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;;;;;;;;;;;;;;;;;;;;; dsp.el ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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;;
;; very rough attempt to allow emacs to control Mosaic.
;; shamefully uses global variables.
;;
;; when you are editing a file XXX you want to display in
;; a running Mosaic with pid nnn, issue the command M-x dsp
;; this will (1) save XXX
;;           (2) create /tmp/Mosaic.nnn
;;               [with appropriate contents]
;;           (3) use kill to tell Mosaic to display XXX
;;
;;
;; load this file using M-x load-file first
;;
;;*****AT THE VERY BOTTOM of this file I
;;*****assign "ALT-a" to the function dsp
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;


;;pick up pid of Mosaic process.
;;haven't tested with >1 Mosaic running

(defun get-pids ()
  (interactive)
  (setq the-pid-string (substring (shell-command "ps | grep Mosaic")0 5))
  (setq the-pid-int (string-to-int the-pid-string))
  (setq the-pid-string (int-to-string the-pid-int))) ;;eliminates spaces

;;construct contents of tmp file
;;it must contain the name of the file being edited

(defun tmp-file-contents ()
  (interactive)
  (setq line-1 "goto")
  (setq line-2 (concat "file://localhost" (buffer-file-name))))

;;get rid of the old tmp file if it exists

(defun remove-old-tmp-file ()
  (interactive)
  (setq the-tmp-file (concat "/tmp/Mosaic." the-pid-string))
  (if (file-exists-p the-tmp-file)(delete-file the-tmp-file)))

;;make a new tmp file and put info in it

(defun create-new-tmp-file ()
  (interactive)
  (find-file the-tmp-file)
  (insert-string line-1)
  (newline)
  (insert-string line-2)
  (newline)
  (save-buffer 0)
  (kill-buffer nil))

;;tell mosaic to visit file using "kill"

(defun tell-mosaic ()
  (interactive)
  (setq the-command (concat "kill -USR1 " the-pid-string))
  (shell-command the-command))

;;here is the "top-level" function

(defun dsp ()
  (interactive)
  (save-buffer 0)
  (get-pids)
  (tmp-file-contents)
  (remove-old-tmp-file)
  (create-new-tmp-file)
  (tell-mosaic))

(global-set-key [?\A-a] 'dsp)