Detecting if inside a tikzpicture
\documentclass{article}
\usepackage{tikz}
\makeatletter
\newcommand{\IfInTikzPic}{% https://tex.stackexchange.com/a/121309/4301
\ifx\pgfpictureid\@undefined
\expandafter\@firstoftwo
\else
\expandafter\@secondoftwo
\fi
}
\makeatother
\newcommand*{\DrawLine}[1]{%
\IfInTikzPic
{\begin{tikzpicture}[remember picture]
\draw[ultra thick, ->, #1] (0,) -- (1,1) node [right] {output of DrawLine};
\end{tikzpicture}}%
{\draw[ultra thick, ->, #1] (0,) -- (1,1) node [right] {output of DrawLine};}%
}
\begin{document}
%%% The commented out code here is to show that \IfInTikzPic works as desired
%%% (in a tikzpicture, outside of a \node).
%%%
\textbf{IfInTikzPic}\par
\IfInTikzPic{inside}{outside}
\begin{tikzpicture}
\IfInTikzPic{\draw [red, ultra thick]}{\draw [blue, ultra thick]} (0,0) -- (1,0);
\end{tikzpicture}
\medskip% --------------------------
\textbf{DrawLine}: Actual Output\par
\DrawLine{blue}% <---- How do I get this case to work?
\begin{tikzpicture}
\DrawLine{orange}
\end{tikzpicture}
\medskip% --------------------------
\textbf{DrawLine}: Desired Output\par
\begin{tikzpicture}
\DrawLine{blue}
\end{tikzpicture}
\begin{tikzpicture}
\DrawLine{orange}
\end{tikzpicture}
\end{document}
Or this version which directly forces tikz rather than having an if-then-else construct
\documentclass{article}
\usepackage{tikz}
\makeatletter
\newcommand{\ensuretikz}{% https://tex.stackexchange.com/a/121309/4301
\ifx\pgfpictureid\@undefined
\expandafter\tikzify
\else
\expandafter\@firstofone
\fi
}
\makeatother
\def\tikzify#1{\begin{tikzpicture}#1\end{tikzpicture}}
\newcommand*{\DrawLine}[1]{%
\ensuretikz
{\draw[ultra thick, ->, #1] (0,) -- (1,1) node [right] {output of DrawLine};}%
}
\begin{document}
%%% The commented out code here is to show that \IfInTikzPic works as desired
%%% (in a tikzpicture, outside of a \node).
%%%
\medskip% --------------------------
\textbf{DrawLine}: Actual Output\par
\DrawLine{blue}% <---- How do I get this case to work?
\begin{tikzpicture}
\DrawLine{orange}
\end{tikzpicture}
\medskip% --------------------------
\textbf{DrawLine}: Desired Output\par
\begin{tikzpicture}
\DrawLine{blue}
\end{tikzpicture}
\begin{tikzpicture}
\DrawLine{orange}
\end{tikzpicture}
\end{document}
The following example defines \IfInTikzPic
to check the curr
ent envir
onment against tikzpicture
and define a \tikzstart
...\tikzend
pair accordingly:
\documentclass{article}
\usepackage{tikz}
\makeatletter
\def\@tikzenvironment{tikzpicture}
\newcommand{\IfInTikzPic}{%
\edef\tikzstart{%
\ifx\@currenvir\@tikzenvironment\else
\noexpand\tikzpicture[remember picture]%
\fi
}%
\edef\tikzend{%
\ifx\@currenvir\@tikzenvironment\else
\noexpand\endtikzpicture%
\fi
}%
}
\newcommand*{\DrawLine}[1]{%
\IfInTikzPic
\tikzstart
\draw[ultra thick, ->, #1] (0,) -- (1,1) node [right] {output of DrawLine};
\tikzend%
}
\makeatother
\begin{document}
\textbf{DrawLine}: Actual Output\par
\DrawLine{blue}
\begin{tikzpicture}
\DrawLine{orange}
\end{tikzpicture}
\medskip% --------------------------
\textbf{DrawLine}: Desired Output\par
\begin{tikzpicture}
\DrawLine{blue}
\end{tikzpicture}
\begin{tikzpicture}
\DrawLine{orange}
\end{tikzpicture}
\end{document}
You could also group the tikzpicture
if needed:
\newcommand{\IfInTikzPic}{%
\edef\tikzstart{%
\ifx\@currenvir\@tikzenvironment\else
\noexpand\begin{tikzpicture}[remember picture]%
\fi
}%
\edef\tikzend{%
\ifx\@currenvir\@tikzenvironment\else
\noexpand\end{tikzpicture}%
\fi
}%
}