%% Dimension line for LaTeX/TikZ
%% Copyright © 2013 Sébastien Gross  <seb•ɑƬ•chezwam•ɖɵʈ•org>
%%
%% This file may be distributed and/or modified
%%
%% 1. under the LaTeX Project Public License and/or
%% 2. under the WTF Public License.
%%
%%
%% This simplify the creation drawing of dimension arrows.
%%
%%
%% To install it copy the tango directory to either:
%%   - $TEXHOME/tex/latex/
%%   - ~/texmf/tex/latex/
%%   - ~/Library/texmf/tex/latex
%%

\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{tikz-dimline}[2013/03/13 v1.0 initial version]

\RequirePackage{tikz}
\RequirePackage{pgfplots}
\RequirePackage{ifthen}

\usetikzlibrary{calc,decorations.markings,arrows}

\makeatletter



\pgfkeys {
  /dimline/.cd,
  execute style/.style = {#1},
  execute macro/.style = {/dimline/execute style/.expand once=#1},
}


\newdimen\dimline@arrow@linewidth

\pgfarrowsdeclare{dimline}{dimline}
{
  \arrowsize=1\pgflinewidth
  \pgfarrowsleftextend{0\arrowsize}
  \pgfarrowsrightextend{5\arrowsize}
} {
  \arrowsize=1\pgflinewidth
  \pgfsetdash{}{0pt} %  do not dash
  % |
  \pgfsetlinewidth{.5\arrowsize}
  \pgfpathmoveto{\pgfpoint{4.75\arrowsize}{3\arrowsize}}
  \pgfpathlineto{\pgfpoint{4.75\arrowsize}{-3\arrowsize}}
  \pgfusepathqstroke
  % >
  \pgfsetlinewidth{0.01pt}
  \pgfpathmoveto{\pgfpoint{4.5\arrowsize}{0pt}}
  \pgfpathlineto{\pgfpoint{-3\arrowsize}{2\arrowsize}}
  \pgfpathlineto{\pgfpoint{-3\arrowsize}{-2\arrowsize}}
  \pgfpathclose
  \pgfusepathqfillstroke
}


\pgfarrowsdeclare{dimline reverse}{dimline reverse}
{
  \arrowsize=1\pgflinewidth
  \pgfarrowsleftextend{-5\arrowsize}
  \pgfarrowsrightextend{0\arrowsize}
} {
  \arrowsize=1\pgflinewidth
  \pgfsetdash{}{0pt} %  do not dash
  % |
  \pgfsetlinewidth{0.5\arrowsize}
  \pgfpathmoveto{\pgfpoint{-0.25\arrowsize}{3\arrowsize}}
  \pgfpathlineto{\pgfpoint{-0.25\arrowsize}{-3\arrowsize}}
  \pgfusepathqstroke
  % >
  \pgfsetlinewidth{0.01pt}
  \pgfpathmoveto{\pgfpoint{0pt}{0pt}}
  \pgfpathlineto{\pgfpoint{7.5\arrowsize}{2\arrowsize}}
  \pgfpathlineto{\pgfpoint{7.5\arrowsize}{-2\arrowsize}}
  \pgfpathclose
  \pgfusepathqfillstroke
}


% measure lenght
% http://tex.stackexchange.com/questions/123913


\newcommand{\dimline@do@nothing}[1]{#1}%
% http://tex.stackexchange.com/questions/58283/tikz-how-to-determine-the-vector-between-two-co-ordinates


% #1: optional keys parameters
% #2: start point
% #3: end point
% #4: text
\newcommand{\dimline}[4][]{%

  \pgfplotsifinaxis{%
    \let\dimline@internal\pgfplotsextra%
  }{%
    \let\dimline@internal\dimline@do@nothing%
  }%

  \dimline@internal{
    \pgfkeys{
      dimline/.is family,
      dimline,
      color/.initial = black,
      extension start length/.initial=1cm,
      extension end length/.initial=1cm,
      extension start angle/.initial=-90,
      extension end angle/.initial=90,
      line style/.initial = {},
      label style/.initial = {},
      extension style/.initial = {},
      extension start style/.initial = {},
      extension start path/.initial = {},
      extension end style/.initial = {},
      extension end path/.initial = {},
      #1,
      line style/.get = \dimline@line@style,
      label style/.get = \dimline@label@style,
      extension style/.get = \dimline@extension@style,
      extension start style/.get = \dimline@extension@start@style,
      extension start path/.get = \dimline@extension@start@path,
      extension end style/.get = \dimline@extension@end@style,
      extension end path/.get = \dimline@extension@end@path,
    }

    \begin{scope} [
      line/.style = {
        color=\pgfkeysvalueof{/dimline/color},
        arrows=dimline-dimline,
        /dimline/execute macro = \dimline@line@style,
      },
      extension/.style = {
        color=\pgfkeysvalueof{/dimline/color}!40, line width=0.01,
        /dimline/execute macro = \dimline@extension@style,
      },
      extension start/.style = {
        extension,
        /dimline/execute macro = \dimline@extension@start@style
      },
      extension end/.style = {
        extension,
        /dimline/execute macro = \dimline@extension@end@style,
      },
      label/.style = {
        fill=white, align=center, sloped=true, pos=0.5,
        /dimline/execute macro = \dimline@label@style
      },
      ]

      \coordinate (a) at #2 {};
      \coordinate (b) at #3 {};

      \ifthenelse{\equal{\dimline@extension@start@path}{}}{
        \coordinate (a to b) at ($(a)!\pgfkeysvalueof{/dimline/extension start length}!\pgfkeysvalueof{/dimline/extension start angle}:(b)$);
        \draw [extension start] (a.center) -- (a to b);
      } {
        \draw [extension start] plot coordinates {\dimline@extension@start@path};
      }

      \ifthenelse{\equal{\dimline@extension@end@path}{}}{
        \coordinate (b to a) at ($(b)!\pgfkeysvalueof{/dimline/extension end length}!\pgfkeysvalueof{/dimline/extension end angle}:(a)$);
        \draw [extension end] (b.center) -- (b to a);
      } {
        \draw [extension end] plot coordinates {\dimline@extension@end@path};
      }

      \draw[line] (a.center) -- (b.center) node[label] {#4};
    \end{scope}
  }
}



\@ifclassloaded{beamer}{%
  \renewcommand<>{\dimline}[4][]{\only#5{\beameroriginal{\dimline}[#1]{#2}{#3}{#4}}}
}
\makeatother


\endinput
%% tikz-dimline.sty ends here.