[Tex/LaTex] How to change the page layout back and forth

geometrymarginspage-breaking

I'm trying to do some absolute placement on a page but because I use pdflscape, I can't use the textpos package for this. I tried around a bit with moving with \hspace* and \vspace* but this is very tedious and produces overfull boxes galore. So I tried to change the page layout for just one page which basically works but the next page is broken in ways I cannot comprehend.

Here is what I did; I store the old dimensions, set everything to zero or whatever (pdf)LaTeX needs to make it zero and then restore the old dimensions from the saved values:

\documentclass{article}

\usepackage[english]{babel}
\usepackage{blindtext}

\newlength{\oldtextheight}
\newlength{\oldtextwidth}
\newlength{\oldevensidemargin}
\newlength{\oldoddsidemargin}
\newlength{\oldcolumnsep}
\newlength{\oldtopmargin}
\newlength{\oldheadheight}
\newlength{\oldheadsep}
\newlength{\oldfootskip}

\begin{document}

\blindtext[5]

\newpage%
% save old page dimensions
\setlength{\oldtextheight}{\textheight}%
\setlength{\oldtextwidth}{\textwidth}%
\setlength{\oldevensidemargin}{\evensidemargin}%
\setlength{\oldoddsidemargin}{\oddsidemargin}%
\setlength{\oldcolumnsep}{\columnsep}%
\setlength{\oldtopmargin}{\topmargin}%
\setlength{\oldheadheight}{\headheight}%
\setlength{\oldheadsep}{\headsep}%
\setlength{\oldfootskip}{\footskip}%
% set all margins to 0
\setlength{\textheight}{\paperheight}%
\setlength{\textwidth}{\paperwidth}%
\setlength{\evensidemargin}{-1in}%
\setlength{\oddsidemargin}{-1in}%
\setlength{\columnsep}{0pt}%
\setlength{\topmargin}{-1in}%
\setlength{\headheight}{0pt}%
\setlength{\headsep}{0pt}%
\setlength{\footskip}{0pt}%
% do absolute placement stuff where textpos doesn't work:
\noindent\rule{5mm}{5mm}\newpage% the necessity for this \newpage is also strange
% reset page dimensions
\setlength{\textheight}{\oldtextheight}%
\setlength{\textwidth}{\oldtextwidth}%
\setlength{\evensidemargin}{\oldevensidemargin}%
\setlength{\oddsidemargin}{\oldoddsidemargin}%
\setlength{\columnsep}{\oldcolumnsep}%
\setlength{\topmargin}{\oldtopmargin}%
\setlength{\headheight}{\oldheadheight}%
\setlength{\headsep}{\oldheadsep}%
\setlength{\footskip}{\oldfootskip}%
%\newpage % this wouldn't help a bit

\blindtext[10]

\end{document}

While the margins seem more or less intact, the type area is larger than the actual page. As I reset \textheight along with everything else, this makes no sense to me. The following image shows page 3 from the above example (click to enlarge):

One page later, everything is back to normal. Any help on what is happening and how I can make a clean reset would be much appreciated.

Maybe I should add that I've read that newer versions of the geometry package have \newgeometry and \restoregeometry commands that appear to do just what I'm trying to do manually but the TeXLive distribution on my current Beta Ubuntu (Precise) isn't new enough and I'd rather not mess with my package manager (it always pays me back one day) or my TeX trees in general (it's dark art and never works like it should).

I did try the gmeometric package (\geometry{textheight=\paperheight,textwidth=\paperwidth} and \geometry{textheight=\oldtextheight,textwidth=\oldtextwidth}) but to no avail.

Best Answer

If you can afford to make your code depend on a version of geometry that is not yet included in Debian, Ubuntu nor in Fedora, you can use the following code to replace the one in the question. It is much shorter to be sure.

\documentclass{article}

\usepackage[english]{babel}
\usepackage{blindtext}

\usepackage{geometry}[2010/09/12]
\begin{document}

\blindtext[5]

\newgeometry{textheight=\paperheight,textwidth=\paperwidth}
% do absolute placement stuff where textpos doesn't work:
\noindent\rule{5mm}{5mm}
\restoregeometry

\blindtext[10]

\end{document}

I couldn't make out which trick geometry uses though. The last thing \restoregeometry does is to invoke \Gm@changelayout which just sets some lengths, some standard, some internal to geometry. Not even so much as a \clearpage.

So an answer that actually explains why the code in the question behaves so strangely would still be much appreciated and accepted as correct answer.

Related Solutions

[Tex/LaTex] Storing the original document class page layout with geometry

With pass option, geometry package will change nothing and use the original layout. You can restore the original layout with \restoregeometry. For example,

\documentclass[a4paper,10pt]{report}
\usepackage[pass]{geometry}

\begin{document}%<-- the original layout for 'report' is saved here.
\newgeometry{top=2.5cm,bottom=2.3cm}
\input{the_title_page}
\restoregeometry %<-- the original layout is restored.
\input{the_rest}
\end{document}

The \newgeometry/\restoregeometry commands have been introduced since v5.0, but use v5.6 or later, because in v5.6 a bug was fixed where \newgeometry didn't work when pass is specified in the preamble.

[Tex/LaTex] Change page layout after first page

In the model that TeX uses there is no way to achieve your goal other than manually or in very very restricted contexts. As TeX is first generating paragraphs and only at the end of a paragraph checking whether or not to cut a page you will always end up on the second page with some part of the paragraph already been typeset (and thus to the width of the previous page).

You can achieve your goal by manually splitting the paragraph yourself (and effectively restarting a new one (with different settings afterwards)). I.e., if you know what the last word on the first page is you can put special command at this point, say, \EndOfFirstPage. The define this command in the preamble or in your class file as follows:

\newcommand\EndOfFirstPage{%
  \setlength\parfillskip{0pt}%  line should end at the right
  \par                       %  finish paragraph for now
  \setlength\parfillskip{0pt plus 1fil}% default again
  \pagebreak
   ...                        % <--- change your geometry settings here
  \noindent                   % new paragraph on the new page that claims to be
                              % a continuation
}

Of course, whenever you later change the text of the first page you may need to move the split point around. Or you could combine the above with your approach using the atbegshi package for setting the geometry and the \EndOfFirstPage only to produce the split. This has the advantage that the geometry would be nearly correct even if the command is not there to indicate the split (only the par at the page break wrong) and you could delay adding \EndOfFirstPage to a time when you are mostly done with the editing.

Automatic methods would involve keeping track of where you are on the page (how many more lines would fit) somehow capturing each paragraph untypeset, trial typesetting it to find out how long it would be, then if necessary generating a complex \parshape so that the lines of the last paragraph on the page change width on the page boundary.

Bottom line, such thing doesn't exist and it is not something that is in any way easy or even possible to be worked out reliably (non of the experts in the last 20 years overcame that limitation). We now think that we do have code for it in the LaTeX3 project but so far only an idea (and one that wouldn't work with current 2e's output routine, so this isn't going to help easily).

Best Answer

Related Solutions

[Tex/LaTex] Storing the original document class page layout with geometry

[Tex/LaTex] Change page layout after first page

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