%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% outlines.sty - Provides an "outline" environment for mixed-level
% outline lists
%
% Charles Pecheur, UCL, March 2005
% pecheur@info.ucl.ac.be
%
% Note: this package has no connection with outline.sty or outliner.sty, 
% that are available on CTAN
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Usage: 
%
% \usepackage{outlines}
%
% \begin{outline}[<list-style>] 
%   \1 <level 1 text>
%   \1[<label>] <level 1 text>
%      \2 <level 2 text>
%         \3 <level 3 text>
%            \4 <level 4 text>
% \0 <normal paragraph>
%   ...
% \end{outline}
%
% where:
% + <list-style> is an optional list environment name 
%   (e.g. itemize, enumerate, ...).  The default is itemize.
%   The same style is used for all levels.
% + <label> is an optional label, as in \item[<label>].
% + Levels may be mixed freely, except that a \1 must come before
%   the first \2, a \2 before the first \3, etc. 
%   (this restriction is inherited from list environments).
% + \0 gives a normal, non-list paragraph.
% 
% Do not nest outlines inside outlines or other lists.  Lists inside outlines
% should work fine.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\ProvidesClass{outlines}

\makeatletter
% \ol@type stores the (list) environment name used in outlines
\newcommand{\ol@type}{itemize}
% \ol@inc, \ol@dec increase/decrease the indentation level
\newcommand{\ol@inc}{\begin{\ol@type}}
\newcommand{\ol@dec}{\end{\ol@type}}

% \ol@toz .. \ol@toiiii "transition" to indentation level 0..4 by opening or
% closing nested list levels as needed.
% They are dynamically modified according to the current level.
\newcommand{\ol@toz}{}
\newcommand{\ol@toi}{}
\newcommand{\ol@toii}{}
\newcommand{\ol@toiii}{}
\newcommand{\ol@toiiii}{}

% \ol@commands{C0}{C1}{C2}{C3}{C4} set the level transition commands 
% above to C0..C4
\newcommand{\ol@commands}[5]{%
  \renewcommand{\ol@toz}{#1}%
  \renewcommand{\ol@toi}{#2}%
  \renewcommand{\ol@toii}{#3}%
  \renewcommand{\ol@toiii}{#4}%
  \renewcommand{\ol@toiiii}{#5}%
}

% \ol@exit resets transition commands.  This is not mandatory, just cleaner.
\newcommand{\ol@exit}{%
  \ol@commands{}{}{}{}{}}
% \ol@z .. \ol@iiii update all transitions for level 0..4
\newcommand{\ol@z}{%
  \ol@commands{}{\ol@inc}{\ol@inc\ol@inc}%
    {\ol@inc\ol@inc\ol@inc}{\ol@inc\ol@inc\ol@inc\ol@inc}}
\newcommand{\ol@i}{%
  \ol@commands{\ol@dec}{}{\ol@inc}%
    {\ol@inc\ol@inc}{\ol@inc\ol@inc\ol@inc}}
\newcommand{\ol@ii}{%
  \ol@commands{\ol@dec\ol@dec}{\ol@dec}{}{\ol@inc}{\ol@inc\ol@inc}}
\newcommand{\ol@iii}{%
  \ol@commands{\ol@dec\ol@dec\ol@dec}{\ol@dec\ol@dec}{\ol@dec}%
    {}{\ol@inc}}
\newcommand{\ol@iiii}{%
  \ol@commands{\ol@dec\ol@dec\ol@dec\ol@dec}{\ol@dec\ol@dec\ol@dec}%
	    {\ol@dec\ol@dec}{\ol@dec}{}}

% the outline environment provides commands \1..\4 for 
% introducing items at level 1..4, and \0 for normal paragraphs 
% within the outline section.
\newenvironment{outline}[1][itemize]{%
  \renewcommand{\ol@type}{#1}%
  \ol@z%
  \newcommand{\0}{\ol@toz\ol@z}%
  \newcommand{\1}{\ol@toi\ol@i\item}%
  \newcommand{\2}{\ol@toii\ol@ii\item}%
  \newcommand{\3}{\ol@toiii\ol@iii\item}%  
  \newcommand{\4}{\ol@toiiii\ol@iiii\item}%  
}{%
  \ol@toz\ol@exit%
}
\makeatother