<html><head><meta name="color-scheme" content="light dark"></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">% This file is part of the Lecturer package.
% Paul Isambert -- July 2010.
% 
%
% ATTRIBUTES
%
\def\setarea#1#2\par{%
  \ltr@space_loop{\ltr@setarea_do{#2}}{#1 }%
  }
\long\def\ltr@setarea_do#1#2{%
  \ltr@ifattribute {ltr@#2@inner_area}:visible;
    {\setparameter {ltr@#2@inner_area}:}
    {\ltr@setarea_new{#2}}%
    #1\par
  }%
\def\ltr@area_list{}%
\def\ltr@setarea_new#1{%
  \global\eaddright\ltr@area_list{ltr@#1@inner_area,}%
  \passcs{\usecs{newbox}}{ltr@#1@inner_area:box}%
  \restrictparameter ltr@#1@inner_area:
    width height hshift hshift* vshift vshift* left right top bottom
    foreground background topskip baselineskip parindent parskip hpos vpos
    visible frame frame_width frame_color frame_corner frame_dash
    everyposition everyfreeposition font hsize vsize image
    \par
  \ltr@restrictattribute ltr@#1@inner_area:visible; true false step\par
  \ltr@restrictattribute ltr@#1@inner_area:frame_corner; miter round bevel\par
  \ltr@restrictattribute ltr@#1@inner_area:hpos; ff rr fr rf\par
  \defactiveparameter ltr@#1@inner_area {%
    \ltr@delete_empty{##1:background}%
    \ltr@todim_loop{##1}{width height hshift hshift* vshift vshift* left right top bottom hsize vsize
    topskip baselineskip parindent frame_width }%
    \ltr@dimen_set{##1}{hshift*}{hshift}{width}{\pdfpagewidth}%
    \ltr@dimen_set{##1}{vshift*}{vshift}{height}{\pdfpageheight}%
    \ltr@deleteattribute ##1:hshift*;%
    \ltr@deleteattribute ##1:vshift*;%
    \ltr@dimen_set{##1}{right}{left}{hsize}{\ltr@area_width{##1}}%
    \ltr@dimen_set{##1}{bottom}{top}{vsize}{\ltr@area_height{##1}}%
    \ltr@deleteattribute ##1:right;%
    \ltr@deleteattribute ##1:bottom;%
    \ltr@ifattribute##1:frame;
      {\def\ltr@area_name{#1}\ltr@passvalue{\ltr@option_launchloop{area}}##1:frame;}{}%
    \ltr@deleteattribute##1:frame;
    \ltr@todim_loop{##1}{frame_width }%
    \ltr@ifattribute##1:frame_color;{}
      {\ltr@ifattribute##1:background;
         {\ltr@setattribute##1:frame_color; = {\ltr@usevalueor##1:background;{white}} }{}}%
    }%
  \setparameter {ltr@#1@inner_area}:
     visible = true
  }
\def\ltr@area_usepair#1#2{%
  \ltr@setattribute ltr@\ltr@area_name @inner_area:frame_#1;={#2}
  }
%
%
%
\def\ltr@area_hshift#1{%
  \ltr@usevalueor #1:hshift;{0pt}%
  }
\def\ltr@area_vshift#1{%
  \ltr@usevalueor #1:vshift;{0pt}%
  }
\def\ltr@area_width#1{%
  \ltr@usevalueor #1:width;{\dimexpr(\pdfpagewidth-\ltr@area_hshift{#1})}%
  }
\def\ltr@area_height#1{%
  \ltr@usevalueor #1:height;{\dimexpr(\pdfpageheight-\ltr@area_vshift{#1})}%
  }
\def\ltr@area_left#1{%
  \ltr@usevalueor #1:left;{0pt}%
  }
\def\ltr@area_top#1{%
  \ltr@usevalueor #1:top;{0pt}%
  }
\def\ltr@area_hsize#1{%
  \ltr@usevalueor #1:hsize;{\dimexpr(\ltr@area_width{#1}-\ltr@area_left{#1})\relax}%
  }
\def\ltr@area_vsize#1{%
  \ltr@usevalueor #1:vsize;{\dimexpr(\ltr@area_height{#1}-\ltr@area_top{#1})\relax}%
  }
%
% POSITION
% No attributes, except the optional argument,
% which takes the x and y (downward, \'a la TeX)
% shifts. Most of this is box manipulation.
%
\newcount\ltr@temp_count
\newcount\ltr@position_count
\def\position#1{%
  \ifnextnospace[{\ltr@position{#1}}{\ltr@position{#1}[]}%
  }
\newife\ifltr@area_do
\long\def\ltr@position#1[#2]{%
  \ltr@ifattribute ltr@#1@inner_area:visible;
    {\ltr@area_check{#1}%
     \ifltr@area_do
       {\ltr@position_do{#2}{ltr@#1@inner_area}}
       {\gobbleone}}
    {\ltr@error{Area `#1' doesn't exist. Material is discarded}\gobbleone}
  }
\def\ltr@area_check#1{%
  \ltr@area_dotrue
  \ltr@ifattribute ltr@inner_slide:areas*;
    {\ltr@ifvalue ltr@inner_slide:areas*; = all
       {\ltr@area_dofalse}
       {\ltr@storevalue\ltr@temp ltr@inner_slide:areas*;
        \addright\ltr@temp{ }\addleft\ltr@temp{ }%
        \passexpanded{\iffcontains{ #1 }}{\ltr@temp}\ltr@area_dofalse}}
    {}%
  \ltr@ifattribute ltr@inner_slide:areas;
    {\ltr@ifvalue ltr@inner_slide:areas; = all
       {}
       {\ltr@storevalue\ltr@temp ltr@inner_slide:areas;
        \addright\ltr@temp{ }\addleft\ltr@temp{ }%
        \passexpanded{\ifcontains{ #1 }}{\ltr@temp}\ltr@area_dotrue\ltr@area_dofalse}}
    {}%
  }
\newbox\ltr@temp_box
\newdimen\ltr@temp_dimen
\long\def\ltr@position_do#1#2#3{%
  \ifemptystring{#1}
    % Normal position.
    {\setbox\ltr@temp_box=\ltr@position_dobox{#2}{\ltr@usevalue #2:everyposition;#3}}
    % Free position.
    {\setbox\ltr@temp_box=\vbox{%
       \ltr@position_dobox{#2}{\ltr@usevalue #2:everyfreeposition;#3}}%
     \ltr@position_getposition#1
     \setbox\ltr@temp_box=\vbox{%
       \kern\dimexpr(\ltr@position_top+\ltr@usevalueor #2:topskip;\topskip-\ht\ltr@temp_box)\relax
       \moveright\ltr@position_left\box\ltr@temp_box
       }%
     \dp\ltr@temp_box=0pt	\ht\ltr@temp_box=0pt
     }%
  % How to apply topskip?
  % If the box isn't empty, that doesn't mean it shouldn't be used,
  % since the content of the box might be material freely positioned,
  % which doesn't exist, so to speak.
  % We can't measure the box either, because if topskip
  % is 0pt, one-line material without depth will fill the box
  % with height and depth 0pt, as if there were nothing, and
  % topskip will be applied again on the next material.
  % Hence this pseudo-conditional turned to true the first
  % time real material is added.
  \ifemptystring{#1}
    {\begingroup
     \ltr@usevalue #2:font;% So em and ex are right.
     \ifcsname #2:done\endcsname
       \global\ltr@temp_dimen=\dimexpr(%
         \dimexpr(\ltr@usevalueor #2:baselineskip;\baselineskip+\ltr@usevalueor #2:parskip;{0pt})\relax
         -\dimexpr(\ht\ltr@temp_box+\dp\usecs{#2:box}))\relax
       \ifdim\ltr@temp_dimen&lt;\lineskiplimit
         \global\ltr@temp_dimen=\lineskip
       \fi
     \else
       \global\ltr@temp_dimen=\dimexpr(\ltr@usevalueor #2:topskip;\topskip-\ht\ltr@temp_box)\relax%
       \global\letcs{#2:done}\relax
     \fi
     \endgroup}
    {\edef\ltr@position_left{\the\ht\usecs{#2:box}}% I could have used special dimensions
     \edef\ltr@position_top{\the\dp\usecs{#2:box}}}% but it's a time of austerity.
  \global\setbox\usecs{#2:box}=\vbox{%
    \unless\ifvoid\usecs{#2:box}
      \unvcopy\usecs{#2:box}
    \fi
    \ifemptystring{#1}
      {\kern\ltr@temp_dimen}
      {\kern-\dimexpr(\ht\usecs{#2:box}+\dp\usecs{#2:box})\relax}
    \ifx\ltr@step_current\emptycs
      \ifemptystring{#1}\unvbox\box\ltr@temp_box
      \reverse\iffcs{ltr@#2_\the\slideno @inner_area:group}
        {\global\letcs{ltr@#2_\the\slideno @inner_area:group}\emptycs}
    \else
      \global\advance\ltr@position_count1
      \pdfliteral {/OC/ltr@position_\the\ltr@position_count:content BDC}
      \ifemptystring{#1}\unvbox\box\ltr@temp_box
      \pdfliteral {EMC}
      \addproperties{ltr@position_\the\ltr@position_count:content}{\ltr@step_current}
      \reverse\iffcs{#2_\the\slideno:group}
        {\global\letcs{#2_\the\slideno:group}\ltr@step_current
         \addproperties{#2_\the\slideno:background}{\usecs{#2_\the\slideno:group}}}
    \fi
    \reverse\iffemptystring{#1} % Restore the box to its original dimensions.
      {\prevdepth-1000pt \vbox to \ht\usecs{#2:box}{\vfil\hbox{\vrule height0pt width0pt depth\dp\usecs{#2:box}}}}%
    }%
  \ltr@temp_dimen=0pt
  }
\def\ltr@position_getposition#1,#2 {%
  \edef\ltr@position_left{\ifemptystring{#1}{0pt}{\dimexpr(#1)}}%
  \edef\ltr@position_top{\ifemptystring{#2}{0pt}{\dimexpr(#2)}}
  }
\long\def\ltr@position_dobox#1#2{%
  \vtop{%
    \ltr@usevalue #1:font;
    \parindent\ltr@usevalueor #1:parindent;{0pt}\relax
    \hsize=\ltr@area_hsize{#1}\relax
    \ltr@settovalue\baselineskip #1:baselineskip;
    \parskip=\ltr@usevalueor #1:parskip;{0pt}\relax
    \leftskip=0pt \rightskip=0pt plus 1fill\relax
    \ltr@ifcasevalue #1:hpos;
      \val ff \rightskip=0pt
      \val rr \leftskip=0pt plus 1fill\relax
      \val rf \leftskip=0pt plus 1fill \rightskip=0pt
    \endval
    #2}%
  }

\endinput</pre></body></html>