Point to a Verbatim Line using TikZ

Question

I'm trying to use TikZ in beamer to point to a line of code. Here's what I have so far:

\documentclass{beamer}
\usepackage{tikz}
\usepackage{fancyvrb}

\begin{document}

\begin{frame}[fragile,t] 
\frametitle{test}
\begin{Verbatim}
example code 
lines
\end{Verbatim}
\tikz \node [circle,fill=black] {};
\begin{Verbatim}
here 
\end{Verbatim}
\end{frame}

\end{document}

The node, however, appears on a new line. I want to put it on the right of the line saying, "lines" so that I can then use TikZ overlays to point an arrow to it and put some explanatory lines on the right.

I have seen examples of this but they either use math or plain text. How can I do this with Verbatim?

Answer 1

You need to use commandchars. In my example |replaces \. §and !are used to replace the accolades {and }

\documentclass{beamer}
\usepackage{tikz}
\usepackage{fancyvrb}

\begin{document}
 \def\firstnode{\tikz[remember picture] \node[circle,fill=blue] (n1) {};}  
 \def\secondnode{\tikz[remember picture] \node[circle,fill=red] (n2) {};} 

\begin{frame}[fragile,t] 
\frametitle{test} 

\begin{Verbatim} [commandchars=\|\§\! ]
example code 
lines here |firstnode  
\end{Verbatim}

\begin{Verbatim}[commandchars=\|\§\! ]      
 |secondnode   Explanation
\end{Verbatim} 

 \begin{tikzpicture}[remember picture,overlay]
        \path[->,line width=1pt,dashed,red!40,>=latex] (n1) edge [bend left] (n2);
\end{tikzpicture} 
\end{frame}     
\end{document}