%% Mathematical Institute, University of Oxford
%% LaTeX Beamer Presentation Theme
%%
%% v1.0 Original theme: Tim Hosgood 2015 (based on department PowerPoint Template)
%% v2.0 Reimplementation: Karl Welzel May 2024 (reimplementation from a standard theme)
%% v2.1 Further adjustments and tweaks: Keith Gillow May 2024

% Use infolines as base
\useoutertheme{infolines} 

% tweak colours for Oxford Blue
\definecolor{oxfordblue}{RGB}{0,33,71}
\usecolortheme[named=oxfordblue]{structure}

%turn off the navigation symbols
\setbeamertemplate{navigation symbols}{}

% define useful layout lengths
\newlength{\textmargin}
\setlength{\textmargin}{10mm} % Left and right margin for main content
\setbeamersize{text margin left=\textmargin,text margin right=\textmargin}
\newlength{\titlehmargin}
\setlength{\titlehmargin}{5mm} % Left and right margin for title and footline
\newlength{\titlevmargin}
\setlength{\titlevmargin}{1mm} % Top and bottom margin for title and footline
\newlength{\fullpagewidth}
\setlength{\fullpagewidth}{\dimexpr\textwidth+\textmargin+\textmargin\relax}

% Calculate widths from heights for the logos
\newlength{\oxfordlogowidth}
\setlength{\oxfordlogowidth}{\dimexpr  10mm * 214 / 311 \relax}
\newlength{\mathslogowidth}
\setlength{\mathslogowidth}{\dimexpr 3mm * 347 / 105 \relax}

%% Title slide formatting %%
\setbeamertemplate{title page}{
    \begin{picture}(0,0)
        \put(-\textmargin, \dimexpr -\paperheight*6/10 \relax){%
        \ifdim\paperwidth>400pt
           \includegraphics[width=\paperwidth]{title-slide-background-wide.png}
        \else
           \includegraphics[width=\paperwidth]{title-slide-background.png}
        \fi
        }
        \put(-\textmargin +7mm, -55pt){%
            \begin{minipage}[b][4.5cm][t]{0.7\textwidth}
                \raggedright
                \color{white}
                \usebeamerfont{title}
                    {\inserttitle\\[0.9cm]}
                \usebeamerfont{subtitle}
                    {\sc\insertauthor\\[0.1cm]}
                    {\it\insertinstitute\\[0.3cm]}
                    {\insertdate}
            \end{minipage}
        }
    \end{picture}
}

%% General slide header %%
\setbeamertemplate{frametitle}{%
   \rlap{%
     \begin{beamercolorbox}[sep=\titlevmargin,left,wd=\dimexpr\fullpagewidth-\titlehmargin*2+\titlevmargin*2\relax]{frametitle}%
      \begin{minipage}{\dimexpr\fullpagewidth-\oxfordlogowidth-\titlehmargin*3-0.1cm\relax}%
        \strut\insertframetitle\strut\par%
      \end{minipage}%
      \hspace{\titlehmargin}%
      \begin{minipage}{\dimexpr\oxfordlogowidth+1mm\relax}%
        \hfill
        \vspace*{-4mm}
        \includegraphics[width=\oxfordlogowidth]{oxford-logo.png}%
      \end{minipage}%
     \end{beamercolorbox}%
   }%
   \vspace{\dimexpr-\baselineskip+1ex\relax}%
   \noindent\rlap{\hspace{-\textmargin}\hspace{\titlehmargin}\rule{\dimexpr\fullpagewidth-\titlehmargin*2\relax}{0.4pt}}%
   \vspace{-0.6ex}%
}

%% General slide footer %%
\setbeamertemplate{footline}{%
  \noindent\hspace{\titlehmargin}\rule{\dimexpr\fullpagewidth-\titlehmargin*2\relax}{0.4pt}\par%
  \vspace{\titlevmargin}%
  \leavevmode%
  \noindent\hspace{\dimexpr\titlehmargin-\titlevmargin\relax}%
  \begin{beamercolorbox}[sep=\titlevmargin,wd=\dimexpr\fullpagewidth-\titlehmargin*2+\titlevmargin*2\relax]{footline}%
    \begin{minipage}{\dimexpr\mathslogowidth+1pt\relax}%
      \includegraphics[width=\mathslogowidth]{mathematics-logo.png}%
    \end{minipage}%
    \hfill%
    {\usebeamercolor[fg]{title in head/foot}\usebeamerfont{title in head/foot}\insertshorttitle}%
    \hfill%
    {\usebeamercolor[fg]{date in head/foot}\usebeamerfont{date in head/foot}\insertshortdate{}}%
    \hfill%
    {\usebeamercolor[fg]{page number in head/foot}\usebeamerfont{page number in head/foot}\usebeamertemplate{page number in head/foot}}%
  \end{beamercolorbox}
  \vspace{\titlevmargin}%
}