%D \module
%D   [       file=page-pls,
%D        version=2003.03.16,
%D          title=\CONTEXT\ Page Macros,
%D       subtitle=Page Setup,
%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.

\writestatus{loading}{ConTeXt Page Macros / Extra Page Building}

%D This still needs some work, especially the dimensions need to be checked cq.\
%D optimized. Beware: method has become alternative!

%D This feature has been present for a while but has never been exploited: pluggable
%D pagebuilders. The next example code demonstrates the application of one such a
%D plug-in. This variant support \type {page}, \type {leftpage} and \type
%D {rightpage} definitions where specific areas are placed with the \type
%D {\pagearea} command.
%D
%D \starttyping
%D \setupheadertexts[the header text]
%D \setupfootertexts[a pretty long left footer text][something footer right]
%D \setupbottomtexts[a not so long left bottom text][another right footer thing]
%D \setuptexttexts  [margin][something marginal][indeed]
%D
%D \startsetups pagelayout:table:left
%D     \setupTABLE[offset=overlay]%
%D     \setupTABLE[c][1][width=\leftmarginwidth]%
%D     \setupTABLE[c][2][width=\textwidth]%
%D     \setupTABLE[c][3][width=\rightmarginwidth]%
%D \stopsetups
%D
%D \startsetups pagelayout:table:right
%D     \setupTABLE[offset=overlay]%
%D     \setupTABLE[c][1][width=\leftmarginwidth]%
%D     \setupTABLE[c][2][width=\textwidth]%
%D     \setupTABLE[c][3][width=\rightmarginwidth]%
%D \stopsetups
%D
%D \startpagelayout[leftpage]
%D   \directsetup{pagelayout:table:left}%
%D   \bTABLE
%D     \bTR
%D       \bTD[nx=3,background=color,backgroundcolor=green]
%D         \pagearea[header][text][middle]
%D       \eTD
%D     \eTR
%D     \bTR
%D       \bTD \pagearea[text][margin][left] \eTD
%D       \bTD[nx=2] \pagearea[text] \eTD
%D     \eTR
%D     \bTR
%D       \bTD[nx=3,offset=overlay]
%D         {\directsetup{pagelayout:table:left}%
%D          \bTABLE
%D            \bTR
%D              \bTD[nx=2] \pagearea[footer][text][left] \eTD
%D              \bTD \pagearea[bottom][text][left] \eTD
%D            \eTR
%D          \eTABLE}
%D        \eTD
%D     \eTR
%D   \eTABLE
%D \stoppagelayout
%D
%D \startpagelayout[rightpage]
%D   \directsetup{pagelayout:table:right}%
%D   \bTABLE
%D     \bTR
%D       \bTD[nx=3] \pagearea[header][text][middle] \eTD
%D     \eTR
%D     \bTR
%D       \bTD \pagearea[text][margin][left] \eTD
%D       \bTD[nx=2] \pagearea[text] \eTD
%D     \eTR
%D     \bTR
%D       \bTD[nx=3,offset=overlay]
%D         {\directsetup{pagelayout:table:right}%
%D          \bTABLE
%D            \bTR
%D              \bTD \pagearea[bottom][text][right] \eTD
%D              \bTD[nx=2] \pagearea[footer][text][right] \eTD
%D            \eTR
%D          \eTABLE}
%D       \eTD
%D     \eTR
%D   \eTABLE
%D \stoppagelayout
%D
%D \startpagelayout[page]
%D     \pagelayout[rightpage]
%D \stoppagelayout
%D
%D \enabletrackers[pagelayout]
%D
%D \setuppagenumbering[alternative=doublesided,location=middle]
%D
%D \setuplayout
%D   [alternative=makeup,
%D    backspace=15mm,
%D    cutspace=20mm,
%D    leftmargin=15mm,
%D    rightmargin=25mm,
%D    topspace=0pt,
%D    width=10cm]
%D
%D \definetextbackground
%D   [test]
%D   [state=start,
%D    background=color,
%D    backgroundcolor=yellow]
%D
%D \starttext
%D
%D     \dorecurse{10}{\samplefile{tufte}\par}
%D
%D     \samplefile{tufte} \starttest \samplefile{tufte} \stoptest \samplefile{tufte}
%D
%D     \starttabulate
%D     \NC test \NC \starttest \samplefile{tufte} \stoptest \NC \NR
%D     \stoptabulate
%D
%D     \dorecurse{10}{\samplefile{tufte}\par}
%D
%D \stoptext
%D \stoptyping

\unprotect

\startcontextdefinitioncode

\installcorenamespace{layoutmakeupalternative}

\definecolor[\v!makeup:trace][s=.5,a=1,t=.5]

\installtextracker
  {pagelayout}
  {\def\page_boxes_show_box{\backgroundline[\v!makeup:trace]}}
  {\let\page_boxes_show_box\relax}

\let\page_boxes_show_box\relax

\def\page_boxes_construct_content_makeup#1#2#3% targetbox flusher box
  {\setbox#1\vpack\bgroup
     \offinterlineskip
     \calculatereducedvsizes
     \calculatehsizes
     \page_layouts_swap_margins\v!page
     \setbox#1\hbox\bgroup
       \vbox to \textheight\bgroup
          \offinterlineskip
          \vskip{-1\topskip+\strutheight}% could be an option
          \textwidth\makeupwidth
          \hsize\textwidth
          \boxmaxdepth\maxdepth
          \noindent
          \hpack to \zeropoint{\anch_positions_place_anchors}%
          \page_boxes_show_box\bgroup
            \page_otr_command_package_contents#2#3%
          \egroup
       \egroup
     \egroup
     \wd#1\makeupwidth
     \ht#1\textheight
     \dp#1\zeropoint
     \hsize\paperwidth
     \vsize\paperheight
     \setbox#1\vbox\bgroup
      %\settexthoffset
      %\doifbothsidesoverruled\relax\relax{\hkern{-\texthoffset-\cutspace+\backspace}}%
       \doifbothsidesoverruled\relax\relax{\hkern{-\paperwidth+\backspace+\makeupwidth-\cutspace+\backspace}}%
       \page_boxes_show_box\bgroup
         \csname\??layoutmakeupalternative\doifbothsidesoverruled\v!page\v!rightpage\v!leftpage\endcsname
       \egroup
     \egroup
     \wd#1\paperwidth
     \ht#1\paperheight
     \dp#1\zeropoint
    %\smashbox#1%
     \box#1%
   \egroup}

\installlayoutalternative\v!makeup{\page_boxes_construct_content_makeup}

\newbox\b_page_area

\permanent\tolerant\protected\def\pagearea[#1]#*[#2]#*[#3]%
  {\ifarguments
     \expandafter\gobblethreeoptionals
   \or
     \expandafter\page_area_one
   \or
     \expandafter\page_area_two
   \or
     \expandafter\page_area_three
   \fi[#1][#2][#3]}

\def\page_area_three[#1][#2][#3]%
  {\edef\m_page_area_three{#3}%
   \ifx\m_page_area_three\v!left
     \let\m_page_area_three\c!lefttext
   \orelse\ifx\m_page_area_three\v!right
     \let\m_page_area_three\c!righttext
   \else
     \let\m_page_area_three\c!middletext
   \fi
   \page_area_indeed{#1}{#2}\m_page_area_three}

\def\page_area_two[#1][#2][#3]%
  {\edef\m_page_area_three{\doifbothsidesoverruled\c!righttext\c!righttext\c!lefttext}%
   \page_area_indeed{#1}{#2}\m_page_area_three}

\def\page_area_one[#1][#2][#3]%
  {\ifcstok{#1}\v!text
     \iftrialtypesetting
       \fakebox\pagebox
     \else
       \page_backgrounds_add_to_text\pagebox
       \page_grids_add_to_box\pagebox
       \box\pagebox
     \fi
   \fi}

\def\page_area_indeed#1#2#3%
  {\setbox\b_page_area\vbox{\getspecificlayouttext{#1}{#2}{#3}}%
   \iftrialtypesetting
     \fakebox\b_page_area
   \orelse\ifcsname\??layoutbackgrounds#1#2\endcsname
     \page_area_indeed_yes{#1}{#2}%
   \else
     \box\b_page_area
   \fi}

\def\page_area_indeed_yes#1#2%
  {% todo: \localbackgroundframed{\??layoutbackgrounds#1#2}{#1:#2}
   \localframed % todo:
     [\??layoutbackgrounds#1#2]
     [\c!width=\wd\b_page_area,
      \c!height=\ht\b_page_area,
      \c!offset=\v!overlay]
     {\box\b_page_area}}

% to be done nicely (proper namespacing)

\defcsname\??layoutmakeupalternative\v!leftpage \endcsname{\csname\??layoutmakeupalternative\v!page\endcsname}
\defcsname\??layoutmakeupalternative\v!rightpage\endcsname{\csname\??layoutmakeupalternative\v!page\endcsname}

\permanent\protected\def\startpagelayout
  {\bgroup
   \catcode\endoflineasciicode\ignorecatcode
   \page_layouts_start_layout}

\aliased\let\stoppagelayout\relax

\def\page_layouts_start_layout[#1]#2\stoppagelayout
  {\egroup
   \defcsname\??layoutmakeupalternative#1\endcsname{#2}}

\permanent\protected\def\pagelayout[#1]% new
  {\csname\??layoutmakeupalternative#1\endcsname}

\stopcontextdefinitioncode

\protect \endinput