# (Framed) Boxes are too long / Textwidth doesn't work

I want to create a box/frame (in math mode) with its content centered horizontally and vertically such that I can adjust the height of the box and such the width of the box automatically (!) is the width of the context.

The following MWE does almost what I want:

\documentclass[12pt,a4paper]{article}
\usepackage[latin1]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\begin{document}

$\fbox{\parbox[c][4pt][c]{\textwidth}{a first try}}$

$\framebox[\width]{\parbox[c][2pt][c]{\textwidth}{another one}}$

\end{document}


The problems are the following:

• both of the boxes aren't as long as their contents, i.e. as long as "a first try" resp. "another one", so \textwidthdoesn't seem to work very well. Of course I could manually try to adjust the width to the right size, but I'm going to create boxes very often so fiddling with the width every time to get it right is unfeasible.

• the vertical centering doesn't work very well since in both boxes the text is moved to the top

I'm open to different approaches to this, as long as they do what I want, like defining new commands - for example with tikz - that do what I want, as long as I don't have to type very much for using them, since as I said, I will need to create a lot of boxes.
Btw., using to box commands to almost achieving this is a lot of typing - I would be happy if only one command would suffice.

EDIT

The height of the box usually is like this: whereas I would like it to be like this: , i.e. the box should just barely cover it's contents vertically. Decrease the height parameter in \fbox does nothing after a certain point (the first box was created with height of 8pt and decreasing it didn't do anything; to get the second picture I edited the first in some editing program)

Your lines are overfull in both directions.

Horizontally the line contains

• 1 paragraph indentation
• 1 rule of thickness \fboxrule
• padding space of \fboxsep
• 1 box of width \textwidth
• padding space of \fboxsep
• 1 rule of thickness \fboxrule

This comes to more than \textwidth :-) I adjust for that below. I left in the $ although they are doing nothing, the contents of a box always start in text mode. Vertically you have a row of 10pt text being forced into a box with vertical size 4pt. To use the natural width however you don't want \parbox at all, just use \fbox: \documentclass[12pt,a4paper]{article} \usepackage[latin1]{inputenc} \usepackage{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \begin{document} \noindent$\fbox{\parbox[c][15pt][c]{\dimexpr\textwidth-2\fboxsep-2\fboxrule}%
{a first try}}$\noindent$\fbox{\rule[-20pt]{0pt}{40pt}a first try}$\end{document}  • But your corrected version still has a box whose length is longer than its contents. (Thanks for explaining though, of what the box is made. What does the \dimexpr do ?) – l7ll7 Mar 30 '13 at 15:47 • @user10324 see update for using natural width. \dimexpr is an e-tex primitive that allows infix arithmetic on dimensions. – David Carlisle Mar 30 '13 at 15:57 • That's almost perfect, but I still have a small problem with the height: I can increase it, but I can't decrease it, so that the box barely covers my text. Please see the edit of my question for some pictures of what I mean (sorry, should have been more specific in the first place). – l7ll7 Mar 30 '13 at 16:11 • \setlength\fboxsep{0pt} either locally or globally to remove the padding added by \fbox. – David Carlisle Mar 30 '13 at 16:21 • Excellent! Thanks a lot, that did the trick! – l7ll7 Mar 30 '13 at 16:23 you can try the varwidth package, like this: \documentclass[12pt,a4paper]{article} \usepackage[latin1]{inputenc} \usepackage{amsmath} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{varwidth} \begin{document}$\framebox{\begin{varwidth}{1in}a first try\end{varwidth}}\framebox{\begin{varwidth}{1in}another one\end{varwidth}}\$

\end{document}


result:

• ah, sorry, I misread your question, I thought you wanted the box width to be equal to the text – Old Nick Mar 30 '13 at 15:46
• Well, that is indeed what I wanted. What did you thought I wanted ? Our solution is almost perfect, except I can't adjust the height of the box. And do you know what the "1in" does ? Changing it doesn't seem to do anything. – l7ll7 Mar 30 '13 at 15:53
• the 1in is the maximum width of the box, that is the value from the documentation example, I forgot to replace it with \textwidth. If the text is longer than the value it will go automatically to the next line. After re-reading your post I thought you wanted the two boxes to be of equal width. Sorry again, my bad – Old Nick Mar 30 '13 at 15:59
• But do you perhaps also have an idea how to adjust the height of the box ? – l7ll7 Mar 30 '13 at 16:05
• I see you solved it already, anyway the \rule etc. command by David Carlisle works also with my answer. – Old Nick Mar 30 '13 at 16:29