I know that I can Remove colon in the caption of a figure if the caption is empty when I simply use the caption package. But let's say I am using a journal-specific class (e.g. elsarticle) that has it's own definition of caption layout. So adding the caption package gives me an unsupported document class (or package) warning.
So the question it - can I remove the colon from the caption of a figure if the caption is empty WITHOUT using the caption package?
A preliminary remark: If a journal you're submitting an article to requires you to use the elsarticle document class, it may be a poor idea to modify the caption style defined by the class. Your journal's style guidelines probably also state something to the effect that every float should have a (nonempty) caption, in which case some kind of separator (such as a colon) between the float's number and caption is generally needed.
Here's the definition of the \@makecaption command contained in the file elsarticle.cls
\long\def\@makecaption#1#2{%
\vskip\abovecaptionskip\footnotesize
\sbox\@tempboxa{#1: #2}%
\ifdim \wd\@tempboxa >\hsize
#1: #2\par
\else
\global \@minipagefalse
\hb@xt@\hsize{\hfil\box\@tempboxa\hfil}%
\fi
\vskip\belowcaptionskip}
The two arguments of the \@makecaption macro are [Float] <num> and the caption's text, respectively. [Float] can be "Figure", "Table", or the name of any other floating environment recognized by LaTeX.
There are two ways to suppress the insertion of a colon following the float's name and number.
Method 1 : Remove the colon globally because the mandatory arguments (the stuff inside curly braces) of all \caption commands will always be empty. To achieve this, you could load the etoolbox package and issue the following commands:
\makeatletter
\patchcmd{\@makecaption}{#1: #2}{#1}{}{}
\makeatother
Method 2: Remove the colon whenever (and only if) the mandatory argument of the \caption command is empty. In this case, you may want to employ the following redefinition of the \@makecaption command:
\makeatletter
\long\def\@makecaption#1#2{%
\vskip\abovecaptionskip\footnotesize
\sbox\@tempboxa{#2} % place contents of #2 into a scratch TeX box
\ifdim \wd\@tempboxa = 0pt % test if scratch box has zero width
\centering #1 \par % if yes, typeset only #1 (the float's name and number)
\else % if no, proceed with default definition
\sbox\@tempboxa{#1: #2}%
\ifdim \wd\@tempboxa >\hsize
#1: #2\par
\else
\global \@minipagefalse
\hb@xt@\hsize{\hfil\box\@tempboxa\hfil}%
\fi
\fi
\vskip\belowcaptionskip}
\makeatother
\caption command is truly empty.
– Mico
Jan 19 '12 at 15:55
\@makecaption as you, @egreg and @Holle suggested...
– Geek On Acid
Jan 19 '12 at 16:07
\clearpage\listoffigures\clearpage. This generates the equivalent of a table of contents, but containing only the figures. Likewise, the command \listoftables generates a list of all tables.
– Mico
Jan 19 '12 at 16:51
\listoffigures without giving any name in curly brackets for \caption (i.e. \caption[text]{}) it will create the list but also create a colon for the figure label - which is what I am trying to avoid:)
– Geek On Acid
Jan 19 '12 at 17:27
First of all, let me remark that if you're preparing a paper for a submission to a journal, such a change will be probably removed (and will annoy the people in charge of production). If the publisher's style wants a colon there, it means that no caption should be empty.
Anyway, here's a patch for elsarticle:
\documentclass{elsarticle}
\usepackage{etoolbox}
\makeatletter
\patchcmd{\@makecaption}{#1: #2}
{#1\sbox8{#2}\ifdim\wd8=\z@\else: #2\fi}
{}{\ddt}
\makeatother
\begin{document}
\begin{figure}
\caption{Here}
\end{figure}
\begin{figure}
\caption{}
\end{figure}
\end{document}
The original definition is
\long\def\@makecaption#1#2{%
\vskip\abovecaptionskip\footnotesize
\sbox\@tempboxa{#1: #2}%
\ifdim \wd\@tempboxa >\hsize
#1: #2\par
\else
\global \@minipagefalse
\hb@xt@\hsize{\hfil\box\@tempboxa\hfil}%
\fi
\vskip\belowcaptionskip}
so I patch the command with a check that the argument #2 (the caption text) is empty. However the usual \if\relax\detokenize{#2}\relax fails, because the caption text always begins with \ignorespaces. Thus it's better to check if the caption text typesets something.
\else part of the \ifdim clause will only be entered if the width of the box containing #1: #2 exceeds \hsize. This, in turn, will only ever happen (unless \hsize is truly minuscule!) if #2 is nonempty, won't it?
– Mico
Jan 19 '12 at 17:02
If you use the class elsarticle than you can (re)format the figure caption with the following lines:
\makeatletter
\long\def\@makecaption#1#2{%
\vskip\abovecaptionskip\footnotesize
\sbox\@tempboxa{#1: #2}%
\ifdim \wd\@tempboxa >\hsize
#1: #2\par
\else
\global \@minipagefalse
\hb@xt@\hsize{\hfil\box\@tempboxa\hfil}%
\fi
\vskip\belowcaptionskip}
\makeatother
