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I keep on studying the use of nested tikzpicture environments (sorry) and I discover the next problem. I'm not sure but it sounds like a problem with "fragile" commands. Perhaps, the problem is the nested environments but I do not think so because the code works in many cases. It's very strange, that $\mathbf{\Pi}$ gives no problem while \textbf{textbf} is catastrophic !.

In the next code, I use the macro \place to put an object ( some tex's code) with the help of a node. I simplify a little bit the chain of macros but I keep the essential things.

Code I work with pgf 2.1 CVS

Uncomment the line 

\documentclass{scrartcl}
\usepackage{amsmath,tikz}

\makeatletter
\def\place{\pgfutil@ifnextchar[{\place@i}{\place@i[]}}%
\def\place@i[#1]#2(#3)#{\place@ii[#1]{#2}(#3)}%
\def\place@ii[#1]#2(#3)#4{% 
\begin{tikzpicture}[overlay]
  \path (0,0)--(#3);
  \node[anchor=#1,rotate=#2] at (#3) {#4};
\end{tikzpicture}%
}% 

\begin{document}

Baseline%
\begin{tikzpicture}
 \draw[help lines] (0,-4) grid (5,1);
 \place[west]{0}(1,-2){$ \frac{2}{3}$} 
 \place[west]{-30}(2,-3){$\mathbf{\Pi}$} 
\end{tikzpicture}% 

% uncomment the next line with \place to see the problem
\begin{tikzpicture}
 %\place[west]{0}(4,0){\textbf{textbf}} 
\end{tikzpicture} 

% \noexpand resolves the problem 
\begin{tikzpicture}
 \place[west]{0}(2,0){\noexpand\textbf{textbf}} 
\end{tikzpicture}  

\end{document}

Results

enter image description here

but if I don't use \noexpand:

enter image description here

What kind of problem I encountered?

Alain Matthes
  • 95,075
  • It works with the TeX Live version. – egreg Mar 04 '12 at 18:57
  • @egreg do you have uncomment the line ? – Alain Matthes Mar 04 '12 at 19:05
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    @Altermundus: A small explanation is given here: http://tex.stackexchange.com/questions/18602/how-can-i-use-an-hbox-inside-a-tikz-environment-for-text-dimension-measurement You see that your solution doens't provide a bold output – Marco Daniel Mar 04 '12 at 19:19
  • @MarcoDaniel yes the link is interesting, I need to test some ideas in this answer. How I can transform my code to avoid this problem? – Alain Matthes Mar 04 '12 at 19:36
  • @Altermundus You're right. PGF doesn't like changing fonts, while math doesn't harm. I suggest you to use Martin's way of doing it. – egreg Mar 04 '12 at 20:18

1 Answers1

3

Marco,thanks for the link to the answer of Martin and Martin thanks for the explanation using pgfinterruptpicture

The next code seems to remove the problem 

\newbox\mybox   

\makeatletter
\def\place{\pgfutil@ifnextchar[{\place@i}{\place@i[]}}%
\def\place@i[#1]#2(#3)#{\place@ii[#1]{#2}(#3)}%
\def\place@ii[#1]#2(#3)#4{%
 %\setbox\mybox=\hbox{\pgfinterruptpicture #4\endpgfinterruptpicture}            
 \sbox\mybox{\pgfinterruptpicture#4\endpgfinterruptpicture}% from Martin Scharrer and egreg
\begin{tikzpicture}[overlay]
     \path (0,0)--(#3);
     \node[anchor=#1,rotate=#2] at (#3) {\box\mybox};
    \end{tikzpicture}%
}%
Community
  • 1
Alain Matthes
  • 95,075
  • 2
    I'd use \sbox\mybox{\pgfinterruptpicture#4\endpgfinterruptpicture} which is color safe. – egreg Mar 04 '12 at 21:19
  • @egreg Please, can you explain your comment ? The subtlety seems to be interesting ! I used Martin's code but I saw after your comment, the last line : \sbox\mybox{<content>} instead of\setbox\mybox=\hbox{... I don't understand why ! – Alain Matthes Mar 04 '12 at 21:30
  • 1
    \sbox\mybox{...} takes some supplementary precautions against possible color leaking that the primitive \setbox\mybox=\hbox{...} can't. – egreg Mar 04 '12 at 21:39
  • 1
    ok thanks. I need to find a link about this. It's amazing what you should know to make a correct code ! This site is incredible to find answer but sometimes it's difficult to find the good link. Fortunately some users have a good memory – Alain Matthes Mar 04 '12 at 21:48