# Text margins in beamer vs adjustwidth (changepage.sty)

Some (not all) slides in my beamer presentation need to have a wider text block. I know that I can use a columns env with a single column of arbitrary width, but that's a bit verbose. When I discovered changepage.sty it first seemed that the \adjustwidth env does precisely what I want.

However, I can't get beamer's block environment to play nice with \adjustwidth (cf part 5 in MWE below). What am I doing wrong ?

\documentclass{beamer}

\usecolortheme{orchid}

\usepackage{changepage}

\begin{document}
\begin{frame}

\centerline{1}
\rule{\linewidth}{1pt} % 1: used for reference

\bigskip
\bigskip
\centerline{2}
\rule{\linewidth}{1pt} % looks fine

\bigskip
\bigskip
\centerline{3}
\rule{\linewidth}{1pt} % looks fine too (i.e. full \paperwidth)

\bigskip
\bigskip
\centerline{4}
\rule{128mm}{1pt} % still fine (paper is 128mm wide by default)

\bigskip
\bigskip

\centerline{5}
\begin{block}{}
\rule{128mm}{1pt} % goes beyond the edge of the page

\rule{\linewidth}{1pt} % does not have the intented length
\end{block}

\end{frame}
\end{document}



You can define your own adjustwidth environment (based on columns environment):

\documentclass{beamer}

\usecolortheme{orchid}

%\usepackage{changepage}

\begin{columns}
\column{\dimexpr\linewidth-#1-#2}
}{\end{columns}}

\begin{document}
\begin{frame}

\centerline{1}
\rule{\linewidth}{1pt} % 1: used for reference

\bigskip
\bigskip
\centerline{2}
\rule{\linewidth}{1pt} % looks fine

\bigskip
\bigskip
\centerline{3}
\rule{\linewidth}{1pt} % looks fine too (i.e. full \paperwidth)

\bigskip
\bigskip
\centerline{4}
\rule{128mm}{1pt} % still fine (paper is 128mm wide by default)

\bigskip
\bigskip

\centerline{5}