Open pdf viewer at a certain line (forward-search) from within an .Rnw (Sweave) file

Question

I am working with Ubuntu 12.04, Emacs 24, and the (pdf) viewer Okular 0.14. I would like to be able to open Okular (and jump to a specific line) from an .Rnw (Sweave) file. By using

(setq TeX-view-program-list
      '(("Okular" "okular --unique %o#src:%n`pwd`/./%b")))

in ~/.emacs, this already works for .tex files, even in multi-file projects, consisting of a master.tex and a chapter chapter.tex. By using C-c C-v (or C-c C-c View) one can then jump to the corresponding line (this feature is also known as forward-search).

I would like to have forward-search from within .Rnw files, too, where chapter.tex is replaced by chapter.Rnw (Sweave). With the above setup, however, C-c C-c View (executed from within chapter.Rnw) gives me "Output file "chapter.pdf" does not exist.". Clearly, master.pdf should have been opened.

I tried to set Local Variables in chapter.Rnw (this works for pure .tex documents on C-c C-_), but it seems to be ignored for .Rnw files in both senses: First, C-c C-_ doesn't insert anything anymore and, second, on C-c C-c, still the wrong file chapter.pdf is tried being opened. On C-c C-c View, I see the actual call to which %o, %n, and %b ... expand:

okular --unique chapter.pdf#src:8`pwd`/./chapter.Rnw

If I manually replace chapter.pdf by master.pdf, then I can jump from chapter.Rnw to the corresponding line in master.pdf. So the command basically works, but it does not find the correct master file from within .Rnw files.

Here is a minimal example:

chapter.Rnw:

% patchDVI setup (see vignette)
\SweaveOpts{concordance=TRUE}
<<echo=FALSE>>=
.TexRoot <- "master.tex" 
@

foo bar foo bar
\clearpage
<<hist, echo=TRUE, fig=true>>=
X <- rnorm(50, mean=20, sd = 3)
hist(X)
@
foo bar foo bar

%%% Local Variables:
%%% mode: latex
%%% TeX-master: "master.tex"
%%% End:

master.tex:

\documentclass{scrbook}

\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage[american]{babel}
\usepackage{blindtext}
\usepackage{amsmath}
\usepackage{hyperref}
\usepackage{fancyvrb}
\usepackage{Sweave}

\fvset{listparameters={\setlength{\topsep}{0pt}}}
\renewenvironment{Schunk}{\vspace{\topsep}}{\vspace{\topsep}}

\begin{document}

\input{chapter}

\end{document}

%%% Local Variables:
%%% mode: latex
%%% TeX-master: t
%%% End:

wrapper.Rnw:

% patchDVI setup (see vignette)
<<echo=FALSE>>=
.SweaveFiles <- c("chapter.Rnw") 
@

I compile it using Rscript -e "patchDVI::SweavePDF('chapter.Rnw', encoding='utf8')" (so using Duncan Murdoch's R package patchDVI to get syncronization with .Rnw files. One can also compile the whole project, just replace chapter.Rnw by wrapper.Rnw.

Answer 1

The problem is that TeX-normal-mode is lost in .Rnw files and thus forward search as for .tex documents is not working anymore. To keep TeX-normal-mode, use:

(add-hook 'noweb-select-doc-mode-hook
      '(lambda ()
         (unless (boundp 'in-noweb-select-doc-mode-hook)
           (let* ((in-noweb-select-doc-mode-hook t)
              (deactivate-mark))
         (TeX-normal-mode t)))))