Figures on left pages, text on right ones with class book (cont.)

Question

In addition to the very useful discussion Figures on left pages, text on right ones with class book, numbering only on right pages, I would like to handle 2 other features:

• the suppression of blank pages automatically inserted by book,
• the possibility to switch between figure and table captions.

Regarding the first, 3 blank pages are added before a new chapter (probably also before a new part) where only 1 should be. I managed to remove one redefining \chapter as follows (removing the first line involving \clearpage) but not the other.

\renewcommand\chapter{
                    \thispagestyle{plain}%
                    \global\@topnum\z@
                    \@afterindentfalse
                    \secdef\@chapter\@schapter}

For the second, I defined a new command \switchcaption as follows which I call before and after a table respectively with "table" and "figure" as argument.

\newcommand\switchcaption[1]{\def\@captype{#1}}

By the way, I would be very interested in better understanding

• when it is useful to use directly \def instead of \(re)newcommand (\newcommand\@captype{figure} seems to work just as well as \def\@captype{figure}),
• when it is needed to work within \makeatletter \makeatother (apparently \newcommand works differently in both cases: it "reads" the new command name with subsequent braces outside \makeatletter \makeatother and without braces otherwise),
• why \addfig definition needs two statements (one for \@addfig and another apparently for its argument).

Thank you very much in advance for your help!

Answer 1

After viewing the comments, it seems like the only thing left (even though it is actually not in question form), is to efficiently switch between table and caption. You mention that you currently do this manually:

\switchcaption{table}% Switch to table caption
\begin{table}[..]
   ...
\end{table}
\switchcaption{figure}% Switch to figure caption

This manual interaction could be avoided by adding some code to the beginning and ending of the table environment. Such "patching" is possible using the etoolbox package. It provides \AtBeginEnvironment{<env>}{<code>} and \AtEndEnvironment{<env>}{<code>} (also \BeforeBeginEnvironment{<env>}{<code>} and \AfterEndEnvironment{<env>}{<code>}) to insert <code> at the beginning/end of environment <env>. A little bit more efficient would be to just add:

\usepackage{etoolbox}% http://ctan.org/pkg/etoolbox
\makeatletter
\AtBeginEnvironment{table}{\def\@captype{table}}% Switch to table captions at beginning of table environment
\AtBeginEnvironment{figure}{\def\@captype{figure}}% Switch to figure captions at beginning of figure environment
\makeatother

to your document preamble that should switch as needed depending on the environment used.

---

Edit: The above "solution" may be moot if you are using the figure environment for all your figures and tables. If that is the case, the your \switchcaption combination will still be necessary.

To that end, note that you can still use the table environment within the command \addfig, which necessarily modifies the caption to read Table x: .... This is a common misinterpretation of the table and figure environments, stemming from their respective names. They are merely wrappers for any content, allowing you to place \includegraphics commands inside table and a tabular (say) inside figure.