, bubbleTop, bubbleWidth, bubbleHeight, radius, radius);
	_p->setPen(st::msgServiceFg[_palette]);
	_p->setFont(st::msgServiceFont);
	_p->drawText(bubbleLeft + st::msgServicePadding.left(), bubbleTop + st::msgServicePadding.top() + st::msgServiceFont->ascent, text);
	_historyBottom = bubbleTop - st::msgServiceMargin.top();
}

void Generator::paintUserpic(int x, int y, Row::Type type, int index, QString letters) {
	const auto colorIndex = Ui::EmptyUserpic::ColorIndex(index);
	const auto colors = Ui::EmptyUserpic::UserpicColor(colorIndex);
	auto userpic = Ui::EmptyUserpic(colors, letters);

	const auto size = st::defaultDialogRow.photoSize;
	auto image = QImage(
		QSize(size, size) * style::DevicePixelRatio(),
		QImage::Format_ARGB32_Premultiplied);
	image.setDevicePixelRatio(cRetinaFactor());
	image.fill(Qt::transparent);
	{
		Painter p(&image);
		userpic.paintCircle(p, 0, 0, size, size);
	}
	_p->drawImage(rtl() ? (_rect.width() - x - size) : x, y, image);
}

void Generator::paintHistoryShadows() {
	_p->fillRect(_history.x() + st::lineWidth, _history.y(), _history.width() - st::lineWidth, st::lineWidth, st::shadowFg[_palette]);
	_p->fillRect(_history.x() + st::lineWidth, _history.y() + _history.height() - st::lineWidth, _history.width() - st::lineWidth, st::lineWidth, st::shadowFg[_palette]);
	_p->fillRect(_history.x(), _body.y(), st::lineWidth, _body.height(), st::shadowFg[_palette]);
}

void Generator::setTextPalette(const style::TextPalette &st) {
	_textPalette.linkFg = st.linkFg[_palette].clone();
	_textPalette.monoFg = st.monoFg[_palette].clone();
	_textPalette.spoilerFg = st.spoilerFg[_palette].clone();
	_textPalette.selectBg = st.selectBg[_palette].clone();
	_textPalette.selectFg = st.selectFg[_palette].clone();
	_textPalette.selectLinkFg = st.selectLinkFg[_palette].clone();
	_textPalette.selectMonoFg = st.selectMonoFg[_palette].clone();
	_textPalette.selectSpoilerFg = st.selectSpoilerFg[_palette].clone();
	_textPalette.selectOverlay = st.selectOverlay[_palette].clone();
	_p->setTextPalette(_textPalette);
}

void Generator::restoreTextPalette() {
	_p->restoreTextPalette();
}

} // namespace

QString CachedThemePath(uint64 documentId) {
	return QString::fromLatin1("special://cached-%1").arg(documentId);
}

std::unique_ptr<Preview> PreviewFromFile(
		const QByteArray &bytes,
		const QString &filepath,
		const Data::CloudTheme &cloud) {
	auto result = std::make_unique<Preview>();
	auto &object = result->object;
	object.cloud = cloud;
	object.pathAbsolute = filepath.isEmpty()
		? CachedThemePath(cloud.documentId)
		: QFileInfo(filepath).absoluteFilePath();
	object.pathRelative = filepath.isEmpty()
		? object.pathAbsolute
		: QDir().relativeFilePath(filepath);
	const auto instance = &result->instance;
	const auto cache = &result->instance.cached;
	if (bytes.isEmpty()) {
		if (!LoadFromFile(filepath, instance, cache, &object.content)) {
			return nullptr;
		}
	} else {
		object.content = bytes;
		if (!LoadFromContent(bytes, instance, cache)) {
			return nullptr;
		}
	}
	return result;
}

std::unique_ptr<Preview> GeneratePreview(
		const QByteArray &bytes,
		const QString &filepath,
		const Data::CloudTheme &cloud,
		CurrentData &&data,
		PreviewType type) {
	auto result = PreviewFromFile(bytes, filepath, cloud);
	if (!result) {
		return nullptr;
	}
	result->preview = Generator(
		result->instance,
		std::move(data),
		type
	).generate();
	return result;
}

QImage GeneratePreview(
		const QByteArray &bytes,
		const QString &filepath) {
	const auto preview = GeneratePreview(
		bytes,
		filepath,
		Data::CloudTheme(),
		CurrentData{ Data::ThemeWallPaper().id() },
		PreviewType::Normal);
	return preview ? preview->preview : QImage();
}

int DefaultPreviewTitleHeight() {
	return st::defaultWindowTitle.height;
}

void DefaultPreviewWindowTitle(Painter &p, const style::palette &palette, QRect body, int outerWidth) {
	auto titleRect = QRect(body.x(), body.y() - st::defaultWindowTitle.height, body.width(), st::defaultWindowTitle.height);
	p.fillRect(titleRect, QColor(0, 0, 0));
	p.fillRect(titleRect, st::titleBgActive[palette]);
	auto right = st::defaultWindowTitle.close.width;
	st::defaultWindowTitle.close.icon[palette].paint(p, titleRect.x() + titleRect.width() - right + st::defaultWindowTitle.close.iconPosition.x(), titleRect.y() + st::windowTitleButtonClose.iconPosition.y(), outerWidth);
	right += st::defaultWindowTitle.maximize.width;
	st::defaultWindowTitle.maximize.icon[palette].paint(p, titleRect.x() + titleRect.width() - right + st::defaultWindowTitle.maximize.iconPosition.x(), titleRect.y() + st::defaultWindowTitle.maximize.iconPosition.y(), outerWidth);
	right += st::defaultWindowTitle.minimize.width;
	st::defaultWindowTitle.minimize.icon[palette].paint(p, titleRect.x() + titleRect.width() - right + st::defaultWindowTitle.minimize.iconPosition.x(), titleRect.y() + st::defaultWindowTitle.minimize.iconPosition.y(), outerWidth);
	p.fillRect(titleRect.x(), titleRect.y() + titleRect.height() - st::lineWidth, titleRect.width(), st::lineWidth, st::titleShadow[palette]);
}

void DefaultPreviewWindowFramePaint(QImage &preview, const style::palette &palette, QRect body, int outerWidth) {
	auto mask = QImage(st::windowShadow.size() * cIntRetinaFactor(), QImage::Format_ARGB32_Premultiplied);
	mask.setDevicePixelRatio(cRetinaFactor());
	{
		Painter p(&mask);
		p.setCompositionMode(QPainter::CompositionMode_Source);
		st::windowShadow.paint(p, 0, 0, st::windowShadow.width(), QColor(0, 0, 0));
	}
	auto maxSize = 0;
	auto currentInt = static_cast<uint32>(0);
	auto lastLineInts = reinterpret_cast<const uint32*>(mask.constBits() + (mask.height() - 1) * mask.bytesPerLine());
	for (auto end = lastLineInts + mask.width(); lastLineInts != end; ++lastLineInts) {
		if (*lastLineInts < currentInt) {
			break;
		}
		currentInt = *lastLineInts;
		++maxSize;
	}
	if (maxSize % cIntRetinaFactor()) {
		maxSize -= (maxSize % cIntRetinaFactor());
	}
	auto size = maxSize / cIntRetinaFactor();
	auto bottom = size;
	auto left = size - st::windowShadowShift;
	auto right = left;
	auto top = size - 2 * st::windowShadowShift;

	auto sprite = st::windowShadow[palette];
	auto topLeft = QImage(sprite.size() * cIntRetinaFactor(), QImage::Format_ARGB32_Premultiplied);
	topLeft.setDevicePixelRatio(cRetinaFactor());
	{
		Painter p(&topLeft);
		p.setCompositionMode(QPainter::CompositionMode_Source);
		sprite.paint(p, 0, 0, sprite.width());
	}
	auto width = sprite.width();
	auto height = sprite.height();
	auto topRight = topLeft.mirrored(true, false);
	auto bottomRight = topLeft.mirrored(true, true);
	auto bottomLeft = topLeft.mirrored(false, true);

	Painter p(&preview);
	DefaultPreviewWindowTitle(p, palette, body, outerWidth);

	auto inner = QRect(body.x(), body.y() - st::defaultWindowTitle.height, body.width(), body.height() + st::defaultWindowTitle.height);
	p.setClipRegion(QRegion(inner.marginsAdded(QMargins(size, size, size, size))) - inner);
	p.drawImage(inner.x() - left, inner.y() - top, topLeft);
	p.drawImage(inner.x() + inner.width() + right - width, inner.y() - top, topRight);
	p.drawImage(inner.x() + inner.width() + right - width, inner.y() + inner.height() + bottom - height, bottomRight);
	p.drawImage(inner.x() - left, inner.y() + inner.height() + bottom - height, bottomLeft);
	p.drawImage(QRect(inner.x() - left, inner.y() - top + height, left, top + inner.height() + bottom - 2 * height), topLeft, QRect(0, topLeft.height() - cIntRetinaFactor(), left * cIntRetinaFactor(), cIntRetinaFactor()));
	p.drawImage(QRect(inner.x() - left + width, inner.y() - top, left + inner.width() + right - 2 * width, top), topLeft, QRect(topLeft.width() - cIntRetinaFactor(), 0, cIntRetinaFactor(), top * cIntRetinaFactor()));
	p.drawImage(QRect(inner.x() + inner.width(), inner.y() - top + height, right, top + inner.height() + bottom - 2 * height), topRight, QRect(topRight.width() - right * cIntRetinaFactor(), topRight.height() - cIntRetinaFactor(), right * cIntRetinaFactor(), cIntRetinaFactor()));
	p.drawImage(QRect(inner.x() - left + width, inner.y() + inner.height(), left + inner.width() + right - 2 * width, bottom), bottomRight, QRect(0, bottomRight.height() - bottom * cIntRetinaFactor(), cIntRetinaFactor(), bottom * cIntRetinaFactor()));
}

} // namespace Theme
} // namespace Window