Navigation frames in sidebar

Question

I am writing a beamer presentation and I want to show a circle for each frame on the navigation sidebar. Can this be done? Here's a MWE:

\documentclass{beamer}

% Set Theme
\usetheme{Marburg}
\usecolortheme{beaver}

% Set sections in sidebar color
\makeatletter{}
    \setbeamercolor{section in sidebar}{fg=yellow}
    \setbeamercolor{section in sidebar shaded}{fg=white}
\setbeamercolor{title in sidebar}{fg=yellow}
\setbeamertemplate{section in toc}[sections numbered]
\setbeamertemplate{section in sidebar right}[sections numbered]
\makeatother{}

\begin{document}

\begin{frame}{Outline}
    \tableofcontents
\end{frame}

\section{sec1}
\begin{frame}{frame1.1}
        blah, blah, blah
    \end{frame}
\begin{frame}{frame1.2}
        blah, blah, blah
    \end{frame}

\section{sec2}
\begin{frame}{frame2.1}
        blah, blah, blah
    \end{frame}
\begin{frame}{frame2.2}
        blah, blah, blah
    \end{frame}

\end{document}

any ideas?

Answer 1

One could borrow the navigation bar from the miniframe theme and rotate it.

\documentclass{beamer}

% removing section names from navigation
\makeatletter
\def\sectionentry#1#2#3#4#5{% section number, section title, page
    \ifnum#5=\c@part%
    \beamer@section@set@min@width
    \box\beamer@sectionbox\hskip1.875ex plus 1fill%
    \beamer@xpos=0\relax%
    \beamer@ypos=0\relax%
    \ht\beamer@sectionbox=1.875ex%
    \dp\beamer@sectionbox=0ex%
    \fi\ignorespaces}
\makeatother

% Set Theme
\usetheme[width=0.8cm]{Marburg}

% insert dots in sidebar
\setbeamertemplate{sidebar right}{\hskip0.3cm\rotatebox{270}{\insertnavigation{.98\paperheight}}}

\begin{document}

    \begin{frame}{Outline}
        \tableofcontents
    \end{frame}

    \section{sec1}
    \subsection{s1}
    \begin{frame}{frame1.1}
        blah, blah, blah
    \end{frame}
    \begin{frame}{frame1.2}
        blah, blah, blah
    \end{frame}

    \section{sec2}
        \subsection{s2}
    \begin{frame}{frame2.1}
        blah, blah, blah
    \end{frame}
    \begin{frame}{frame2.2}
        blah, blah, blah
    \end{frame}

    \section{sec3}
    \subsection{s3}
    \begin{frame}{frame3.1}
        blah, blah, blah
    \end{frame}
    \begin{frame}{frame3.2}
        blah, blah, blah
    \end{frame}


\end{document}