Re: caption width in LateX export

[Juan Manuel Macías]

Sebastian P. Luque writes:

> This is great, and very interesting to learn about the BIND keyword.
>
> Thank you,

You're welcome. Of course, if you use the filter very often, it is not
necessary to include it in a document or use the bind keyword. It
would be enough to add the function to your init and the line:

(add-to-list 'org-export-filter-final-output-functions #'caption-auto-width)

In a case like this, however, I would prefer to use the other function
in Lua within LuaTeX, since two commands could be defined: one to enable
the automatic caption width and one to disable it, throughout the
document. E.g.:

#+begin_src latex
  \usepackage{luacode}

  \begin{luacode*}
    function caption_width ( text )
      text = string.gsub ( text, "(\\includegraphics.+)", "\\sbox0{%1}")
      text = string.gsub ( text, "(\\caption.+)", 
"\\begin{minipage}{\\wd0}\\usebox0%1\\end{minipage}")
      return text
    end
  \end{luacode*}

\newcommand\CaptionAutoWidthOn{\directlua{luatexbase.add_to_callback
  ( "process_input_buffer" , caption_width , "caption_width" )}}

\newcommand\CaptionAutoWidthOff{\directlua{luatexbase.remove_from_callback
  ( "process_input_buffer" , "caption_width" )}}
#+end_src

\CaptionAutoWidthOn

#+CAPTION: Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Donec 
hendrerit tempor tellus 
#+ATTR_LaTeX: :width .3\linewidth
[[img.jpg]]

\CaptionAutoWidthOff

#+CAPTION: Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Donec 
hendrerit tempor tellus
#+ATTR_LaTeX: :width .1\linewidth
[[img.jpg]]