% --------------------------------------------------------------------------
%
% the CHEMMACROS package -- module: `symbols'
%
% --------------------------------------------------------------------------
% Clemens Niederberger
% --------------------------------------------------------------------------
% https://github.org/cgnieder/chemmacros/
% contact@mychemistry.eu
% --------------------------------------------------------------------------
% If you have any ideas, questions, suggestions or bugs to report, please
% feel free to contact me.
% --------------------------------------------------------------------------
% Copyright 2011--2020 Clemens Niederberger
%
% 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 Clemens Niederberger.
% --------------------------------------------------------------------------
\ChemModule{symbols}{2015/06/09 symbols}

\RequirePackage{amstext}

% ---------------------------------------------------------------------------
% transition state symbol
\cs_new_protected:Npn \__chemmacros_transition_state:
  {
    \text
      {
        \skip_horizontal:n { .1ex }
        \hbox_overlap_right:n
          { \rule { .6ex } { 0pt } \rule { .05ex } { 1.3ex } }
        \hbox_overlap_right:n { \rule [ .4ex ] { 1.3ex } { .05ex } }
        \rule [ .85ex ] { 1.3ex } { .05ex }
        \skip_horizontal:n { .1ex }
      }
  }

\cs_new_protected:Npn \chemmacros_transition_state:
  {
    \ensuremath
      {
        \mathchoice
          { \displaystyle }
          { \textstyle }
          { \scriptstyle }
          { \scriptscriptstyle }
        \__chemmacros_transition_state:
      }
  }

% \DeclareDocumentCommand?
\cs_new_eq:NN \transitionstatesymbol \chemmacros_transition_state:

% \standardstate as defined by the chemstyle package. Thanks to Joseph Wright
% the `chemstyle' provides it with \providecommand so it doesn't matter which
% package defines it first
\ProvideDocumentCommand \standardstate {}
  { { \ensuremath { \chemmacros_standardstate: } } }

\cs_new_protected:Npn \chemmacros_standardstate:
  { \mathpalette \chemmacros_standardstate_aux: \circ }

\cs_new_protected:Npn \chemmacros_standardstate_aux: #1#2
  {
    \ooalign
      {
        \tex_hfil:D
        \c_math_toggle_token #1- \c_math_toggle_token
        \tex_hfil:D
        \tex_cr:D
        \tex_hfil:D
        \c_math_toggle_token #1#2 \c_math_toggle_token
        \tex_hfil:D
        \tex_cr:D
      }
  }

\cs_new_protected:Npn \changestate { \ensuremath { \mathop{} \! \chemDelta } }

% --------------------------------------------------------------------------
