Detecting if inside a tikzpicture node

Question

I would like to detect if a macro is executed inside a tikzpicture or more specific inside a node of a picture. In my MWE I used \ifpgfpicture which does not do the job because it considers the node content as 'outside' the picture. I would like to see 'INSIDE' as node text.

I am not looking for any additions to the tikzpicture environment like some every picture tricks to remember that we are inside the environment. Is there any already existing state macro/variable of pgf/tikz which can be questioned for this purpose?

\documentclass{article}
\usepackage{tikz}

\newcommand{\testinpic}{%
  \ifpgfpicture INSIDE \else OUTSIDE\fi%
}

\begin{document}

\testinpic

\begin{tikzpicture}
  \fill[blue!10!white] (-4,-1) rectangle (4,1);
  \node {\testinpic};
\end{tikzpicture}

\end{document}

enter image description here

I think the answer is no but not 100% sure. The text is put into an hbox or minipage environment before placed in the node shape. So you need to patch the node placement code to insert a hook. Otherwise it will never be inside since everything is expanded before the placement. — percusse, Jun 27 '13 at 08:58
I'm with percusse on this. Looking at the code, then TikZ goes to a lot of trouble to ensure that what happens inside a node is pretty similar to what happens in ordinary text. So I think I would go for a new conditional and add it to every tikzpicture via the execute at begin picture style. I think that would be more reliable than trying to hook into something in the node structure. — Andrew Stacey, Jun 27 '13 at 09:11

score 6 · Accepted Answer · edited Jun 27 '13 at 12:38

6

You can do

\documentclass{article}
\usepackage{tikz}


\makeatletter
\newcommand{\testinpic}{%
  \ifx\pgfpictureid\@undefined OUTSIDE \else INSIDE\fi%
}
\makeatother

\begin{document}

\testinpic

\begin{tikzpicture}
  \fill[blue!10!white] (-4,-1) rectangle (4,1);
  \node {\testinpic};
\end{tikzpicture}

\end{document}

edited Jun 27 '13 at 12:38

Thomas F. Sturm

25,210

answered Jun 27 '13 at 08:57

David Carlisle

757,742

I fear I have to expect nested environments. Therefore, this solution would not help. – Thomas F. Sturm Jun 27 '13 at 11:40
@ThomasF.Sturm try now:-) – David Carlisle Jun 27 '13 at 11:55
@DavidCarlisle Yes, that's it! :-) I've just checked it with my application and it does what it should do. Thank you! – Thomas F. Sturm Jun 27 '13 at 12:37

score 3 · Answer 2 · answered Jun 27 '13 at 10:42

With some possibly unwise hacking like this maybe? With multiple nesting it would get confusing.

\documentclass{standalone}
\usepackage{tikz}

\makeatletter
\newif\iftikzinsidepicture
\newif\iftikzinsidenode
\def\tikz@picture[#1]{%
  \pgfpicture%
  \tikzinsidepicturetrue%
  \let\tikz@atbegin@picture=\pgfutil@empty%
  \let\tikz@atend@picture=\pgfutil@empty%
  \let\tikz@transform=\relax%
  \def\tikz@time{.5}%
  \tikz@installcommands\scope[every picture,#1]%
  \expandafter\tikz@atbegin@picture%
  \tikz@lib@scope@check%
}

\let\tikz@do@fig@main@orig=\tikz@fig@main
\def\tikz@fig@main{%
    \tikzinsidepicturefalse%
    \tikzinsidenodetrue%
    \tikz@do@fig@main@orig%
}
\makeatother

\def\test{{\footnotesize
    \iftikzinsidenode
        INSIDE-NODE
        \iftikzinsidepicture 
            INSIDE-NODE-PICTURE
        \else
            OUTSIDE-NODE-PICTURE
        \fi
    \else%
        \iftikzinsidepicture 
            INSIDE-PICTURE
            OUTSIDE-NODE
        \else
            OUTSIDE-PICTURE
        \fi
    \fi}}

\begin{document}

\begin{tabular}{l}

\test \\    

\begin{tikzpicture}

\fill[blue!20] (-4,-1) rectangle (4,1);
\pgftext{\test}

\node [fill=red!20] at (0,-0.5){\test};

\node [fill=white] at (0,0.5){ \tikz{\pgftext{\test}} };

\end{tikzpicture}

\end{tabular}
\end{document}

enter image description here

This is not the answer I hoped for, since it is hacking the tikz code. That's too risky for the application I have in mind, but nevertheless I think it could be very interesting for other applications. — Thomas F. Sturm, Jun 27 '13 at 11:34

Detecting if inside a tikzpicture node

2 Answers2

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