Function readBackground

Telegram/SourceFiles/storage/localstorage.cpp:656–771

}

bool readBackground() {
	FileReadDescriptor bg;
	auto &backgroundKey = Window::Theme::IsNightMode()
		? _backgroundKeyNight
		: _backgroundKeyDay;
	if (!ReadEncryptedFile(bg, backgroundKey, _basePath, SettingsKey)) {
		if (backgroundKey) {
			ClearKey(backgroundKey, _basePath);
			backgroundKey = 0;
			writeSettings();
		}
		return false;
	}

	qint32 legacyId = 0;
	bg.stream >> legacyId;
	const auto paper = [&] {
		if (legacyId == kWallPaperLegacySerializeTagId) {
			quint64 id = 0;
			quint64 accessHash = 0;
			quint32 flags = 0;
			QString slug;
			bg.stream
				>> id
				>> accessHash
				>> flags
				>> slug;
			return Data::WallPaper::FromLegacySerialized(
				id,
				accessHash,
				flags,
				slug);
		} else if (legacyId == kWallPaperSerializeTagId) {
			QByteArray serialized;
			bg.stream >> serialized;
			return Data::WallPaper::FromSerialized(serialized);
		} else {
			return Data::WallPaper::FromLegacyId(legacyId);
		}
	}();
	if (bg.stream.status() != QDataStream::Ok || !paper) {
		return false;
	}

	QByteArray imageData;
	bg.stream >> imageData;
	const auto isOldEmptyImage = (bg.stream.status() != QDataStream::Ok);
	if (isOldEmptyImage
		|| Data::IsLegacy1DefaultWallPaper(*paper)
		|| (Data::IsLegacy2DefaultWallPaper(*paper) && bg.version < 1000000)
		|| (Data::IsLegacy3DefaultWallPaper(*paper) && bg.version < 1000000)
		|| (Data::IsLegacy4DefaultWallPaper(*paper) && bg.version < 1000000)
		|| Data::IsDefaultWallPaper(*paper)) {
		_backgroundCanWrite = false;
		if (isOldEmptyImage || bg.version < 1000000) {
			Window::Theme::Background()->set(Data::DefaultWallPaper());
		} else {
			Window::Theme::Background()->set(*paper);