pgfkeys - is choice + value pass to graphicx

Question

I'm trying to implement a macro which is a wrapper over the graphicx \includegraphics command (because I'd like to pass the parameters for cropping in a key-value fashion). While doing so, at first I introduced a key to set the width (option of includegraphics). Later on I needed the same macro where I set the scale and height option.

Now I have three macros doing basically the same which I'd like to merge into one. I saw there is the .is choice key which I tried using, but there I fail to additionally pass a value and later on passing the key-value pair to graphicx. But see my try:

\documentclass{article}

\usepackage{pgfkeys}
\usepackage{graphicx}

% \pgfkeys{
%   /testing/.cd,
%   scaling/.is choice,
%   scaling/width/.code=\def\testing{width=#1},
%   scaling/height/.code=\def\testing{height=#1},
%   scaling/scale/.code=\def\testing{scale=#1},
% }

\pgfkeys{
    /graphicx/.cd,
    left/.initial=0cm, left/.default=0cm,
    % left/.store in=\owngraphicx@left,
    right/.initial=0cm, right/.default=0cm,
    top/.initial=0cm, top/.default=0cm,
    bottom/.initial=0cm, bottom/.default=0cm,
    page/.initial={1}, page/.default={1},
    width/.initial=\linewidth, width/.default=\linewidth,
}
\newcommand{\slidesS}[2][]{%
    \pgfkeys{/graphicx/.cd,left,right,top,bottom,page,#1}%
    \fbox{%
        \includegraphics[%
        page=\pgfkeysvalueof{/graphicx/page},%
        scale=\pgfkeysvalueof{/graphicx/width},%
        clip,%
        trim=\pgfkeysvalueof{/graphicx/left} \pgfkeysvalueof{/graphicx/bottom} \pgfkeysvalueof{/graphicx/right} \pgfkeysvalueof{/graphicx/top},%
        ]{#2}%
    }%
}
\newcommand{\slidesW}[2][]{%
    \pgfkeys{/graphicx/.cd,left,right,top,bottom,page,#1}%
    \fbox{%
        \includegraphics[%
        page=\pgfkeysvalueof{/graphicx/page},%
        width=\pgfkeysvalueof{/graphicx/width},%
        clip,%
        trim=\pgfkeysvalueof{/graphicx/left} \pgfkeysvalueof{/graphicx/bottom} \pgfkeysvalueof{/graphicx/right} \pgfkeysvalueof{/graphicx/top},%
        ]{#2}%
    }%
}
\newcommand{\slidesH}[2][]{%
    \pgfkeys{/graphicx/.cd,left,right,top,bottom,page,#1}%
    \fbox{%
        \includegraphics[%
        page=\pgfkeysvalueof{/graphicx/page},%
        height=\pgfkeysvalueof{/graphicx/width},%
        clip,%
        trim=\pgfkeysvalueof{/graphicx/left} \pgfkeysvalueof{/graphicx/bottom} \pgfkeysvalueof{/graphicx/right} \pgfkeysvalueof{/graphicx/top},%
        ]{#2}%
    }%
}
\newcommand{\inputFile}{image.png}

\begin{document}

% \pgfkeys{
%   /testing/.cd,
%   scaling={height=10cm},
% }

\slidesS[left=1.8982075471698134cm, right=10cm, bottom=1cm, top=5.75cm, width=1]{\inputFile}
% \includegraphics[\testing]{\inputPdfFile}

\end{document}

the commented things are me trying to capture key+value of the is choice.

Any ideas on how to properly do this (using \testing in \includegraphics does not work, since width=10cm is perceived as an option, not as key=value I think)

Answer 1

This answer is similar to the one using expkv-cs, but this time with pgfkeys. The idea remains the same: Only define the four keys left, bottom, right, top, and forward all unknown keys to \includegraphics. Just the forwarding part is a bit more complicated for pgfkeys. This answer doesn't incorporate the omission of clip and trim if they aren't necessary (if you want this I could build it in pgfkeys as well, just leave a comment).

\documentclass{article}

\usepackage{graphicx}
\usepackage{pgfkeys}

\makeatletter
\pgfqkeys{/graphicx}
  {
    .is family
    ,left/.initial=0pt, left/.default=0pt
    ,bottom/.initial=0pt, bottom/.default=0pt
    ,right/.initial=0pt, right/.default=0pt
    ,top/.initial=0pt, top/.default=0pt
    ,.unknown/.code=%
      \edef\graphicwrap@unknown
        {%
          \unexpanded\expandafter{\graphicwrap@unknown},%
          \pgfkeyscurrentname
          \ifx\pgfkeysnovalue#1\else={\unexpanded{#1}}\fi
        }%
  }
\newcommand*\graphicwrap@unknown{}
\newcommand\graphicwrap[2][]
  {%
    \begingroup
      \pgfqkeys{/graphicx}{#1}%
      \expandafter\graphicwrap@\expandafter{\graphicwrap@unknown}{#2}%
    \endgroup
  }
\newcommand\graphicwrap@[2]
  {%
    \includegraphics
      [%
         clip
        ,trim=\pgfkeysvalueof{/graphicx/left}
              \pgfkeysvalueof{/graphicx/bottom}
              \pgfkeysvalueof{/graphicx/right}
              \pgfkeysvalueof{/graphicx/top}
        ,#1%
      ]%
      {#2}%
  }
\makeatother

\begin{document}
\graphicwrap[width=5cm, left=2cm]{example-image-duck}
\graphicwrap[scale=0.5, left=2cm]{example-image-duck}

% of course old names still work as well
\graphicwrap[clip, trim=2cm 0 0 0]{example-image-duck}
\end{document}

---

A version that only uses clip and trim if one of the keys were used (without a second layer of keys, instead by letting the keys do more than just storing their value):

\documentclass{article}

\usepackage{graphicx}
\usepackage{pgfkeys}

\makeatletter
\pgfqkeys{/graphicx}
  {
    .is family
    ,left/.initial=0pt, left/.default=0pt
    ,bottom/.initial=0pt, bottom/.default=0pt
    ,right/.initial=0pt, right/.default=0pt
    ,top/.initial=0pt, top/.default=0pt
    ,left/.code=\pgfkeyssetvalue{/graphicx/left}{#1}\let\graphicwrap@do\graphicwrap@clip
    ,bottom/.code=\pgfkeyssetvalue{/graphicx/bottom}{#1}\let\graphicwrap@do\graphicwrap@clip
    ,right/.code=\pgfkeyssetvalue{/graphicx/right}{#1}\let\graphicwrap@do\graphicwrap@clip
    ,top/.code=\pgfkeyssetvalue{/graphicx/top}{#1}\let\graphicwrap@do\graphicwrap@clip
    ,.unknown/.code=%
      \edef\graphicwrap@unknown
        {%
          \unexpanded\expandafter{\graphicwrap@unknown},%
          \pgfkeyscurrentname
          \ifx\pgfkeysnovalue#1\else={\unexpanded{#1}}\fi
        }%
  }
\newcommand\graphicwrap@clip[1]
  {%
    \includegraphics
      [%
         clip
        ,trim=\pgfkeysvalueof{/graphicx/left}
              \pgfkeysvalueof{/graphicx/bottom}
              \pgfkeysvalueof{/graphicx/right}
              \pgfkeysvalueof{/graphicx/top}
        ,#1%
      ]%
  }
\newcommand\graphicwrap@noclip[1]{\includegraphics[#1]}
\let\graphicwrap@do\graphicwrap@noclip
\newcommand*\graphicwrap@unknown{}
\newcommand\graphicwrap[2][]
  {%
    \begingroup
      \pgfqkeys{/graphicx}{#1}%
      \expandafter\graphicwrap@do\expandafter{\graphicwrap@unknown}{#2}%
    \endgroup
  }
\makeatother

\begin{document}
\graphicwrap[width=5cm, left=2cm]{example-image-duck}
\graphicwrap[scale=0.5, left=2cm]{example-image-duck}

% of course old names still work as well
\graphicwrap[clip, trim=2cm 0 0 0]{example-image-duck}
\end{document}

Answer 2

The following uses expkv-cs, because setting up a small macro taking only a handful of keys is much easier there, imho (well, I'm the package author, so maybe not-so-humble, and pretty biased). Here it could be simpler by omitting the check whether clip and trim are necessary at all.

expkv-cs supports the special ... key, meaning all unknown keys are collected there. This allows to easily forward unknown keys to graphicx. Drawback of this approach: If any of the left, bottom, right, or top keys are used they are put first in the key=value list of \includegraphics, so the order of keys isn't identical (which shouldn't be much of a problem).

\documentclass{article}

\usepackage{graphicx}

\usepackage{expkv-cs} % <- sorry, not pgfkeys here
\makeatletter
% optional argument grabbing, expkv-cs uses mandatory arguments
\newcommand\graphicwrap[1][]{\graphicwrap@{#1}}
% internal keys and their initial values here
\ekvcSplitAndForward\graphicwrap@\graphicwrap@do
  {
     internal-left   = 0pt      % #1
    ,internal-bottom = 0pt      % #2
    ,internal-right  = 0pt      % #3
    ,internal-top    = 0pt      % #4
    ,internal-any    = \@gobble % #5: used as a flag that clip is needed
    ,...                        % #6: unknown keys
  }
% additional keys (the front-facing ones) and what they do
\ekvcSecondaryKeys\graphicwrap@
  {
     meta left   = {internal-any=\@firstofone, internal-left   = {#1}}
    ,meta bottom = {internal-any=\@firstofone, internal-bottom = {#1}}
    ,meta right  = {internal-any=\@firstofone, internal-right  = {#1}}
    ,meta top    = {internal-any=\@firstofone, internal-top    = {#1}}
  }
% output macro
\newcommand\graphicwrap@do[7]
  {\expandafter\includegraphics\expandafter[#5{clip, trim=#1 #2 #3 #4}, #6]{#7}}
\makeatother

\begin{document}
\graphicwrap[width=5cm, left=2cm]{example-image-duck}
\graphicwrap[scale=0.5, left=2cm]{example-image-duck}

% of course old names still work as well
\graphicwrap[clip, trim=2cm 0 0 0]{example-image-duck}
\end{document}

---

For comparison, the following would be the variant without checking whether clip and trim are required:

\documentclass{article}

\usepackage{graphicx}

\usepackage{expkv-cs} % <- sorry, not pgfkeys here
\makeatletter
% optional argument grabbing, expkv-cs uses mandatory arguments
\newcommand\graphicwrap[1][]{\graphicwrap@{#1}}
% keys and their initial values here
\ekvcSplitAndForward\graphicwrap@\graphicwrap@do
  {
     left   = 0pt      % #1
    ,bottom = 0pt      % #2
    ,right  = 0pt      % #3
    ,top    = 0pt      % #4
    ,...               % #5: unknown keys
  }
% output macro
\newcommand\graphicwrap@do[6]{\includegraphics[clip, trim=#1 #2 #3 #4, #5]{#6}}
\makeatother

\begin{document}
\graphicwrap[width=5cm, left=2cm]{example-image-duck}
\graphicwrap[scale=0.5, left=2cm]{example-image-duck}

% of course old names still work as well
\graphicwrap[clip, trim=2cm 0 0 0]{example-image-duck}
\end{document}