# Mixing overprint with blocks of enumerations

I'd like to overlay a series of different blocks, each of which includes an enumeration that pauses with each item. The overprint environment handles this pretty well, but it doesn't seem to be mixing with the theme I'd like to use: Warsaw. Here's a minimal example of my problem:

\documentclass{beamer}

\usetheme{Warsaw}

\begin{document}

\begin{frame}{Test}
\begin{center}
text before
\pause
\begin{overprint}%
\onslide<2-3>\begin{center}{
\begin{block}{Some title here}
\begin{enumerate}[<+->]
\item One
\item Two
\end{enumerate}
\end{block}
}\end{center}
\onslide<4->\begin{center}{
\begin{block}{Some title here}
\begin{enumerate}[<+->]
\item CHicken
\item Duck
\item Rooster
\end{enumerate}
\end{block}
}\end{center}
\end{overprint}
text after
\end{center}
\end{frame}

\end{document}


The blocks are overlayed ontop of each other nicely but the bullet points that get generated go haywire. Here's a screen shot of what happens by the last slide:

Things work fine if I don't include the pauses between each enumeration item. Things also work well if I don't use the Warsaw theme.

Any thoughts as to why the Warsaw theme is corrupting my enumerations?

-

## 1 Answer

It's not just Warsaw; using CambridgeUS, for example, the problem also appears. Removing the inner center environments (which in your concrete example have no real effect) or using \centering instead solves the problem:

\documentclass{beamer}
\usetheme{Warsaw}

\begin{document}

\begin{frame}{Test}
\begin{center}
text before
\pause
\begin{overprint}%
\onslide<2-3>{%
\centering
\begin{block}{Some title here}
\begin{enumerate}[<+->]
\item One
\item Two
\end{enumerate}
\end{block}\par}
\onslide<4->{%
\centering
\begin{block}{Some title here}
\begin{enumerate}[<+->]
\item CHicken
\item Duck
\item Rooster
\end{enumerate}
\end{block}\par}
\end{overprint}
text after
\end{center}
\end{frame}

\end{document}


An image of the last slide:

I am not sure if perhaps the effect that you are trying to achieve is this one (using overlayarea instead of overprint):

\documentclass{beamer}
\usetheme{Warsaw}

\begin{document}

\begin{frame}{Test}
\begin{center}
text before
\pause
\begin{overlayarea}{\textwidth}{3.3cm}
\only<2-3>{%
\begin{block}{Some title here}
\begin{enumerate}[<+->]
\item One
\item Two
\end{enumerate}
\end{block}}
\only<4-7>{%
\begin{block}{Some title here}
\begin{enumerate}[<+(2)->]
\item CHicken
\item Duck
\item Rooster
\end{enumerate}
\end{block}}
\end{overlayarea}
text after
\end{center}
\end{frame}

\end{document}


The last slide:

By the way, you were using \onslide<2-3>\begin{center}{...}\end{center} and the proper syntax would be \onslide<2-3>{\begin{center}...\end{center}}; this, however doesn't solve the problem in this case; one possible solution is the one I described above.

-
Your second suggestion almost does exactly what I want, except it creates only 4 slides instead of 7. On the last slide, the second enumeration block is completely printed, so you can't walk through the bullet points as they're added. I did the \onslide<2-3>\begin{center{...}} business since it let me center the blocks on top of each other and let me enumerate the blocks as I wanted, sans the horrible side effect noted. Putting the center block inside {..} ends up with a totally different layout. –  fozziethebeat Aug 24 '12 at 4:52
@fozziethebeat please see the second code in my updated answer. Is something like that what you want? –  Gonzalo Medina Aug 24 '12 at 5:05
oooo yes, that's exactly what I needed! –  fozziethebeat Aug 24 '12 at 5:22