AucTex: Output PDF Buffer Location

Question

When hitting C-c C-a to display a PDF, the buffer opens automatically below the TeX source code. How can I force it to open on the right side?

I am currently using shackle to manually control the location of buffers, but the line below does not work (this shackle setup has been tested with other buffers):

(use-package shackle
  :ensure t
  :custom
  (shackle-rules '(("^.*\\.pdf$" :regexp t :align 'right :size 0.25 :select t)
           ))
  (shackle-default-rule nil)
  )

(shackle-mode 1)

Surprisingly, I am able to control the relative size of the buffer (:size) as long as I specify :align `below (which also indicates the regular expression is being correctly matched).

Is this perhaps related to the TeX-view function?

Answer 1

I ended up finding the answer to my own question.

The package shackle fiddles with pop-buffer, which in turn is used by TeX-pdf-tools-sync-view, one of the functions being called when running AucTex's TeX-command-run-all (bind to C-c C-a). By avoiding shackle altogether for *.pdf buffers one can modify the standard splitting behaviour of pop-buffer as follows (as described here):

(setq
   split-width-threshold 80
   split-height-threshold nil)

To further control the width of the output buffer one can extend TeX-command-run-all (inspired by this):

(defun reduce-this-window-width ()
  "Reduce current window based on the the width of the other window."
  (shrink-window-horizontally (/ (window-width (next-window)) 5)))

(defun my-TeX-command-run-all (arg)
  (interactive "P")
  (TeX-command-run-all arg)
  (reduce-this-window-width)
  (pdf-view-auto-slice-minor-mode)
  (pdf-view-fit-width-to-window)
  )

(add-hook 'LaTeX-mode-hook
          (lambda () (local-set-key (kbd "C-c C-a") #'my-TeX-command-run-all)))

where pdf-view-auto-slice-minor-mode and pdf-view-fit-width-to-window can be used to, respectively, slice the margins and fit the *.pdf to the buffer width. The value 5 can be tuned according to personal preference.