Shaded continuous across new enumerate environment

Question

I'm trying to write up solutions where I include the original problem text, in a light gray shaded box. I had been creating the shading with the 'framed' package shaded environment, but some of the problems have enumerated parts, with some text before the parts. I would like to have the starting text and the first part continuously shaded, but apparently the shaded environment can't cross a \begin{enumerate}. So what I have right now is

\begin{shaded}Starting text...\end{shaded}
\begin{enumerate}
\begin{shaded}\item This is the first problem.\end{shaded}
This is the first solution.
\begin{shaded}\item This is the second problem.\end{shaded}
Second solution.
\end{enumerate}

Is there a way to have the shading continuous instead of that first gap?

Answer 1

Basic Solution:

I would recommend that you use the mdframed package instead (as it will work across page breaks), and use the resume* option with lists via the enumitem package:

---

Better Solution:

As @MarcoDaniel suggested, a better looking solution is to use the frametitle option with mdframed.

\newenvironment{Question}[1]{
    \begin{mdframed}[
       frametitle={#1},
       frametitlerule=true,
       frametitlebackgroundcolor=red!20,
       frametitlebelowskip=2pt,
       innerlinewidth=1.0pt
    ]
}{
    \end{mdframed}
}

With this you simply enclose the part you wanted shaded in the first parameter to the Question environment, and the body of this environment is the answer, i.e., the part you don't wanted shaded. This yields:

• For some reason there is a display issue with this. There are lines at the top and bottom but with increasing magnification from 150% and incrementing by 1% with Acrobat Reader 10.1.2 on Mac different lines appear and disappear. I have updated this to use framemthod=tikz and innerlinewidth=1.0pt option as this make this display problem less noticeable (but problem is still there).

---

Even Better Solution (Custom Counter):

If you are only using the enumerate to create a numbered list, you could simplify things even further by using a custom counter. This is also courtesy of @MarcoDaniel.

Notes:

• If you are not already using enumitem, you should have a look at:

  What are the differences between using paralist vs. enumitem

  Suggestions for transitioning from paralist to enumitem package

• If you happen to be using this within minipages, please do make a note of Resuming a list started within a minipage

• To adjust the settings of enumitem, refer to Can't get my head around enumitem's spacing parameters

---

Code: Basic Solution

\documentclass{article}
\usepackage{xcolor}
\usepackage{enumitem}
\usepackage{mdframed}

\newmdenv[backgroundcolor=yellow]{shaded}

\begin{document}
\begin{shaded}
    Starting text...
    \begin{enumerate}[series=MyQuestions,leftmargin=*]
    \item This is the first problem.
    \end{enumerate}
\end{shaded}
\begin{enumerate}[resume*=MyQuestions]
\item[] This is the first solution (not shaded)
\end{enumerate}
%
\begin{shaded}
    \begin{enumerate}[resume*=MyQuestions]
    \item This is the second problem.
    \end{enumerate}
\end{shaded}
\begin{enumerate}[resume*=MyQuestions]
\item[] Second solution (not shaded)
\end{enumerate}
\end{document}

Code: Better Solution:

\documentclass{article}
\usepackage{xcolor}
\usepackage{enumitem}
\usepackage[framemethod=tikz]{mdframed}

\newenvironment{Question}[1]{
    \begin{mdframed}[
        frametitle={#1},
        frametitlerule=true,
        frametitlebackgroundcolor=red!20,
        frametitlebelowskip=2pt,
        innerlinewidth=1.0pt
    ]
}{
    \end{mdframed}
}

\begin{document}
\begin{Question}{
        Starting text...
        \begin{enumerate}[series=MyQuestions,leftmargin=*]
        \item This is the first problem.
        \end{enumerate}
    }
    This is the first solution (not shaded)
\end{Question}

\bigskip
\begin{Question}{
        \begin{enumerate}[resume*=MyQuestions]
        \item This is the second problem.
        \end{enumerate}
    }
    \begin{enumerate}[resume*=MyQuestions]
    \item[] Second solution (not shaded)
    \end{enumerate}
\end{Question}
\end{document}

Code: Even Better Solution (Custom Counter):

\documentclass{article}
\usepackage{mdframed}
\mdfdefinestyle{QuestionsStyle}{%
    frametitlerule=true,
    frametitlebackgroundcolor=yellow,
    linewidth=2pt,
    frametitlerulewidth=1pt,
    innerleftmargin=30pt,
    frametitlebelowskip=.5\topskip,
    innertopmargin=\topskip
}
\newcounter{QuestionCounter}
\setcounter{QuestionCounter}{0}
\newrobustcmd*\SetQuestionNum{\mbox{}\llap{\stepcounter{QuestionCounter}\theQuestionCounter\hspace*{10pt}}}
\newmdenv[style=QuestionsStyle]{Question}
\begin{document}
\begin{Question}[frametitle={
    Some Text\\
    \\
    \SetQuestionNum This is the first problem.}]
This is the first solution (not shaded)
\end{Question}

\bigskip
\begin{Question}[frametitle={
    \SetQuestionNum This is the second problem.}]
Second solution (not shaded)
\end{Question}
\end{document}