Accolade to take objects together in TikZ

Question

Is there a way to draw an accolade ({-symbol) that groups things together in TikZ? I want the accolade to group let's say three rectangles. That means the top of the upper reactangle must be the top of the accolade, and the bottom of the lower triangle the bottom of the accolade. Of course I can draw an accolade using a node, but I haven't found a way yet to make sure the size meets this constraint. Is there a solution or a workaround for it?

Answer 1

A solution more simple ( for me ) and with the possibility of scaling. I add the solution with Andrew's idea The code is very clear but we can not make a scale and perhaps there is a better solution to create more space vertically. The brace is more pretty with the matrix's delimiter.

\documentclass[]{scrartcl}
\usepackage{tikz}
\usetikzlibrary{fit,calc,positioning,decorations.pathreplacing,matrix}
\begin{document}   
\begin{tikzpicture}[decoration={brace}][scale=2] 
   \node [draw] (A) {A}; 
   \node [draw,yshift=1cm] (B) at (A) {B};
   \node [draw,yshift=1cm] (C) at (B) {C};
   \node [fit=(A) (B) (C)] (fit) {};              
  \draw [decorate,line width=1pt] (fit.south west) -- (fit.north west);
\end{tikzpicture} 
 \hspace*{1cm}
\begin{tikzpicture}[scale=2] 
\matrix [matrix of nodes,left delimiter=\{,nodes={draw}] {
A  \\[12pt] B \\[12pt] C \\
}; 
\end{tikzpicture}

\end{document} 

Answer 2

You can use the fit TikZ library to create a rectangular node which encompasses the nodes, e.g. your three rectangles. Then you can use the node anchors to draw your { either using a scaled { character (\resizebox{!}{<height of fit>}{\{}) or using drawing commands. Two bezier curves should do it.

\documentclass[png]{standalone}

\usepackage{tikz}
\usetikzlibrary{fit,calc,positioning}

\begin{document}
\begin{tikzpicture}
   \node [draw] (A) {A};
   \node [draw,below of=A] (B) {B};
   \node [draw,below of=B] (C) {C};
   \node [fit=(A) (B) (C)] (fit) {};
   \path let \p1=(fit.north west), \p2 = (fit.south east) in
       node [left of=fit] {%
       \pgfmathsetmacro\heightoffit{.8*(\y1-\y2)}%
       \resizebox{!}{\heightoffit pt}{\{}%
     };%
\end{tikzpicture}
\end{document}

Result: