Method updatePapers

Telegram/SourceFiles/boxes/background_box.cpp:533–589

}

void BackgroundBox::Inner::updatePapers() {
	if (forChannel()) {
		if (_session->data().cloudThemes().chatThemes().empty()) {
			return;
		}
	} else {
		if (_session->data().wallpapers().empty()) {
			return;
		}
	}
	_over = _overDown = Selection();

	const auto was = base::take(_papers);
	if (forChannel()) {
		const auto now = _forPeer->wallPaper();
		const auto &list = _session->data().cloudThemes().chatThemes();
		if (list.empty()) {
			return;
		}
		using Type = Data::CloudThemeType;
		const auto type = Window::Theme::IsNightMode()
			? Type::Dark
			: Type::Light;
		_papers.reserve(list.size() + 1);
		const auto nowEmojiId = now ? now->emojiId() : QString();
		if (!now || !now->emojiId().isEmpty()) {
			_papers.push_back({ Window::Theme::Background()->paper() });
			_currentId = _papers.back().data.id();
		} else {
			_papers.push_back({ *now });
			_currentId = now->id();
		}
		for (const auto &theme : list) {
			const auto i = theme.settings.find(type);
			if (i != end(theme.settings) && i->second.paper) {
				_papers.push_back({ *i->second.paper });
				if (nowEmojiId == theme.emoticon) {
					_currentId = _papers.back().data.id();
				}
			}
		}
	} else {
		_papers = _session->data().wallpapers(
		) | ranges::views::filter([&](const Data::WallPaper &paper) {
			return (!paper.isPattern() || !paper.backgroundColors().empty())
				&& (!_forPeer
					|| (!Data::IsDefaultWallPaper(paper)
						&& (Data::IsCloudWallPaper(paper)
							|| Data::IsCustomWallPaper(paper))));
		}) | ranges::views::transform([](const Data::WallPaper &paper) {
			return Paper{ paper };
		}) | ranges::to_vector;
		pushCustomPapers();
		sortPapers();
	}
	resizeToContentAndPreload();
}