Using overlays in itemize with nested items for stepwise alerts

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.

1 Answer

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}


• I used essentially the same form, but instead of \alert explicitly, I used \item<alert@x>, which was not working. I assume that must have been setting a default, inherited by the nested items? – mlh3789 Aug 28 '13 at 19:01
• @mlh3789 to achive the desired effect, one could've used \item\action<alert@1-2>{Parent 1} instead, but not just <\alert@1-2> without \action. – Gonzalo Medina Aug 28 '13 at 19:04
• A side effect of the two syntaxes \item<alert@1> versus \item\action<alert@1> appears to be the bullets are not alerted in the second method. So, how about the above question with a default overlay spec (ie completely specified at the \begin{itemize} )? – mlh3789 Aug 28 '13 at 19:15
• @mlh3789 please see my updated answer with an automated possibility for the inner itemize. – Gonzalo Medina Aug 28 '13 at 20:32
• That is indeed the method I ended up using, though not totally automated it is most likely the most practical and intuitive. – mlh3789 Aug 29 '13 at 17:51