1 ;;; vcursor.el --- manipulate an alternative ("virtual") cursor.
3 ;; Copyright (C) 1994, 1996, 1998 Free Software Foundation, Inc.
5 ;; Author: Peter Stephenson <pws@ifh.de>
6 ;; Keywords: virtual cursor, display, copying
8 ;; This file is part of GNU Emacs.
10 ;; GNU Emacs is free software; you can redistribute it and/or modify
11 ;; it under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation; either version 2, or (at your option)
15 ;; GNU Emacs is distributed in the hope that it will be useful,
16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 ;; GNU General Public License for more details.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs; see the file COPYING. If not, write to the
22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 ;; Boston, MA 02111-1307, USA.
27 ;; Latest changes (1.6)
28 ;; ====================
30 ;; - works on dumb terminals with Emacs 19.29 and later
31 ;; - new keymap vcursor-map for binding to a prefix key
32 ;; - vcursor-compare-windows substantially improved
33 ;; - vcursor-execute-{key,command} much better about using the
34 ;; right keymaps and arranging for the correct windows to be used
35 ;; - vcursor-window-funcall can call functions interactively
36 ;; - vcursor-interpret-input for special effects
41 ;; Virtual cursor commands. I got this idea from the old BBC micro.
42 ;; You need Emacs 19 or 20 and a window system for the best effects.
43 ;; For character terminals, at least Emacs 19.29 is required
44 ;; (special behaviour for the overlay property
45 ;; "before-string" must be implemented). Search for "dumb terminals"
46 ;; for more information.
48 ;; This is much easier to use than the instructions are to read.
49 ;; I suggest you simply load it and play around with holding down Ctrl
50 ;; and Shift and pressing up, down, left, right, tab, return, and see
51 ;; what happens. (Find a scratch buffer before using C-S-tab: that
54 ;; Most of the functions described in this documentation are in
55 ;; parentheses so that if you have the package loaded you can type C-h
56 ;; f on top of them for help.
58 ;; Using the cursor keys with both control and shift held down moves
59 ;; around a virtual cursor, which is initially at point. When active,
60 ;; it appears with an underline through it to distinguish it from the
61 ;; normal cursor. You can then use one of the other commands to copy
62 ;; characters from the location of the virtual cursor to point. This
63 ;; is very useful, for example, when copying some previous text while
64 ;; making changes to it at the same time, since you never have to move
65 ;; the "real" cursor away from where you are inserting.
67 ;; The remaining default key bindings are based around the PC-type
68 ;; cluster found above the cursor keys on a lot of keyboards, the
69 ;; function keys which my limited knowledge of X terminals expects to
70 ;; find at the top. Some functions are duplicated in more obvious
71 ;; places for the X version.
73 ;; All the keybindings require you to hold down control and shift at
74 ;; once. I assumed this combination wouldn't be heavily bound by most
75 ;; people and that it would be easy to type with the left hand.
76 ;; Inevitably it will clash with some other packages, but I can't help
77 ;; that: an intuitive binding is a prerequisite here. See below for
78 ;; other alternatives (search for "Oemacs"). There is also a keymap
79 ;; which you can bind to a prefix key, which may give some more
80 ;; intuitive alternatives in some cases, see `The vcursor keymap' below.
82 ;; Holding down control and shift and pressing insert (vcursor-copy)
83 ;; copies one character from wherever the virtual cursor is to point;
84 ;; point and the virtual cursor advance in the separate and equal
85 ;; station to which... (etc.). M-C-S-return (vcursor-copy-line)
86 ;; copies to the end of the line instead of just one character,
87 ;; C-S-delete or C-S-remove (vcursor-copy-word) copies a word.
89 ;; A more general way of copying is to use C-S-tab, which is a toggle.
90 ;; In the "on" state, moving the virtual cursor will copy the
91 ;; moved-over text to the normal cursor position (including when going
92 ;; backwards, though each piece of text moved over is copied forwards:
93 ;; compare the behaviour of C-S-up and C-S-left).
95 ;; However, that's just a small part of the magic. If the virtual
96 ;; cursor goes off the display, it will be redisplayed in some other
97 ;; window. (See the function (vcursor-find-window) for details of how
98 ;; this window is chosen.) This gives you fingertip control over two
101 ;; C-S-return (vcursor-disable) disables the virtual cursor, removing
102 ;; it so that it starts from point whenever you move it again --- note
103 ;; that simply moving the cursor and virtual cursor on top of one
104 ;; another does not have this effect.
106 ;; If you give C-S-return a positive prefix arg, it will also delete the
107 ;; window (unless it's the current one). Whenever the virtual cursor
108 ;; goes off-screen in its own window, point in that window is moved as
109 ;; well to restore it to view. (It's easier that way, that's why.
110 ;; However, point doesn't move unless the view in the window does, so
111 ;; it's not tied to the virtual cursor location.)
113 ;; You can also use C-S-return with a negative prefix argument which
114 ;; forces the vcursor to appear at point. This is particularly useful if
115 ;; you actually want to edit in another window but would like to
116 ;; remember the current cursor location for examining or copying from
117 ;; that buffer. (I just hit C-S-right C-S-left, but I'm a hopeless
120 ;; There is also C-S-f6 (vcursor-other-window) which behaves like
121 ;; C-x o on the virtual rather than the real cursor, except that it
122 ;; will create another window if necessary.
124 ;; The keys C-S-prior (vcursor-scroll-down) and C-S-next
125 ;; (vcursor-scroll-up) (i.e., PageUp and PageDown) will scroll the
126 ;; virtual cursor window, appropriately chosen. They will always
127 ;; create a new window or take over an old one if necessary.
128 ;; Likewise, M-C-S-left and M-C-S-right move you to the
129 ;; beginning or end of a line, C-S-home and C-S-end the
130 ;; beginning or end of a buffer (these are also on M-C-S-up and
131 ;; M-C-S-down for those of us stuck with DEC keyboards).
133 ;; C-S-f7 (vcursor-goto) will take you to the vcursor position
134 ;; (swapping windows if it seems sensible) and (unless you give it a
135 ;; prefix argument) delete the virtual cursor, so this is useful for
136 ;; you to take over editing at the virtual cursor position. It is not
137 ;; an error if the virtual cursor is not active; it simply leaves you
138 ;; at point, because that is where the virtual cursor would start
141 ;; In a similar vein, M-C-S-tab (hope your left hand's flexible;
142 ;; C-S-select on DEC keyboards) (vcursor-swap-point) will take you to
143 ;; the virtual cursor position but simultaneously put the virtual
144 ;; cursor at the old cursor position. It is also supposed to ensure
145 ;; that both are visible.
147 ;; C-S-f8 (C-S-find on DEC keyboards) (vcursor-isearch-forward)
148 ;; allows you to do an isearch in another window. It works a bit like
149 ;; vcursor-scroll-*; it moves into another window, calls isearch
150 ;; there, and sets the virtual cursor position to the point found. In
151 ;; other words, it works just like isearch but with the virtual cursor
152 ;; instead of the real one (that's why it's called a "virtual
153 ;; cursor"). While you are isearching, you are editing in the virtual
154 ;; cursor window, but when you have finished you return to where you
155 ;; started. Note that once you are in isearch all the keys are normal
156 ;; --- use C-s, not C-S-f8, to search for the next occurrence.
158 ;; If you set the variable vcursor-auto-disable, then any command
159 ;; which does not involve moving or copying from the virtual cursor
160 ;; causes the virtual cursor to be disabled. If you don't intend to
161 ;; use this, you can comment out the `add-hook' line at the bottom of
162 ;; this file. (This feature partially emulates the way the "copy" key
163 ;; on the BBC micro worked; actually, the copy cursor was homed when
164 ;; you hit return. This was in keeping with the line-by-line way of
165 ;; entering BASIC, but is less appropriate here.)
167 ;; vcursor-compare-windows is now a reliable adaption of
168 ;; compare-windows, which compares between point in the current buffer
169 ;; and the vcursor location in the other one. It is an error if
170 ;; vcursor is not set, however it will be brought up in another window
171 ;; if it is not currently visible. The prefix argument acts just like
172 ;; compare-windows, ignoring whitespace if set. (In versions before
173 ;; 1.6, this simply called compare-windows, which was much less likely
174 ;; to pick the two windows you wanted.)
176 ;; There is a way of moving the virtual cursor using ordinary
177 ;; commands: C-S-f9 (vcursor-execute-key) reads a key string,
178 ;; moves to the virtual cursor position, executes the command bound to
179 ;; the string, then returns to the original point. Thus C-S-f9 M-m
180 ;; moves the virtual cursor back to the first non-whitespace character
181 ;; on its line. As the command is called interactively all the usual
182 ;; ways of passing information to the command called, such as by a
183 ;; prefix argument, are available. This has many uses not necessarily
184 ;; related to moving the vcursor itself; it can do essentially
185 ;; everything that the \C-x 4 series of commands can do and a lot
186 ;; more. Note, however, that a new window is not used if the vcursor
187 ;; is visible in the current one: this can lead to some strange effects,
188 ;; but it is preferable to making a new window every time the vcursor
189 ;; is moved in this may.
191 ;; C-S-f10 (C-S-x) (vcursor-execute-command) behaves the same way but
192 ;; you enter the name of the command. To do anything really
193 ;; complicated, you are better off using M-C-S-tab
194 ;; (vcursor-swap-point), doing whatever it is, then calling M-C-S-tab
197 ;; If you want to add your own moving or copying functions you should
198 ;; be able to do this fairly easily with (vcursor-relative-move) and
199 ;; (vcursor-copy) together with (vcursor-get-char-count). If you want to
200 ;; do something in a different window, use (vcursor-window-funcall).
205 ;; There is an alternative set of key bindings which will be used
206 ;; automatically for a PC if Oemacs is detected. This set uses separate
207 ;; control, shift and meta keys with function keys 1 to 10. In
208 ;; particular, movement keys are concentrated on f5 to f8 with (in
209 ;; increasing order of distance travelled) C-, M- and S- as prefixes.
210 ;; See the actual bindings below (search for C-f1). This is because the
211 ;; C-S- prefix is represented by weird key sequences and the set is
212 ;; incomplete; if you don't mind that, some hints are given in comments
215 ;; You can specify the usual or the Oemacs bindings by setting the
216 ;; variable vcursor-key-bindings to `xterm' or `oemacs'. You can also set
217 ;; it to nil, in which case vcursor will not make any key bindings
218 ;; and you can define your own. The default is t, which makes vcursor
219 ;; guess (it will use xterm unless it thinks Oemacs is running). The
220 ;; oemacs set will work on an X terminal with function keys, but the
221 ;; xterm set will not work under Oemacs.
223 ;; Usage on dumb terminals
224 ;; =======================
226 ;; If Emacs has set the variable window-system to nil, vcursor will
227 ;; assume that overlays cannot be displayed in a different face,
228 ;; and will instead use an string (the variable vcursor-string, by
229 ;; default "**>") to show its position. This was first implemented
230 ;; in Emacs 19.29. Unlike the old-fashioned overlay arrow (as used
231 ;; by debuggers), this appears between existing text, which can
232 ;; make it hard to read if you're not used to it. (This seemed the
233 ;; better option here.) This means moving the vcursor up and down is
234 ;; a very efficient way of locating it!
236 ;; Everything else should function as expected, but there is no way to
237 ;; get an easy key binding for the vcursor keys on a generic terminal.
238 ;; Consequently a special keymap is defined for you to use traditional
239 ;; methods: the keymap, however, is available on any terminal type.
241 ;; The vcursor keymap
242 ;; ==================
244 ;; In addition to any other bindings, vcursor-map contains key definitions
245 ;; for handling the vcursor. You should assign this to a prefix key
246 ;; in the usual way, e.g.
247 ;; (global-set-key [f14] vcursor-map)
248 ;; and also as usual \C-h in this map will list the key definitions, which
249 ;; are designed to be easy to remember.
251 ;; A special feature is provided by (vcursor-toggle-vcursor-map), bound
252 ;; to t in that keymap. With this in effect, the main keymap
253 ;; is overridden by the vcursor map, so keys like \C-p and so on
254 ;; move the vcursor instead. Remember how to turn it off (type t),
255 ;; or you are in serious trouble! Note that the cursor keys are not
256 ;; bound by default in this keymap and will continue to move the
262 ;; Just occasionally, you may want to pretend the strings copied from
263 ;; the vcursor position are to be interpreted as if you had typed them
264 ;; from the keyboard. Normally, they will just insert themselves anyway,
265 ;; but in some modes (Info and calc for example) typing ordinary characters
266 ;; does something else. To get this effect, set
267 ;; vcursor-interpret-input to t. This is normally not a good idea as
268 ;; interpreting input is very much slower than copying text.
273 ;; - The vcursor will not move to point-max, since otherwise it would
274 ;; disappear. However, no error is flagged as point-max is a valid
275 ;; point in the buffer. Thus cursor right or down at the second
276 ;; last point in the file does not flag an error, which is inconsistent,
277 ;; and if copying is on the last character (typically newline) will
278 ;; be repeatedly copied. (I've tried making it flag an error
279 ;; instead and that's worse since often the vcursor is sent to
280 ;; point in some other window, which may be point-max.)
281 ;; - The vcursor widens when over a tab character or right at the
282 ;; end of the line. You're welcome to consider this a feature;
283 ;; it's just a part of how overlays work.
284 ;; - The vcursor obscures the real cursor. Creative use of overlays
286 ;; - The vcursor does not remember its own previous positions. If
287 ;; you cycle it back into a window it was in before, it will be at
288 ;; point in that window. Often, that is where a previous recenter
289 ;; left point, not where the vcursor was before.
290 ;; (Note, however, that the vcursor does remember where it *is*,
291 ;; even if it's off-screen. This can also lead to surprises, but I
292 ;; don't think it's a bug.)
293 ;; - vcursor-window-funcall could perhaps be smarter about restoring
294 ;; the previous window state on failure.
295 ;; - The logic in vcursor-find-window is rather complicated and
296 ;; therefore bug-prone, though in practice it seems to work OK.
298 ;; Possible enhnacements:
299 ;; It would be easy to implement vcursor-push (save vcursor position
300 ;; as mark and deactivate) and vcursor-pop (deactivate vcursor and
301 ;; move to last pushed position) functions.
305 (defgroup vcursor nil
306 "Manipulate an alternative (\"virtual\") cursor."
310 (or (memq 'vcursor
(face-list))
312 (copy-face 'modeline
'vcursor
)
313 (if (or (fboundp 'oemacs-version
)
314 (and (eq window-system
'x
) (x-display-color-p)))
316 (set-face-foreground 'vcursor
"blue")
317 (set-face-background 'vcursor
"cyan")))
318 (set-face-underline-p 'vcursor t
)))
320 (defcustom vcursor-auto-disable nil
321 "*If non-nil, disable the virtual cursor after use.
322 Any non-vcursor command will force `vcursor-disable' to be called."
326 (defcustom vcursor-key-bindings t
327 "*How to bind keys when vcursor is loaded.
328 If t (the default), guess; if xterm, use bindings suitable for an
329 X terminal; if oemacs, use bindings which work on a PC with Oemacs.
330 If nil, don't define any key bindings."
331 :type
'(choice (const t
) (const xterm
) (const oemacs
) (const nil
))
334 (defcustom vcursor-interpret-input nil
335 "*If non-nil, input from the vcursor is treated as interactive input.
336 This will cause text insertion to be much slower. Note that no special
337 interpretation of strings is done: \"\C-x\" is a string of four
338 characters. The default is simply to copy strings."
342 (defcustom vcursor-string
"**>"
343 "String used to show the vcursor position on dumb terminals."
347 (defvar vcursor-overlay nil
348 "Overlay for the virtual cursor.
349 It is nil if that is not enabled.")
351 (defvar vcursor-window nil
352 "Last window to have displayed the virtual cursor.
353 See the function `vcursor-find-window' for how this is used.")
355 (defvar vcursor-last-command nil
356 "Non-nil if last command was a vcursor command.
357 The commands `vcursor-copy', `vcursor-relative-move' and the ones for
358 scrolling set this. It is used by the `vcursor-auto-disable' code.")
359 ;; could do some memq-ing with last-command instead, but this will
360 ;; automatically handle any new commands using the primitives.
362 (defcustom vcursor-copy-flag nil
363 "*Non-nil means moving vcursor should copy characters moved over to point."
367 (defvar vcursor-temp-goal-column nil
368 "Keeps track of temporary goal columns for the virtual cursor.")
370 (defvar vcursor-use-vcursor-map nil
371 "Non-nil if the vcursor map is mapped directly onto the main keymap.
372 See vcursor-toggle-vcursor-map.")
373 (make-variable-buffer-local 'vcursor-use-vcursor-map
)
375 (defvar vcursor-map nil
"Keymap for vcursor command.")
376 (define-prefix-command 'vcursor-map
)
378 (define-key vcursor-map
"t" 'vcursor-toggle-vcursor-map
)
380 (define-key vcursor-map
"\C-p" 'vcursor-previous-line
)
381 (define-key vcursor-map
"\C-n" 'vcursor-next-line
)
382 (define-key vcursor-map
"\C-b" 'vcursor-backward-char
)
383 (define-key vcursor-map
"\C-f" 'vcursor-forward-char
)
385 (define-key vcursor-map
"\r" 'vcursor-disable
)
386 (define-key vcursor-map
" " 'vcursor-copy
)
387 (define-key vcursor-map
"\C-y" 'vcursor-copy-word
)
388 (define-key vcursor-map
"\C-i" 'vcursor-toggle-copy
)
389 (define-key vcursor-map
"<" 'vcursor-beginning-of-buffer
)
390 (define-key vcursor-map
">" 'vcursor-end-of-buffer
)
391 (define-key vcursor-map
"\M-v" 'vcursor-scroll-down
)
392 (define-key vcursor-map
"\C-v" 'vcursor-scroll-up
)
393 (define-key vcursor-map
"o" 'vcursor-other-window
)
394 (define-key vcursor-map
"g" 'vcursor-goto
)
395 (define-key vcursor-map
"x" 'vcursor-swap-point
)
396 (define-key vcursor-map
"\C-s" 'vcursor-isearch-forward
)
397 (define-key vcursor-map
"\C-r" 'vcursor-isearch-backward
)
398 (define-key vcursor-map
"\C-a" 'vcursor-beginning-of-line
)
399 (define-key vcursor-map
"\C-e" 'vcursor-end-of-line
)
400 (define-key vcursor-map
"\M-w" 'vcursor-forward-word
)
401 (define-key vcursor-map
"\M-b" 'vcursor-backward-word
)
402 (define-key vcursor-map
"\M-l" 'vcursor-copy-line
)
403 (define-key vcursor-map
"c" 'vcursor-compare-windows
)
404 (define-key vcursor-map
"k" 'vcursor-execute-key
)
405 (define-key vcursor-map
"\M-x" 'vcursor-execute-command
)
408 ((not vcursor-key-bindings
)) ;; don't set any key bindings
409 ((or (eq vcursor-key-bindings
'oemacs
)
410 (and (eq vcursor-key-bindings t
) (fboundp 'oemacs-version
)))
411 (global-set-key [C-f1
] 'vcursor-toggle-copy
)
412 (global-set-key [C-f2
] 'vcursor-copy
)
413 (global-set-key [C-f3
] 'vcursor-copy-word
)
414 (global-set-key [C-f4
] 'vcursor-copy-line
)
416 (global-set-key [S-f1
] 'vcursor-disable
)
417 (global-set-key [S-f2
] 'vcursor-other-window
)
418 (global-set-key [S-f3
] 'vcursor-goto
)
419 (global-set-key [S-f4
] 'vcursor-swap-point
)
421 (global-set-key [C-f5
] 'vcursor-backward-char
)
422 (global-set-key [C-f6
] 'vcursor-previous-line
)
423 (global-set-key [C-f7
] 'vcursor-next-line
)
424 (global-set-key [C-f8
] 'vcursor-forward-char
)
426 (global-set-key [M-f5
] 'vcursor-beginning-of-line
)
427 (global-set-key [M-f6
] 'vcursor-backward-word
)
428 (global-set-key [M-f6
] 'vcursor-forward-word
)
429 (global-set-key [M-f8
] 'vcursor-end-of-line
)
431 (global-set-key [S-f5
] 'vcursor-beginning-of-buffer
)
432 (global-set-key [S-f6
] 'vcursor-scroll-down
)
433 (global-set-key [S-f7
] 'vcursor-scroll-up
)
434 (global-set-key [S-f8
] 'vcursor-end-of-buffer
)
436 (global-set-key [C-f9
] 'vcursor-isearch-forward
)
438 (global-set-key [S-f9
] 'vcursor-execute-key
)
439 (global-set-key [S-f10
] 'vcursor-execute-command
)
441 ;;; Partial dictionary of Oemacs key sequences for you to roll your own,
442 ;;; e.g C-S-up: (global-set-key "\M-[\C-f\M-\C-m" 'vcursor-previous-line)
444 ;;; "\M-[\C-f\M-\C-m" C-S-up
445 ;;; "\M-[\C-f\M-\C-q" C-S-down
446 ;;; "\M-[\C-fs" C-S-left
447 ;;; "\M-[\C-ft" C-S-right
449 ;;; "\M-[\C-fw" C-S-home
450 ;;; "\M-[\C-b\C-o" S-tab
451 ;;; "\M-[\C-f\M-\C-r" C-S-insert
452 ;;; "\M-[\C-fu" C-S-end
453 ;;; "\M-[\C-f\M-\C-s" C-S-delete
454 ;;; "\M-[\C-f\M-\C-d" C-S-prior
455 ;;; "\M-[\C-fv" C-S-next
457 ;;; "\M-[\C-f^" C-S-f1
458 ;;; "\M-[\C-f_" C-S-f2
459 ;;; "\M-[\C-f`" C-S-f3
460 ;;; "\M-[\C-fa" C-S-f4
461 ;;; "\M-[\C-fb" C-S-f5
462 ;;; "\M-[\C-fc" C-S-f6
463 ;;; "\M-[\C-fd" C-S-f7
464 ;;; "\M-[\C-fe" C-S-f8
465 ;;; "\M-[\C-ff" C-S-f9
466 ;;; "\M-[\C-fg" C-S-f10
469 (global-set-key [C-S-up
] 'vcursor-previous-line
)
470 (global-set-key [C-S-down
] 'vcursor-next-line
)
471 (global-set-key [C-S-left
] 'vcursor-backward-char
)
472 (global-set-key [C-S-right
] 'vcursor-forward-char
)
474 (global-set-key [C-S-return
] 'vcursor-disable
)
475 (global-set-key [C-S-insert
] 'vcursor-copy
)
476 (global-set-key [C-S-delete
] 'vcursor-copy-word
)
477 (global-set-key [C-S-remove
] 'vcursor-copy-word
)
478 (global-set-key [C-S-tab
] 'vcursor-toggle-copy
)
479 (global-set-key [C-S-home
] 'vcursor-beginning-of-buffer
)
480 (global-set-key [M-C-S-up
] 'vcursor-beginning-of-buffer
)
481 (global-set-key [C-S-end
] 'vcursor-end-of-buffer
)
482 (global-set-key [M-C-S-down
] 'vcursor-end-of-buffer
)
483 (global-set-key [C-S-prior
] 'vcursor-scroll-down
)
484 (global-set-key [C-S-next
] 'vcursor-scroll-up
)
486 (global-set-key [C-S-f6
] 'vcursor-other-window
)
487 (global-set-key [C-S-f7
] 'vcursor-goto
)
489 (global-set-key [C-S-select
] 'vcursor-swap-point
) ; DEC keyboards
490 (global-set-key [M-C-S-tab
] 'vcursor-swap-point
)
492 (global-set-key [C-S-find
] 'vcursor-isearch-forward
) ; DEC keyboards
493 (global-set-key [C-S-f8
] 'vcursor-isearch-forward
)
495 (global-set-key [M-C-S-left
] 'vcursor-beginning-of-line
)
496 (global-set-key [M-C-S-right
] 'vcursor-end-of-line
)
498 (global-set-key [M-C-S-prior
] 'vcursor-backward-word
)
499 (global-set-key [M-C-S-next
] 'vcursor-forward-word
)
501 (global-set-key [M-C-S-return
] 'vcursor-copy-line
)
503 (global-set-key [C-S-f9
] 'vcursor-execute-key
)
504 (global-set-key [C-S-f10
] 'vcursor-execute-command
)
507 (defun vcursor-locate ()
508 "Go to the starting point of the virtual cursor.
509 If that's disabled, don't go anywhere but don't complain."
510 ;; This is where we go off-mass-shell. Assume there is a
511 ;; save-excursion to get us back to the pole, er, point.
513 (and (overlayp vcursor-overlay
)
514 (overlay-buffer vcursor-overlay
)
515 (set-buffer (overlay-buffer vcursor-overlay
))
516 (goto-char (overlay-start vcursor-overlay
)))
519 (defun vcursor-find-window (&optional not-this new-win this-frame
)
520 "Return a suitable window for displaying the virtual cursor.
521 This is the first window in cyclic order where the vcursor is visible.
523 With optional NOT-THIS non-nil never return the current window.
525 With NEW-WIN non-nil, display the virtual cursor buffer in another
526 window if the virtual cursor is not currently visible \(note, however,
527 that this function never changes window-point\).
529 With THIS-FRAME non-nil, don't search other frames for a new window
530 \(though if the vcursor is already off-frame then its current window is
531 always considered, and the value of `pop-up-frames' is always respected\).
533 Returns nil if the virtual cursor is not visible anywhere suitable.
534 Set `vcursor-window' to the returned value as a side effect."
536 ;; The order of priorities (respecting NOT-THIS) is (1)
537 ;; vcursor-window if the virtual cursor is visible there (2) any
538 ;; window displaying the virtual cursor (3) vcursor-window provided
539 ;; it is still displaying the buffer containing the virtual cursor and
540 ;; is not selected (4) any unselected window displaying the vcursor
541 ;; buffer (5) with NEW-WIN, a window selected by display-buffer (so
542 ;; the variables pop-up-windows and pop-up-frames are significant)
545 (let ((thiswin (selected-window)) winok winbuf
)
548 (or (and (window-live-p vcursor-window
)
549 (eq (current-buffer) (window-buffer vcursor-window
))
550 (not (and not-this
(eq thiswin vcursor-window
))))
551 (setq vcursor-window nil
))
552 (or (and vcursor-window
; choice 1
553 (pos-visible-in-window-p (point) vcursor-window
))
559 (eq (current-buffer) (window-buffer win
))
560 (not (and not-this
(eq thiswin win
)))
562 ((pos-visible-in-window-p (point) win
) (setq winok win
))
564 ((not winbuf
) (setq winbuf win
))))))
565 nil
(not this-frame
))
569 ((and vcursor-window
; choice 3
570 (not (eq thiswin vcursor-window
))) vcursor-window
)
572 (new-win (display-buffer (current-buffer) t
)) ; choice 5
573 (t nil
))))))) ; default (choice 6)
577 (defun vcursor-toggle-copy (&optional arg nomsg
)
578 "Toggle copying to point when the vcursor is moved.
579 With a prefix ARG, turn on if non-negative, off if negative.
580 Display a message unless optional NOMSG is non-nil."
582 (setq vcursor-copy-flag
583 (cond ((not arg
) (not vcursor-copy-flag
))
584 ((< (prefix-numeric-value arg
) 0) nil
)
586 vcursor-last-command t
)
587 (or nomsg
(message "Copying from the vcursor is now %s."
588 (if vcursor-copy-flag
"on" "off")))
591 (defun vcursor-move (pt &optional leave-b leave-w
)
592 "Move the virtual cursor to the character to the right of PT.
593 PT is an absolute location in the current buffer. With optional
594 LEAVE-B, PT is in the same buffer the vcursor is currently in.
596 If the new virtual cursor location would not be visible, display it in
597 another window. With LEAVE-W, use the current `vcursor-window'."
598 ;; this works even if we're on-mass-shell, but usually we won't be.
601 (and leave-b
(vcursor-check t
)
602 (set-buffer (overlay-buffer vcursor-overlay
)))
603 (if (eq pt
(point-max))
605 (if (vcursor-check t
)
606 (move-overlay vcursor-overlay pt
(+ pt
1) (current-buffer))
607 (setq vcursor-overlay
(make-overlay pt
(+ pt
1)))
609 (overlay-put vcursor-overlay
'before-string vcursor-string
))
610 (overlay-put vcursor-overlay
'face
'vcursor
))
611 (or leave-w
(vcursor-find-window nil t
))
612 ;; vcursor-window now contains the right buffer
613 (or (pos-visible-in-window-p pt vcursor-window
)
614 (set-window-point vcursor-window pt
)))
617 (defun vcursor-insert (text)
618 "Insert TEXT, respecting `vcursor-interpret-input'."
619 (if vcursor-interpret-input
620 (setq unread-command-events
621 (append (listify-key-sequence text
) unread-command-events
))
625 (defun vcursor-relative-move (fn &rest args
)
626 "Use FUNCTION with arbitrary ARG1 ... to move the virtual cursor.
628 This is called by most of the virtual-cursor motion commands."
632 (setq opoint
(point))
634 (and (eq opoint
(point-max)) (eq opoint
(point))
635 (signal 'end-of-buffer nil
))
636 (vcursor-move (point))
637 (if vcursor-copy-flag
(setq text
(buffer-substring opoint
(point)))))
638 (if text
(vcursor-insert text
)))
639 (setq vcursor-last-command t
)
642 (defun vcursor-goto (&optional arg
)
643 "Move the real cursor to the virtual cursor position.
644 If the virtual cursor is (or was recently) visible in another window,
645 switch to that first. Without a prefix ARG, disable the virtual
649 (and (vcursor-find-window) (select-window vcursor-window
))
650 (let ((buf (and vcursor-overlay
(overlay-buffer vcursor-overlay
))))
651 (and buf
(not (eq (current-buffer) buf
)) (switch-to-buffer buf
)))
653 (or arg
(vcursor-disable))
656 (defun vcursor-swap-point ()
657 "Swap the location of point and that of the virtual cursor.
659 The virtual cursor window becomes the selected window and the old
660 window becomes the virtual cursor window. If the virtual cursor would
661 not be visible otherwise, display it in another window."
664 (let ((buf (current-buffer)) (here (point)) (win (selected-window)))
665 (vcursor-goto) ; will disable the vcursor
668 (setq vcursor-window win
)
669 (vcursor-move here
)))
672 (defun vcursor-scroll-up (&optional n
)
673 "Scroll up the vcursor window ARG lines or near full screen if none.
674 The vcursor will always appear in an unselected window."
677 (vcursor-window-funcall 'scroll-up n
)
680 (defun vcursor-scroll-down (&optional n
)
681 "Scroll down the vcursor window ARG lines or near-full screen if none.
682 The vcursor will always appear in an unselected window."
685 (vcursor-window-funcall 'scroll-down n
)
688 (defun vcursor-isearch-forward (&optional rep norecurs
)
689 "Perform forward incremental search in the virtual cursor window.
690 The virtual cursor is moved to the resulting point; the ordinary
691 cursor stays where it was."
694 (vcursor-window-funcall 'isearch-forward rep norecurs
)
697 (defun vcursor-isearch-backward (&optional rep norecurs
)
698 "Perform backward incremental search in the virtual cursor window.
699 The virtual cursor is moved to the resulting point; the ordinary
700 cursor stays where it was."
703 (vcursor-window-funcall 'isearch-backward rep norecurs
)
706 (defun vcursor-window-funcall (func &rest args
)
707 "Call FUNC with ARGS ... in a virtual cursor window.
708 A window other than the currently-selected one will always be used.
709 The virtual cursor is moved to the value of point when the function
712 If FUNC is a list, call the car of the list interactively, ignoring
713 ARGS. In this case, a new window will not be created if the vcursor
714 is visible in the current one."
715 ;; that's to avoid messing up compatibility with old versions
716 ;; by introducing a new argument, which would have to come before ARGS.
718 (vcursor-find-window (not (and (listp func
) (vcursor-check t
))) t
)
720 (let ((sw (selected-window)) text
)
721 ;; We can't use save-window-excursion because that would restore
722 ;; the original display in the window we may want to alter.
724 (let ((here (point)))
725 (select-window vcursor-window
)
728 (call-interactively (car func
))
730 (setq vcursor-window
(selected-window))
731 (and vcursor-copy-flag
732 (eq (current-buffer) (overlay-buffer vcursor-overlay
))
733 (setq text
(buffer-substring here
(point))))
734 ;; vcursor-window and the current buffer are definitely
735 ;; right, so make sure vcursor-move doesn't pick others.
736 (vcursor-move (point) nil t
))
738 (if text
(vcursor-insert text
))))
739 (setq vcursor-last-command t
)
742 (defun vcursor-get-char-count (fn &rest args
)
743 "Apply FN to ARG1 ... and return the number of characters moved.
744 Point is temporarily set to the virtual cursor position before FN is
747 This is called by most of the virtual-cursor copying commands to find
748 out how much to copy."
752 (set-buffer (overlay-buffer vcursor-overlay
))
753 (let ((start (goto-char (overlay-start vcursor-overlay
))))
754 (- (progn (apply fn args
) (point)) start
)))
757 ;; Make sure the virtual cursor is active. Unless arg is non-nil,
758 ;; report an error if it is not.
759 (defun vcursor-check (&optional arg
)
761 ((and (overlayp vcursor-overlay
) (overlay-start vcursor-overlay
))
764 (t (error "The virtual cursor is not active now.")))
767 (defun vcursor-disable (&optional arg
)
768 "Disable the virtual cursor.
769 Next time you use it, it will start from point.
771 With a positive prefix ARG, the first window in cyclic order
772 displaying the virtual cursor (or which was recently displaying the
773 virutal cursor) will be deleted unless it's the selected
776 With a negative prefix argument, enable the virtual cursor: make it
777 active at the same point as the real cursor.
779 Copying mode is always turned off: the next use of the vcursor will
780 not copy text until you turn it on again."
783 (if (overlayp vcursor-overlay
)
785 (delete-overlay vcursor-overlay
)
786 (setq vcursor-overlay nil
)))
788 ((not (vcursor-find-window t
)))
789 ((or (not arg
) (< (prefix-numeric-value arg
) 0)))
790 ((delete-window vcursor-window
)))
792 ((and arg
(< (prefix-numeric-value arg
) 0))
793 (vcursor-move (point))
794 (setq vcursor-window
(selected-window)))
795 (vcursor-use-vcursor-map (vcursor-toggle-vcursor-map 0)))
796 (setq vcursor-copy-flag nil
)
799 (defun vcursor-other-window (n &optional all-frames
)
800 "Activate the virtual cursor in another window.
801 This is the next window cylically after one currently showing the
802 virtual cursor, or else after the current selected window. If there
803 is no other window, the current window is split.
805 Arguments N and optional ALL-FRAMES are the same as with other-window.
806 ALL-FRAMES is also used to decide whether to split the window."
809 (if (if (fboundp 'oemacs-version
)
811 (one-window-p nil all-frames
))
812 (display-buffer (current-buffer) t
))
814 (save-window-excursion
815 ;; We don't use fancy vcursor-find-window trickery, since we're
816 ;; quite happy to have the vcursor cycle back into the current
818 (let ((sw (selected-window))
819 (win (vcursor-find-window nil nil
(not all-frames
))))
820 (if win
(select-window win
))
821 ;; else start from here
822 (other-window n all-frames
)
823 (vcursor-disable -
1))))
826 ;; vcursor-compare-windows is copied from compare-w.el with only
827 ;; minor modifications; these are too bound up with the function
828 ;; to make it really useful to call compare-windows itself.
829 (defun vcursor-compare-windows (&optional ignore-whitespace
)
830 "Compare text in current window with text in window with vcursor.
831 Compares the text starting at point in the current window and at the
832 vcursor position in the other window, moving over text in each one as
835 A prefix argument, if any, means ignore changes in whitespace.
836 The variable `compare-windows-whitespace' controls how whitespace is skipped.
837 If `compare-ignore-case' is non-nil, changes in case are also ignored."
839 ;; (vcursor-window-funcall 'compare-windows arg)
841 (let* (p1 p2 maxp1 maxp2 b1 b2 w2
845 (skip-whitespace (if ignore-whitespace
846 compare-windows-whitespace
)))
847 (setq p1
(point) b1
(current-buffer))
848 (setq w2
(vcursor-find-window t t
))
849 (if (or (eq w2
(selected-window)) (not w2
))
850 (error "No other window with vcursor"))
853 (setq p2
(point) b2
(current-buffer)))
855 (setq maxp1
(point-max))
858 (setq maxp2
(point-max)))
863 ;; if interrupted, show how far we've gotten
867 ;; If both buffers have whitespace next to point,
868 ;; optionally skip over it.
872 (let (p1a p2a w1 w2 result1 result2
)
874 (if (stringp skip-whitespace
)
875 (compare-windows-skip-whitespace opoint1
)
876 (funcall skip-whitespace opoint1
)))
881 (if (stringp skip-whitespace
)
882 (compare-windows-skip-whitespace opoint2
)
883 (funcall skip-whitespace opoint2
)))
885 (if (or (stringp skip-whitespace
)
886 (and result1 result2
(eq result1 result2
)))
890 ;; Try advancing comparing 1000 chars at a time.
891 ;; When that fails, go 500 chars at a time, and so on.
894 (case-fold-search compare-ignore-case
))
897 ;; Try comparing SIZE chars at a time, repeatedly, till that fails.
899 (setq size
(min size
(- maxp1 p1
) (- maxp2 p2
)))
902 (= 0 (compare-buffer-substrings b2 p2
(+ size p2
)
903 b1 p1
(+ size p1
)))))
905 (setq p1
(+ p1 size
) p2
(+ p2 size
)
907 ;; If SIZE chars don't match, try fewer.
908 (setq size
(/ size
2)))))
912 (if (= (point) opoint1
)
916 (defun vcursor-next-line (arg)
917 "Move the virtual cursor forward ARG lines."
918 ;; This is next-line rewritten for the vcursor. Maybe it would
919 ;; be easier simply to rewrite line-move.
921 (let (temporary-goal-column opoint text
)
924 (setq temporary-goal-column
925 (if (or (eq last-command
'vcursor-next-line
)
926 (eq last-command
'vcursor-previous-line
))
928 (setq last-command
'next-line
) ; trick line-move
929 vcursor-temp-goal-column
)
930 (if (and track-eol
(eolp)
931 (or (not (bolp)) (eq last-command
'end-of-line
)))
936 (and (eq opoint
(point-max)) (eq opoint
(point))
937 (signal 'end-of-buffer nil
))
938 (if vcursor-copy-flag
(setq text
(buffer-substring opoint
(point))))
939 (vcursor-move (point))
940 (setq vcursor-temp-goal-column temporary-goal-column
941 vcursor-last-command t
))
942 (if text
(vcursor-insert text
)))
945 (defun vcursor-previous-line (arg)
946 "Move the virtual cursor back ARG lines."
948 (vcursor-next-line (- arg
))
951 (defun vcursor-forward-char (arg)
952 "Move the virtual cursor forward ARG characters."
954 (vcursor-relative-move 'forward-char arg
)
957 (defun vcursor-backward-char (arg)
958 "Move the virtual cursor backward ARG characters."
960 (vcursor-relative-move 'backward-char arg
)
963 (defun vcursor-forward-word (arg)
964 "Move the virtual cursor forward ARG words."
966 (vcursor-relative-move 'forward-word arg
)
969 (defun vcursor-backward-word (arg)
970 "Move the virtual cursor backward ARG words."
972 (vcursor-relative-move 'backward-word arg
)
975 (defun vcursor-beginning-of-line (arg)
976 "Move the virtual cursor to beginning of its current line.
977 ARG is as for `beginning-of-line'."
979 (vcursor-relative-move 'beginning-of-line
980 (if arg
(prefix-numeric-value arg
)))
983 (defun vcursor-end-of-line (arg)
984 "Move the virtual cursor to end of its current line.
985 ARG is as for `end-of-line'."
987 (vcursor-relative-move 'end-of-line
988 (if arg
(prefix-numeric-value arg
)))
991 (defun vcursor-beginning-of-buffer (&optional arg
)
992 "Move the virtual cursor to the beginning of its buffer.
993 ARG is as for beginning-of-buffer."
995 (vcursor-relative-move
997 (goto-char (if arg
(/ (* arg
(- (point-max) (point-min))) 10)
999 (if arg
(prefix-numeric-value arg
)))
1002 (defun vcursor-end-of-buffer (&optional arg
)
1003 "Move the virtual cursor to the end of its buffer.
1004 ARG is as for end-of-buffer.
1006 Actually, the vcursor is moved to the second from last character or it
1007 would be invisible."
1009 (vcursor-relative-move
1011 (goto-char (if arg
(- (point-max)
1012 (/ (* arg
(- (point-max) (point-min))) 10))
1014 (if arg
(prefix-numeric-value arg
)))
1017 (defun vcursor-execute-command (cmd)
1018 "Execute COMMAND for the virtual cursor.
1019 COMMAND is called interactively. Not all commands (in fact, only a
1020 small subset) are useful."
1021 (interactive "CCommand: ")
1022 (vcursor-window-funcall (list cmd
))
1025 (defun vcursor-execute-key ()
1026 "Read a key sequence and execute the bound command for the virtual cursor.
1027 The key sequence is read at the vcursor location. The command found
1028 is called interactively, so prefix argument etc. are usable."
1032 ;; We'd like to avoid the display changing when we locate
1033 ;; to the vcursor position and read a key sequence.
1034 (vcursor-find-window (not (vcursor-check t
)) t
)
1035 (save-window-excursion
1036 (select-window vcursor-window
)
1038 (setq cmd
(key-binding (read-key-sequence "Key sequence: ")))))
1039 (vcursor-window-funcall (list cmd
)))
1042 (defun vcursor-copy (arg)
1043 "Copy ARG characters from the virtual cursor position to point."
1048 (set-buffer (overlay-buffer vcursor-overlay
))
1049 (let* ((ostart (overlay-start vcursor-overlay
))
1050 (end (+ ostart arg
)))
1052 (buffer-substring ostart end
)
1053 (vcursor-move end
)))))
1054 (setq vcursor-last-command t
)
1057 (defun vcursor-copy-word (arg)
1058 "Copy ARG words from the virtual cursor position to point."
1060 (vcursor-copy (vcursor-get-char-count 'forward-word arg
))
1063 (defun vcursor-copy-line (arg)
1064 "Copy up to ARGth line after virtual cursor position.
1065 With no argument, copy to the end of the current line.
1067 Behaviour with regard to newlines is similar (but not identical) to
1068 `kill-line'; the main difference is that whitespace at the end of the
1069 line is treated like ordinary characters."
1072 (let* ((num (prefix-numeric-value arg
))
1073 (count (vcursor-get-char-count 'end-of-line num
)))
1074 (vcursor-copy (if (or (= count
0) arg
) (1+ count
) count
)))
1077 (defun vcursor-toggle-vcursor-map (&optional force noredisp
)
1078 "Toggle the state of the vcursor key map.
1079 When on, the keys defined in it are mapped directly on top of the main
1080 keymap, allowing you to move the vcursor with ordinary motion keys.
1081 An indication \"!VC\" appears in the mode list. The effect is
1082 local to the current buffer.
1083 With prefix FORCE, turn on, or off if it is 0.
1084 With NOREDISP, don't force redisplay.
1085 Disabling the vcursor automatically turns this off."
1087 (let ((new (cond ((not force
) (not vcursor-use-vcursor-map
))
1090 (or (eq new vcursor-use-vcursor-map
)
1092 (setq vcursor-use-vcursor-map new
)
1093 (or (assq 'vcursor-use-vcursor-map minor-mode-map-alist
)
1094 (setq minor-mode-map-alist
1095 (cons (cons 'vcursor-use-vcursor-map vcursor-map
)
1096 minor-mode-map-alist
)))
1097 (or (assq 'vcursor-use-vcursor-map minor-mode-alist
)
1098 (setq minor-mode-alist
1099 (cons (list 'vcursor-use-vcursor-map
" !VC")
1101 (or noredisp
(redraw-display)))))
1104 (defun vcursor-post-command ()
1105 (and vcursor-auto-disable
(not vcursor-last-command
)
1106 vcursor-overlay
(vcursor-disable))
1107 (setq vcursor-last-command nil
)
1110 (add-hook 'post-command-hook
'vcursor-post-command
)
1114 ;; vcursor.el ends here