%D \module
%D   [       file=page-flt,
%D        version=2010.04,08,
%D          title=\CONTEXT\ Page Macros,
%D       subtitle=Float Management,
%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.

\writestatus{loading}{ConTeXt Page Macros / Float Management}

%D This module has code that previously was in other modules. There is
%D also float related code in \type {strc-flt.mkiv}.

\registerctxluafile{page-flt}{1.001}

\unprotect

%D To be checked and removed

%def\dosavefloatinfo   {\showmessage\m!floatblocks2{\the\totalnoffloats}}
\def\doinsertfloatinfo {\showmessage\m!floatblocks4{\the\totalnoffloats}}
\def\dofloatflushedinfo{\showmessage\m!floatblocks3{\the\numexpr\totalnoffloats-\savednoffloats\relax}}

%D Extra float registers.

\newif\ifsomefloatwaiting     \somefloatwaitingfalse
\newif\ifroomforfloat         \roomforfloattrue
\newif\ifnofloatpermitted     \nofloatpermittedfalse
\newif\ifcenterfloatbox       \centerfloatboxtrue
\newif\iflocalcenterfloatbox  \localcenterfloatboxfalse
\newif\ifglobalcenterfloatbox \globalcenterfloatboxfalse
\newif\ifflushingfloats       \flushingfloatsfalse
\newif\ifpackflushedfloats    \packflushedfloatstrue % for the moment
\newif\ifpackcolumnfloats     \packcolumnfloatstrue

\newcount\totalnoffloats
\newcount\savednoffloats
\newcount\noffloatinserts
\newcount\nofcollectedfloats % communication channel

\newbox  \floatlist
\newbox  \savedfloatlist
\newbox  \floattext

\newdimen\floatwidth
\newdimen\floatheight
\newdimen\floatdepth
\newdimen\floattextwidth
\newdimen\floattextheight

\newbox  \floatbox
\newbox  \savedfloatbox

%D From now on we manage the float stack at the \LUA\ end instead of packing
%D them in a box and splitting off stacked floats. It's not so much less code
%D but it's cleaner this way. It also opens op some posibilities as we can now
%D more conveniently cary additional information around.

\newtoks \everyfloatscheck

\appendtoks
   \ifcase\savednoffloats
     \global\somefloatwaitingfalse
   \else
     \global\somefloatwaitingtrue
   \fi
\to \everyfloatscheck

\def\dofloatsflush#1#2%
  {\ctxlua{floats.flush("#1",\number#2)}%
   \the\everyfloatscheck}

\def\dofloatssave#1%
  {\ctxlua{floats.save("#1")}%
   \the\everyfloatscheck}

\def\dofloatsresave#1%
  {\ctxlua{floats.resave("#1")}%
   \the\everyfloatscheck}

\def\dopushsavedfloats
  {\ctxlua{floats.push()}%
   \the\everyfloatscheck}

\def\dopopsavedfloats
  {\ctxlua{floats.pop()}%
   \the\everyfloatscheck}

\def\dofloatsgetinfo#1%
  {\ctxlua{floats.consult("#1")}}

\def\doifsavedfloatelse#1%
  {\ctxlua{commands.doifsavedfloatelse("#1")}}

\def\dofloatscollect#1#2#3%
  {\ctxlua{floats.collect("#1",\number\dimexpr#2,\number\dimexpr#3)}}

\def\dofloatsnofstacked#1%
  {\ctxlua{floats.thestacked("#1")}}

\def\dofloatsgetvariable#1%
  {\ctxlua{floats.thevar("specification")}}

\let\dopushcolumnfloats\dopushsavedfloats
\let\dopopcolumnfloats \dopopsavedfloats

\def\dofloatssavepagefloat#1#2%
  {\ctxlua{floats.save("#1", { specification = "#2" })}}

%D The following code is in transition as we don't want to break the
%D current single column, multi column, and columnset mechanism.
%D
%D First we reimplement some helpers.

\def\dogetfloat
  {\ifsomefloatwaiting
     \dofloatsflush{text}{1}%
     \ifcenterfloatbox
       \ifdim\wd\globalscratchbox<\hsize
         \global\setbox\floatbox\hbox to \hsize{\hss\box\floatbox\hss}%
       \else
         % retain special alignments
         \ifinsidecolumns
           \ifdim\wd\floatbox>\makeupwidth
             \global\wd\floatbox\makeupwidth
           \fi
         \fi
       \fi
     \fi
   \else
     \global\savednoffloats\zerocount
     \global\setbox\floatbox\emptybox
   \fi}

\def\dosavefloat
  {\dofloatssave{text}%
   \nonoindentation} % brrr nonoindentation here

\def\doresavefloat
  {\dofloatsresave{text}}

\def\doreversesavefloat
  {\dofloatsresave{text}}

\def\doflushsavedfloats % simplified \OTRONEdodoflushfloats
  {\doloop
     {\ifsomefloatwaiting
        \docheckiffloatfits
        \ifroomforfloat
          \dogetfloat
          \doplacefloatbox
        \else
          \exitloop
        \fi
      \else
        \exitloop
      \fi}}

%D Page floats use different stacks.

\newtoks \everybeforeflushedpagefloat

\def\doflushsomepagefloat#1% future releases can do more clever things
  {\dofloatsflush{#1}{1}%
   \edef\floatspecification{\dofloatsgetvariable{specification}}%
   \the\everybeforeflushedpagefloat
   \vbox to \textheight
     {\doifnotinset\v!high\floatspecification\vfill
      \box\floatbox
      \doifnotinset\v!low\floatspecification\vfill}%
   \vfill\eject}

% \def\doflushpagefloats
%   {\doifoddpageelse
%      {\ifnum\dofloatsnofstacked{rightpage}>\zerocount
%         \doflushsomepagefloat{rightpage}%
%       \else\ifnum\dofloatsnofstacked{page}>\zerocount
%         \doflushsomepagefloat{page}
%       \else\ifnum\dofloatsnofstacked{leftpage}>\zerocount
%         \null\vfill\eject
%        %\doflushsomepagefloat{leftpage}%
%       \fi\fi\fi}
%      {\ifnum\dofloatsnofstacked{leftpage}>\zerocount
%         \doflushsomepagefloat{leftpage}%
%       \else\ifnum\dofloatsnofstacked{page}>\zerocount
%         \doflushsomepagefloat{page}
%       \else\ifnum\dofloatsnofstacked{rightpage}>\zerocount
%         \null\vfill\eject
%        %\doflushsomepagefloat{rightpage}%
%       \fi\fi\fi}}

\def\doflushpagefloats
  {\edef\checkedpagefloat{\ctxlua{floats.thecheckedpagefloat()}}% (true) for packed
   \ifx\checkedpagefloat\empty
     % nothing
   \else\ifx\checkedpagefloat\v!empty
      \null\vfill\eject
   \else
      \doflushsomepagefloat\checkedpagefloat
   \fi\fi}

\def\uncenteredfloatbox
  {\ifcenterfloatbox
     \ifhbox\floatbox\relax % remove centering
       \ifdim\wd\floatbox=\hsize
         \ifhbox\floatbox
           \setbox\scratchbox\hbox
             {\unhbox\floatbox
              \unskip\unskip
              \global\setbox\globalscratchbox\lastbox}%
           \box\globalscratchbox
         \else
           \box\floatbox
         \fi
       \else
         \box\floatbox
       \fi
     \else
       \box\floatbox
     \fi
   \else
     \box\floatbox
   \fi}

\ifdefined\doflushfloats\else \let\doflushfloats\relax \fi
\ifdefined\flushfloatbox\else \let\flushfloatbox\relax \fi

\protect \endinput