\newenvironment issues with environment comment

Question

I am trying to setup the formatting for a LaTeX document (it's got the class memoir), so that it would be fairly simple to add to it in the future.

Two of the features I'd like are: Be able to mark certain parts of the text, so that I can produce two versions of the output, one with the complete text, and one without the marked parts of the text. My original idea was to use:

\newenvironment{\marked}{\begin{comment}}{\end{comment}}

and then just change it to

\newenvironment{\marked}{}{}

when I want the full text. However this won't work unless I add a comment block (\begin{comment}...\end{comment}) after I use the marked environment.

To have boxed areas of text. I can achieve this though using:

\begin{center}
    \colorbox{yellow}{
        \parbox{0.8\textwidth}{
            ...text here...
        }
    }
\end{center}

I would like to create another environment for this, but I'm not sure how to go about it as the text to be contained within the environment will be between open parentheses.

Also - how would I go about adding padding to the inside of my box?

I'm sorry if these questions are overly simple. The only languages I've used before to format stuff are HTML and CSS.

Answer 1

The memoir class has a facility just for that:

\newcomment{marked}
\commentson{marked}
%\commentsoff{marked}

It's sufficient to uncomment the third line to exclude the contents of all marked environments. Look at page 284 of memoir's documentation.

For the environment form of a colored background box:

\newsavebox{\coloredbgbox}
\newenvironment{yellowbox}
  {\begin{lrbox}{\coloredbgbox}\begin{minipage}{0.8\textwidth}}
  {\end{minipage}\end{lrbox}%
   \begin{center}\colorbox{yellow}{\usebox{\coloredbgbox}}\end{center}}

With this definition, you can write

\begin{yellowbox}
Text to be produced on a yellow background as wide as 80\%
of the normal line width.
\end{yellowbox}

However, it's better to split different topics into different questions.

Answer 2

There are several ways to do the conditional text:

1. Use \ifdefined
2. Use \newif
3. Use NewEnviron from the environ package

To use \ifdefined use \def to ensure that the condition macro is defined. Then, when you don't want the conditional text, just comment the line \def\DisplayMarked{}:

\documentclass{article}
\def\DisplayMarked{}% Comment this to remove "...marked text..."

\begin{document}
Comment \textbackslash def to remove:
\ifdefined\DisplayMarked
   .. marked text...
\fi
\end{document}

As Martin pointed out, you could also use \newif\ifDisplayMarked to define the condition. Then you can set this condition to true with \DisplayMarkedtrue and to false with \DisplayMarkedfalse. To use this condition, use \ifDisplayMarked and end the clause with an \fi. There is an optional \else that you can put in here in case there is something else you want to do for the false case.

\documentclass{article}
\newif\ifDisplayMarked%
\DisplayMarkedtrue%
%\DisplayMarkedfalse% Un-comment out to remove "...more text..."

\begin{document}
Un-comment \textbackslash DisplayMarkedfalse to remove:
\ifDisplayMarked
   .. more text...
\fi
\end{document}

If you really want an environment for that, a simple way is to use the NewEnviron from the environ package that allows you to use \BODY for the body of the environment.

\documentclass{article}
\usepackage{environ}

\NewEnviron{Marked}{%
    \BODY% Comment this to remove `...more marked tex...`
}%

\begin{document}
Comment \textbackslash BODY to remove:
\begin{Marked}
   .. more marked text...
\end{Marked}
\end{document}

Boxed Areas of Text:

As far as your second question, it is a simple matter of using #1, which represents the first parameter of the macro.

\documentclass{article}
\usepackage{xcolor}

\newcommand{\MyBox}[1]{
\begin{center}%
    \colorbox{yellow}{%
        \parbox{0.8\linewidth}{%
            #1%
        }%
    }%
\end{center}%
}%

\begin{document}
\MyBox{...text here...}
\end{document}

Answer 3

The comment environment uses verbatim mode to skip its area and can't therefore nested in the normal way. As egreg already pointed out their are specific macros to define an environment as comment.

Here my solution which is honestly very similar to egreg's but uses my adjustbox package to format the environment. It is IMHO a little bit more user friendly. Internally it does about the same as egreg's code. It also shows the required code for other classes in the case other people need something similar with normal LaTeX classes.

\documentclass{memoir}
\usepackage{xcolor}
\usepackage{adjustbox}

\newenvironment{marked}{%
    \begin{adjustbox}{minipage=0.8\textwidth,cfbox=yellow,env=center}
}{%
    \end{adjustbox}
}

%% Uncomment to make 'marked' environments disappear. (memoir)
%\newcomment{marked}
%\commentson{marked}

%% Alternative for other classes
% \usepackage{comment}
% \includecomment{marked}
% \let\endmarked\relax

\begin{document}

Some text.
\begin{marked}
test
\end{marked}
Some other text.

\end{document}

Answer 4

The definition

\newenvironment{\marked}{\begin{comment}}{\end{comment}}

will not work- firstly, \marked should be marked. For the rest of the definition, you could use:

\newenvironment{marked}{\comment}{\endcomment}

The other answers address your other questions

Answer 5

As suggested by Peter Grill, just use the environ package and define a boolean as

\newif\ifcomm\commtrue

prepare your environment as

\NewEnviron{marked}{\ifcomm\BODY\fi}

So, you can put into your text

\begin{marked} (stuff) \end{marked}

and adjust things with \commtrue or \commfalse .