code-animation.sty

\ProvidesPackage{code-animation}[2022/05/22 EagleoutIce - animating runs through code with beamer]

\RequirePackage{etoolbox}
\RequirePackage{listings}
\RequirePackage{tikz}
\usetikzlibrary{tikzmark}

\RequirePackage{fontawesome} % used for default symbols
\RequirePackage{xxcolor} % mixin

\newif\ifca@beamermode
\@ifundefined{only}{\ca@beamermodefalse}{\ca@beamermodetrue}

% TODO: allow for symbolic markers in the animations to reuse them instead of the animation number (e.g -> storeXX syntax) (StoreHandoutTo, StoreAnimationTo)
% we may want to add a new literate to be used in the code:
% TODO:
\def\ca@lst@addToLiterate#1{%
    \protected@edef\lst@literate{%
        \unexpanded\expandafter{\lst@literate}\unexpanded{#1}%
    }%
}
\lst@Key{code-animations@add to literate}{}{\ca@lst@addToLiterate{#1}}
% TODO: use those in the code so they are available with the star option

% TODO: redefine to kill that :D
\def\ca@colormixin@env{colormixin}

% i do not use groups as this has problems with lst
% as they can not be nested, one storage is enough
\def\SetCodeAnimationFadeOutMixin#1{\def\ca@colormixin@suff{#1}}
\def\ca@colormixin@suff{!15!lightgray}

\let\ca@oldcolormixin\@empty

\colorlet{ca@base@color}{black}

\def\@ca@@fadeout@start{%
    \let\ca@Mixin\ca@colormixin@env
    \let\ca@oldcolormixin\colorcurrentmixin
    \edef\colorcurrentmixin{\ca@colormixin@suff\colorcurrentmixin}%
    \@declaredcolor{ca@base@color}%
}

\def\@ca@fadeout@start#1{%
    \ca@InCurrentLineActive{#1}%
        \@empty
        {%
            \ca@InOtherLineActive{#1}%
                \@empty
                {\@ca@@fadeout@start}%
        }%
    \relax
}

% guard to not close unnecessary
\def\@ca@fadeout@end{%
    \ifx\ca@colormixin@env\ca@Mixin
        \let\colorcurrentmixin\ca@oldcolormixin
        \@declaredcolor{.}%
    \fi
    \let\ca@Mixin\relax
}

% TODO: include comments
\def\CodeAnimationsNoFadeOut{%
    \let\ca@fadeout@start\@gobble
    \let\ca@fadeout@end\@empty
}

\def\CodeAnimationsWithFadeOut{%
        \let\ca@fadeout@start\@ca@fadeout@start
        \let\ca@fadeout@end\@ca@fadeout@end
}
\CodeAnimationsWithFadeOut

\def\ca@Strut{\vphantom{\ttfamily\strut}}

% TODO: use firstoftwo and second of two
\def\ca@InCurrentLineActive#1#2#3{%
    % AND are we in animation Run? otherwise always # negatives to fake this check!
    \ifnum\ca@anim@currentline=0#2\else
    % are we in the current line?
    \expandafter\ifnum\number\csname c@codeanim@#1@lc\endcsname=\ca@anim@currentline
    #2\else#3\fi\fi
}

\newif\if@ca@@active@found@
\def\ca@InOtherLineActive#1#2#3{%
    \global\@ca@@active@found@false
    \foreach\k in \ca@anim@otherhighlights {% TODO: Speed this up heavily by having macros and check for their existence
        \ifnum\k=\number\csname c@codeanim@#1@lc\endcsname\relax \global\@ca@@active@found@true\breakforeach\fi
    }%
    \if@ca@@active@found@#2\else#3\fi% no groups :)
}

% the initial comments marker
\def\ca@comments@from{0}
% #1 is a coordinate prefix to be used outside
\newcommand\ca@AnimateCode[1][@]{% just to block spaces and stuff for sure
\ifcsname c@codeanim@#1@lc\endcsname\else
\expandafter\newcount\csname c@codeanim@#1@lc\endcsname\fi
% reset counter in any way!
\global\csname c@codeanim@#1@lc\endcsname0\relax
% we appto locally to increment the current line counter
\appto\lsthk@EOL{%
    \tikzmarknode{ca@#1-\expandafter\the\csname c@codeanim@#1@lc\endcsname @end}{\ca@Strut}%
}%
% \appto\lsthk@InitVars{%
%     a\tikzmarknode{ca@#1-\expandafter\the\csname c@codeanim@#1@lc\endcsname @end}{\ca@Strut}w%
% }%
\appto\lsthk@OnNewLine{%
    % get the end marker for this line
    % TODO: tikzmarks listing lib
    % step the line id counter (ensures unique)
    \global\advance\csname c@codeanim@#1@lc\endcsname by1\relax
    % done!
    \ca@fadeout@end
}%
% hook the start marker at the beginning:
% TODO: maybe embed them just around escapings?
\preto\lsthk@OutputBox{\ca@fadeout@start{#1}\appto\lst@righthss{\ca@fadeout@end}}% box to be in the same group
% \appto\lsthk@OutputToken{\ca@fadeout@end}% will automatically hide if not in env
\appto\lsthk@EveryPar{% we do not do this multiple (in case of line breaks) to be safe
    % with markers, therefore we do not use EveryLine using empty so it does not jump!
    \tikzmarknode{ca@#1-\expandafter\the\csname c@codeanim@#1@lc\endcsname @start}{\ca@Strut}%
}%
%
% #1 allows for horiz shift
\newcommand\AnimLoc[2][0pt]{\rlap{\hspace*{##1}\tikzmarknode{ca@#1-\expandafter\the\csname c@codeanim@#1@lc\endcsname @##2}{\ca@Strut}}\expandafter\xdef\csname CodeAnim#1-##2\endcsname{ca@#1-\expandafter\the\csname c@codeanim@#1@lc\endcsname @##2}}%
% furthermore we want to configure some numbers with beamer animations!
% TODO: support for mid-code highlights by literates! like @ as a marker?!
\ca@DecodeHandouts
\ca@DecodeAnimations
}
\newcommand\GetAnimLoc[2][@]{\csname CodeAnim#1-#2\endcsname}
% we make it so that any item is *command* :)
\def\ca@Record#1#2{\immediate\protected@write\@auxout{}{\protect\def\protect#1{#2}}\xdef#1{#2}}
\def\CodeAnimGet#1{\@ifundefined{#1}{0}{\csname#1\endcsname}}
\def\ca@on@handout{}
\def\@AnimationCommands{%
    \ifca@beamermode
    \mode<all>{\def\ca@reset{\def\ca@comments@from{\@anim@on}}}%
    \mode<handout>{\def\ca@reset{% directly reset
    % if anim@on is below current:
    \ifnum\@anim@on<\ca@MapFromHandout{\insertslidenumber}\relax
        \xdef\ca@comments@from{\@anim@on}%
    \else\def\ca@comments@from{\@anim@on}\fi
    }}%
    \else\xdef\ca@comments@from{0}\fi
    % the simple animation
    \def\ca@simple##1{\def\@anim{##1}}%
    % shift commentframe
    \def\ca@resetsimple##1{\ca@simple{##1}\ca@reset}%
    \def\ca@simpleothers##1:##2\@null{\def\@anim{##1}\def\ca@anim@otherhighlights##2}% note: has to be given in braces!
    \def\ca@othersonly{\let\ca@anim@curentlocation\@empty\ca@simpleothers}%
    \def\ca@comment##1:##2\@null{\def\@anim{##1}\def\@comment@text{##2}}%
    \def\ca@resetcomment{\ca@reset\ca@comment}%
    \def\ca@hidden{\let\ca@anim@curentlocation\@empty\def\@anim{-1}\def\ca@anim@otherhighlights{}}%
    \def\ca@custom{% TODO: unify so others use readable syntax as well!
        \def\Line####1{\def\@anim{####1}}%
        \def\NextLine{\RelativeLine1}%
        \def\PreviousLine{\RelativeLine-1}%
        \def\RelativeLine####1{\edef\@anim{\the\numexpr\old@anim+####1\relax}}%
        \def\Comment####1{\def\@comment@text{####1}}%
        \def\Reset{\ca@reset}%
        \def\Hidden{\ca@hidden}%
        \def\Forever{\edef\@anim@on{\@anim@on-}}%
        \def\StoreAnimationTo####1{\ca@Record####1{\@anim@on}}%
        \def\StoreHandoutTo####1{\ca@Record####1{\ca@MapToHandout{\@anim@on}}}%
        \ifca@beamermode
        \mode<all>{\let\StoreTo\StoreAnimationTo}%
        \mode<handout>{\let\StoreTo\StoreHandoutTo}%
        \else\let\StoreTo\StoreHandoutTo\fi
        \def\Location####1{\def\ca@anim@curentlocation{####1}}%
        \def\NoLocation{\let\ca@anim@curentlocation\@empty}%
        \def\Others####1{\def\ca@anim@otherhighlights{####1}}%
    }%
}
% TODO: optional arg for all for custom commands?
\def\ca@DecodeAnimationCommand#1#2\@null{%
    \def\@anim{0}\let\@comment@text\@empty
    \let\ca@anim@otherhighlights\@empty
    \def\ca@anim@curentlocation{start}% default value(s)
    \if#1.\relax\ca@resetsimple{#2}\else
    \if#1:\relax\ca@simpleothers#2\@null\else
    \if#1o\relax\ca@othersonly#2\@null\else
    \if#1/\relax\ca@comment#2\@null\else
    \if#1|\relax\ca@resetcomment#2\@null\else
    \if#1*\relax\ca@custom#2\else
    \if#1h\relax\ca@hidden\else
    \if#1+\relax\ca@simple{\the\numexpr\old@anim+1\relax}\else
    % use the last one! and keep it in memory
    \if#1-\relax\let\@animcode\@animcode@last\expandafter\ca@DecodeAnimationCommand\@animcode@last\@empty\@empty\@null\else
    % else do it at a number:
        \ca@simple{#1#2}%
    \fi\fi\fi\fi\fi\fi\fi\fi\fi
    \if#1-\relax\else % minus is never a last!
        \global\let\@animcode@last\@animcode
    \fi
}
% used for easier expandafter to lock the anim
% we may globalize:
\ifca@beamermode
\def\ca@Only#1#2#3#4#5{\only<\@anim@on|handout:\ca@MapToHandout{\@anim@on}>{% this is the activator
    \gdef\ca@comments@from{#1}% re-account comments from this id
    \gdef\ca@anim@currentline{#2}%
    \gdef\ca@anim@currentcomment{#3}%
    \gdef\ca@anim@curentlocation{#4}%
    \gdef\ca@anim@otherhighlights{#5}% highlight lines (extra) in fade-out
}}
\else
\def\ca@Only#1#2#3#4#5{% we ignore anim on
    \gdef\ca@comments@from{#1}% re-account comments from this id
    \gdef\ca@anim@currentline{#2}%
    \gdef\ca@anim@currentcomment{#3}%
    \gdef\ca@anim@curentlocation{#4}%
    \gdef\ca@anim@otherhighlights{#5}% highlight lines (extra) in fade-out
}
\fi

% if it is not there, do not put it on the handout
\def\ca@MapToHandout#1{\@ifundefined{ca@@map@#1@}{0}{\csname ca@@map@#1@\endcsname}}
\def\ca@MapFromHandout#1{\@ifundefined{ca@@map@inv@#1@}{0}{\csname ca@@map@inv@#1@\endcsname}}
\def\ca@DecodeHandouts{% just create the mappings
    % TODO: update this to use a custom '<from> -> <to>' syntax or so
    % TODO: explain how to use this if 1 is to be on 2-10 and 2 is to be on 4 only (by doing it extra)
    \gdef\@ca@collector{}%
    \foreach \@from/\@to in \ca@onhandout@list {%
        % we make this bidirectional to get comment ranges
        \xappto\@ca@collector{%
            \noexpand\expandafter\noexpand\edef\noexpand\csname ca@@map@\@from @\endcsname{\@to}%
            \noexpand\expandafter\noexpand\edef\noexpand\csname ca@@map@inv@\@to @\endcsname{\@from}%
        }%
    }%
    \@ca@collector% keep the definitions local, only the collector is global and
    % more easily reset than a potentially infinite map :D
}

\def\ca@DecodeAnimations{%
    \def\ca@anim@currentline{0}% default if none is active
    \let\ca@anim@currentcomment\@empty
    \@AnimationCommands
    % clear it on the start
    \ifca@beamermode
    \only<\ca@firstslide>{\def\ca@comments@from{0}}%
    \else\def\ca@comments@from{0}\fi
    \let\@animcode@last\@empty % no last on init
    \foreach[count=\@anim@on from \ca@firstslide,remember=\@anim as \old@anim (initially 0)] \@animcode in \ca@onslide@list {%
        % \typeout{[\ca@cdname] AT: \@anim@on; last: \old@anim code: \meaning\@animcode [last \meaning\@animcode@last]}%
        \expandafter\ca@DecodeAnimationCommand\@animcode\@empty\@empty\@null
        \expandafter\protected@xdef\csname @\@anim@on @comment@text\endcsname{\@comment@text}%
        \expandafter\protected@xdef\csname @\@anim@on @comment@location\endcsname{\@anim}%
        % takeover expanded (protection for comments)
        \protected@edef\@tmpargs{{\ca@comments@from}{\@anim}{\@comment@text}{\ca@anim@curentlocation}{\ca@anim@otherhighlights}}%
        \expandafter\ca@Only\@tmpargs\relax
    }%
}

\pgfqkeys{/ca@animate@code}{%
  onslide/.store in=\ca@onslide@list,
  handout/.store in=\ca@onhandout@list, % list in format {<anim-list>}/<handout>
  first slide/.store in=\ca@firstslide,
  defaults/.style={first slide=1,onslide={},handout={}}
}

\def\ca@Leftmark{\llap{\faAngleRight~}}
\def\ca@Rightmark{\rlap{\faAngleLeft}}% currently there is a buffer :D
\def\ca@Botmark{\smash{\clap{\faAngleUp}}}% currently there is a buffer :D
\def\ca@start{start}\def\ca@end{end}
% TODO: Botmark and stuff
\tikzset{ca@CommentNode/.style={font=\sffamily\small\slshape,gray,right=3mm,yshift=.2mm},ca@CommentNode@out/.style={ca@CommentNode,font=\sffamily\footnotesize\slshape,lightgray}}
\def\ca@DoCodeAnimation{%
\tikzpicture[overlay,remember picture]%
% make the line markers :)
\ifnum\ca@anim@currentline>0\relax
% here we only allow positives (there are no negative lines to place)
\ifx\ca@anim@curentlocation\ca@start
    \node[left] at (ca@\ca@cdname-\ca@anim@currentline @start.west) {\ca@Leftmark};
\else\ifx\ca@anim@curentlocation\ca@end
    \node[right] at (ca@\ca@cdname-\ca@anim@currentline @end.east) {\ca@Rightmark};
\else\ifx\ca@anim@curentlocation\@empty% do nothing in that case
\else
    \node[below] at (ca@\ca@cdname-\ca@anim@currentline @\ca@anim@curentlocation.south) {\ca@Botmark};
\fi\fi\fi
\fi
\ifnum\ca@anim@currentline>0\relax
    \node[ca@CommentNode] at (ca@\ca@cdname-\ca@anim@currentline @end.east) {\ignorespaces\ca@anim@currentcomment};
\fi
% animate all visible ones
% do not go down:
% include '='
\ifca@beamermode
\mode<all>{\edef\ca@Maximum{\the\numexpr\insertslidenumber-1\relax}}%
\mode<handout>{\def\ca@Maximum{\the\numexpr\ca@MapFromHandout{\insertslidenumber}-1\relax}}%
\else
\def\ca@Maximum{1} % without animations, there is only one
\fi
\ifnum\ca@comments@from>\ca@Maximum\else
\foreach \@comment@on in {\ca@comments@from,...,\ca@Maximum} {%
    \@ifundefined{@\@comment@on @comment@text}{}{%
        \edef\@location{\csname @\@comment@on @comment@location\endcsname}%
        \ifnum\@location>0 % guard against negatives
        \node[ca@CommentNode@out] at (ca@\ca@cdname-\@location @end.east) {\ignorespaces\csname @\@comment@on @comment@text\endcsname};
        \fi
    }%
}%
\fi
% \node[above right] at(current page.south west) {\insertslidenumber};
\endtikzpicture}

\newenvironment{AnimateCode}[2][@]{\begingroup
\pgfqkeys{/ca@animate@code}{defaults, #2}%
\def\ca@cdname{#1}\ca@AnimateCode[#1]}{\ca@DoCodeAnimation\endgroup}

\endinput