[Tex/LaTex] How to remove some pages from the navigation bullets in Beamer

Question

I'm making a beamer presentation using the miniframes outer theme, with navigation bullets, and the subsection=false option, meaning the bullets are all on a single row. The problem I have is that, if one section has too many pages, the bullets overflow to the next section:

Section 1 Section 2
oooooooooooooooooooo

I tend to have many frames, some of them just asking a question, leading to the next detailed frame. I don't really need those frames to be represented by navigation bullets, and removing them would fix the problem. Any idea how to do that?

I could cheat by using overlays to have the question and the answer on the same frame, but that would be a mess…

Code example to answer percusse's question: this should give you one circle per frame, not one per subsection. If you add many frames in one subsection, the circles will overflow over the next section.

\documentclass[compress]{beamer}
\useoutertheme[subsection=false]{miniframes}
\begin{document}
\section{S1}
\subsection{SS1}
\frame{1}
\frame{2}
\frame{3}
\subsection{SS2}
\frame{1}
\frame{2}
\frame{3}
...
\end{document}

Answer 1

The mini frames are generated using the \beamer@framepages entries in the auxiliary .nav file. If you remove these for certain frames, they don't appear in the navigation¹. To do so, you have to patch the \beamer@writeslidentry macro responsible for writing the commands to the .nav file:

\makeatletter
\let\beamer@writeslidentry@miniframeson=\beamer@writeslidentry
\def\beamer@writeslidentry@miniframesoff{%
  \expandafter\beamer@ifempty\expandafter{\beamer@framestartpage}{}% does not happen normally
  {%else
    % removed \addtocontents commands
    \clearpage\beamer@notesactions%
  }
}
\newcommand*{\miniframeson}{\let\beamer@writeslidentry=\beamer@writeslidentry@miniframeson}
\newcommand*{\miniframesoff}{\let\beamer@writeslidentry=\beamer@writeslidentry@miniframesoff}
\makeatother

Include this code in your document, then you can switch between the original implementation and the modified one not generating any mini frames by using \miniframeson and \miniframesoff.

¹This may, however, have some unwanted consequences I'm not aware of!

Full example code:

\documentclass[compress]{beamer}
\useoutertheme[subsection=false]{miniframes}
\makeatletter
\let\beamer@writeslidentry@miniframeson=\beamer@writeslidentry
\def\beamer@writeslidentry@miniframesoff{%
  \expandafter\beamer@ifempty\expandafter{\beamer@framestartpage}{}% does not happen normally
  {%else
    % removed \addtocontents commands
    \clearpage\beamer@notesactions%
  }
}
\newcommand*{\miniframeson}{\let\beamer@writeslidentry=\beamer@writeslidentry@miniframeson}
\newcommand*{\miniframesoff}{\let\beamer@writeslidentry=\beamer@writeslidentry@miniframesoff}
\makeatother
\begin{document}
\section{S1}
\subsection{SS1}
\frame{1}
\miniframesoff
\frame{2}
\miniframeson
\frame{3}
\subsection{SS2}
\miniframesoff
\frame{1}
\miniframeson
\frame{2}
\frame{3}
\end{document}

Resulting headline (only four of six mini frames are displayed):