Visible comments (example of a personal extension)

[Matej Cepl]

Hi,

I would love to present (and save for future) a solution to the 
problem I had with Comment environment. I wished to be able to 
make my comments visible with special fonts and with the 
background of the comment shaded (so certainly outstanding from 
other text), but in the same time I would love to make them 
invisible (for publishing document on the Internet, turning it in 
to my professor, etc.). This is what I did.

First of all I have to say, that I use my own class of documents, 
with this layout file:

  #% Do not delete the line below; configure depends on this
  #  \DeclareLaTeXClass[article]{article (like from groff)}
  # $Id: grofflike.layout,v 1.2 2003/09/02 10:35:11 matej Exp matej $
  # General textclass parameters
  Input article.layout
  Input myarticle.inc
  ClassOptions
     Other "11pt"
  End
The result is exactly the same as the normal article but for 
including of myarticle.inc and setting size of font to 11pt (do 
not believe the name of the class -- it is certainly far from 
being the same as groff).

myarticle.inc includes some small personal settings (redefinition 
of footnote, etc.) and then it includes couple of redefinitions 
of the standard environments (because it is not possible to have 
multiple Preamble in a series of .layout files--see thread 
``Repeated Preamble in .layout are not read'' in the archive of 
this group--I prefer to have all parts which should go to the 
preamble in Preamble part of new Styles). So for example, I have 
also this redefinition of Comment style:

  Style Comment
     CopyStyle                   Comment
     Preamble
     \usepackage{ifthen} \usepackage{color}
     \definecolor{lightgray}{gray}{0.9}
     \newboolean{commentvisible} \setboolean{commentvisible}{false}
     [EMAIL PROTECTED] [EMAIL PROTECTED]
     %
     \renewenvironment{comment}%
        [EMAIL PROTECTED]
        {\end{lrbox}%
         \ifthenelse{\boolean{commentvisible}}{%
            \begin{quote}%
              \colorbox{lightgray}{%
                 [EMAIL PROTECTED]
                 [EMAIL PROTECTED]
                 [EMAIL PROTECTED]
                 [EMAIL PROTECTED]
                    [EMAIL PROTECTED]
                       \begin{sffamily}
                       \textbf{\scshape Side note:}
                       [EMAIL PROTECTED]
                       \end{sffamily}
                    }%
              }%
            \end{quote}%
         }{}
        }
     EndPreamble
  End
All business of this Style is to redefine the comment 
environment so that it not only works the same as the original 
one--by saving the content of the environment into savebox which 
is never used effectively eliminate the content of the 
environment from the document. When the Boolean variable 
commentvisible is set to true, then actually this savebox is used 
and put into the environment quote and colorbox with shaded 
background.  Complication with this construction is to find out 
the allowed width of the innermost parbox. The problem is that 
colorbox narrows the space for its contents by width of \fboxrule 
and by space between boxes \fboxsep (twice for both sides of the 
box).

Another quirk of this construct is use of TeX primitive \unhbox, 
which does not include box, but its content--horizontal list of 
the material to be printed.

Herbert, do you think that this could go to your tips (How-To 
create shaded environment and recreation of LyXs Style)? Thanks.

  Have a nice day all and happy LyXing!

     Matej

--
Matej Cepl, http://www.ceplovi.cz/matej
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