(displayed-month, displayed-year): Define for compiler.
[emacs.git] / lisp / calc / calc-undo.el
bloba90a3e166805424cafb606368cfbb18aac3ac590
1 ;;; calc-undo.el --- undo functions for Calc
3 ;; Copyright (C) 1990, 1991, 1992, 1993, 2001 Free Software Foundation, Inc.
5 ;; Author: David Gillespie <daveg@synaptics.com>
6 ;; Maintainers: D. Goel <deego@gnufans.org>
7 ;; Colin Walters <walters@debian.org>
9 ;; This file is part of GNU Emacs.
11 ;; GNU Emacs is distributed in the hope that it will be useful,
12 ;; but WITHOUT ANY WARRANTY. No author or distributor
13 ;; accepts responsibility to anyone for the consequences of using it
14 ;; or for whether it serves any particular purpose or works at all,
15 ;; unless he says so in writing. Refer to the GNU Emacs General Public
16 ;; License for full details.
18 ;; Everyone is granted permission to copy, modify and redistribute
19 ;; GNU Emacs, but only under the conditions described in the
20 ;; GNU Emacs General Public License. A copy of this license is
21 ;; supposed to have been given to you along with GNU Emacs so you
22 ;; can know your rights and responsibilities. It should be in a
23 ;; file named COPYING. Among other things, the copyright notice
24 ;; and this notice must be preserved on all copies.
26 ;;; Commentary:
28 ;;; Code:
30 ;; This file is autoloaded from calc-ext.el.
31 (require 'calc-ext)
33 (require 'calc-macs)
35 (defun calc-Need-calc-undo () nil)
38 ;;; Undo.
40 (defun calc-undo (n)
41 (interactive "p")
42 (when calc-executing-macro
43 (error "Use C-x e, not X, to run a keyboard macro that uses Undo"))
44 (if (<= n 0)
45 (if (< n 0)
46 (calc-redo (- n))
47 (calc-last-args 1))
48 (calc-wrapper
49 (when (null (nthcdr (1- n) calc-undo-list))
50 (error "No further undo information available"))
51 (setq calc-undo-list
52 (prog1
53 (nthcdr n calc-undo-list)
54 (let ((saved-stack-top calc-stack-top))
55 (let ((calc-stack-top 0))
56 (calc-handle-undos calc-undo-list n))
57 (setq calc-stack-top saved-stack-top))))
58 (message "Undo!"))))
60 (defun calc-handle-undos (cl n)
61 (when (> n 0)
62 (let ((old-redo calc-redo-list))
63 (setq calc-undo-list nil)
64 (calc-handle-undo (car cl))
65 (setq calc-redo-list (append calc-undo-list old-redo)))
66 (calc-handle-undos (cdr cl) (1- n))))
68 (defun calc-handle-undo (list)
69 (when list
70 (let ((action (car list)))
71 (cond
72 ((eq (car action) 'push)
73 (calc-pop-stack 1 (nth 1 action) t))
74 ((eq (car action) 'pop)
75 (calc-push-list (nth 2 action) (nth 1 action)))
76 ((eq (car action) 'set)
77 (calc-record-undo (list 'set (nth 1 action)
78 (symbol-value (nth 1 action))))
79 (set (nth 1 action) (nth 2 action)))
80 ((eq (car action) 'store)
81 (let ((v (intern (nth 1 action))))
82 (calc-record-undo (list 'store (nth 1 action)
83 (and (boundp v) (symbol-value v))))
84 (if (y-or-n-p (format "Un-store variable %s? " (nth 1 action)))
85 (progn
86 (if (nth 2 action)
87 (set v (nth 2 action))
88 (makunbound v))
89 (calc-refresh-evaltos v)))))
90 ((eq (car action) 'eval)
91 (calc-record-undo (append (list 'eval (nth 2 action) (nth 1 action))
92 (cdr (cdr (cdr action)))))
93 (apply (nth 1 action) (cdr (cdr (cdr action))))))
94 (calc-handle-undo (cdr list)))))
96 (defun calc-redo (n)
97 (interactive "p")
98 (when calc-executing-macro
99 (error "Use C-x e, not X, to run a keyboard macro that uses Redo"))
100 (if (<= n 0)
101 (calc-undo (- n))
102 (calc-wrapper
103 (when (null (nthcdr (1- n) calc-redo-list))
104 (error "Unable to redo"))
105 (setq calc-redo-list
106 (prog1
107 (nthcdr n calc-redo-list)
108 (let ((saved-stack-top calc-stack-top))
109 (let ((calc-stack-top 0))
110 (calc-handle-redos calc-redo-list n))
111 (setq calc-stack-top saved-stack-top))))
112 (message "Redo!"))))
114 (defun calc-handle-redos (cl n)
115 (when (> n 0)
116 (let ((old-undo calc-undo-list))
117 (setq calc-undo-list nil)
118 (calc-handle-undo (car cl))
119 (setq calc-undo-list (append calc-undo-list old-undo)))
120 (calc-handle-redos (cdr cl) (1- n))))
122 (defun calc-last-args (n)
123 (interactive "p")
124 (when calc-executing-macro
125 (error "Use C-x e, not X, to run a keyboard macro that uses last-args"))
126 (calc-wrapper
127 (let ((urec (calc-find-last-x calc-undo-list n)))
128 (if urec
129 (calc-handle-last-x urec)
130 (error "Not enough undo information available")))))
132 (defun calc-handle-last-x (list)
133 (when list
134 (let ((action (car list)))
135 (if (eq (car action) 'pop)
136 (calc-pop-push-record-list 0 "larg"
137 (delq 'top-of-stack (nth 2 action))))
138 (calc-handle-last-x (cdr list)))))
140 (defun calc-find-last-x (ul n)
141 (when ul
142 (if (calc-undo-does-pushes (car ul))
143 (if (<= n 1)
144 (car ul)
145 (calc-find-last-x (cdr ul) (1- n)))
146 (calc-find-last-x (cdr ul) n))))
148 (defun calc-undo-does-pushes (list)
149 (and list
150 (or (eq (car (car list)) 'pop)
151 (calc-undo-does-pushes (cdr list)))))
153 ;;; calc-undo.el ends here