Method MultiSelect

Telegram/SourceFiles/ui/widgets/multi_select.cpp:512–552

};

MultiSelect::MultiSelect(
	QWidget *parent,
	const style::MultiSelect &st,
	rpl::producer<QString> placeholder,
	const QString &query)
: RpWidget(parent)
, _st(st)
, _scroll(this, _st.scroll) {
	const auto scrollCallback = [=](int activeTop, int activeBottom) {
		scrollTo(activeTop, activeBottom);
	};
	_inner = _scroll->setOwnedWidget(object_ptr<Inner>(
		this,
		st,
		std::move(placeholder),
		query,
		scrollCallback));
	_scroll->installEventFilter(this);
	_inner->setResizedCallback([this](int innerHeightDelta) {
		auto newHeight = resizeGetHeight(width());
		if (innerHeightDelta > 0) {
			_scroll->scrollToY(_scroll->scrollTop() + innerHeightDelta);
		}
		if (newHeight != height()) {
			resize(width(), newHeight);
			if (_resizedCallback) {
				_resizedCallback();
			}
		}
	});
	_inner->setQueryChangedCallback([this](const QString &query) {
		_scroll->scrollToY(_scroll->scrollTopMax());
		if (_queryChangedCallback) {
			_queryChangedCallback(query);
		}
	});

	setAttribute(Qt::WA_OpaquePaintEvent);
	auto defaultWidth = _st.item.maxWidth + _st.fieldMinWidth + _st.fieldCancelSkip;
	resizeToWidth(_st.padding.left() + defaultWidth + _st.padding.right());
}

bool MultiSelect::eventFilter(QObject *o, QEvent *e) {
	if (o == _scroll && e->type() == QEvent::KeyPress) {