How can I prevent environment contents from being broken across pages?

Question

Consider the following code, copied almost verbatim from this answer, except that two calls to \lipsum,

\lipsum[1-4]
\lipsum[5][1-10]

have been added inside the document's body.

\documentclass{article}
\usepackage{lipsum}
\newenvironment{signenv}[1]{%
\par
\smallskip
\noindent\hrulefill\ %
\begin{picture}(20,20)(0,0)
\put(10,0){\makebox(0,0){#1}}
\put(0,0){\line(1,1){10}}
\put(0,0){\line(1,-1){10}}
\put(20,0){\line(-1,1){10}}
\put(20,0){\line(-1,-1){10}}
\end{picture}\ %
\hrulefill
\par
\bigskip}
{\par\medskip\noindent\hrulefill\par\smallskip}
\begin{document}
\lipsum[1-4]
\lipsum[5][1-10]
\begin{signenv}{A}
\lipsum[1]
\end{signenv}
\end{document}

The resulting PDF file has two pages, as follows.

As can be seen, the top line drawn by the signenv environment appears on a different page than the paragraph contained inside the environment. Similarly, if you replace the first two calls to \lipsum by

\lipsum[1-3]
\lipsum[4][1]

the bottom line drawn by the signenv environment appears on a different page than the paragraph contained inside the environment.

How can I arrange it so that both the top and the bottom lines of the signenv environment will always appear on the same page as the text inside the environment?

score 9 · Answer 1 · answered Jul 19 '21 at 13:51

9

as I commented under the original code, you can add \nopagebreak

\documentclass{article}
\usepackage{lipsum}
\newenvironment{signenv}[1]{%
\par
\smallskip
\noindent\hrulefill\ %
\begin{picture}(20,20)(0,0)
\put(10,0){\makebox(0,0){#1}}
\put(0,0){\line(1,1){10}}
\put(0,0){\line(1,-1){10}}
\put(20,0){\line(-1,1){10}}
\put(20,0){\line(-1,-1){10}}
\end{picture}\ %
\hrulefill
\par
\nopagebreak
\bigskip}
{\par\nopagebreak\medskip\noindent\hrulefill\par\smallskip}
\begin{document}
\lipsum[1-4]
\lipsum[5][1-10]
\begin{signenv}{A}
\lipsum[1]
\end{signenv}
\end{document}

answered Jul 19 '21 at 13:51

David Carlisle

757,742

2

but better don't start or end in the environment with a list ;-) – Ulrike Fischer Jul 19 '21 at 13:56
@UlrikeFischer who would do such a thing? – David Carlisle Jul 19 '21 at 14:03
Thank you. What if I don't want the \bigskip after the top line nor the \medskip before the bottom line? Is there a \noskip that works with \nopagebreak? Does the \nopagebreak work before \par? – Evan Aad Jul 19 '21 at 14:07
1

no after the par but you can delete the skips @EvanAad – David Carlisle Jul 19 '21 at 14:18
Thank you. One more thing, please. Your solution doesn't work when the \lipsum[1] that's inside the signenv environment is inserted into a theorem environment: \begin{signenv}{A}\begin{theorem}\lipsum[1]\end{theorem}\end{signenv}. Could you please look into it? (Of course, you need to add \newtheorem{theorem}{Theorem} to the preamble.) – Evan Aad Jul 19 '21 at 14:25
see @UlrikeFischer's first comment.... – David Carlisle Jul 19 '21 at 14:46
1

@EvanAad add after the \bigskip \csname @afterheading\endcsname – Ulrike Fischer Jul 19 '21 at 14:53
@UlrikeFischer: Thanks. This handles the upper line. Is there a way to handle the bottom line too? – Evan Aad Jul 20 '21 at 06:27

How can I prevent environment contents from being broken across pages?

1 Answers1