I have a long presentation which basically is a collection of exercises. Each excercise has its own subsection, shown in the sidebar, like this:
\documentclass{beamer}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usetheme[hideothersubsections,left,width=1.4cm]{Goettingen}
\begin{document}
\begin{frame}
\frametitle{Start page}
\end{frame}
\begin{frame}
\section{section 1}
\subsection{1}
\subsection{2}
\subsection{3}
\subsection{4}
\subsection{5}
\subsection{6}
\subsection{7}
\end{frame}
\end{document}
eventually I got this:
After a certain number the sidebar is filled and some numbers end outside of the frame.
What I would like is a two (or more) columns sidebar navigation, so that I can add more exercises.
Looks like a similar problem was solved here, but I'm not skilled enough to adapt that solution to a vertical sidebar.
Any help is much appreciated.
Followup#1
Now i've got to this point:
What I can't still do is:
1) exclude sections from the multicol environment, i.e. the section 2 should be in the first row, not the second
2) the first subsection of the second column should be horizontally aligned with the first subsection of the first column, i.e. 1.5 should be aligned to 1.1.
This is the code, I just added a multicol environment at the end of the \insertverticalnavigation definition:
\documentclass{beamer}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{multicol}
\usetheme[hideothersubsections,left,width=1.4cm]{Goettingen}
\makeatletter
\def\insertverticalnavigation#1{%
\vbox{%
\def\sectionentry##1##2##3##4##5{%
\ifnum##5=\c@part%
\def\insertsectionhead{##2}%
\def\insertsectionheadnumber{##1}%
\def\insertpartheadnumber{##5}%
\hbox{{%
\usebeamerfont{section in sidebar}\usebeamercolor[fg]{section in sidebar}%
\hyperlink{Navigation##3}{%
\ifnum\c@section=##1%
\ifnum\c@subsection=0\relax%
{\usebeamertemplate{section in sidebar}}%
\else%
\ifx\beamer@nav@css\beamer@hidetext%
{\usebeamertemplate{section in sidebar}}%
\else%
{\usebeamertemplate{section in sidebar shaded}}%
\fi%
\fi%
\else
{\usebeamertemplate{section in sidebar shaded}}%
\fi}}}%
\beamer@currentsubsection=0\relax\fi}%
\def\slideentry##1##2##3##4##5##6{}%
\def\beamer@subsectionentry##1##2##3##4##5{%
\ifnum##1=\c@part%
\def\insertpartheadnumber{##1}%
\def\insertsectionheadnumber{##2}%
\def\insertsubsectionheadnumber{##3}%
\def\insertsubsectionhead{##5}%
\beamer@tocifnothide{\ifnum\c@section=##2\ifnum\c@subsection=##3\beamer@nav@css\else\beamer@nav@oss\fi\else\beamer@nav@ooss\fi}%
{\hbox{{%
\usebeamerfont{subsection in sidebar}\usebeamercolor[fg]{subsection in sidebar}%
\hyperlink{Navigation##4}{%
\ifnum\c@section=##2%
\ifnum\c@subsection=##3%
\ifnum\c@subsubsection=0\relax%
{\usebeamertemplate{subsection in sidebar}}%
\else%
{\usebeamertemplate{subsection in sidebar shaded}}%
\fi%
\else%
{\usebeamertemplate{subsection in sidebar shaded}}%
\fi%
\else%
{\usebeamertemplate{subsection in sidebar shaded}}%
\fi}}}%
}%
\fi}%
\def\beamer@subsubsectionentry##1##2##3##4##5##6{%
\ifnum##1=\c@part%
\def\insertpartheadnumber{##1}%
\def\insertsectionheadnumber{##2}%
\def\insertsubsectionheadnumber{##3}%
\def\insertsubsubsectionheadnumber{##3}%
\def\insertsubsubsectionhead{##6}%
\beamer@tocifnothide{\ifnum\c@section=##2\ifnum\c@subsection=##3\beamer@nav@css\else\beamer@nav@oss\fi\else\beamer@nav@ooss\fi}%
{\hbox{{%
\usebeamerfont{subsubsection in sidebar}\usebeamercolor[fg]{subsubsection in sidebar}%
\hyperlink{Navigation##5}{%
\ifnum\c@section=##2%
\ifnum\c@subsection=##3%
\ifnum\c@subsubsection=##4%
{\usebeamertemplate{subsubsection in sidebar}}%
\else
{\usebeamertemplate{subsubsection in sidebar shaded}}%
\fi%
\else%
{\usebeamertemplate{subsubsection in sidebar shaded}}%
\fi%
\else%
{\usebeamertemplate{subsubsection in sidebar shaded}}%
\fi}}}%
}%
\fi}%
\hspace*{0.1em}\parbox[c][1cm][c]{1cm}{ %%%%%%%%%%%%%%%%
\begin{multicols}{2} % multicol %
\dohead\end{multicols} % code %
} %%%%%%%%%%%%%%%%
}%
}
\makeatother
\begin{document}
\section{1}
\subsection{1.1}
\frame{test}
\subsection{1.2}
\frame{test}
\subsection{1.3}
\frame{test}
\subsection{1.4}
\frame{test}
\subsection{1.5}
\frame{test}
\subsection{1.6}
\frame{test}
\subsection{1.7}
\frame{test}
\section{2}
\subsection{2.1}
\frame{test}
\subsection{2.2}
\frame{test}
\end{document}
