\includegraphics: a command in the optional argument

Question

I want to pass some arguments to \includegraphics via a command, but I can't get it working as I would expect. My M(n)WE:

\documentclass{article}
\usepackage{graphicx}
\begin{document}

\newcommand{\widthText}{,width=3cm}
\includegraphics[scale=0.5 \widthText]{picture}

\end{document}

I guess that the point would be to expand \widthText before...

In my actual code, the command \widthText is actually either the one given above, or empty, depending on some boolean, and I have also a \heightText to set the height.

Answer 1

Staying with the desire of the OP, here is a solution.

\documentclass{article}
\usepackage{graphicx}
\makeatletter
\protected\def\includeGraphics{\@testopt\roy@includegraphics{}}
\def\roy@includegraphics[#1]#2{%
  \begingroup
  % Every expandable token in #1 may be expanded here:
  \edef\x{\endgroup\noexpand\includegraphics[#1]}\x{#2}%
}
\makeatother
\begin{document}
\newcommand{\widthText}{,width=3cm}
% Since double comma (,,) in the key-value pairs doesn't hurt both keyval and 
% xkeyval packages, and since the user of \widthText might forget to insert
% a comma before 'width', let us add a potentially redundant comma in the 
% following:
\includeGraphics[viewport=20 21 590 400,scale=0.5, \widthText]{./Graphics/comet1}
\end{document}

Answer 2

The code handling the key=value pairs must be able to see the separating comma, therefore it must not be included in a macro. You either need to expand the content of the macro manually or feed it to \includegraphics in another way. For the first method you can use \expandafter or \edef.

There is also my adjustbox package which provides the keys min width and max width, either using \adjincludegraphics[<key options>]{<filename>} or \adjustimage{<key option>}{<filename>} or by loading the package with the export option which makes all new key options available to the normal \includegraphics. I think this might also help you depending on what exactly you want to do.

Answer 3

The keyval system used by graphicx goes to some trouble not to expand macros while parsing, so that the macros can be used as the values of the keys. the intended usage is more like

\newcommand{\widthText}{\ifsomething 3cm \else \Gin@nat@width \fi}
\includegraphics[scale=0.5, width=\widthText]{picture}

where \Gin@nat@width is the natural width.

My original answer suggested \width could be used, thanks for the correction in the comments. \Gin@nat@width works, but means that your definition has to be in a package or inside \makeatletter... In the following, the first two are equivalent, the second is scaled to half size.

\documentclass{article}
\usepackage{graphicx}
\begin{document}

\makeatletter

\fbox{\includegraphics[]{fj.png}}


\fbox{\includegraphics[width=\Gin@nat@width]{fj.png}}


\fbox{\includegraphics[width=0.5\Gin@nat@width]{fj.png}}

\end{document}

Answer 4

Try this way and it works

\documentclass{article}
\usepackage[demo]{graphicx}
\begin{document}
\def\test#1{%
  \includegraphics[scale=0.5,#1]{picture}}
\test{width=3cm}\par
\test{width=1cm}

\def\keepaspectratio{keepaspectratio}
\test{width=1cm,height=3cm,\keepaspectratio}
\end{document}

Answer 5

Not an aswer but maybe an alternative way …

If you want to predefine some keys you can seth them with \setkeys{Gin}{<options>}. These keys can be overwritten locally.

\documentclass{article}

\usepackage[demo]{graphicx}

\setkeys{Gin}{width=4cm,height=2cm}


\begin{document}
\includegraphics{file1}

\includegraphics[width=2cm]{file1}
\end{document}

Note: This work not with all options, e.g. using scalein \setkeys won’t give the desired result.