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+;;; yatexflt.el --- YaTeX filter command utilizer -*- coding: sjis -*-
+;;; 
+;;; (c)1993-2018 by HIROSE Yuuji.[yuuji@yatex.org]
+;;; Last modified Sun Jan  7 11:38:12 2018 on firestorm
+;;; $Id$
+
+;;; Commentary:
+;;;
+;;;	This lisp enables passing inline text to some external filter
+;;;	command to generate files such as graphic files.
+;;; 
+;;;	Typical situation is using blockdiag/dot(graphviz) command to
+;;;	generate png/pdf file.
+;;;
+;;; Example:
+;;;
+;;;	[[LaTeX Source]]
+;;;	%#BEGIN FILTER{foo.pdf}{dot -T %t -o o}
+;;;	\if0
+;;;	===
+;;;	digraph {
+;;;	  A -> B;
+;;;	  B -> C;
+;;;	}
+;;;	===
+;;;	\fi
+;;;	%#END
+;;;	\includegraphics{foo.pdf}
+;;;
+;;;	In this  case above, when  you type  `[prefix] t e'  between two
+;;;	`===' lines, the  content in a region are fed  to dot command as
+;;;	follows:
+;;;	
+;;;	    echo TEXT | dot -T pdf -o foo.pdf 
+;;;
+;;;	Then foo.pdf file will be generated and the image (as PNG) will
+;;;	be displayed in the next window.
+
+;;; Code:
+(defun YaTeX-filter-filter-set-conversion-flag ()
+  (let ((ovl (get 'YaTeX-filter-filter-sentinel 'overlay)))
+    (if ovl				;; When successful conversion met,
+	(progn				;; (1)Set conversion complete flag
+	  (add-hook			;; (2)Add hook of seim-automatic
+	   'write-file-hooks		;;    update of convert to write-
+	   'YaTeX-filter-update-all)	;;    file hook.
+	  (overlay-put ovl 'converted t)))))
+
+(defun YaTeX-filter-filter-unset-conversion-flag
+    (ovl after beg end &optional length) 
+  (if after (overlay-put ovl 'converted nil)))
+
+
+(defun YaTeX-filter-pngify-sentinel (proc msg)
+  (save-excursion
+    (let ((b (process-buffer proc)) (selw (selected-window))
+	  img)
+      (set-buffer b)
+      (cond
+       ((eq (process-status proc) 'run)
+	(put-text-property (point-min) (point-max) 'invisible t))
+       ((eq (process-status proc) 'exit)
+	(set-buffer b)
+	(YaTeX-popup-image
+	 (YaTeX-buffer-substring
+	  (get 'YaTeX-filter-pngify-sentinel 'start) (point-max))
+	 b)
+	(YaTeX-filter-filter-set-conversion-flag))
+       (t
+	(set-buffer b)
+	(remove-text-properties (point-min) (point-max) '(invisible t))
+	(insert "\nProcess aborted %s\n" msg))))))
+
+(defvar YaTeX-filter-pdf2png-stdout
+  (cond
+   ((YaTeX-executable-find "convert")	"convert -trim %s PNG:-")
+   (t
+    "gs -dNOPAUSE -sDEVICE=png256 -sOutputFile=- -dBATCH -q -r75 %s"))
+  "Command line syntax to convert PDF file to PNG stream")
+
+(defun YaTeX-filter-modified-BEGEND-regions ()
+  "Return the list of overlays which contains un-converted text."
+  (save-excursion
+    (save-restriction
+      (widen)
+      (let (r pl (list (overlays-in (point-min) (point-max))))
+	(while list
+	  (if (and (overlay-get (car list) 'filter-input)
+		   (setq pl (plist-member (overlay-properties (car list))
+					  'converted))
+		   (not (plist-get pl 'converted)))
+	      (setq r (cons (car list) r)))
+	  (setq list (cdr list)))
+	(nconc r)
+	r))))
+
+(defun YaTeX-filter-update-all ()
+  "Update all destination files from built-in source text."
+  (interactive)
+  (let ((timeout 4)
+	ans ovl (update-list (YaTeX-filter-modified-BEGEND-regions)))
+    (if update-list
+	(save-excursion
+	  (save-window-excursion
+	    (catch 'abort
+	      (while update-list
+		(goto-char (overlay-start (setq ovl (car update-list))))
+		(or (pos-visible-in-window-p)
+		    (set-window-start nil (point)))
+		(unwind-protect
+		    (progn
+		      (overlay-put ovl 'face 'YaTeX-on-the-fly-activated-face)
+		      (message "Non-update source found: Update here: %s "
+			       "Y)es N)o A)bort")
+		      (setq ans (read-char))
+		      (cond
+		       ((memq ans '(?Y ?y))
+			(YaTeX-filter-BEGEND)
+			(while (and (> (setq timeout (1- timeout)))
+				    (eq (process-status "Filter") 'run))
+			  (message "Waiting for conversion process to finish")
+			  (sit-for 1)))
+		       ((memq ans '(?A ?a)) (throw 'abort t))
+		       (t nil)))
+		  (overlay-put ovl 'face nil))
+		(setq update-list (cdr update-list)))))))
+    ;; Write file hook should return nil
+    nil))
+
+(defun YaTeX-filter-filter-sentinel (proc msg)
+  (put 'YaTeX-filter-pngify-sentinel 'start nil)
+  (let ((b (process-buffer proc))
+	(imagefile (get 'YaTeX-filter-filter-sentinel 'outfile))
+	ovl
+	(selw (selected-window)))
+    (save-excursion
+      (cond
+       ((eq (process-status proc) 'run))
+       ((eq (process-status proc) 'exit)
+	(set-buffer b)
+	(remove-images (point-min) (point-max))
+	(if (and (file-regular-p imagefile)
+		 (file-readable-p imagefile))
+	    (save-excursion
+	      (setq buffer-read-only nil)
+	      (cond
+	       ((string-match "\\.\\(jpg\\|png\\)" imagefile)
+		(erase-buffer)
+		(YaTeX-popup-image imagefile b)
+		(YaTeX-filter-filter-set-conversion-flag))
+	       (t 			;Convert again to PNG file
+		(goto-char (point-max))
+		(insert "\nConvert Again to PNG file...\n")
+		(put 'YaTeX-filter-pngify-sentinel 'start (point))
+		(set-process-sentinel
+		 (start-process
+		  "Filter" b		;Safe to reuse
+		  shell-file-name YaTeX-shell-command-option
+		  (format YaTeX-filter-pdf2png-stdout imagefile))
+		 'YaTeX-filter-pngify-sentinel)
+		(set-buffer-multibyte nil)
+		))
+	      (select-window selw)))
+	(YaTeX-preview-image-mode)
+	)
+       (t					;Other status might be an error
+	(set-buffer b)
+	(goto-char (point-max))
+	(insert (format "%s\n" (process-status proc))))))))
+
+(defun YaTeX-filter-pass-to-filter (begend-info)
+  "Pass current BEGIN FILTER environment to external command."
+  (put 'YaTeX-filter-filter-sentinel 'outfile nil)
+  ;; begend-info is from YaTeX-in-BEGEND-p: (BEG END ARGS)
+  (let ((b (car begend-info)) (e (nth 1 begend-info))
+	(args (nth 2 begend-info))
+	(p (point)) openb closeb outfile cmdline point-if0 point-fi)
+    (save-excursion
+      (if (and begend-info
+	       (string-match "FILTER" args) ;easy test
+	       (goto-char (car begend-info))
+	       (re-search-forward
+		"FILTER\\s *{\\([^}]+\\)}" e t)
+	       (setq outfile (YaTeX-match-string 1))
+	       (goto-char (match-end 0))
+	       (prog2			;Step into the second brace
+		   (skip-chars-forward "\t ")
+		   (looking-at "{")	;Check if 2nd brace surely exists
+		 (skip-chars-forward "{")
+		 (skip-chars-forward "\t"))
+	       (setq openb (point))
+	       (condition-case nil
+		   (progn (up-list 1) t)
+		 (error nil))
+	       (setq closeb (1- (point))
+		     cmdline (YaTeX-buffer-substring openb closeb))
+	       (re-search-forward "^\\\\if0\\>" p t)
+	       (setq point-if0 (point))
+	       (re-search-forward "^\\\\fi\\>" e t)
+	       (setq point-fi (match-beginning 0)))
+	  (let*((case-fold-search t)
+		(type (cond
+		       ((string-match "\\.png$" outfile) "png")
+		       ((string-match "\\.svg$" outfile) "svg")
+		       (t				 "pdf")))
+		(newcmdline (YaTeX-replace-formats
+			     cmdline
+			     (list (cons "t" type)
+				   (cons "o" outfile))))
+		(delim (progn (goto-char point-if0)
+			      (forward-line 1)
+			      (and (looking-at "\\(.\\)\\1\\1") ;Triple chars
+				   (prog1
+				       (YaTeX-match-string 0)
+				     (forward-line 1)))))
+		(text-start (point))
+		(text-end (if (and delim
+				   (re-search-forward
+				    (concat "^" (regexp-quote delim))
+				    point-fi t))
+			      (match-beginning 0)
+			    point-fi))
+		(text (YaTeX-buffer-substring text-start text-end))
+		;;
+		;; Now it's time to start filter process
+		;;
+		(procbuf (YaTeX-system newcmdline "Filter" 'force))
+		(proc (get-buffer-process procbuf))
+		;(procbuf (get-buffer-create " *Filter*"))
+		(ovl (progn
+		       (remove-overlays text-start text-end)
+		       (make-overlay text-start text-end)))
+		(ovlmodhook	;hook function to reset conv-success flag
+		 'YaTeX-filter-filter-unset-conversion-flag))
+	    (if proc
+		(progn
+		  (overlay-put ovl 'filter-input outfile)
+		  (overlay-put ovl 'converted nil)
+		  (overlay-put ovl 'modification-hooks (list ovlmodhook))
+		  (set-process-coding-system proc 'undecided 'utf-8)
+		  (set-process-sentinel proc 'YaTeX-filter-filter-sentinel)
+		  (YaTeX-showup-buffer procbuf)
+		  (set-buffer procbuf)
+		  (setq buffer-read-only nil)
+		  (erase-buffer)
+		  (insert (format "Starting process `%s'...\n" newcmdline))
+		  (set-marker (process-mark proc) (point-max))
+		  (process-send-string proc text)
+		  (process-send-string proc "\n")
+		  (process-send-eof proc) ;Notify stream chunk end
+		  (process-send-eof proc) ;Notify real EOF
+		  (put 'YaTeX-filter-filter-sentinel 'outfile outfile)
+		  (put 'YaTeX-filter-filter-sentinel 'overlay ovl))))))))
+
+(defun YaTeX-insert-filter-special (filter list &optional region-p)
+  (let ((f (YaTeX-read-string-or-skip "Output file: ")))
+    (if region-p
+	(if (< (point) (mark)) (exchange-point-and-mark)))
+    (save-excursion (insert "===\n\\fi\n%#END\n"))
+    (and region-p (exchange-point-and-mark))
+    (insert (format "%%#BEGIN FILTER{%s}{%s}\n\\if0\n===\n"
+		    f (or (car list) "")))
+    (save-excursion (insert (or (car (cdr list)) "\n") "\n"))))
+
+(provide 'yatexflt)
+
+; Local variables:
+; fill-prefix: ";;;	"
+; paragraph-start: "^$\\|\\|;;;$"
+; paragraph-separate: "^$\\|\\|;;;$"
+; End: