[Emacs-diffs] Changes to emacs/lisp/cus-edit.el

[Richard M. Stallman]

Index: emacs/lisp/cus-edit.el
diff -c emacs/lisp/cus-edit.el:1.161 emacs/lisp/cus-edit.el:1.162
*** emacs/lisp/cus-edit.el:1.161        Sun Sep  8 20:26:14 2002
--- emacs/lisp/cus-edit.el      Mon Sep 16 11:20:20 2002
***************
*** 2303,2308 ****
--- 2303,2311 ----
         (and (get (widget-value widget) 'standard-value)
            (memq (widget-get widget :custom-state)
                  '(modified set changed saved rogue)))))
+     ("Use Backup Value" custom-variable-reset-backup
+      (lambda (widget)
+        (get (widget-value widget) 'backup-value)))
      ("---" ignore ignore)
      ("Add Comment" custom-comment-show custom-comment-invisible-p)
      ("---" ignore ignore)
***************
*** 2369,2374 ****
--- 2372,2378 ----
             (setq comment nil)
             ;; Make the comment invisible by hand if it's empty
             (custom-comment-hide comment-widget))
+          (custom-variable-backup-value widget)
           (funcall set symbol (eval (setq val (widget-value child))))
           (put symbol 'customized-value (list val))
           (put symbol 'variable-comment comment)
***************
*** 2378,2383 ****
--- 2382,2388 ----
             (setq comment nil)
             ;; Make the comment invisible by hand if it's empty
             (custom-comment-hide comment-widget))
+          (custom-variable-backup-value widget)
           (funcall set symbol (setq val (widget-value child)))
           (put symbol 'customized-value (list (custom-quote val)))
           (put symbol 'variable-comment comment)
***************
*** 2426,2438 ****
      (custom-redraw-magic widget)))
  
  (defun custom-variable-reset-saved (widget)
!   "Restore the saved value for the variable being edited by WIDGET."
    (let* ((symbol (widget-value widget))
         (set (or (get symbol 'custom-set) 'set-default))
         (value (get symbol 'saved-value))
         (comment (get symbol 'saved-variable-comment)))
      (cond ((or value comment)
           (put symbol 'variable-comment comment)
           (condition-case nil
               (funcall set symbol (eval (car value)))
             (error nil)))
--- 2431,2446 ----
      (custom-redraw-magic widget)))
  
  (defun custom-variable-reset-saved (widget)
!   "Restore the saved value for the variable being edited by WIDGET.
! The value that was current before this operation
! becomes the backup value, so you can get it again."
    (let* ((symbol (widget-value widget))
         (set (or (get symbol 'custom-set) 'set-default))
         (value (get symbol 'saved-value))
         (comment (get symbol 'saved-variable-comment)))
      (cond ((or value comment)
           (put symbol 'variable-comment comment)
+          (custom-variable-backup-value widget)
           (condition-case nil
               (funcall set symbol (eval (car value)))
             (error nil)))
***************
*** 2447,2457 ****
  (defun custom-variable-reset-standard (widget)
    "Restore the standard setting for the variable being edited by WIDGET.
  This operation eliminates any saved setting for the variable,
! restoring it to the state of a variable that has never been customized."
    (let* ((symbol (widget-value widget))
         (set (or (get symbol 'custom-set) 'set-default)))
      (if (get symbol 'standard-value)
!       (funcall set symbol (eval (car (get symbol 'standard-value))))
        (error "No standard setting known for %S" symbol))
      (put symbol 'variable-comment nil)
      (put symbol 'customized-value nil)
--- 2455,2469 ----
  (defun custom-variable-reset-standard (widget)
    "Restore the standard setting for the variable being edited by WIDGET.
  This operation eliminates any saved setting for the variable,
! restoring it to the state of a variable that has never been customized.
! The value that was current before this operation
! becomes the backup value, so you can get it again."
    (let* ((symbol (widget-value widget))
         (set (or (get symbol 'custom-set) 'set-default)))
      (if (get symbol 'standard-value)
!       (progn
!         (custom-variable-backup-value widget)
!         (funcall set symbol (eval (car (get symbol 'standard-value)))))
        (error "No standard setting known for %S" symbol))
      (put symbol 'variable-comment nil)
      (put symbol 'customized-value nil)
***************
*** 2461,2466 ****
--- 2473,2514 ----
        (put symbol 'saved-variable-comment nil)
        (custom-save-all))
      (widget-put widget :custom-state 'unknown)
+     ;; This call will possibly make the comment invisible
+     (custom-redraw widget)))
+ 
+ (defun custom-variable-backup-value (widget)
+   "Back up the current value for WIDGET's variable.
+ The backup value is kept in the car of the `backup-value' property."
+   (let* ((symbol (widget-value widget))
+        (get (or (get symbol 'custom-get) 'default-value))
+        (type (custom-variable-type symbol))
+        (conv (widget-convert type))
+        (value (if (default-boundp symbol)
+                   (funcall get symbol)
+                 (widget-get conv :value))))
+     (put symbol 'backup-value (list value))))
+ 
+ (defun custom-variable-reset-backup (widget)
+   "Restore the backup value for the variable being edited by WIDGET.
+ The value that was current before this operation
+ becomes the backup value, so you can use this operation repeatedly
+ to switch between two values."
+   (let* ((symbol (widget-value widget))
+        (set (or (get symbol 'custom-set) 'set-default))
+        (value (get symbol 'backup-value))
+        (comment-widget (widget-get widget :comment-widget))
+        (comment (widget-value comment-widget)))
+     (if value
+       (progn
+         (custom-variable-backup-value widget)
+         (condition-case nil
+             (funcall set symbol (car value))
+            (error nil)))
+       (error "No backup value for %s" symbol))
+     (put symbol 'customized-value (list (car value)))
+     (put symbol 'variable-comment comment)
+     (put symbol 'customized-variable-comment comment)
+     (custom-variable-state-set widget)
      ;; This call will possibly make the comment invisible
      (custom-redraw widget)))