[pdftex] line breaking in pdfannot

[Heiko Oberdiek]

On Tue, Mar 24, 2009 at 02:15:02PM +0300, kuzn at htsc.mephi.ru wrote:

> \def\tip#1#2{%
>   \pdfannot width 0pt height 0pt depth 0pt {
>     /Subtype /Text
>     /Open false
>     /T (sample)
>     /Contents (#1)
>     /NM (ctip Text 0)
> 	}%
> }
> 
> used with pdflatex provides the following output in annotation
> 
> \tip{a
> b}       -> a b
> 
> \tip{a\n b}     % newline recommended by PDF 1.7
> ! Undefined control sequence.
> <argument> a\n

Manually: \string\n

But be aware, that #1 can contain code that breaks the PDF structure,
e.g. unmatched parentheses. Therefore there is \pdfescapestring.

\def\tip#1#2{%
  % keep definition of \n locally
  \begingroup
    % define \n to be LF with catcode 12
    \begingroup
      \lccode`\9=10 % (13 for CR)
    \lowercase{\endgroup
      \def\n{9}%
    }%
    \pdfannot ...
      ...
      /Contents (\pdfescapestring{#1})
      ...
    \relax
  \endgroup
}

If you are using hyperref:

\pdfstringdefDisableCommands{%
  \let\n\textLF
}
\newcommand*{\tip}[2]{%
  \pdfstringdef\ContentsString{#1}
  \pdfannot ...
     ...
     /Contents (\ContentsString)
     ...
  \relax
}

Yours sincerely
  Heiko <oberdiek at uni-freiburg.de>
--