frames dedicated to buffers, or, always see specific buffers in a specific frame

["João Távora" <joaotavora@gmail.com>]

So I needed to scratch a code-browsing itch and came up with this monster:

(defvar joaot/browse-frame)
(setq joaot/browse-frame (new-frame))
(setq display-buffer-alist
      `((joaot/browse-buffer-p . (joaot/browse-buffer-in-special-frame . nil))))

(defun joaot/browse-buffer-p (buffer action)
  (declare (ignore action))
  (let ((buffer (and buffer
                     (get-buffer buffer))))
    (and (frame-live-p joaot/browse-frame)
         buffer
         (buffer-file-name buffer)
         (string-match "someproject" (buffer-file-name buffer)))))

(defun joaot/browse-buffer-in-special-frame (buffer alist)
  (let ((window (frame-selected-window joaot/browse-frame)))
    (window--display-buffer buffer window 'reuse alist)))

(defadvice switch-to-buffer (around joaot/browse-buffer-maybe activate)
  (if (joaot/browse-buffer-p buffer-or-name nil)
      (display-buffer buffer-or-name)
    ad-do-it))

Do you see what it is doing? Whenever I switch to a buffer or file
belonging to "someproject", which I only want to read, it makes sure
the buffer is displayed in a special "browse-frame" created beforehand
and that lives in my secondary monitor.

This is not quite "dedicated windows". It's sort of frames dedicated
to buffers.

Does anyone know of a less hackish way to do this? The defadvice is
particularly nasty... Do you see this breaking anything important that
I'm not seeing??

Thanks in advance,
J

PS: yes I refuse to open a secondary emacs instance on principle :-)