ox: Use tabulated list mode for asynchronous stack

* lisp/ox.el (org-export-stack): Rewrite.
(org-export-stack-refresh): Refactor.
(org-export-stack-remove, org-export-stack-view): Apply renaming.
(org-export-stack-mode-map): Use tabulated list map as a basis.
(org-export-stack--generate, org-export-stack--num-predicate): New
function.

lisp/ox.el

@@ -77,6 +77,7 @@
 ;;; Code:
 
 (eval-when-compile (require 'cl))
+(require 'tabulated-list)
 (require 'org-element)
 (require 'org-macro)
 (require 'ob-exp)
@@ -5142,74 +5143,27 @@ removed beforehand.  Return the new stack."
   "Menu for asynchronous export results and running processes."
   (interactive)
   (let ((buffer (get-buffer-create "*Org Export Stack*")))
-    (set-buffer buffer)
-    (when (zerop (buffer-size)) (org-export-stack-mode))
-    (org-export-stack-refresh)
+    (with-current-buffer buffer
+      (org-export-stack-mode)
+      (tabulated-list-print t))
     (pop-to-buffer buffer))
   (message "Type \"q\" to quit, \"?\" for help"))
 
-(defun org-export--stack-source-at-point ()
-  "Return source from export results at point in stack."
-  (let ((source (car (nth (1- (org-current-line)) org-export-stack-contents))))
-    (if (not source) (error "Source unavailable, please refresh buffer")
-      (let ((source-name (if (stringp source) source (buffer-name source))))
-	(if (save-excursion
-	      (beginning-of-line)
-	      (looking-at (concat ".* +" (regexp-quote source-name) "$")))
-	    source
-	  ;; SOURCE is not consistent with current line.  The stack
-	  ;; view is outdated.
-	  (error "Source unavailable; type `g' to update buffer"))))))
-
 (defun org-export-stack-clear ()
   "Remove all entries from export stack."
   (interactive)
   (setq org-export-stack-contents nil))
 
-(defun org-export-stack-refresh (&rest dummy)
-  "Refresh the asynchronous export stack.
-DUMMY is ignored.  Unavailable sources are removed from the list.
-Return the new stack."
-  (let ((inhibit-read-only t))
-    (org-preserve-lc
-     (erase-buffer)
-     (insert (concat
-	      (let ((counter 0))
-		(mapconcat
-		 (lambda (entry)
-		   (let ((proc-p (processp (nth 2 entry))))
-		     (concat
-		      ;; Back-end.
-		      (format " %-12s  " (or (nth 1 entry) ""))
-		      ;; Age.
-		      (let ((data (nth 2 entry)))
-			(if proc-p (format " %6s  " (process-status data))
-			  ;; Compute age of the results.
-			  (org-format-seconds
-			   "%4h:%.2m  "
-			   (float-time (time-since data)))))
-		      ;; Source.
-		      (format " %s"
-			      (let ((source (car entry)))
-				(if (stringp source) source
-				  (buffer-name source)))))))
-		 ;; Clear stack from exited processes, dead buffers or
-		 ;; non-existent files.
-		 (setq org-export-stack-contents
-		       (org-remove-if-not
-			(lambda (el)
-			  (if (processp (nth 2 el))
-			      (buffer-live-p (process-buffer (nth 2 el)))
-			    (let ((source (car el)))
-			      (if (bufferp source) (buffer-live-p source)
-				(file-exists-p source)))))
-			org-export-stack-contents)) "\n")))))))
+(defun org-export-stack-refresh ()
+  "Refresh the asynchronous export stack."
+  (interactive)
+  (tabulated-list-print t))
 
 (defun org-export-stack-remove (&optional source)
   "Remove export results at point from stack.
 If optional argument SOURCE is non-nil, remove it instead."
   (interactive)
-  (let ((source (or source (org-export--stack-source-at-point))))
+  (let ((source (or source (org-export-stack--source-at-point))))
     (setq org-export-stack-contents
 	  (org-remove-if (lambda (el) (equal (car el) source))
 			 org-export-stack-contents))))
@@ -5219,7 +5173,7 @@ If optional argument SOURCE is non-nil, remove it instead."
 With an optional prefix argument IN-EMACS, force viewing files
 within Emacs."
   (interactive "P")
-  (let ((source (org-export--stack-source-at-point)))
+  (let ((source (org-export-stack--source-at-point)))
     (cond ((processp source)
 	   (org-switch-to-buffer-other-window (process-buffer source)))
 	  ((bufferp source) (org-switch-to-buffer-other-window source))
@@ -5227,11 +5181,10 @@ within Emacs."
 
 (defconst org-export-stack-mode-map
   (let ((km (make-sparse-keymap)))
+    (set-keymap-parent km tabulated-list-mode-map)
     (define-key km " " 'next-line)
-    (define-key km "n" 'next-line)
     (define-key km "\C-n" 'next-line)
     (define-key km [down] 'next-line)
-    (define-key km "p" 'previous-line)
     (define-key km "\C-p" 'previous-line)
     (define-key km "\C-?" 'previous-line)
     (define-key km [up] 'previous-line)
@@ -5239,10 +5192,11 @@ within Emacs."
     (define-key km "v" 'org-export-stack-view)
     (define-key km (kbd "RET") 'org-export-stack-view)
     (define-key km "d" 'org-export-stack-remove)
+    (define-key km "r" 'org-export-stack-refresh)
     km)
   "Keymap for Org Export Stack.")
 
-(define-derived-mode org-export-stack-mode special-mode "Org-Stack"
+(define-derived-mode org-export-stack-mode tabulated-list-mode "Org-Stack"
   "Mode for displaying asynchronous export stack.
 
 Type \\[org-export-stack] to visualize the asynchronous export
@@ -5256,17 +5210,67 @@ Removing entries in an Org Export Stack buffer doesn't affect
 files or buffers, only the display.
 
 \\{org-export-stack-mode-map}"
-  (abbrev-mode 0)
-  (auto-fill-mode 0)
-  (setq buffer-read-only t
-	buffer-undo-list t
-	truncate-lines t
-	header-line-format
-	'(:eval
-	  (format "  %-12s | %6s | %s" "Back-End" "Age" "Source")))
+  (setq tabulated-list-format
+	(vector (list "#" 4 'org-export-stack--num-predicate)
+		(list "Back-End" 12 t)
+		(list "Age" 6 nil)
+		(list "Source" 0 nil)))
+  (setq tabulated-list-sort-key (cons "#" nil))
+  (setq tabulated-list-entries 'org-export-stack--generate)
+  (add-hook 'tabulated-list-revert-hook 'org-export-stack--generate nil t)
   (add-hook 'post-command-hook 'org-export-stack-refresh nil t)
-  (set (make-local-variable 'revert-buffer-function)
-       'org-export-stack-refresh))
+  (tabulated-list-init-header))
+
+(defun org-export-stack--generate ()
+  "Generate the asynchronous export stack for display.
+Unavailable sources are removed from the list.  Return a list
+appropriate for `tabulated-list-print'."
+  ;; Clear stack from exited processes, dead buffers or non-existent
+  ;; files.
+  (setq org-export-stack-contents
+	(org-remove-if-not
+	 (lambda (el)
+	   (if (processp (nth 2 el))
+	       (buffer-live-p (process-buffer (nth 2 el)))
+	     (let ((source (car el)))
+	       (if (bufferp source) (buffer-live-p source)
+		 (file-exists-p source)))))
+	 org-export-stack-contents))
+  ;; Update `tabulated-list-entries'.
+  (let ((counter 0))
+    (mapcar (lambda (entry)
+	      (let ((source (car entry)))
+		(list source
+		      (vector
+		       ;; Counter.
+		       (number-to-string (incf counter))
+		       ;; Back-End.
+		       (if (nth 1 entry) (symbol-name (nth 1 entry)) "")
+		       ;; Age.
+		       (let ((info (nth 2 entry)))
+			 (if (processp info) (symbol-name (process-status info))
+			   (org-format-seconds "%h:%.2m"
+					       (float-time (time-since info)))))
+		       ;; Source.
+		       (if (stringp source) source (buffer-name source))))))
+	    org-export-stack-contents)))
+
+(defun org-export-stack--num-predicate (A B)
+  (< (string-to-number (aref (nth 1 A) 0))
+     (string-to-number (aref (nth 1 B) 0))))
+
+(defun org-export-stack--source-at-point ()
+  "Return source from export results at point in stack."
+  (let ((source (car (nth (1- (org-current-line)) org-export-stack-contents))))
+    (if (not source) (error "Source unavailable, please refresh buffer")
+      (let ((source-name (if (stringp source) source (buffer-name source))))
+	(if (save-excursion
+	      (beginning-of-line)
+	      (looking-at (concat ".* +" (regexp-quote source-name) "$")))
+	    source
+	  ;; SOURCE is not consistent with current line.  The stack
+	  ;; view is outdated.
+	  (error "Source unavailable; type `r' to refresh buffer"))))))