grouping enumerated list

Question

I am trying to generate a numbered list with a bracket to the right of the list to group the list items into additional categories. I am trying to get something like:

I have fiddled around with \mbox and \frame, and even thought about using a table, but I would have to re-start the list numbering, and I want to make sure that the alignment is correct.

Is this something that can be done?

Glenn

Answer 1

Yep, this can easily be done with \tikzmark. With this you

• complete the enumerate list as you normally would
• mark specfic points with a \tikzmark{<name>}
• access these \tikzmarks in a \tikzpicture with the [overlay,remember picture] options and draw as desired.

Note:

• This does require two runs. First one to determine the locations, and the second to do the drawing.

• The \tikzmark is from Adding a large brace next to a body of text.

References:

• Enclose an entry in an enumerate list in parentheses
• Box around a few items in an itemize environment

Code:

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{decorations.pathreplacing}

\newcommand{\tikzmark}[1]{\tikz[overlay,remember picture] \node[baseline] (#1) {};}

\tikzset{My Node Style/.style={midway, right, xshift=3.0ex, align=left, font=\small, draw=none, thin, text=black}}

\newcommand\VerticalBrace[4][]{%
    % #1 = draw options
    % #2 = top mark
    % #2 = bottom mark
    % #4 = label
\begin{tikzpicture}[overlay,remember picture]
  \draw[decorate,decoration={brace, amplitude=1.5ex}, #1] 
    ([yshift=1ex]#2.north east)  -- ([yshift=-1ex]#3.south east)
        node[My Node Style] {#4};
\end{tikzpicture}
}

\begin{document}
\begin{enumerate}
\item Item 1\tikzmark{top 1}
\item Item 2\tikzmark{bottom 1}
\item Item 3\tikzmark{top 2}
\item Item 4
\item Item 5
\item Item 6\tikzmark{bottom 2}
\end{enumerate}

\VerticalBrace[ultra thick, blue]{top 1}{bottom 1}{The first two items}
\VerticalBrace[ultra thick, blue]{top 2}{bottom 2}{The last four items}
\end{document}

Answer 2

This example uses the tikzmark library which was developed in response to questions asked on this site of the sort Peter Grill linked to in his answer:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{tikzmark,calc,decorations.pathreplacing}

\begin{document}

\begin{tikzpicture}[remember picture, overlay]
  \node (rightenum) at (.15\textwidth,0) {};
  \draw [decorate, decoration={brace}, thick] ($({pic cs:top1} -| rightenum) + (0, 1em)$) -- ({pic cs:bot1} -| rightenum) node [midway, right] {first two items};
  \draw [decorate, decoration={brace}, ultra thick] ($({pic cs:top2} -| rightenum) + (0, 1em)$) -- ({pic cs:bot2} -| rightenum) node [midway, right] {last four items};
\end{tikzpicture}

\begin{enumerate}
    \item\tikzmark{top1} first
    \item\tikzmark{bot1} second
    \item\tikzmark{top2} third
    \item fourth
    \item fifth
    \item\tikzmark{bot2} sixth
\end{enumerate}

\end{document}