page-flt.mkiv / last modification: 2020-01-30 14:16
%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 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 / 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}{}

\unprotect

\defineinsertion[\s!topfloat]
\defineinsertion[\s!bottomfloat]
\defineinsertion[\s!pagefloat]

\newdimen   \d_page_floats_inserted_bottom
\newdimen   \d_page_floats_inserted_top
\newdimen   \d_page_floats_inserted_page
\newcount   \c_page_floats_n_of_top         \c_page_floats_n_of_top   \plustwo
\newcount   \c_page_floats_n_of_bottom      \c_page_floats_n_of_bottom\zerocount
\newcount   \c_page_floats_n_of_page        \c_page_floats_n_of_page  \plustwo

\newconstant\c_page_floats_insertions_topskip_mode  % 1 = no topskip

% \def\page_floats_report_saved
%   {\showmessage\m!floatblocks2
%      {\the\totalnoffloats}}

\def\page_floats_report_total
  {\showmessage\m!floatblocks4%
     {\the\totalnoffloats
      \ifx\floatlocationmethod\empty
        \ifx\floatlocation\empty\else,\floatlocation\fi
      \else
        ,\floatlocationmethod
      \fi}}

\def\page_floats_report_flushed
  {\showmessage\m!floatblocks3%
    {\the\numexpr\totalnoffloats-\savednoffloats\relax}}

%D Extra float registers.

\newconditional\c_page_floats_room
\newconditional\c_page_floats_some_waiting
\newconditional\c_page_floats_not_permitted
\newconditional\c_page_floats_flushing
\newconditional\c_page_floats_center_box          \settrue\c_page_floats_center_box
\newconditional\c_page_floats_center_box_local
\newconditional\c_page_floats_center_box_global
\newconditional\c_page_floats_compress_flushed       \settrue\c_page_floats_compress_flushed

\newdimen      \d_page_floats_compress_distance

%D For the moment we keep this but they will become private too.

\newcount\totalnoffloats           % these will be redone ... handled at the lua end anyway
\newcount\savednoffloats           % these will be redone ... handled at the lua end anyway
\newcount\nofcollectedfloats       % communication channel
\newdimen\maxcollectedfloatstotal  % communication channel

\newcount\noffloatinserts          % these will be redone ... handled at the lua end anyway

\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\setfalse\c_page_floats_some_waiting
   \else
     \global\settrue\c_page_floats_some_waiting
   \fi
\to \everyfloatscheck

\unexpanded\def\page_floats_flush#1#2%
  {\clf_flushfloat{#1}#2\relax
   \the\everyfloatscheck}

\unexpanded\def\page_floats_flush_by_label#1#2%
  {\clf_flushlabeledfloat{#1}{#2}\relax
   \the\everyfloatscheck}

\unexpanded\def\page_floats_save#1%
  {\clf_savefloat{#1}\relax
   \the\everyfloatscheck}

\unexpanded\def\page_floats_resave#1%
  {\clf_resavefloat{#1}\relax
   \the\everyfloatscheck}

\unexpanded\def\page_floats_push_saved
  {\clf_pushfloat
   \the\everyfloatscheck}

\unexpanded\def\page_floats_pop_saved
  {\clf_popfloat
   \the\everyfloatscheck}

\unexpanded\def\page_floats_get_info#1%
  {\clf_consultfloat{#1}}

\unexpanded\def\page_floats_if_else#1%
  {\clf_doifelsestackedfloats{#1}}

\unexpanded\def\page_floats_collect#1#2#3%
  {\clf_collectfloat{#1}\dimexpr#2\relax\dimexpr#3\relax}

\def\nofstackedfloatincategory#1%
  {\clf_nofstackedfloats{#1}}

\let\page_floats_column_push_saved\page_floats_push_saved % overloaded in page-mul
\let\page_floats_column_pop_saved \page_floats_pop_saved  % overloaded in page-mul

\unexpanded\def\page_floats_save_page_float#1#2%
  {\clf_savespecificfloat{#1}{specification{#2}}\relax}

\unexpanded\def\page_floats_save_somewhere_float#1#2% #1=method
  {\clf_savespecificfloat{#1}{specification{#2}label{\floatlabel}}\relax}

%D This is an experimental new feature (for Alan Braslau), a prelude to more:
%D
%D \starttyping
%D test \placefigure{}{}
%D test \placefigure[somewhere:alpha][whatever]{}{}
%D test \placefigure[somewhere:beta] [whatever]{}{}
%D test \placefigure[somewhere:gamma][whatever]{}{}
%D test \placefigure[somewhere:delta][whatever]{}{}
%D test \placefigure{}{}
%D
%D in \in{figure}[whatever] bla bla
%D
%D \placenamedfloat[figure][*l*]
%D \placenamedfloat[figure][gamma]
%D \placenamedfloat[figure][beta]
%D \stoptyping

\unexpanded\def\placenamedfloat
  {\dodoubleargument\page_floats_place_named}

\def\page_floats_place_named[#1][#2]%
  {\doloop
     {\page_floats_flush_by_label\s!somewhere{#2}%
      \ifvoid\floatbox
        \exitloop
      \else
        \def\currentfloat{#1}%
        \blank[\rootfloatparameter\c!spacebefore]%
        \box\floatbox
        \blank[\rootfloatparameter\c!spaceafter]%
      \fi}}

% \setupcaption [figure]   [align=flushleft]
% \setupcaption [figure-1] [align=flushleft,leftmargin=10mm]
% \setupcaption [figure-2] [align=flushleft,leftmargin=10mm,rightmargin=-10mm,width=\textwidth]
%
% \startsetups somefigure
%     \ifdim\floatsetupwidth>\textwidth
%         \placesetupfloat[figure-2]
%     \else
%         \placesetupfloat[figure-1]
%     \fi
% \stopsetups
%
% \placefloatwithsetups[somefigure]{}{\externalfigure[dummy][width=5cm,height=2cm]}

\unexpanded\def\placefloatwithsetups
  {\dotripleempty\page_floats_place_with_setups}

\def\page_floats_place_with_setups[#1][#2][#3]#4%
  {\def\floatsetupcaption   {#4}%
   \def\floatsetupcontent   {\copy\nextbox}%
   \def\floatsetupwidth     {\wd\nextbox}%
   \def\floatsetupheight    {\ht\nextbox}%
   \def\placesetupfloat[##1]{\placefloat[##1][#2][#3]{#4}{\floatsetupcontent}}% #4 and not \floatsetupcaption (unexpanded)
   \dowithnextbox{\setups[#1]}\vbox}

%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\page_floats_get_used_hsize{\hsize}

\unexpanded\def\page_floats_get
  {\ifconditional\c_page_floats_some_waiting
     \page_floats_flush\s!text\plusone
     \ifconditional\c_page_floats_center_box
       \ifdim\wd\globalscratchbox<\page_floats_get_used_hsize
         \global\setbox\floatbox\hpack to \page_floats_get_used_hsize{\hss\box\floatbox\hss}%
       \else
         % retain special alignments
         \ifinsidecolumns
           \ifdim\wd\floatbox>\makeupwidth
             \wd\floatbox\makeupwidth
           \fi
         \fi
       \fi
     \fi
   \else
     \global\savednoffloats\zerocount
     \global\setbox\floatbox\emptybox
   \fi}

\unexpanded\def\page_floats_flush_saved
  {\doloop
     {\ifconditional\c_page_floats_some_waiting
        \page_otr_command_check_if_float_fits
        \ifconditional\c_page_floats_room
          \page_floats_get
          \doplacefloatbox
        \else
          \exitloop
        \fi
      \else
      % \ifconditional\c_page_margin_blocks_present % not here, here just as many floats as fit
      %   \page_otr_command_flush_margin_blocks
      % \else
          \exitloop
      % \fi
      \fi}}

%D This is a future mechamism that will be integrated once we're sure about it:
%D
%D \starttyping
%D \dorecurse{10}
%D   {\input thuan
%D    \placefigure{}{\framed[height=1.5cm]{test}}
%D    \placefloatplaceholder}
%D \stoptyping

\unexpanded\def\placefloatplaceholder
  {\ifconditional\c_page_floats_room \else
     \ifdim\dimexpr\pagegoal-\pagetotal-3\lineheight\relax>\zeropoint
       \startlinecorrection[blank]
       \mhbox{\inframed{\labeltexts{placeholder}{\lastcaptiontag}}}%
       \stoplinecorrection
     \else
       \allowbreak
     \fi
   \fi}

\setuplabeltext
  [placeholder={\Word{\lastplacedfloat}~, moved}]

%D Page floats use different stacks.

\newtoks\everybeforeflushedpagefloat

\def\page_floats_flush_page_floats_indeed#1% future releases can do more clever things
  {\page_floats_flush{#1}\plusone
   \edef\floatspecification{\clf_getfloatvariable{specification}}% Is this okay?
   \the\everybeforeflushedpagefloat
   \vpack to \textheight
     {\doifnotinset\v!high\floatspecification\vfill
      \box\floatbox
      \doifnotinset\v!low\floatspecification\vfill}%
   \page_otr_fill_and_eject_page}

\let\m_page_otr_checked_page_float\relax

\unexpanded\def\page_floats_flush_page_floats % used in postpone
  {\edef\m_page_otr_checked_page_float{\clf_checkedpagefloat}%
   \ifx\m_page_otr_checked_page_float\empty
     % nothing
   \else\ifx\m_page_otr_checked_page_float\v!empty
      \emptyhbox \page_otr_fill_and_eject_page % why not dummy_page
   \else
      \page_floats_flush_page_floats_indeed\m_page_otr_checked_page_float
   \fi\fi}

% temp hack, needed to prevent floatbox being forgotten during
% output, this will change to using another box for flushing
%
% \dorecurse{700}{text } \placefigure[top][]{First} {\framed{bla 1}}
%                        \placefigure[top][]{Second}{\framed{bla 2}}
% \dorecurse {40}{text } \placefigure[top][]{Third} {\framed{bla 3}}

\appendtoks
    \global\setbox\savedfloatbox\box\floatbox
\to \everybeforeoutput

\appendtoks
    \global\setbox\floatbox\box\savedfloatbox
\to \everyafteroutput

\protect \endinput

% hm, where is this one used (was in save/restore, see old implementation)
%
% \unexpanded\def\uncenteredfloatbox
%   {\ifconditional\c_page_floats_center_box
%      \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}