%-------------------------------------------------------------------------------
% bchart (LaTeX package)
%-------------------------------------------------------------------------------
% Version: 0.1.1
% Date: 16 March 2012
% Author: Tobias Kuhn
%-------------------------------------------------------------------------------

\ProvidesPackage{bchart}

\usepackage{ifthen}
\usepackage{tikz}
\usetikzlibrary{calc}


% Lengths

\newlength{\bcpos}
\newlength{\bcwidth}


% Chart Arguments

\newcommand{\bcunit}{}
\newcommand{\bcmin}{}
\newcommand{\bcmax}{}
\newcommand{\bcstep}{}
\newcommand{\bcsteps}{}
\newcommand{\bcscale}{}
\newcommand{\bcplainchart}{}
\makeatletter
\define@key{bchart}{unit}{\renewcommand{\bcunit}{#1}}
\define@key{bchart}{width}{\setlength{\bcwidth}{#1}}
\define@key{bchart}{min}{\renewcommand{\bcmin}{#1}}
\define@key{bchart}{max}{\renewcommand{\bcmax}{#1}}
\define@key{bchart}{step}{\renewcommand{\bcstep}{#1}}
\define@key{bchart}{steps}{\renewcommand{\bcsteps}{#1}}
\define@key{bchart}{scale}{\renewcommand{\bcscale}{#1}}
\define@key{bchart}{plain}[false]{\renewcommand{\bcplainchart}{true}}
\makeatother


% Bar Arguments

\newcommand{\bcbarcolor}{}
\newcommand{\bcbartext}{}
\newcommand{\bcbarlabel}{}
\newcommand{\bcbarvalue}{}
\newcommand{\bcplainbar}{}
\makeatletter
\define@key{bcbar}{color}{\renewcommand{\bcbarcolor}{#1}}
\define@key{bcbar}{text}{\renewcommand{\bcbartext}{#1}}
\define@key{bcbar}{label}{\renewcommand{\bcbarlabel}{#1}}
\define@key{bcbar}{value}{\renewcommand{\bcbarvalue}{#1}}
\define@key{bcbar}{plain}[false]{\renewcommand{\bcplainbar}{true}}
\makeatother


% Skip Arguments

\newcommand{\bcskiplabel}{}
\makeatletter
\define@key{bcskip}{label}{\renewcommand{\bcskiplabel}{#1}}
\makeatother


% Bar Charts

\newenvironment{bchart}[1][]{%
  % Bars:
  \newcommand{\bcbar}[2][]{
    % Set defaults:
    \renewcommand{\bcbarcolor}{blue!20}
    \renewcommand{\bcbartext}{}
    \renewcommand{\bcbarlabel}{}
    \renewcommand{\bcbarvalue}{##2\bcunit}
    \renewcommand{\bcplainbar}{false}
    % Read parameters:
    \setkeys{bcbar}{##1}
    % Draw bar:
    \fill[color=\bcbarcolor,fill,draw] (0,\bcpos) rectangle ($##2-\bcmin*(\bcwidth/\bcrange,0) + (0,\bcpos-5mm)$);
    \draw (0,\bcpos) rectangle ($##2-\bcmin*(\bcwidth/\bcrange,0) + (0,\bcpos-5mm)$);
    \ifthenelse{\equal{\bcplainbar}{true}}{}{
      % Write value:
      \node[anchor=west] at ($##2-\bcmin*(\bcwidth/\bcrange,0) + (0,\bcpos-2.5mm)$) {\sf \bcbarvalue};
    }
    % Write text:
    \node[anchor=west] at (0,\bcpos-2.5mm) {\sf \bcbartext};
    % Write label:
    \node[anchor=east] at (0,\bcpos-2.5mm) {\sf \bcbarlabel};
    % Move vertical position downward:
    \addtolength{\bcpos}{-5mm}
  }%
  % Labels:
  \newcommand{\bclabel}[1]{
    % Write label:
    \node[anchor=east] at (0,\bcpos) {\sf ##1};
  }%
  % General skips:
  \newcommand{\bcskip}[2][]{
    % Set defaults:
    \renewcommand{\bcskiplabel}{}
    % Read parameters:
    \setkeys{bcskip}{##1}
    % Write label:
    \node[anchor=east] at ($(0,\bcpos) - 0.5*(0,##2)$) {\sf \bcskiplabel};
    % Move vertical position downward:
    \addtolength{\bcpos}{-##2}
  }%
  % Small skips:
  \renewcommand{\smallskip}[1][]{\bcskip[##1]{2.5mm}}%
  % Medium skips:
  \renewcommand{\medskip}[1][]{\bcskip[##1]{5.0mm}}%
  % Large skips:
  \renewcommand{\bigskip}[1][]{\bcskip[##1]{7.5mm}}%
  % X-axis label:
  \newcommand{\getbcxlabel}{}%
  \newcommand{\bcxlabel}[1]{
    \renewcommand{\getbcxlabel}{##1}
  }%
  \newcommand{\bcrange}{\bcstripunit{\dimexpr\bcmax pt-\bcmin pt\relax}}
  % Set defaults:
  \renewcommand{\bcunit}{}%
  \renewcommand{\bcmin}{0}%
  \renewcommand{\bcmax}{100}%
  \renewcommand{\bcstep}{\bcrange}%
  \renewcommand{\bcsteps}{0,\bcstep,...,\bcrange}%
  \renewcommand{\bcscale}{1}%
  \renewcommand{\bcplainchart}{false}%
  \setlength{\bcpos}{-2.5mm}%
  \setlength{\bcwidth}{8cm}%
  % Read parameters:
  \setkeys{bchart}{#1}%
  % Draw chart:
  \begin{tikzpicture}[scale=\bcscale]
}{
    % Draw axes:
    \addtolength{\bcpos}{-2.5mm}
    \draw (0,\bcpos) -- (\bcwidth,\bcpos);
    \draw (0,0) -- (0,\bcpos);
    % Draw scale:
    \ifthenelse{\equal{\bcplainchart}{true}}
    { % Scale off
      % Set position for x-axis label:
      \coordinate (labelpos) at (0,\bcpos-2mm);
    }{ % Scale on
      % Draw start value and set position for x-axis label:
      \draw (0,\bcpos) -- (0,\bcpos-1mm);
      \node[anchor=north] (n) at (0,\bcpos-1mm)
        {\sf \bcstripunit{\dimexpr\bcmin pt\relax}\bcunit};
      \coordinate (labelpos) at (n.south);
      % Draw other values:
      \foreach \x in \bcsteps {
        \ifthenelse{\equal{\x}{0}}{}{
          \draw ($\x*(\bcwidth/\bcrange,0) + (0,\bcpos)$) -- ($\x*(\bcwidth/\bcrange,0) + (0,\bcpos-1mm)$);
          \node[anchor=north] at ($\x*(\bcwidth/\bcrange,0) + (0,\bcpos-1mm)$)
            {\sf \bcstripunit{\dimexpr\bcmin pt+\x pt\relax}\bcunit};
        }
      }
    }
    % Write x-axis label:
    \ifthenelse{\equal{\getbcxlabel}{}}{}{
      \node[anchor=north,inner sep=0.5mm] at ($0.5*(\bcwidth,0) + (labelpos)$) {\sf \getbcxlabel};
    }
  \end{tikzpicture}%
}


% Auxiliary commands:

\makeatletter
\newcommand*{\bcstripunit}[1]{\strip@pt#1}
\makeatother