% Copyright 2003--2007 by Till Tantau
% Copyright 2010 by Vedran Mileti\'c
% Copyright 2017 by Joseph Wright
%
% This file may be distributed and/or modified
%
% 1. under the LaTeX Project Public License and/or
% 2. under the GNU Public License.
%
% See the file doc/licenses/LICENSE for more details.
%
% version 1.71 bugfix for \pgfpagescurrentpagewillbelogicalpage (hv)
%
%
\mode
<presentation>

\newif\ifbeamer@twoscreenstext
\newif\ifbeamer@dosecondmode

\defbeameroption{previous slide on second screen}[right]%
{%
  \ifx\@onlypreamble\@notprerr 
    \ltx@ifpackageloaded{pgfpages}{}{%
      \ClassError{beamer}{`pgfpages' package necessary for this option}{}%
    }%
  \else%
    \RequirePackage{pgfpages}%
  \fi%
  \pgfpagesuselayout{two screens with lagging second}[second #1]%
  \beamer@twoscreenstexttrue
  \nofiles
}

\defbeameroption{second mode text on second screen}[right]%
{%
  \ifx\@onlypreamble\@notprerr 
    \ltx@ifpackageloaded{pgfpages}{}{%
      \ClassError{beamer}{`pgfpages' package necessary for this option}{}%
    }%
  \else%
    \RequirePackage{pgfpages}%
  \fi%
  \pgfpagesuselayout{two screens with optional second}[second #1]%
  \beamer@twoscreenstexttrue
}

\defbeameroption{always typeset second mode}[true]%
{%
  \def\beamer@defaultdosecondmode{#1}%
}
\def\beamer@defaultdosecondmode{false}

\long\def\beamer@dosecondscreennow#1{% called from \beamer@doseveralframes
  \ifbeamer@dosecondmode%
    {%
      \clearpage
      \def\beamer@currentmode{second}%
      \gdef\beamer@doifnotinframe{}%
      \def\beamer@doifinframe{\begin{beamer@frameslide}%
          #1%
        \end{beamer@frameslide}%
        \pgfpagescurrentpagewillbelogicalpage{2}%
        \clearpage
      }%
      \beamer@masterdecode{\beamer@whichframes}%
      \beamer@donow
    }%
  \fi
}

\mode
<all>
