Circle text inside tikz environment

Question

I am trying to circle some numbers inside tikz enviroment. I followed answers for this question: Good way to make \textcircled numbers?

And I used this solution, which work excellent inside normal text.

\documentclass{article}
\usepackage{tikz}  
\newcommand*\circled[1]{\tikz[baseline=(char.base)]{
        \node[shape=circle,draw,inner sep=2pt] (char) {#1};}} 
 \begin{document}
 Numbers aligned with the text:  \circled{1} \circled{2} \circled{3} end.
 \end{document}

Unfortunately I encountered a problem. I want to create a few numbers in circle inside bigger tikz node. But it seems like new "nested" node inherits minimum width from "parent" node so the circle became very huge. Is there any way to work around this?

Thanks for any help.

EDIT:

I added MWE with my problem.

\documentclass{standalone}

\usepackage{tikz}

\newcommand*\circled[1]{\tikz[baseline=(char.base)]{
    \node[shape=circle,draw,inner sep=2pt] (char) {#1};}} 

\begin{document}
\begin{tikzpicture}
\tikzstyle{big}=[draw,rectangle,rounded corners, fill=blue!20,minimum width=2cm, minimum height=2cm]

\node[big] (0) {First number = \circled{20},  Second number = \circled{20}};
\end{tikzpicture}
\end{document}

Answer 1

Do you want something like this?

I have modified the \circled command so that it now accepts a comma separated list. If the list contains only one entry then that entry is circled. If the list contains more than one entry then each entry is circled and then another circle is drawn around all of the circled numbers. So the right-hand entry above is the result of \circled{1,2,3}.

My macro avoids nesting tikzpicture environments by remembering the number of items in the comma separated list. If the comma separated list contains more than than one entry then it uses the tikz fit library to draw the outside circle around all of the nodes. Here is the complete code:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{fit}
\newcommand*\circled[1]{%
  \begin{tikzpicture}[baseline=(1.base), 
      circ/.style={shape=circle,draw,inner sep=1pt}]
    \foreach \num [count=\c,remember=\c as \C (initially 0)] in {#1}{
      \node[circ] (\c) at (\c*3ex,0) {\num};% hack the node placement
    }                   % probably should use the positioning library
    \ifnum\C>1\node[circ,fit=(1)(\C)]{};\fi% circle multiple entries
  \end{tikzpicture}%
}

\begin{document}

  Numbers aligned with the text: \circled{1} \circled{2} 
  \circled{3} end and then we have \circled{1,2,3}

\end{document}

I have implicitly assumed that all of the circled entries in the comma separated list are all single characters. If this is not the case then it would be easy to modify the code above so that it uses the tikz positioning library to place the nodes next to each other.

Answer 2

The problem in your MWE can be solved by adding minimum size=0pt to the options of the node style in \circled.

\documentclass{standalone}

\usepackage{tikz}

\newcommand*\circled[1]{\tikz[baseline=(char.base)]{
    \node[shape=circle,draw,inner sep=2pt,minimum size=0pt] (char) {#1};}} 

\begin{document}
\begin{tikzpicture}
\tikzset{big/.style={draw,rectangle,rounded corners, fill=blue!20,minimum
width=2cm, minimum height=2cm}}

\node[big] (0) {First number = \circled{20},  Second number = \circled{20}};
\end{tikzpicture}
\end{document}

Note that \tikzstyle is deprecated.

However, this is not a clean solution, and it may yield unpredictable results. A clean solution is to put the inner tikz picture in a \savebox.

\documentclass{standalone}

\usepackage{tikz}

\newcommand*\circled[1]{\tikz[baseline=(char.base)]{
    \node[shape=circle,draw,inner sep=2pt,minimum size=0pt] (char) {#1};}} 
\newsavebox\SBoxA   
\begin{document}
\savebox\SBoxA{\circled{20}}%
\begin{tikzpicture}
\tikzset{big/.style={draw,rectangle,rounded corners, fill=blue!20,minimum
width=2cm, minimum height=2cm}}

\node[big] (0) {First number = \usebox\SBoxA,  Second number = \usebox\SBoxA};
\end{tikzpicture}
\end{document}