%D \module
%D   [       file=scrn-pag,
%D        version=1998.01.15,
%D          title=\CONTEXT\ Screen Macros,
%D       subtitle=Pages, % moved code
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
%C details.

% pagecomments will be done differently

\writestatus{loading}{ConTeXt Screen Macros / Pages}

\registerctxluafile{scrn-pag}{1.001}

\unprotect

\installparameterhandler \??sc {interactionscreen}
\installsetuphandler     \??sc {interactionscreen}

\newdimen\canvaswidth
\newdimen\canvasheight
\newdimen\canvasbackoffset
\newdimen\canvastopoffset

\def\scrn_canvas_calculate
  {\begingroup
   \edef\currentinteractionscreenwidth {\interactionscreenparameter\c!width }%
   \edef\currentinteractionscreenheight{\interactionscreenparameter\c!height}%
   \canvasbackoffset\backspace
   \canvastopoffset\topoffset
   \ifx\currentinteractionscreenwidth\v!fit
     \global\canvaswidth\leftcombitotal
     \ifdim\backspace>\canvaswidth
       \ifdim\backspace>\zeropoint\relax
         \global\advance\canvasbackspace -\canvaswidth
       \fi
     \fi
     \global\advance\canvaswidth\dimexpr
       \rightcombitotal
     + 2\dimexpr
          \interactionscreenparameter\c!backspace
        + \interactionscreenparameter\c!horoffset
        \relax
     \relax
     \donetrue
   \else\ifx\currentinteractionscreenwidth\v!max
     \global\canvaswidth\printpaperwidth
     \donetrue
   \else
     \global\canvaswidth\currentinteractionscreenwidth
     \donefalse
   \fi\fi
   \ifdone
     \ifdim\canvaswidth>\paperwidth\ifdim\canvaswidth>\zeropoint
       \global\paperwidth\canvaswidth % kills location=middle
     \fi\fi
   \fi
   \ifx\currentinteractionscreenheight\v!fit
     \global\canvasheight\dimexpr\topheight+\topdistance\relax
     \ifdim\topspace>\canvasheight
       \ifdim\topspace>\zeropoint\relax
         \global\advance\canvastopspace -\canvasheight
       \fi
     \fi
     \global\advance\canvasheight\dimexpr
       \makeupheight
     + \bottomdistance
     + \bottomheight
     + 2\dimexpr
          \interactionscreenparameter\c!topspace
        + \interactionscreenparameter\c!veroffset
        \relax
     \relax
     \donetrue
   \else\ifx\currentinteractionscreenheight\v!max
     \global\canvasheight\printpaperheight
     \donetrue
   \else
     \global\canvasheight\currentinteractionscreenheight
     \donefalse
   \fi\fi
   \ifdone
     \ifdim\canvasheight>\paperheight\ifdim\canvasheight>\zeropoint
       \global\paperheight\canvasheight % kills location=middle
     \fi\fi
   \fi
   \endgroup}

\appendtoks
    \ifproductionrun
      \scrn_canvas_calculate
    \fi
\to \everysetupinteractionscreen

\def\scrn_canvas_synchronize_simple % this will be done differently (or disappear)
  {\begingroup
   \ifx\@@ppleft   \empty
   \ifx\@@ppright  \empty
   \ifx\@@pptop    \empty
   \ifx\@@ppbottom \empty
   \ifx\@@pcstate\v!start
     \locationfalse\fi\else
     \locationfalse\fi\else
     \locationfalse\fi\else
     \locationfalse\fi\else
     \locationfalse\fi
   \iflocation % without screen settings
      \ctxcommand{setupcanvas{
        paperwidth  = \number\paperwidth,
        paperheight = \number\paperheight
      }}%
   \else
      \ctxcommand{setupcanvas{
        paperwidth  = \number\printpaperwidth,
        paperheight = \number\printpaperheight
      }}%
   \fi
   \endgroup}

\def\scrn_canvas_synchronize_complex
  {\ctxcommand{setupcanvas{
      mode        = "\interactionscreenparameter\c!option",
      singlesided = \ifsinglesided true\else false\fi,
      doublesided = \ifdoublesided true\else false\fi,
      leftoffset  = \number\dimexpr\canvasbackoffset\relax,
      topoffset   = \number\dimexpr\canvastopoffset\relax,
      width       = \number\dimexpr\canvaswidth\relax,
      height      = \number\dimexpr\canvasheight\relax,
      paperwidth  = \number\paperwidth,
      paperheight = \number\paperheight
   }}}

\let\scrn_canvas_synchronize\scrn_canvas_synchronize_simple

\appendtoks
    \ifproductionrun
      \doifelse\@@pcstate\v!start
        {\let\scrn_canvas_synchronize\scrn_canvas_synchronize_simple }
        {\let\scrn_canvas_synchronize\scrn_canvas_synchronize_complex}%
    \fi
\to \everysetupinteractionscreen

\appendtoks
    \scrn_canvas_synchronize
\to \everyshipout

\setupinteractionscreen
  [\c!width=\printpaperwidth,
   \c!height=\printpaperheight,
   \c!horoffset=\zeropoint,
   \c!veroffset=\zeropoint,
   \c!backspace=\backspace,
   \c!topspace=\topspace,
   \c!option=\v!auto]

%D Conditional page breaks:

\unexpanded\def\screen
  {\dosingleempty\scrn_screen}

\def\scrn_screen[#list]%
  {\iflocation
     \page[#list]%
   \fi}

%D Page transitions:

\let\scrn_transitions_list\empty

\unexpanded\def\setuppagetransitions
  {\dosingleempty\scrn_transitions_setup}

\def\scrn_transitions_setup[#list]%
  {\edef\scrn_transitions_list{#list}}

\def\scrn_transitions_set
  {\iflocation \ifx\scrn_transitions_list\empty \else
     \scrn_transitions_set_indeed
   \fi \fi}

\def\scrn_transitions_set_indeed
  {\begingroup
   \edef\currentinteractionscreendelay{\interactionscreenparameter\c!delay}%
   \ctxcommand{setpagetransition{
      n     = "\scrn_transitions_list",
      delay = "\ifx\currentinteractionscreendelay\v!none 0\else\currentinteractionscreendelay\fi"
   }}%
   \endgroup}

\prependtoks
    \scrn_transitions_set
\to \everyshipout

\setupinteractionscreen
  [\c!delay=\v!none]

\setuppagetransitions
  [\v!reset]

\protect \endinput