How to make different caption placement for figures on odd and even pages?

Question

For small figures, I want for captions to go on the right or on the left depending on the page number, whether it is odd or even. To do that I define the command \row as follows:

\newcommand{\row}[2]{%
    \ifodd\value{page}
        #2 \hfil #1
    \else
        #1 \hfil #2
    \fi
}

Typically, it is used inside the figure environment, for example,

\begin{figure}
\row{%
  \begin{minipage}[c]{0.67\textwidth}
    \includegraphics[width=\textwidth]{2011-03-03}
  \end{minipage}%
}{%
  \begin{minipage}[c]{0.3\textwidth}
    \caption{The transition temperature vs. density of the hydrogen} 
    \label{fig:03-03}
  \end{minipage}}
\end{figure}

This works as desired in most cases, however, sometimes, placement of the caption goes wrong. I wonder why? And how to modify my code to avoid troubles?

Answer 1

You can use the refcount package:

\usepackage{refcount}
\newcounter{figureposcount}
\newcommand{\row}[2]{%
  \refstepcounter{figureposcount}\label{figurepos\thefigureposcount}%
  \ifodd\getpagerefnumber{figurepos\thefigureposcount}
    #2 \hfil #1%
  \else
    #1 \hfil #2%
  \fi
}

However you could also consider the sidecap package that does what you want without a special syntax (apart using SCfigure instead of figure).

Answer 2

Due to the asynchronous nature of the output routine, the page counter isn't reliable. Use, e.g., the scrextend package and its \ifthispageodd macro instead.