TodayViewController.swift

func widgetActiveDisplayModeDidChange(_ activeDisplayMode: NCWidgetDisplayMode, withMaximumSize maxSize: CGSize) {
    if activeDisplayMode == .expanded {
        //1
        preferredContentSize = CGSize(width: maxSize.width, height: maxSize.width)
    } else if activeDisplayMode == .compact {
        //2
        preferredContentSize = maxSize
    }
}