framed
I am looking for something like \fbox but it seems that you cannot use it when a math environment is included. However its not only a math environment (then you could use \boxed I know) but also text, I need to be in a frame.
example:
\rdmframeboxaroundwhatever{
blablabla
\begin{align}
Formula of the universe
\end{align}
Hoaray
}
Regarding \fbox, as Joseph said: there's a closing brace missing, determining the end of the argument.
For the whole text width you could use the framed package and its environment with the same name, such as
\usepackage{framed}
...
\begin{figure}[htbp]
\begin{framed}
\centering
text\\
$\begin{cases}
abcdefghijklmn\\
cdefg
\end{cases}$
\end{framed}
\caption{a caption}
\label{a_label}
\end{figure}
Another option is the improved version mdframed.
For framing math environments, there's the \boxed command of amsmath.
You have at least two options to correct for this behaviour.
If your mathematical equations (contained within the escaping $...$) is fairly simple and usually only contains a one line, and perhaps even does not have any other code above/below it, then you can \smash the escaped content:
\documentclass{article}
\usepackage{listings}% http://ctan.org/pkg/listings
\usepackage{xcolor}% http://ctan.org/pkg/xcolor
\begin{document}
\lstset{%
backgroundcolor=\color[gray]{0.9},%
frame=single,%
mathescape=true,%
}
\lstset{language=C++}%
\begin{lstlisting}
for(i = 0; i < 10; i++)
{
// gratuitious equation $\smash{\mathcal{D}_3(x) = \frac{x^n}{n} \int_{0_0}^{x^2} \frac{t^n}{e^t-1}dt}$
*p++ = i;
House h = new house();
int romms = h.getRooms():
}
\end{lstlisting}
\end{document}
However, as you can see, even from this small example, the bottom part of the equation is overwritten with the background colour. This is because the algorithm is typeset sequentially, overwriting anything with a depth below the baseline. So this option is very restrictive, and typically only works if your mathematical expression does not drop below the baseline. Pretty restrictive...
You can use a different environment to draw the frame and background. The mdframed package does an excellent job of this:
\documentclass{article}
\usepackage{listings}% http://ctan.org/pkg/listings
\usepackage{xcolor}% http://ctan.org/pkg/listings
\usepackage[framemethod=TikZ]{mdframed}% http://ctan.org/pkg/mdframed
\begin{document}
\lstset{%
% backgroundcolor=\color[gray]{0.9},
% frame=single,
mathescape=true,
}
\lstset{language=C++}%
\begin{mdframed}[backgroundcolor=black!15,outerlinewidth=0.25pt,outerlinecolor=black,%
innerleftmargin=5pt,innerrightmargin=5pt,innertopmargin=0pt,innerbottommargin=0pt]
\begin{lstlisting}
for(i = 0; i < 10; i++)
{
// gratuitious equation $\mathcal{D}_3(x) = \frac{x^n}{n} \int_{0_0}^{x^2} \frac{t^n}{e^t-1}dt$
*p++ = i;
House h = new house();
int romms = h.getRooms():
}
\end{lstlisting}
\end{mdframed}
\end{document}
In the above example, mdframed uses tikz to draw the frame. It is possible to automate this process of using mdframed in conjunction with listings. For this, the etoolbox package provides hooked to add code before the beginning and after the end of an environment (lstlisting in this case). For this, the macros \BeforeBeginEnvironment and \AfterEndEnvironment is helpful. It is crucial to add code in this manner, since lstlisting modified catcodes for formatting:
\documentclass{article}
\usepackage{listings}% http://ctan.org/pkg/listings
\usepackage{xcolor}% http://ctan.org/pkg/listings
\usepackage[framemethod=TikZ]{mdframed}% http://ctan.org/pkg/mdframed
\usepackage{etoolbox}{% http://ctan.org/pkg/etoolbox
\mdfdefinestyle{listingstyle}{%
backgroundcolor=black!15,outerlinewidth=0.25pt,outerlinecolor=black,%
innerleftmargin=5pt,innerrightmargin=5pt,innertopmargin=0pt,innerbottommargin=0pt%
}
\begin{document}
\lstset{mathescape=true,language=C++}%
\BeforeBeginEnvironment{lstlisting}{\begin{mdframed}[style=listingstyle]}
\AfterEndEnvironment{lstlisting}{\end{mdframed}}
\begin{lstlisting}
for(i = 0; i < 10; i++)
{
// gratuitious equation $\mathcal{D}_3(x) = \frac{x^n}{n} \int_{0_0}^{x^2} \frac{t^n}{e^t-1}dt$
*p++ = i;
House h = new house();
int romms = h.getRooms():
}
\end{lstlisting}
\end{document}
In the above modification, a new mdframed style listingstyle is defined and used as style=listingstyle in the option argument to the mdframed environment. The output is similar to the previous example.
Best Answer
You can also use
tcolorbox:Code: