 %% drawstack.sty
  %% Copyright 2010 Matthieu Moy <Matthieu.Moy@imag.fr>
  %
  % This work may be distributed and/or modified under the
  % conditions of the LaTeX Project Public License, either version 1.3
  % of this license or (at your option) any later version.
  % The latest version of this license is in
  %   http://www.latex-project.org/lppl.txt
  % and version 1.3 or later is part of all distributions of LaTeX
  % version 2005/12/01 or later.
  %
  % This work has the LPPL maintenance status `maintained'.
  %
  % The Current Maintainer of this work is M. Matthieu Moy.
  %
  % This work consists of the files drawstack.sty and the example file
  % stack-example.tex.

\NeedsTeXFormat{LaTeX2e}

\ProvidesPackage{drawstack}[2010/08/06 Draw Execution Stack in LaTeX]

\RequirePackage{tikz}
\RequirePackage{ifthen}

% Default styles definition.
\tikzstyle{freecell}=[fill=green!10,draw=green!30!black]
\tikzstyle{freestruct}=[fill=blue!10,draw=blue!30!black]
\tikzstyle{occupiedcell}=[fill=green!10!red!10,draw=green!30!black]
\tikzstyle{padding}=[fill=green!10!black!10,draw=green!30!black]
\tikzstyle{highlight}=[draw=red!50!black,text=red!50!black]

\DeclareOption{nocolor}{
  \tikzstyle{freecell}=[fill=white!95!black,draw=black]
  \tikzstyle{freestruct}=[fill=white!93!black,draw=black]
  \tikzstyle{occupiedcell}=[fill=white!60!black,draw=black]
  \tikzstyle{padding}=[fill=white!90!black!10,draw=black]
  \tikzstyle{highlight}=[draw=black,text=black]
}
\ProcessOptions

\pgfdeclarelayer{background layer}
\pgfdeclarelayer{foreground layer}
\pgfsetlayers{background layer,main,foreground layer}
\usetikzlibrary{shapes} % ellipse
\usetikzlibrary{snakes} % braces

\newcounter{cellnb}
\newcounter{structnb}
\setcounter{cellnb}{0}

\newcommand{\llcell}[3]{
    \addtocounter{cellnb}{-#1}
    \setcounter{ptrnb}{0}
    \draw[#2] (0,\value{cellnb}) +(-2,-.5) rectangle +(2,-.5+#1);
    \draw (0,\value{cellnb}+#1/2-0.5)  node(currentcell) {#3};
}
\newcommand{\bigcell}[2]{
  \llcell{#1}{freecell}{#2}
  \foreach \c in {2,...,#1} {
    \draw[freecell]
    (-2,\value{cellnb}+\c-1.5) -- (-1.7,\value{cellnb}+\c-1.5);
    \draw[freecell]
    (1.7,\value{cellnb}+\c-1.5) -- (2,\value{cellnb}+\c-1.5);
  }
}
\newcommand{\cell}[2][freecell]{%
\llcell{1}{#1}{#2}}

\newcommand{\separator}[1][freecell,very thick]{
  \draw[#1] (0,\value{cellnb}) +(-2,-.5) -- +(2,-.5);
}

% Pointer to the next cell, useful if the next cell has size != 0.
\newcommand{\cellptrnext}[1]{
  \draw[<-,line width=0.7pt] (0,\value{cellnb}-1) +(2,\value{ptrnb}*0.1) -- +(2.5,\value{ptrnb}*0.45);
  \draw (2.5,\value{ptrnb}*0.5+\value{cellnb}-1) node[anchor=west] {#1};
  \addtocounter{ptrnb}{1}
}
\newcounter{ptrnb}
\newcommand{\cellptr}[1]{
  \draw[<-,line width=0.7pt] (0,\value{cellnb}) +(2,\value{ptrnb}*0.1) -- +(2.5,\value{ptrnb}*0.45);
  \draw (2.5,\value{ptrnb}*0.5+\value{cellnb}) node[anchor=west] {#1};
  \addtocounter{ptrnb}{1}
}
\newcommand{\esp}{\cellptr{\%esp}}
\newcommand{\ebp}{\cellptr{\%ebp}}

% like cellptr, but without the arrow
\newcommand{\cellcom}[1]{
  \draw (2.4,\value{ptrnb}*0.5+\value{cellnb}) node[anchor=west] {#1};
  \addtocounter{ptrnb}{1}
}
% like cellcom, but on the left hand side
\newcommand{\cellcomL}[1]{
  \draw (-2,\value{ptrnb}*0.5+\value{cellnb}) node[anchor=east] {#1};
  \addtocounter{ptrnb}{1}
}

\newcommand{\cellround}[1]{
  \begin{pgfonlayer}{foreground layer}
    \draw[highlight] (0,\value{cellnb})
    node[shape=ellipse,draw, minimum width=3cm, minimum height=0.9cm]
    (marked) {};
    \draw[highlight] (0,\value{cellnb}) +(3,1.3) node[anchor=west] (textmarked) {#1};
    \draw[highlight,->] (marked) -- (textmarked.text);
  \end{pgfonlayer}
}

\newcommand{\stacktop}[2][freecell]{
  \setcounter{cellnb}{0}
  \ifthenelse{\equal{#2}{}}{}{
    \draw (0,\value{cellnb}) node {#2};
    \addtocounter{cellnb}{-1}
  }

  \draw[#1] (0,\value{cellnb})
  +(-2,.5) -- +(-2,-.5) -- +(2,-.5) -- +(2,.5);
  \draw (0,\value{cellnb}) node{...};
}
\newcommand{\stackbottom}[1][freecell]{
  \addtocounter{cellnb}{-1}
  \draw[#1] (0,\value{cellnb})
  +(-2,-.5) -- +(-2,+.5) -- +(2,+.5) -- +(2,-.5);
  \draw (0,\value{cellnb}) node{...};
}
\newenvironment{drawstack}[1][]%
{\begin{tikzpicture}[#1]\stacktop{}}%
{\stackbottom\end{tikzpicture}}

\newcommand{\bcell}[1]{\cell[occupiedcell]{#1}}
\newcommand{\padding}[2]{\llcell{#1}{padding}{#2}}
\newcommand{\bstacktop}[0]{\stacktop[occupiedcell]}
\newcommand{\bstackbottom}[0]{\stackbottom[occupiedcell]}

\newcounter{startframe}
\newcommand{\startframe}[0]{
  \setcounter{startframe}{\value{cellnb}}
}
\newcommand{\finishframe}[1]{
  \draw[snake=brace, line width=0.6pt, segment amplitude=7pt]
  (-2,\value{cellnb}-0.5) -- (-2,\value{startframe}-0.5);
  \draw (-4.2cm,\value{cellnb}*0.5+\value{startframe}*0.5-0.5) node
  {\parbox{3cm}{%
\begin{flushright}
#1
\end{flushright}}};
}
\newcommand{\stackframe}[3]{
  \draw[snake=brace] (-2,-#1-0.5) -- (-2,-#2-0.5);
  \draw (0, #1) node {#3};
}

\newcommand{\drawstruct}[1]{
  \setcounter{structnb}{0}
  \path #1 coordinate (structpos);
  \path (structpos) ++ (0,\value{structnb}) +(-1.6,-.5) coordinate (structtopleft);
}

\newcommand{\llstructcell}[3]{
    \addtocounter{structnb}{-#1}
    \path (structpos) ++ (0,\value{structnb}) +(-1.6,-.5) coordinate (topleft);
    \path (structpos) ++ (0,\value{structnb}) +(-1.6,-.5+#1) coordinate (bottomleft);
    \path (structpos) ++ (0,\value{structnb}) +( 1.6,-.5+#1) coordinate (bottomright);
    \draw[#2] (topleft) rectangle (bottomright);
    \draw (structpos) ++ (0,\value{structnb}+#1/2-0.5) node (currentcell){#3};
}

\newcommand{\structcell}[2][freestruct]{%
  \llstructcell{1}{#1}{#2}
}

\newcommand{\structname}[1]{
  \path (structpos) ++ (0,\value{structnb}) +(-1.6,-.5) coordinate (structbottomleft);
  \draw (barycentric cs:structtopleft=.5,structbottomleft=.5)
  node[rotate=90,anchor=south] {#1};
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
