[Tex/LaTex] Using overlays in itemize with nested items for stepwise alerts

Question

I am wondering if there is a default (or manual) overlay specification that produces the following –

\begin{itemize}
\item<alerted on slides 1-2> Parent 1
\begin{itemize}
\item<alerted on slide 1 only> 1.1
\item<alerted on slide 2 only> 1.2
\end{itemize}
\item<alerted on slides 3-4> Parent 2
\begin{itemize}
\item<alerted on slide 3 only> 2.1
\item<alerted on slide 4 only> 2.2
\end{itemize}
\end{itemize}

The gist is that all items and subitems are visible, but the slides proceed stepwise alerting each subitem in turn, and the parent item remains alerted while focus is on any child subitem of that parent. Thanks in advance.

Answer 1

Yes, you can use [<alert@+>] for the inner itemize and something of the form \alert<m-n> for the \items of the outer itemize:

\documentclass{beamer}

\begin{document}

\begin{frame}
\begin{itemize}
\item\alert<1-3>{Parent 1}
\begin{itemize}[<alert@+>]
\item1.1
\item1.2
\item1.3
\end{itemize}
\item\alert<4-5>{Parent 2}
\begin{itemize}[<alert@+>]
\item2.1
\item2.2
\end{itemize}
\item\alert<6-10>{Parent 3}
\begin{itemize}[<alert@+>]
\item3.1
\item3.2
\item3.3
\item3.4
\item3.5
\end{itemize}
\end{itemize}
\end{frame}

\end{document}