Change the contents of footline in a beamer presentation

Question

For my presentation, I am using Madrid theme; however, I'd like to change the contents of the footline. Currently, the footline shows, "short author" in the left, "short title" in the middle, and "date and framenumber/total number of frames" in the right side. I need to change these contents as follows:

Left side: Section name

Center: Subsection

Right: The same which is Date and frame number/total number of frames

I really appreciate if someone help me.

Answer 1

Madrid uses the infolines outer theme, so you need to redefine the footline template as implemented for this outer theme; here are the necessary changes:

\documentclass{beamer}
\usetheme{Madrid}

\makeatletter
\setbeamertemplate{footline}
{
  \leavevmode%
  \hbox{%
  \begin{beamercolorbox}[wd=.333333\paperwidth,ht=2.25ex,dp=1ex,center]{author in head/foot}%
    \usebeamerfont{author in head/foot}\insertsection
  \end{beamercolorbox}%
  \begin{beamercolorbox}[wd=.333333\paperwidth,ht=2.25ex,dp=1ex,center]{title in head/foot}%
    \usebeamerfont{title in head/foot}\insertsubsection
  \end{beamercolorbox}%
  \begin{beamercolorbox}[wd=.333333\paperwidth,ht=2.25ex,dp=1ex,right]{date in head/foot}%
    \usebeamerfont{date in head/foot}\insertshortdate{}\hspace*{2em}
    \insertframenumber{} / \inserttotalframenumber\hspace*{2ex} 
  \end{beamercolorbox}}%
  \vskip0pt%
}
\makeatother

\title{The Title}
\author{The Author}

\begin{document}

\section{Test Section One}
\subsection{Test Subsection One One}
\begin{frame}
test
\end{frame}
\subsection{Test Subsection One Two}
\begin{frame}
test
\end{frame}

\end{document}