%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 ADE \& \CONTEXT\ Development Team}]
%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}{}

\unprotect

\installcorenamespace{interactionscreen}

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

\newdimen\canvaswidth
\newdimen\canvasheight
\newdimen\canvasbackoffset
\newdimen\canvastopoffset
\newdimen\canvasmaxwidth
\newdimen\canvasmaxheight
\newdimen\canvascropoffset
\newdimen\canvastrimoffset
\newdimen\canvasbleedoffset
\newdimen\canvasartoffset

\newconditional\c_scrn_canvas_tight_page

\def\scrn_canvas_calculate
  {\begingroup
   \edef\currentinteractionscreenwidth {\interactionscreenparameter\c!width }%
   \edef\currentinteractionscreenheight{\interactionscreenparameter\c!height}%
   \canvasbackoffset\backspace
   \canvastopoffset\topspace
   \donetrue
   \ifx\currentinteractionscreenwidth\v!max
     \global\canvaswidth\printpaperwidth
   \else\ifx\currentinteractionscreenwidth\v!fit
     \donefalse
     \global\canvaswidth\dimexpr
       \leftcombitotal
     + \makeupwidth
     + \rightcombitotal
     + 2\dimexpr
          \interactionscreenparameter\c!backspace
        + \interactionscreenparameter\c!horoffset
        \relax
     \relax
   \else\ifx\currentinteractionscreenwidth\v!tight
     \donefalse
     \ifdim\backspace>\canvaswidth
       \ifdim\backspace>\zeropoint\relax
         \global\advance\canvasbackoffset -\canvaswidth
       \fi
     \fi
     \global\advance\canvaswidth\dimexpr
       \makeupwidth
     + \rightcombitotal
     + 2\dimexpr
          \interactionscreenparameter\c!backspace
        + \interactionscreenparameter\c!horoffset
        \relax
     \relax
   \else
     \donefalse
     \global\canvaswidth\currentinteractionscreenwidth
   \fi\fi\fi
   \ifx\currentinteractionscreenheight\v!max
     \global\canvasheight\printpaperheight
   \else\ifx\currentinteractionscreenheight\v!fit
     \donefalse
     \global\canvasheight\dimexpr
       \topheight
     + \topdistance
     + \makeupheight
     + \bottomdistance
     + \bottomheight
     + 2\dimexpr
          \interactionscreenparameter\c!topspace
        + \interactionscreenparameter\c!veroffset
        \relax
     \relax
   \else\ifx\currentinteractionscreenheight\v!tight
     \donefalse
     \global\canvasheight\dimexpr\topheight+\topdistance\relax
     \ifdim\topspace>\canvasheight
       \ifdim\topspace>\zeropoint\relax
         \global\advance\canvastopoffset -\canvasheight
       \fi
     \fi
     \global\advance\canvasheight\dimexpr
       \makeupheight
     + \bottomdistance
     + \bottomheight
     + 2\dimexpr
          \interactionscreenparameter\c!topspace
        + \interactionscreenparameter\c!veroffset
        \relax
     \relax
   \else
     \donefalse
     \global\canvasheight\currentinteractionscreenheight
   \fi\fi\fi
   \ifconditional\c_page_layouts_location_is_set
     \global\setfalse\c_scrn_canvas_tight_page
   \fi
   \ifconditional\c_scrn_canvas_tight_page
     \global\canvasmaxwidth \paperwidth
     \global\canvasmaxheight\paperheight
   \else
     \global\canvasmaxwidth \printpaperwidth
     \global\canvasmaxheight\printpaperheight
   \fi
   % new:
   \ifdone
     \global\canvascropoffset \layoutcropoffset
     \global\canvastrimoffset \layouttrimoffset
     \global\canvasbleedoffset\layoutbleedoffset
     \global\canvasartoffset  \layoutartoffset
   \else
     \global\canvascropoffset \zeropoint
     \global\canvastrimoffset \zeropoint
     \global\canvasbleedoffset\zeropoint
     \global\canvasartoffset  \zeropoint
   \fi
   \endgroup}

\newdimen\layoutcropoffset
\newdimen\layouttrimoffset
\newdimen\layoutbleedoffset
\newdimen\layoutartoffset

\appendtoks
   \edef\p_cropoffset{\layoutparameter\c!cropoffset}%
   \ifx\p_cropoffset\v!auto
     \ifconditional\c_page_layouts_location_is_middle
       \scratchheight\dimexpr(\printpaperheight-\paperheight)/2\relax
       \scratchwidth \dimexpr(\printpaperwidth -\paperwidth )/2\relax
       \layoutcropoffset\ifdim\scratchheight>\scratchwidth\scratchheight\else\scratchwidth\fi
       \layouttrimoffset \layoutparameter\c!trimoffset
       \layoutbleedoffset\layoutparameter\c!bleedoffset
       \layoutartoffset  \layoutparameter\c!artoffset
     \else
       \writestatus\m!system{auto crop etc only supported when location=middle}%
       \layoutcropoffset \zeropoint
       \layouttrimoffset \zeropoint
       \layoutbleedoffset\zeropoint
       \layoutartoffset  \zeropoint
     \fi
   \else
     \layoutcropoffset \layoutparameter\c!cropoffset
     \layouttrimoffset \layoutparameter\c!trimoffset
     \layoutbleedoffset\layoutparameter\c!bleedoffset
     \layoutartoffset  \layoutparameter\c!artoffset
   \fi
   \relax
\to \everysetuplayout

\setuplayout
  [\c!cropoffset=\zeropoint,
   \c!trimoffset=\zeropoint,
   \c!bleedoffset=\zeropoint,
   \c!artoffset=\zeropoint]

% test the next when something is changed here:
%
% \setuppapersize[A5][A3]  \showframe
%
% % \setuplayout[location=middle] \setupinteractionscreen[option=fit]
% % \setuplayout[location=middle] \setupinteractionscreen[option=auto]
% %                               \setupinteractionscreen[option=fit]
% %                               \setupinteractionscreen[option=auto]
%
% \starttext \input ward \stoptext

\let\scrn_canvas_synchronize_simple \relax
\let\scrn_canvas_synchronize_complex\relax

\appendtoks
    \glet\scrn_canvas_synchronize_simple \scrn_canvas_synchronize_simple_indeed
    \glet\scrn_canvas_synchronize_complex\scrn_canvas_synchronize_complex_indeed
\to \everysetuplayout

\appendtoks
    \glet\scrn_canvas_synchronize_simple \scrn_canvas_synchronize_simple_indeed
    \glet\scrn_canvas_synchronize_complex\scrn_canvas_synchronize_complex_indeed
\to \everysetuplayouttarget

\def\scrn_canvas_synchronize_only
  {\clf_setupcanvas
     paperwidth  \printpaperwidth
     paperheight \printpaperheight
   \relax}

\def\scrn_canvas_synchronize_set#1#2%
  {\clf_setupcanvas
     paperwidth  \dimexpr#1\relax
     paperheight \dimexpr#2\relax
   \relax}

\let\scrn_canvas_synchronize_reset\scrn_canvas_synchronize_only

\def\scrn_canvas_synchronize_simple_indeed
  {\scrn_canvas_synchronize_only
  %\glet\scrn_canvas_synchronize_simple \relax
   \glet\scrn_canvas_synchronize_complex\relax}

\def\scrn_canvas_synchronize_complex_indeed
  {\scrn_canvas_calculate % otherwise we need to hook it into setuppage etc
   \clf_setupcanvas
        mode        {\interactionscreenparameter\c!option}%
        singlesided \ifsinglesided true\else false\fi\space
        doublesided \ifdoublesided true\else false\fi\space
        leftoffset  \canvasbackoffset
        topoffset   \canvastopoffset
        width       \canvaswidth
        height      \canvasheight
        paperwidth  \canvasmaxwidth
        paperheight \canvasmaxheight
        cropoffset  \canvascropoffset
        trimoffset  \canvastrimoffset
        bleedoffset \canvasbleedoffset
        artoffset   \canvasartoffset
        copies      \numexpr\interactionscreenparameter\c!copies\relax
        print       {\interactionscreenparameter\c!print}%
   \relax
  %\glet\scrn_canvas_synchronize_simple \relax
   \glet\scrn_canvas_synchronize_complex\relax}

\appendtoks
    \begingroup
    \edef\p_option{\interactionscreenparameter\c!option}%
    \ifx\p_option\v!max
      \global\settrue \c_scrn_canvas_tight_page
    \else\ifx\p_option\v!fit
      \global\settrue \c_scrn_canvas_tight_page
    \else
      \global\setfalse\c_scrn_canvas_tight_page
    \fi\fi
    \endgroup
\to \everysetupinteractionscreen

\setupinteractionscreen
  [\c!width=\printpaperwidth,
   \c!height=\printpaperheight,
   \c!horoffset=\zeropoint,
   \c!veroffset=\zeropoint,
   \c!backspace=\backspace,
   \c!topspace=\topspace,
   \c!copies=\plusone, % not the best place but backend anyway
   \c!option=\v!auto]

\appendtoks
    \glet\scrn_canvas_synchronize_simple \scrn_canvas_synchronize_simple_indeed
    \glet\scrn_canvas_synchronize_complex\scrn_canvas_synchronize_complex_indeed
\to \everysetupinteractionscreen

%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}%
   \ifx\scrn_transitions_list\v!reset
     \let\scrn_transitions_list\empty
   \fi}

\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}%
   \clf_setpagetransition
      n     {\scrn_transitions_list}%
      delay \ifx\currentinteractionscreendelay\v!none \zerocount\else\currentinteractionscreendelay\fi
   \relax
   \endgroup}

\prependtoks
    \scrn_transitions_set
\to \everyshipout

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

\setuppagetransitions
  [\v!reset]

\protect \endinput