% Floats.tex copyright 1992/3 Victor Eijkhout
% these macros handle inserts for the Lollipop format
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%% Floating insertions %%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\@GenericConstruct{Insertion}

\NewTrace:ins

\@InsertionOption{location}{
  \switch {\if\EqualString{#1}}
  {top} {}
  {bot} {}
  {mid} {}
  {default} {\Wmessage{Unknown qualifier: <location:#1>}}
  \endswitch}
\newif\ifsplit@insert
\add@Insertion@default{\split@insertno}
\@InsertionOption{split}{
  \switch {\if\EqualString{#1}}
  {no}  {\split@insertno}
  {default} {\split@insertyes}
  \endswitch}

\def\@DefineInsertion{
  \csarg\newinsert{\@name @ins}
  \csarg\edef{\@name}{\insert\CSname{\@name @ins}
    \ifsplit@insert\else\vbox\fi % make this a box if no split allowed
    \bgroup \the\before@coms
    }
  \@DefineStopCommand{\the\after@coms \egroup}
  }
\endinput
\newinsert\footins
\def\footnote#1{\let\@sf\empty % parameter #2 (the text) is read later
  \ifhmode\edef\@sf{\spacefactor\the\spacefactor}\/\fi
  #1\@sf\vfootnote{#1}}
\def\vfootnote#1{\insert\footins\bgroup
  \interlinepenalty\interfootnotelinepenalty
  \splittopskip\ht\strutbox % top baseline for broken footnotes
  \splitmaxdepth\dp\strutbox \floatingpenalty\@MM
  \leftskip\z@skip \rightskip\z@skip \spaceskip\z@skip \xspaceskip\z@skip
  \textindent{#1}\footstrut\futurelet\next\fo@t}
\def\fo@t{\ifcat\bgroup\noexpand\next \let\next\f@@t
  \else\let\next\f@t\fi \next}
\def\f@@t{\bgroup\aftergroup\@foot\let\next}
\def\f@t#1{#1\@foot}
\def\@foot{\strut\egroup}
\def\footstrut{\vbox to\splittopskip{}}
\skip\footins=\bigskipamount % space added when footnote is present
\count\footins=1000 % footnote magnification factor (1 to 1)
\dimen\footins=8in % maximum footnotes per page

\newif\ifp@ge \newif\if@mid
\let\p@getrue=\p@geyes \let\p@gefalse=\p@geno
\let\@midtrue=\@midyes \let\@midfalse=\@midno
\def\topinsert{\@midfalse\p@gefalse\@ins}
\def\midinsert{\@midtrue\@ins}
\def\pageinsert{\@midfalse\p@getrue\@ins}
\skip\topins=\z@skip % no space added when a topinsert is present
\count\topins=1000 % magnification factor (1 to 1)
\dimen\topins=\maxdimen % no limit per page
\def\@ins{\par\begingroup\setbox\z@\vbox\bgroup} % start a \vbox
\def\endinsert{\egroup % finish the \vbox
  \if@mid \dimen@\ht\z@ \advance\dimen@\dp\z@
    \advance\dimen@12\p@ \advance\dimen@\pagetotal
    \ifdim\dimen@>\pagegoal\@midfalse\p@gefalse\fi\fi
  \if@mid \bigskip\box\z@\bigbreak
  \else\insert\topins{\penalty100 % floating insertion
    \splittopskip\z@skip
    \splitmaxdepth\maxdimen \floatingpenalty\z@
    \ifp@ge \dimen@\dp\z@
    \vbox to\vsize{\unvbox\z@\kern-\dimen@}% depth is zero
    \else \box\z@\nobreak\bigskip\fi}\fi\endgroup}