Forcing a single column, full width table

Question

I am writing multiple documents like paper.tex, report.tex, book.tex etc. They all have different formats like single/double column, landscape/portrait etc.

All these (wrapper like) document tex files, include a single core contents file called "content.tex". Thus, this content gets formatted according to different formats declared by the wrapper tex files.

Question is: I wish to have a table inside content.tex, which gets displayed, only as single-column-full-paper-width and landscape mode, irrespective of wrapper tex's settings.

Possible?

Tried: Before this table I can say \onecolumn. But at the end of the table, I would not know whether to reset it to \onecolumn or \twocolumn as content.tex is not aware of who is including it.

Answer 1

Single/double column detection

LaTeX maintains a switch \if@twocolumn for the status of two column mode. An example for the detection of the column mode with restoring the previous setting can be found in the definition for the index, e.g. article.cls:

\newenvironment{theindex}{%
  \if@twocolumn
    \@restonecolfalse
  \else
    \@restonecoltrue
  \fi
  \twocolumn[\section*{\indexname}]%
  ...
}{%
  \if@restonecol
    \onecolumn
  \else
    \clearpage
  \fi
}

In a similar way, a environment can be defined to set its contents in one column mode:

\makeatletter
\newenvironment{one-column}{%
  \if@twocolumn
    \def\restorecolumnmode{\twocolumn\relax}%
    \onecolumn
  \else
    \def\restorecolumnmode{\clearpage}%
  \fi
}{%
  \restorecolumnmode
}

Detecting landscape setting

If option landscape is set (class option, package geometry, ...), then the paper width is larger than paper height, which can be detected by a comparison in \ifdim:

\ifdim\paperwidth>\paperheight
  % landscape setting
\else
  % portrait setting
\fi