lisp/register.el

   1 ;;; register.el --- register commands for Emacs
   2
   3 ;; Copyright (C) 1985, 1993-1994, 2001-2012 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: FSF
   6 ;; Keywords: internal
   7 ;; Package: emacs
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; This package of functions emulates and somewhat extends the venerable
  27 ;; TECO's `register' feature, which permits you to save various useful
  28 ;; pieces of buffer state to named variables.  The entry points are
  29 ;; documented in the Emacs user's manual.
  30
  31 (eval-when-compile (require 'cl))
  32
  33 (declare-function semantic-insert-foreign-tag "semantic/tag" (foreign-tag))
  34 (declare-function semantic-tag-buffer "semantic/tag" (tag))
  35 (declare-function semantic-tag-start "semantic/tag" (tag))
  36
  37 ;;; Global key bindings
  38
  39 (define-key ctl-x-r-map "\C-@" 'point-to-register)
  40 (define-key ctl-x-r-map [?\C-\ ] 'point-to-register)
  41 (define-key ctl-x-r-map " " 'point-to-register)
  42 (define-key ctl-x-r-map "j" 'jump-to-register)
  43 (define-key ctl-x-r-map "s" 'copy-to-register)
  44 (define-key ctl-x-r-map "x" 'copy-to-register)
  45 (define-key ctl-x-r-map "i" 'insert-register)
  46 (define-key ctl-x-r-map "g" 'insert-register)
  47 (define-key ctl-x-r-map "r" 'copy-rectangle-to-register)
  48 (define-key ctl-x-r-map "n" 'number-to-register)
  49 (define-key ctl-x-r-map "+" 'increment-register)
  50 (define-key ctl-x-r-map "w" 'window-configuration-to-register)
  51 (define-key ctl-x-r-map "f" 'frame-configuration-to-register)
  52
  53 ;;; Code:
  54
  55 (defstruct
  56   (registerv (:constructor nil)
  57              (:constructor registerv--make (&optional data print-func
  58                                                       jump-func insert-func))
  59              (:copier nil)
  60              (:type vector)
  61              :named)
  62   (data        nil :read-only t)
  63   (print-func  nil :read-only t)
  64   (jump-func   nil :read-only t)
  65   (insert-func nil :read-only t))
  66
  67 (defun* registerv-make (data &key print-func jump-func insert-func)
  68   "Create a register value object.
  69
  70 DATA can be any value.
  71 PRINT-FUNC if provided controls how `list-registers' and
  72 `view-register' print the register.  It should be a function
  73 receiving one argument DATA and print text that completes
  74 this sentence:
  75   Register X contains [TEXT PRINTED BY PRINT-FUNC]
  76 JUMP-FUNC if provided, controls how `jump-to-register' jumps to the register.
  77 INSERT-FUNC if provided, controls how `insert-register' insert the register.
  78 They both receive DATA as argument."
  79   (registerv--make data print-func jump-func insert-func))
  80
  81 (defvar register-alist nil
  82   "Alist of elements (NAME . CONTENTS), one for each Emacs register.
  83 NAME is a character (a number).  CONTENTS is a string, number, marker, list
  84 or a struct returned by `registerv-make'.
  85 A list of strings represents a rectangle.
  86 A list of the form (file . FILE-NAME) represents the file named FILE-NAME.
  87 A list of the form (file-query FILE-NAME POSITION) represents
  88  position POSITION in the file named FILE-NAME, but query before
  89  visiting it.
  90 A list of the form (WINDOW-CONFIGURATION POSITION)
  91  represents a saved window configuration plus a saved value of point.
  92 A list of the form (FRAME-CONFIGURATION POSITION)
  93  represents a saved frame configuration plus a saved value of point.")
  94
  95 (defun get-register (register)
  96   "Return contents of Emacs register named REGISTER, or nil if none."
  97   (cdr (assq register register-alist)))
  98
  99 (defun set-register (register value)
 100   "Set contents of Emacs register named REGISTER to VALUE.  Returns VALUE.
 101 See the documentation of the variable `register-alist' for possible VALUEs."
 102   (let ((aelt (assq register register-alist)))
 103     (if aelt
 104         (setcdr aelt value)
 105       (push (cons register value) register-alist))
 106     value))
 107
 108 (defun point-to-register (register &optional arg)
 109   "Store current location of point in register REGISTER.
 110 With prefix argument, store current frame configuration.
 111 Use \\[jump-to-register] to go to that location or restore that configuration.
 112 Argument is a character, naming the register."
 113   (interactive "cPoint to register: \nP")
 114   ;; Turn the marker into a file-ref if the buffer is killed.
 115   (add-hook 'kill-buffer-hook 'register-swap-out nil t)
 116   (set-register register
 117                 (if arg (list (current-frame-configuration) (point-marker))
 118                   (point-marker))))
 119
 120 (defun window-configuration-to-register (register &optional _arg)
 121   "Store the window configuration of the selected frame in register REGISTER.
 122 Use \\[jump-to-register] to restore the configuration.
 123 Argument is a character, naming the register."
 124   (interactive "cWindow configuration to register: \nP")
 125   ;; current-window-configuration does not include the value
 126   ;; of point in the current buffer, so record that separately.
 127   (set-register register (list (current-window-configuration) (point-marker))))
 128
 129 (defun frame-configuration-to-register (register &optional _arg)
 130   "Store the window configuration of all frames in register REGISTER.
 131 Use \\[jump-to-register] to restore the configuration.
 132 Argument is a character, naming the register."
 133   (interactive "cFrame configuration to register: \nP")
 134   ;; current-frame-configuration does not include the value
 135   ;; of point in the current buffer, so record that separately.
 136   (set-register register (list (current-frame-configuration) (point-marker))))
 137
 138 (defalias 'register-to-point 'jump-to-register)
 139 (defun jump-to-register (register &optional delete)
 140   "Move point to location stored in a register.
 141 If the register contains a file name, find that file.
 142 \(To put a file name in a register, you must use `set-register'.)
 143 If the register contains a window configuration (one frame) or a frame
 144 configuration (all frames), restore that frame or all frames accordingly.
 145 First argument is a character, naming the register.
 146 Optional second arg non-nil (interactively, prefix argument) says to
 147 delete any existing frames that the frame configuration doesn't mention.
 148 \(Otherwise, these frames are iconified.)"
 149   (interactive "cJump to register: \nP")
 150   (let ((val (get-register register)))
 151     (cond
 152      ((registerv-p val)
 153       (assert (registerv-jump-func val) nil
 154               "Don't know how to jump to register %s"
 155               (single-key-description register))
 156       (funcall (registerv-jump-func val) (registerv-data val)))
 157      ((and (consp val) (frame-configuration-p (car val)))
 158       (set-frame-configuration (car val) (not delete))
 159       (goto-char (cadr val)))
 160      ((and (consp val) (window-configuration-p (car val)))
 161       (set-window-configuration (car val))
 162       (goto-char (cadr val)))
 163      ((markerp val)
 164       (or (marker-buffer val)
 165           (error "That register's buffer no longer exists"))
 166       (switch-to-buffer (marker-buffer val))
 167       (goto-char val))
 168      ((and (consp val) (eq (car val) 'file))
 169       (find-file (cdr val)))
 170      ((and (consp val) (eq (car val) 'file-query))
 171       (or (find-buffer-visiting (nth 1 val))
 172           (y-or-n-p (format "Visit file %s again? " (nth 1 val)))
 173           (error "Register access aborted"))
 174       (find-file (nth 1 val))
 175       (goto-char (nth 2 val)))
 176      ((and (fboundp 'semantic-foreign-tag-p)
 177            semantic-mode
 178            (semantic-foreign-tag-p val))
 179       (switch-to-buffer (semantic-tag-buffer val))
 180       (goto-char (semantic-tag-start val)))
 181      (t
 182       (error "Register doesn't contain a buffer position or configuration")))))
 183
 184 (defun register-swap-out ()
 185   "Turn markers into file-query references when a buffer is killed."
 186   (and buffer-file-name
 187        (dolist (elem register-alist)
 188          (and (markerp (cdr elem))
 189               (eq (marker-buffer (cdr elem)) (current-buffer))
 190               (setcdr elem
 191                       (list 'file-query
 192                             buffer-file-name
 193                             (marker-position (cdr elem))))))))
 194
 195 (defun number-to-register (number register)
 196   "Store a number in a register.
 197 Two args, NUMBER and REGISTER (a character, naming the register).
 198 If NUMBER is nil, a decimal number is read from the buffer starting
 199 at point, and point moves to the end of that number.
 200 Interactively, NUMBER is the prefix arg (none means nil)."
 201   (interactive "P\ncNumber to register: ")
 202   (set-register register
 203                 (if number
 204                     (prefix-numeric-value number)
 205                   (if (looking-at "\\s-*-?[0-9]+")
 206                       (progn
 207                         (goto-char (match-end 0))
 208                         (string-to-number (match-string 0)))
 209                     0))))
 210
 211 (defun increment-register (number register)
 212   "Add NUMBER to the contents of register REGISTER.
 213 Interactively, NUMBER is the prefix arg."
 214   (interactive "p\ncIncrement register: ")
 215   (or (numberp (get-register register))
 216       (error "Register does not contain a number"))
 217   (set-register register (+ number (get-register register))))
 218
 219 (defun view-register (register)
 220   "Display what is contained in register named REGISTER.
 221 The Lisp value REGISTER is a character."
 222   (interactive "cView register: ")
 223   (let ((val (get-register register)))
 224     (if (null val)
 225         (message "Register %s is empty" (single-key-description register))
 226       (with-output-to-temp-buffer "*Output*"
 227         (describe-register-1 register t)))))
 228
 229 (defun list-registers ()
 230   "Display a list of nonempty registers saying briefly what they contain."
 231   (interactive)
 232   (let ((list (copy-sequence register-alist)))
 233     (setq list (sort list (lambda (a b) (< (car a) (car b)))))
 234     (with-output-to-temp-buffer "*Output*"
 235       (dolist (elt list)
 236         (when (get-register (car elt))
 237           (describe-register-1 (car elt))
 238           (terpri))))))
 239
 240 (defun describe-register-1 (register &optional verbose)
 241   (princ "Register ")
 242   (princ (single-key-description register))
 243   (princ " contains ")
 244   (let ((val (get-register register)))
 245     (cond
 246      ((registerv-p val)
 247       (if (registerv-print-func val)
 248           (funcall (registerv-print-func val) (registerv-data val))
 249         (princ "[UNPRINTABLE CONTENTS].")))
 250
 251      ((numberp val)
 252       (princ val))
 253
 254      ((markerp val)
 255       (let ((buf (marker-buffer val)))
 256         (if (null buf)
 257             (princ "a marker in no buffer")
 258           (princ "a buffer position:\n    buffer ")
 259           (princ (buffer-name buf))
 260           (princ ", position ")
 261           (princ (marker-position val)))))
 262
 263      ((and (consp val) (window-configuration-p (car val)))
 264       (princ "a window configuration."))
 265
 266      ((and (consp val) (frame-configuration-p (car val)))
 267       (princ "a frame configuration."))
 268
 269      ((and (consp val) (eq (car val) 'file))
 270       (princ "the file ")
 271       (prin1 (cdr val))
 272       (princ "."))
 273
 274      ((and (consp val) (eq (car val) 'file-query))
 275       (princ "a file-query reference:\n    file ")
 276       (prin1 (car (cdr val)))
 277       (princ ",\n    position ")
 278       (princ (car (cdr (cdr val))))
 279       (princ "."))
 280
 281      ((consp val)
 282       (if verbose
 283           (progn
 284             (princ "the rectangle:\n")
 285             (while val
 286               (princ "    ")
 287               (princ (car val))
 288               (terpri)
 289               (setq val (cdr val))))
 290         (princ "a rectangle starting with ")
 291         (princ (car val))))
 292
 293      ((stringp val)
 294       (if (eq yank-excluded-properties t)
 295           (set-text-properties 0 (length val) nil val)
 296         (remove-list-of-text-properties 0 (length val)
 297                                         yank-excluded-properties val))
 298       (if verbose
 299           (progn
 300             (princ "the text:\n")
 301             (princ val))
 302         (cond
 303          ;; Extract first N characters starting with first non-whitespace.
 304          ((string-match (format "[^ \t\n].\\{,%d\\}"
 305                                 ;; Deduct 6 for the spaces inserted below.
 306                                 (min 20 (max 0 (- (window-width) 6))))
 307                         val)
 308           (princ "text starting with\n    ")
 309           (princ (match-string 0 val)))
 310          ((string-match "^[ \t\n]+$" val)
 311           (princ "whitespace"))
 312          (t
 313           (princ "the empty string")))))
 314      (t
 315       (princ "Garbage:\n")
 316       (if verbose (prin1 val))))))
 317
 318 (defun insert-register (register &optional arg)
 319   "Insert contents of register REGISTER.  (REGISTER is a character.)
 320 Normally puts point before and mark after the inserted text.
 321 If optional second arg is non-nil, puts mark before and point after.
 322 Interactively, second arg is non-nil if prefix arg is supplied."
 323   (interactive "*cInsert register: \nP")
 324   (push-mark)
 325   (let ((val (get-register register)))
 326     (cond
 327      ((registerv-p val)
 328       (assert (registerv-insert-func val) nil
 329               "Don't know how to insert register %s"
 330               (single-key-description register))
 331       (funcall (registerv-insert-func val) (registerv-data val)))
 332      ((consp val)
 333       (insert-rectangle val))
 334      ((stringp val)
 335       (insert-for-yank val))
 336      ((numberp val)
 337       (princ val (current-buffer)))
 338      ((and (markerp val) (marker-position val))
 339       (princ (marker-position val) (current-buffer)))
 340      ((and (fboundp 'semantic-foreign-tag-p)
 341            semantic-mode
 342            (semantic-foreign-tag-p val))
 343       (semantic-insert-foreign-tag val))
 344      (t
 345       (error "Register does not contain text"))))
 346   (if (not arg) (exchange-point-and-mark)))
 347
 348 (defun copy-to-register (register start end &optional delete-flag)
 349   "Copy region into register REGISTER.
 350 With prefix arg, delete as well.
 351 Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
 352 START and END are buffer positions indicating what to copy."
 353   (interactive "cCopy to register: \nr\nP")
 354   (set-register register (filter-buffer-substring start end))
 355   (if delete-flag (delete-region start end)))
 356
 357 (defun append-to-register (register start end &optional delete-flag)
 358   "Append region to text in register REGISTER.
 359 With prefix arg, delete as well.
 360 Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
 361 START and END are buffer positions indicating what to append."
 362   (interactive "cAppend to register: \nr\nP")
 363   (let ((reg (get-register register))
 364         (text (filter-buffer-substring start end)))
 365     (set-register
 366      register (cond ((not reg) text)
 367                     ((stringp reg) (concat reg text))
 368                     (t (error "Register does not contain text")))))
 369   (if delete-flag (delete-region start end)))
 370
 371 (defun prepend-to-register (register start end &optional delete-flag)
 372   "Prepend region to text in register REGISTER.
 373 With prefix arg, delete as well.
 374 Called from program, takes four args: REGISTER, START, END and DELETE-FLAG.
 375 START and END are buffer positions indicating what to prepend."
 376   (interactive "cPrepend to register: \nr\nP")
 377   (let ((reg (get-register register))
 378         (text (filter-buffer-substring start end)))
 379     (set-register
 380      register (cond ((not reg) text)
 381                     ((stringp reg) (concat text reg))
 382                     (t (error "Register does not contain text")))))
 383   (if delete-flag (delete-region start end)))
 384
 385 (defun copy-rectangle-to-register (register start end &optional delete-flag)
 386   "Copy rectangular region into register REGISTER.
 387 With prefix arg, delete as well.
 388 To insert this register in the buffer, use \\[insert-register].
 389
 390 Called from a program, takes four args: REGISTER, START, END and DELETE-FLAG.
 391 START and END are buffer positions giving two corners of rectangle."
 392   (interactive "cCopy rectangle to register: \nr\nP")
 393   (set-register register
 394                 (if delete-flag
 395                     (delete-extract-rectangle start end)
 396                   (extract-rectangle start end))))
 397
 398 (provide 'register)
 399 ;;; register.el ends here