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1 | ;;; vcursor.el --- manipulate an alternative ("virtual") cursor. |
2 | ||
83d7d14c | 3 | ;; Copyright (C) 1994, 1996 Free Software Foundation, Inc. |
bf078b46 RS |
4 | |
5 | ;; Author: Peter Stephenson <pws@ifh.de> | |
6 | ;; Keywords: virtual cursor, display, copying | |
7 | ||
83d7d14c RS |
8 | ;; This file is part of GNU Emacs. |
9 | ||
10 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
bf078b46 | 11 | ;; it under the terms of the GNU General Public License as published by |
83d7d14c RS |
12 | ;; the Free Software Foundation; either version 2, or (at your option) |
13 | ;; any later version. | |
bf078b46 | 14 | |
83d7d14c | 15 | ;; GNU Emacs is distributed in the hope that it will be useful, |
bf078b46 RS |
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. | |
19 | ||
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. | |
24 | ||
25 | ;;; Commentary: | |
26 | ||
27 | ;; Virtual cursor commands. I got this idea from the old BBC micro. | |
28 | ;; You need Emacs 19 (I have not tried XEmacs) and a windowing | |
29 | ;; system: I have tried X Windows and Oemacs but any system which | |
30 | ;; supports multiple windows should have the ability to run vcursor. | |
31 | ;; In fact, only overlays are required to work, though some of the | |
32 | ;; key-bindings may need changing. | |
33 | ;; | |
34 | ;; This is much easier to use than the instructions are to read. | |
35 | ;; I suggest you simply load it and play around with holding down Ctrl | |
36 | ;; and Shift and pressing up, down, left, right, tab, return, and see | |
37 | ;; what happens. (Find a scratch buffer before using C-S-tab: that | |
38 | ;; toggles copying.) | |
39 | ;; | |
40 | ;; Most of the functions described in this documentation are in | |
41 | ;; parentheses so that if you have the package loaded you can type C-h | |
42 | ;; f on top of them for help. | |
43 | ;; | |
44 | ;; Using the cursor keys with both control and shift held down moves | |
45 | ;; around a virtual cursor, which is initially at point. When active, | |
46 | ;; it appears with an underline through it to distinguish it from the | |
47 | ;; normal cursor. You can then use one of the other commands to copy | |
48 | ;; characters from the location of the virtual cursor to point. This | |
49 | ;; is very useful, for example, when copying some previous text while | |
50 | ;; making changes to it at the same time, since you never have to move | |
51 | ;; the "real" cursor away from where you are inserting. | |
52 | ;; | |
53 | ;; The remaining default key bindings are based around the PC-type | |
54 | ;; cluster found above the cursor keys on a lot of keyboards, the | |
55 | ;; function keys which my limited knowledge of X terminals expects to | |
56 | ;; find at the top. Some functions are duplicated in more obvious | |
57 | ;; places for the X version. | |
58 | ;; | |
59 | ;; All the keybindings require you to hold down control and shift at | |
60 | ;; once. I assumed this combination wouldn't be heavily bound by most | |
61 | ;; people and that it would be easy to type with the left hand. | |
62 | ;; Inevitably it will clash with some other packages, but I can't help | |
63 | ;; that: an intuitive binding is a prerequisite here. See below for | |
64 | ;; other alternatives (search for "Oemacs"). | |
65 | ;; | |
66 | ;; Holding down control and shift and pressing insert (vcursor-copy) | |
67 | ;; copies one character from wherever the virtual cursor is to point; | |
68 | ;; point and the virtual cursor advance in the separate and equal | |
69 | ;; station to which... (etc.). M-C-S-return (vcursor-copy-line) | |
70 | ;; copies to the end of the line instead of just one character, | |
71 | ;; C-S-delete or C-S-remove (vcursor-copy-word) copies a word. | |
72 | ;; | |
73 | ;; A more general way of copying is to use C-S-tab, which is a toggle. | |
74 | ;; In the "on" state, moving the virtual cursor will copy the | |
75 | ;; moved-over text to the normal cursor position (including when going | |
76 | ;; backwards, though each piece of text moved over is copied forwards: | |
77 | ;; compare the behaviour of C-S-up and C-S-left). | |
78 | ;; | |
79 | ;; However, that's just a small part of the magic. If the virtual | |
80 | ;; cursor goes off the display, it will be redisplayed in some other | |
81 | ;; window. (See the function (vcursor-find-window) for details of how | |
82 | ;; this window is chosen.) This gives you fingertip control over two | |
83 | ;; windows at once. | |
84 | ;; | |
85 | ;; C-S-return (vcursor-disable) disables the virtual cursor, removing | |
86 | ;; it so that it starts from point whenever you move it again --- note | |
87 | ;; that simply moving the cursor and virtual cursor on top of one | |
88 | ;; another does not have this effect. | |
89 | ;; | |
90 | ;; If you gave C-S-return a positive prefix arg, it will also delete the | |
91 | ;; window (unless it's the current one). Whenever the virtual cursor | |
92 | ;; goes off-screen in its own window, point in that window is moved as | |
93 | ;; well to restore it to view. (It's easier that way, that's why. | |
94 | ;; However, point doesn't move unless the view in the window does, so | |
95 | ;; it's not tied to the virtual cursor location.) | |
96 | ;; | |
97 | ;; You can also use C-S-return with a negative prefix argument which | |
98 | ;; forces the vcursor to appear at point. This is particularly useful if | |
99 | ;; you actually want to edit in another window but would like to | |
100 | ;; remember the current cursor location for examining or copying from | |
101 | ;; that buffer. (I just hit C-S-right C-S-left, but I'm a hopeless | |
102 | ;; lowbrow.) | |
103 | ;; | |
104 | ;; There is also C-S-f6 (vcursor-other-window) which behaves like | |
105 | ;; C-x o on the virtual rather than the real cursor, except that it | |
106 | ;; will create another window if necessary. | |
107 | ;; | |
108 | ;; The keys C-S-prior (vcursor-scroll-down) and C-S-next | |
109 | ;; (vcursor-scroll-up) (i.e., PageUp and PageDown) will scroll the | |
110 | ;; virtual cursor window, appropriately chosen. They will always | |
111 | ;; create a new window or take over an old one if necessary. | |
112 | ;; Likewise, M-C-S-left and M-C-S-right move you to the | |
113 | ;; beginning or end of a line, C-S-home and C-S-end the | |
114 | ;; beginning or end of a buffer (these are also on M-C-S-up and | |
115 | ;; M-C-S-down for those of us stuck with DEC keyboards). | |
116 | ;; | |
117 | ;; C-S-f7 (vcursor-goto) will take you to the vcursor position | |
118 | ;; (swapping windows if it seems sensible) and (unless you give it a | |
119 | ;; prefix argument) delete the virtual cursor, so this is useful for | |
120 | ;; you to take over editing at the virtual cursor position. It is not | |
121 | ;; an error if the virtual cursor is not active; it simply leaves you | |
122 | ;; at point, because that is where the virtual cursor would start | |
123 | ;; from. | |
124 | ;; | |
125 | ;; In a similar vein, M-C-S-tab (hope your left hand's flexible; | |
126 | ;; C-S-select on DEC keyboards) (vcursor-swap-point) will take you to | |
127 | ;; the virtual cursor position but simultaneously put the virtual | |
128 | ;; cursor at the old cursor position. It is also supposed to ensure | |
129 | ;; that both are visible. | |
130 | ;; | |
131 | ;; C-S-f8 (C-S-find on DEC keyboards) (vcursor-isearch-forward) | |
132 | ;; allows you to do an isearch in another window. It works a bit like | |
133 | ;; vcursor-scroll-*; it moves into another window, calls isearch | |
134 | ;; there, and sets the virtual cursor position to the point found. In | |
135 | ;; other words, it works just like isearch but with the virtual cursor | |
136 | ;; instead of the real one (that's why it's called a "virtual | |
137 | ;; cursor"). While you are isearching, you are editing in the virtual | |
138 | ;; cursor window, but when you have finished you return to where you | |
139 | ;; started. Note that once you are in isearch all the keys are normal | |
140 | ;; --- use C-s, not C-S-f8, to search for the next occurrence. | |
141 | ;; | |
142 | ;; If you set the variable vcursor-auto-disable, then any command | |
143 | ;; which does not involve moving or copying from the virtual cursor | |
144 | ;; causes the virtual cursor to be disabled. If you don't intend to | |
145 | ;; use this, you can comment out the `add-hook' line at the bottom of | |
146 | ;; this file. (This feature partially emulates the way the "copy" key | |
147 | ;; on the BBC micro worked; actually, the copy cursor was homed when | |
148 | ;; you hit return. This was in keeping with the line-by-line way of | |
149 | ;; entering BASIC, but is less appropriate here.) | |
150 | ;; | |
151 | ;; There is a way of moving the virtual cursor using ordinary | |
152 | ;; commands: C-S-f9 (vcursor-execute-key) reads a key string, | |
153 | ;; moves to the virtual cursor position, executes the command bound to | |
154 | ;; the string, then returns to the original point. Thus C-S-f9 M-m | |
155 | ;; moves the virtual cursor back to the first non-whitespace character | |
156 | ;; on its line. As the command is called interactively all the usual | |
157 | ;; ways of passing information to the command called, such as by a | |
158 | ;; prefix argument, are available. C-S-f10 (C-S-x) | |
159 | ;; (vcursor-execute-command) behaves the same way but you enter the | |
160 | ;; name of the command. Of course, only some commands are useful | |
161 | ;; here, mainly simple movement commands. Killing at the virtual | |
162 | ;; cursor position in this way works as well; you can even save | |
163 | ;; another buffer with C-S-f9 C-x C-s. To do anything more | |
164 | ;; complicated, you are better off using M-C-S-tab | |
165 | ;; (vcursor-swap-point), doing whatever it is, then calling M-C-S-tab | |
166 | ;; again. | |
167 | ;; | |
168 | ;; If you want to add your own moving or copying functions you should | |
169 | ;; be able to do this fairly easily with (vcursor-relative-move) and | |
170 | ;; (vcursor-copy) together with (vcursor-get-char-count). If you want to | |
171 | ;; do something in a different window, use (vcursor-window-funcall). | |
172 | ;; | |
173 | ;; There is an alternative set of key bindings which will be used | |
174 | ;; automatically for a PC if Oemacs is detected. This set uses separate | |
175 | ;; control, shift and meta keys with function keys 1 to 10. In | |
176 | ;; particular, movement keys are concentrated on f5 to f8 with (in | |
177 | ;; increasing order of distance travelled) C-, M- and S- as prefixes. | |
178 | ;; See the actual bindings below (search for C-f1). This is because the | |
179 | ;; C-S- prefix is represented by weird key sequences and the set is | |
180 | ;; incomplete; if you don't mind that, some hints are given in comments | |
181 | ;; below. | |
182 | ;; | |
183 | ;; You can specify the usual or the Oemacs bindings by setting the | |
184 | ;; variable vcursor-key-bindings to `xterm' or `oemacs'. You can also set | |
185 | ;; it to nil, in which case vcursor will not make any key bindings | |
186 | ;; and you can define your own. The default is t, which makes vcursor | |
187 | ;; guess (it will use xterm unless it thinks Oemacs is running). The | |
188 | ;; oemacs set will work on an X terminal with function keys, but the | |
189 | ;; xterm set will not work under Oemacs. | |
190 | ;; | |
191 | ;; Un-features: | |
192 | ;; - The vcursor will not move to point-max, since otherwise it would | |
193 | ;; disappear. However, no error is flagged as point-max is a valid | |
194 | ;; point in the buffer. Thus cursor right or down at the second | |
195 | ;; last point in the file does not flag an error, which is inconsistent, | |
196 | ;; and if copying is on the last character (typically newline) will | |
197 | ;; be repeatedly copied. (I've tried making it flag an error | |
198 | ;; instead and that's worse since often the vcursor is sent to | |
199 | ;; point in some other window, which may be point-max.) | |
200 | ;; - The vcursor widens when over a tab character or right at the | |
201 | ;; end of the line. You're welcome to consider this a feature; | |
202 | ;; it's just a part of how overlays work. | |
203 | ;; - The vcursor obscures the real cursor. Creative use of overlays | |
204 | ;; could cure this. | |
205 | ;; - The vcursor does not remember its own previous positions. If | |
206 | ;; you cycle it back into a window it was in before, it will be at | |
207 | ;; point in that window. Often, that is where a previous recenter | |
208 | ;; left point, not where the vcursor was before. | |
209 | ;; (Note, however, that the vcursor does remember where it *is*, | |
210 | ;; even if it's off-screen. This can also lead to surprises, but I | |
211 | ;; don't think it's a bug.) | |
212 | ;; - vcursor-window-funcall could perhaps be smarter about restoring | |
213 | ;; the previous window state on failure. | |
214 | ;; - The logic in vcursor-find-window is rather complicated and | |
215 | ;; therefore bug-prone, though in practice it seems to work OK. | |
216 | ;; | |
217 | ;; Possible enhnacements: | |
218 | ;; It would be easy to implement vcursor-push (save vcursor position | |
219 | ;; as mark and deactivate) and vcursor-pop (deactivate vcursor and | |
220 | ;; move to last pushed position) functions. | |
221 | ||
222 | ;;; Code: | |
223 | ||
224 | (or (memq 'vcursor (face-list)) | |
225 | (progn | |
226 | (copy-face 'modeline 'vcursor) | |
227 | (if (or (fboundp 'oemacs-version) (x-display-color-p)) | |
228 | (progn | |
229 | (set-face-foreground 'vcursor "blue") | |
230 | (set-face-background 'vcursor "cyan"))) | |
231 | (set-face-underline-p 'vcursor t))) | |
232 | ||
233 | (defvar vcursor-auto-disable nil | |
234 | "*If non-nil, disable the virtual cursor after use. | |
235 | Any non-vcursor command will force `vcursor-disable' to be called.") | |
236 | ||
237 | (defvar vcursor-key-bindings t | |
238 | "*How to bind keys when vcursor is loaded. | |
239 | If t (the default), guess; if xterm, use bindings suitable for an | |
240 | X terminal; if oemacs, use bindings which work on a PC with Oemacs. | |
241 | If nil, don't define any key bindings.") | |
242 | ||
243 | (defvar vcursor-overlay nil | |
244 | "Overlay for the virtual cursor. | |
245 | It is nil if that is not enabled.") | |
246 | ||
247 | (defvar vcursor-window nil | |
248 | "Last window to have displayed the virtual cursor. | |
249 | See the function `vcursor-find-window' for how this is used.") | |
250 | ||
251 | (defvar vcursor-last-command nil | |
252 | "Non-nil if last command was a vcursor command. | |
253 | The commands `vcursor-copy', `vcursor-relative-move' and the ones for | |
254 | scrolling set this. It is used by the `vcursor-auto-disable' code.") | |
255 | ;; could do some memq-ing with last-command instead, but this will | |
256 | ;; automatically handle any new commands using the primitives. | |
257 | ||
258 | (defvar vcursor-copy-flag nil | |
259 | "*Non-nil means moving vcursor should copy characters moved over to point.") | |
260 | ||
261 | (defvar vcursor-temp-goal-column nil | |
262 | "Keeps track of temporary goal columns for the virtual cursor.") | |
263 | ||
264 | (cond | |
265 | ((not vcursor-key-bindings)) ;; don't set any key bindings | |
266 | ((or (eq vcursor-key-bindings 'oemacs) | |
267 | (and (eq vcursor-key-bindings t) (fboundp 'oemacs-version))) | |
268 | (global-set-key [C-f1] 'vcursor-toggle-copy) | |
269 | (global-set-key [C-f2] 'vcursor-copy) | |
270 | (global-set-key [C-f3] 'vcursor-copy-word) | |
271 | (global-set-key [C-f4] 'vcursor-copy-line) | |
272 | ||
273 | (global-set-key [S-f1] 'vcursor-disable) | |
274 | (global-set-key [S-f2] 'vcursor-other-window) | |
275 | (global-set-key [S-f3] 'vcursor-goto) | |
276 | (global-set-key [S-f4] 'vcursor-swap-point) | |
277 | ||
278 | (global-set-key [C-f5] 'vcursor-backward-char) | |
279 | (global-set-key [C-f6] 'vcursor-previous-line) | |
280 | (global-set-key [C-f7] 'vcursor-next-line) | |
281 | (global-set-key [C-f8] 'vcursor-forward-char) | |
282 | ||
283 | (global-set-key [M-f5] 'vcursor-beginning-of-line) | |
284 | (global-set-key [M-f6] 'vcursor-backward-word) | |
285 | (global-set-key [M-f6] 'vcursor-forward-word) | |
286 | (global-set-key [M-f8] 'vcursor-end-of-line) | |
287 | ||
288 | (global-set-key [S-f5] 'vcursor-beginning-of-buffer) | |
289 | (global-set-key [S-f6] 'vcursor-scroll-down) | |
290 | (global-set-key [S-f7] 'vcursor-scroll-up) | |
291 | (global-set-key [S-f8] 'vcursor-end-of-buffer) | |
292 | ||
293 | (global-set-key [C-f9] 'vcursor-isearch-forward) | |
294 | ||
295 | (global-set-key [S-f9] 'vcursor-execute-key) | |
296 | (global-set-key [S-f10] 'vcursor-execute-command) | |
297 | ||
298 | ;;; Partial dictionary of Oemacs key sequences for you to roll your own, | |
299 | ;;; e.g C-S-up: (global-set-key "\M-[\C-f\M-\C-m" 'vcursor-previous-line) | |
300 | ;;; Sequence: Sends: | |
301 | ;;; "\M-[\C-f\M-\C-m" C-S-up | |
302 | ;;; "\M-[\C-f\M-\C-q" C-S-down | |
303 | ;;; "\M-[\C-fs" C-S-left | |
304 | ;;; "\M-[\C-ft" C-S-right | |
305 | ;;; | |
306 | ;;; "\M-[\C-fw" C-S-home | |
307 | ;;; "\M-[\C-b\C-o" S-tab | |
308 | ;;; "\M-[\C-f\M-\C-r" C-S-insert | |
309 | ;;; "\M-[\C-fu" C-S-end | |
310 | ;;; "\M-[\C-f\M-\C-s" C-S-delete | |
311 | ;;; "\M-[\C-f\M-\C-d" C-S-prior | |
312 | ;;; "\M-[\C-fv" C-S-next | |
313 | ;;; | |
314 | ;;; "\M-[\C-f^" C-S-f1 | |
315 | ;;; "\M-[\C-f_" C-S-f2 | |
316 | ;;; "\M-[\C-f`" C-S-f3 | |
317 | ;;; "\M-[\C-fa" C-S-f4 | |
318 | ;;; "\M-[\C-fb" C-S-f5 | |
319 | ;;; "\M-[\C-fc" C-S-f6 | |
320 | ;;; "\M-[\C-fd" C-S-f7 | |
321 | ;;; "\M-[\C-fe" C-S-f8 | |
322 | ;;; "\M-[\C-ff" C-S-f9 | |
323 | ;;; "\M-[\C-fg" C-S-f10 | |
324 | ) | |
325 | (t | |
326 | (global-set-key [C-S-up] 'vcursor-previous-line) | |
327 | (global-set-key [C-S-down] 'vcursor-next-line) | |
328 | (global-set-key [C-S-left] 'vcursor-backward-char) | |
329 | (global-set-key [C-S-right] 'vcursor-forward-char) | |
330 | ||
331 | (global-set-key [C-S-return] 'vcursor-disable) | |
332 | (global-set-key [C-S-insert] 'vcursor-copy) | |
333 | (global-set-key [C-S-delete] 'vcursor-copy-word) | |
334 | (global-set-key [C-S-remove] 'vcursor-copy-word) | |
335 | (global-set-key [C-S-tab] 'vcursor-toggle-copy) | |
336 | (global-set-key [C-S-home] 'vcursor-beginning-of-buffer) | |
337 | (global-set-key [M-C-S-up] 'vcursor-beginning-of-buffer) | |
338 | (global-set-key [C-S-end] 'vcursor-end-of-buffer) | |
339 | (global-set-key [M-C-S-down] 'vcursor-end-of-buffer) | |
340 | (global-set-key [C-S-prior] 'vcursor-scroll-down) | |
341 | (global-set-key [C-S-next] 'vcursor-scroll-up) | |
342 | ||
343 | (global-set-key [C-S-f6] 'vcursor-other-window) | |
344 | (global-set-key [C-S-f7] 'vcursor-goto) | |
345 | ||
346 | (global-set-key [C-S-select] 'vcursor-swap-point) ; DEC keyboards | |
347 | (global-set-key [M-C-S-tab] 'vcursor-swap-point) | |
348 | ||
349 | (global-set-key [C-S-find] 'vcursor-isearch-forward) ; DEC keyboards | |
350 | (global-set-key [C-S-f8] 'vcursor-isearch-forward) | |
351 | ||
352 | (global-set-key [M-C-S-left] 'vcursor-beginning-of-line) | |
353 | (global-set-key [M-C-S-right] 'vcursor-end-of-line) | |
354 | ||
355 | (global-set-key [M-C-S-prior] 'vcursor-backward-word) | |
356 | (global-set-key [M-C-S-next] 'vcursor-forward-word) | |
357 | ||
358 | (global-set-key [M-C-S-return] 'vcursor-copy-line) | |
359 | ||
360 | (global-set-key [C-S-f9] 'vcursor-execute-key) | |
361 | (global-set-key [C-S-f10] 'vcursor-execute-command) | |
362 | )) | |
363 | ||
364 | (defun vcursor-locate () | |
365 | "Go to the starting point of the virtual cursor. | |
366 | If that's disabled, don't go anywhere but don't complain." | |
367 | ;; This is where we go off-mass-shell. Assume there is a | |
368 | ;; save-excursion to get us back to the pole, er, point. | |
369 | ||
370 | (and (overlayp vcursor-overlay) | |
371 | (overlay-buffer vcursor-overlay) | |
372 | (set-buffer (overlay-buffer vcursor-overlay)) | |
373 | (goto-char (overlay-start vcursor-overlay))) | |
374 | ) | |
375 | ||
376 | (defun vcursor-find-window (&optional not-this new-win this-frame) | |
377 | "Return a suitable window for displaying the virtual cursor. | |
378 | This is the first window in cyclic order where the vcursor is visible. | |
379 | ||
380 | With optional NOT-THIS non-nil never return the current window. | |
381 | ||
382 | With NEW-WIN non-nil, display the virtual cursor buffer in another | |
383 | window if the virtual cursor is not currently visible \(note, however, | |
384 | that this function never changes window-point\). | |
385 | ||
386 | With THIS-FRAME non-nil, don't search other frames for a new window | |
387 | \(though if the vcursor is already off-frame then its current window is | |
388 | always considered, and the value of `pop-up-frames' is always respected\). | |
389 | ||
390 | Returns nil if the virtual cursor is not visible anywhere suitable. | |
391 | Set `vcursor-window' to the returned value as a side effect." | |
392 | ||
393 | ;; The order of priorities (respecting NOT-THIS) is (1) | |
394 | ;; vcursor-window if the virtual cursor is visible there (2) any | |
395 | ;; window displaying the virtual cursor (3) vcursor-window provided | |
396 | ;; it is still displaying the buffer containing the virtual cursor and | |
397 | ;; is not selected (4) any unselected window displaying the vcursor | |
398 | ;; buffer (5) with NEW-WIN, a window selected by display-buffer (so | |
399 | ;; the variables pop-up-windows and pop-up-frames are significant) | |
400 | ;; (6) nil. | |
401 | ||
402 | (let ((thiswin (selected-window)) winok winbuf) | |
403 | (save-excursion | |
404 | (vcursor-locate) | |
405 | (or (and (window-live-p vcursor-window) | |
406 | (eq (current-buffer) (window-buffer vcursor-window)) | |
407 | (not (and not-this (eq thiswin vcursor-window)))) | |
408 | (setq vcursor-window nil)) | |
409 | (or (and vcursor-window ; choice 1 | |
410 | (pos-visible-in-window-p (point) vcursor-window)) | |
411 | (progn | |
412 | (walk-windows | |
413 | (function | |
414 | (lambda (win) | |
415 | (and (not winok) | |
416 | (eq (current-buffer) (window-buffer win)) | |
417 | (not (and not-this (eq thiswin win))) | |
418 | (cond | |
419 | ((pos-visible-in-window-p (point) win) (setq winok win)) | |
420 | ((eq thiswin win)) | |
421 | ((not winbuf) (setq winbuf win)))))) | |
422 | nil (not this-frame)) | |
423 | (setq vcursor-window | |
424 | (cond | |
425 | (winok) ; choice 2 | |
426 | ((and vcursor-window ; choice 3 | |
427 | (not (eq thiswin vcursor-window))) vcursor-window) | |
428 | (winbuf) ; choice 4 | |
429 | (new-win (display-buffer (current-buffer) t)) ; choice 5 | |
430 | (t nil))))))) ; default (choice 6) | |
431 | vcursor-window | |
432 | ) | |
433 | ||
434 | (defun vcursor-toggle-copy (&optional arg nomsg) | |
435 | "Toggle copying to point when the vcursor is moved. | |
436 | With a prefix ARG, turn on if non-negative, off if negative. | |
437 | Display a message unless optional NOMSG is non-nil." | |
438 | (interactive "P") | |
439 | (setq vcursor-copy-flag | |
440 | (cond ((not arg) (not vcursor-copy-flag)) | |
441 | ((< (prefix-numeric-value arg) 0) nil) | |
442 | (t)) | |
443 | vcursor-last-command t) | |
444 | (or nomsg (message "Copying from the vcursor is now %s." | |
445 | (if vcursor-copy-flag "on" "off"))) | |
446 | ) | |
447 | ||
448 | (defun vcursor-move (pt) | |
449 | "Move the virtual cursor to the character to the right of PT. | |
450 | PT is an absolute location in the current buffer. | |
451 | ||
452 | If the new virtual cursor location would not be visible, display it in | |
453 | another window." | |
454 | ;; this works even if we're on-mass-shell, but usually we won't be. | |
455 | ||
456 | (if (eq pt (point-max)) (setq pt (1- pt))) | |
457 | (if (vcursor-check t) | |
458 | (move-overlay vcursor-overlay pt (+ pt 1) (current-buffer)) | |
459 | (setq vcursor-overlay (make-overlay pt (+ pt 1))) | |
460 | (overlay-put vcursor-overlay 'face 'vcursor)) | |
461 | (vcursor-find-window nil t) | |
462 | ;; vcursor-window now contains the right buffer | |
463 | (or (pos-visible-in-window-p pt vcursor-window) | |
464 | (set-window-point vcursor-window pt)) | |
465 | ) | |
466 | ||
467 | (defun vcursor-relative-move (fn &rest args) | |
468 | "Use FUNCTION with arbitrary ARG1 ... to move the virtual cursor. | |
469 | ||
470 | This is called by most of the virtual-cursor motion commands." | |
471 | (let (text opoint) | |
472 | (save-excursion | |
473 | (vcursor-locate) | |
474 | (setq opoint (point)) | |
475 | (apply fn args) | |
476 | (and (eq opoint (point-max)) (eq opoint (point)) | |
477 | (signal 'end-of-buffer nil)) | |
478 | (vcursor-move (point)) | |
479 | (if vcursor-copy-flag (setq text (buffer-substring opoint (point))))) | |
480 | (if text (insert text))) | |
481 | (setq vcursor-last-command t) | |
482 | ) | |
483 | ||
484 | (defun vcursor-goto (&optional arg) | |
485 | "Move the real cursor to the virtual cursor position. | |
486 | If the virtual cursor is (or was recently) visible in another window, | |
487 | switch to that first. Without a prefix ARG, disable the virtual | |
488 | cursor as well." | |
489 | ||
490 | (interactive "P") | |
491 | (and (vcursor-find-window) (select-window vcursor-window)) | |
492 | (let ((buf (and vcursor-overlay (overlay-buffer vcursor-overlay)))) | |
493 | (and buf (not (eq (current-buffer) buf)) (switch-to-buffer buf))) | |
494 | (vcursor-locate) | |
495 | (or arg (vcursor-disable)) | |
496 | ) | |
497 | ||
498 | (defun vcursor-swap-point () | |
499 | "Swap the location of point and that of the virtual cursor. | |
500 | ||
501 | The virtual cursor window becomes the selected window and the old | |
502 | window becomes the virtual cursor window. If the virtual cursor would | |
503 | not be visible otherwise, display it in another window." | |
504 | ||
505 | (interactive) | |
506 | (let ((buf (current-buffer)) (here (point)) (win (selected-window))) | |
507 | (vcursor-goto) ; will disable the vcursor | |
508 | (save-excursion | |
509 | (set-buffer buf) | |
510 | (setq vcursor-window win) | |
511 | (vcursor-move here))) | |
512 | ) | |
513 | ||
514 | (defun vcursor-scroll-up (&optional n) | |
515 | "Scroll up the vcursor window ARG lines or near full screen if none. | |
516 | The vcursor will always appear in an unselected window." | |
517 | ||
518 | (interactive "P") | |
519 | (vcursor-window-funcall 'scroll-up n) | |
520 | ) | |
521 | ||
522 | (defun vcursor-scroll-down (&optional n) | |
523 | "Scroll down the vcursor window ARG lines or near-full screen if none. | |
524 | The vcursor will always appear in an unselected window." | |
525 | ||
526 | (interactive "P") | |
527 | (vcursor-window-funcall 'scroll-down n) | |
528 | ) | |
529 | ||
530 | (defun vcursor-isearch-forward (&optional rep norecurs) | |
531 | "Perform forward incremental search in the virtual cursor window. | |
532 | The virtual cursor is moved to the resulting point; the ordinary | |
533 | cursor stays where it was." | |
534 | ||
535 | (interactive "P") | |
536 | (vcursor-window-funcall 'isearch-forward rep norecurs) | |
537 | ) | |
538 | ||
539 | (defun vcursor-window-funcall (func &rest args) | |
540 | "Call FUNC with ARGS ... in a virtual cursor window. | |
541 | A window other than the currently-selected one will always be used. | |
542 | The virtual cursor is moved to the value of point when the function | |
543 | returns." | |
544 | ||
545 | (vcursor-find-window t t) | |
546 | (let ((sw (selected-window)) text) | |
547 | ;; We can't use save-window-excursion because that would restore | |
548 | ;; the original display in the window we may want to alter. | |
549 | (unwind-protect | |
550 | (let ((here (point))) | |
551 | (select-window vcursor-window) | |
552 | (vcursor-locate) | |
553 | (apply func args) | |
554 | (if vcursor-copy-flag (setq text (buffer-substring here (point)))) | |
555 | (vcursor-move (point))) | |
556 | (select-window sw)) | |
557 | (if text (insert text))) | |
558 | (setq vcursor-last-command t) | |
559 | ) | |
560 | ||
561 | (defun vcursor-get-char-count (fn &rest args) | |
562 | "Apply FN to ARG1 ... and return the number of characters moved. | |
563 | Point is temporarily set to the virtual cursor position before FN is | |
564 | called. | |
565 | ||
566 | This is called by most of the virtual-cursor copying commands to find | |
567 | out how much to copy." | |
568 | ||
569 | (vcursor-check) | |
570 | (save-excursion | |
571 | (set-buffer (overlay-buffer vcursor-overlay)) | |
572 | (let ((start (goto-char (overlay-start vcursor-overlay)))) | |
573 | (- (progn (apply fn args) (point)) start))) | |
574 | ) | |
575 | ||
576 | ;; Make sure the virtual cursor is active. Unless arg is non-nil, | |
577 | ;; report an error if it is not. | |
578 | (defun vcursor-check (&optional arg) | |
579 | (cond | |
580 | ((and (overlayp vcursor-overlay) (overlay-start vcursor-overlay)) | |
581 | t) | |
582 | (arg nil) | |
583 | (t (error "The virtual cursor is not active now."))) | |
584 | ) | |
585 | ||
586 | (defun vcursor-disable (&optional arg) | |
587 | "Disable the virtual cursor. | |
588 | Next time you use it, it will start from point. | |
589 | ||
590 | With a positive prefix ARG, the first window in cyclic order | |
591 | displaying the virtual cursor (or which was recently displaying the | |
592 | virutal cursor) will be deleted unless it's the selected | |
593 | window. | |
594 | ||
595 | With a negative prefix argument, enable the virtual cursor: make it | |
596 | active at the same point as the real cursor. | |
597 | ||
598 | Copying mode is always turned off: the next use of the vcursor will | |
599 | not copy text until you turn it on again." | |
600 | ||
601 | (interactive "P") | |
602 | (if (overlayp vcursor-overlay) | |
603 | (progn | |
604 | (delete-overlay vcursor-overlay) | |
605 | (setq vcursor-overlay nil))) | |
606 | (cond | |
607 | ((not (vcursor-find-window t))) | |
608 | ((or (not arg) (< (prefix-numeric-value arg) 0))) | |
609 | ((delete-window vcursor-window))) | |
610 | (and arg (< (prefix-numeric-value arg) 0) | |
611 | (progn | |
612 | (vcursor-move (point)) | |
613 | (setq vcursor-window (selected-window)))) | |
614 | (setq vcursor-copy-flag nil) | |
615 | ) | |
616 | ||
617 | (defun vcursor-other-window (n &optional all-frames) | |
618 | "Activate the virtual cursor in another window. | |
619 | This is the next window cylically after one currently showing the | |
620 | virtual cursor, or else after the current selected window. If there | |
621 | is no other window, the current window is split. | |
622 | ||
623 | Arguments N and optional ALL-FRAMES are the same as with other-window. | |
624 | ALL-FRAMES is also used to decide whether to split the window." | |
625 | ||
626 | (interactive "p") | |
627 | (if (if (fboundp 'oemacs-version) | |
628 | (one-window-p nil) | |
629 | (one-window-p nil all-frames)) | |
630 | (display-buffer (current-buffer) t)) | |
631 | (save-excursion | |
632 | (save-window-excursion | |
633 | ;; We don't use fancy vcursor-find-window trickery, since we're | |
634 | ;; quite happy to have the vcursor cycle back into the current | |
635 | ;; window. | |
636 | (let ((sw (selected-window)) | |
637 | (win (vcursor-find-window nil nil (not all-frames)))) | |
638 | (if win (select-window win)) | |
639 | ;; else start from here | |
640 | (other-window n all-frames) | |
641 | (vcursor-disable -1)))) | |
642 | ) | |
643 | ||
644 | (defun vcursor-compare-windows (&optional arg) | |
645 | "Call `compare-windows' in the vcursor window. | |
646 | This has the effect of comparing the vcursor window with whichever | |
647 | window `next-window' returns there, which may not be the selected one. | |
648 | ||
649 | A prefix argument, if any, is passed to `compare-windows'." | |
650 | (interactive "P") | |
651 | (vcursor-window-funcall 'compare-windows arg)) | |
652 | ||
653 | (defun vcursor-next-line (arg) | |
654 | "Move the virtual cursor forward ARG lines." | |
655 | ;; This is next-line rewritten for the vcursor. Maybe it would | |
656 | ;; be easier simply to rewrite line-move. | |
657 | (interactive "p") | |
658 | (let (temporary-goal-column opoint text) | |
659 | (save-excursion | |
660 | (vcursor-locate) | |
661 | (setq temporary-goal-column | |
662 | (if (or (eq last-command 'vcursor-next-line) | |
663 | (eq last-command 'vcursor-previous-line)) | |
664 | (progn | |
665 | (setq last-command 'next-line) ; trick line-move | |
666 | vcursor-temp-goal-column) | |
667 | (if (and track-eol (eolp) | |
668 | (or (not (bolp)) (eq last-command 'end-of-line))) | |
669 | 9999 | |
670 | (current-column))) | |
671 | opoint (point)) | |
672 | (line-move arg) | |
673 | (and (eq opoint (point-max)) (eq opoint (point)) | |
674 | (signal 'end-of-buffer nil)) | |
675 | (if vcursor-copy-flag (setq text (buffer-substring opoint (point)))) | |
676 | (vcursor-move (point)) | |
677 | (setq vcursor-temp-goal-column temporary-goal-column | |
678 | vcursor-last-command t)) | |
679 | (if text (insert text))) | |
680 | ) | |
681 | ||
682 | (defun vcursor-previous-line (arg) | |
683 | "Move the virtual cursor back ARG lines." | |
684 | (interactive "p") | |
685 | (vcursor-next-line (- arg)) | |
686 | ) | |
687 | ||
688 | (defun vcursor-forward-char (arg) | |
689 | "Move the virtual cursor forward ARG characters." | |
690 | (interactive "p") | |
691 | (vcursor-relative-move 'forward-char arg) | |
692 | ) | |
693 | ||
694 | (defun vcursor-backward-char (arg) | |
695 | "Move the virtual cursor backward ARG characters." | |
696 | (interactive "p") | |
697 | (vcursor-relative-move 'backward-char arg) | |
698 | ) | |
699 | ||
700 | (defun vcursor-forward-word (arg) | |
701 | "Move the virtual cursor forward ARG words." | |
702 | (interactive "p") | |
703 | (vcursor-relative-move 'forward-word arg) | |
704 | ) | |
705 | ||
706 | (defun vcursor-backward-word (arg) | |
707 | "Move the virtual cursor backward ARG words." | |
708 | (interactive "p") | |
709 | (vcursor-relative-move 'backward-word arg) | |
710 | ) | |
711 | ||
712 | (defun vcursor-beginning-of-line (arg) | |
713 | "Move the virtual cursor to beginning of its current line. | |
714 | ARG is as for `beginning-of-line'." | |
715 | (interactive "P") | |
716 | (vcursor-relative-move 'beginning-of-line | |
717 | (if arg (prefix-numeric-value arg))) | |
718 | ) | |
719 | ||
720 | (defun vcursor-end-of-line (arg) | |
721 | "Move the virtual cursor to end of its current line. | |
722 | ARG is as for `end-of-line'." | |
723 | (interactive "P") | |
724 | (vcursor-relative-move 'end-of-line | |
725 | (if arg (prefix-numeric-value arg))) | |
726 | ) | |
727 | ||
728 | (defun vcursor-beginning-of-buffer (&optional arg) | |
729 | "Move the virtual cursor to the beginning of its buffer. | |
730 | ARG is as for beginning-of-buffer." | |
731 | (interactive "P") | |
732 | (vcursor-relative-move | |
733 | (lambda (arg) | |
734 | (goto-char (if arg (/ (* arg (- (point-max) (point-min))) 10) | |
735 | (point-min)))) | |
736 | (if arg (prefix-numeric-value arg))) | |
737 | ) | |
738 | ||
739 | (defun vcursor-end-of-buffer (&optional arg) | |
740 | "Move the virtual cursor to the end of its buffer. | |
741 | ARG is as for end-of-buffer. | |
742 | ||
743 | Actually, the vcursor is moved to the second from last character or it | |
744 | would be invisible." | |
745 | (interactive "P") | |
746 | (vcursor-relative-move | |
747 | (lambda (arg) | |
748 | (goto-char (if arg (- (point-max) | |
749 | (/ (* arg (- (point-max) (point-min))) 10)) | |
750 | (point-max)))) | |
751 | (if arg (prefix-numeric-value arg))) | |
752 | ) | |
753 | ||
754 | (defun vcursor-execute-command (cmd) | |
755 | "Execute COMMAND for the virtual cursor. | |
756 | COMMAND is called interactively. Not all commands (in fact, only a | |
757 | small subset) are useful." | |
758 | (interactive "CCommand: ") | |
759 | (let (text opoint) | |
760 | (save-excursion | |
761 | (vcursor-locate) | |
762 | (setq opoint (point)) | |
763 | (call-interactively cmd) | |
764 | (if vcursor-copy-flag (setq text (buffer-substring opoint (point)))) | |
765 | (vcursor-move (point))) | |
766 | (if text (insert text))) | |
767 | (setq vcursor-last-command t) | |
768 | ) | |
769 | ||
770 | (defun vcursor-execute-key (keys) | |
771 | "Execute the command bound to KEYS for the virtual cursor. | |
772 | The command found is called interactively, so prefix argument etc. | |
773 | are usable." | |
774 | ||
775 | (interactive "kKey sequence: ") | |
776 | (let ((cmd (key-binding keys))) | |
777 | (if cmd (vcursor-execute-command (key-binding keys)))) | |
778 | ) | |
779 | ||
780 | (defun vcursor-copy (arg) | |
781 | "Copy ARG characters from the virtual cursor position to point." | |
782 | (interactive "p") | |
783 | (vcursor-check) | |
784 | (insert | |
785 | (save-excursion | |
786 | (set-buffer (overlay-buffer vcursor-overlay)) | |
787 | (let* ((ostart (overlay-start vcursor-overlay)) | |
788 | (end (+ ostart arg))) | |
789 | (prog1 | |
790 | (buffer-substring ostart end) | |
791 | (vcursor-move end))))) | |
792 | (setq vcursor-last-command t) | |
793 | ) | |
794 | ||
795 | (defun vcursor-copy-word (arg) | |
796 | "Copy ARG words from the virtual cursor position to point." | |
797 | (interactive "p") | |
798 | (vcursor-copy (vcursor-get-char-count 'forward-word arg)) | |
799 | ) | |
800 | ||
801 | (defun vcursor-copy-line (arg) | |
802 | "Copy up to ARGth line after virtual cursor position. | |
803 | With no argument, copy to the end of the current line. | |
804 | ||
805 | Behaviour with regard to newlines is similar (but not identical) to | |
806 | `kill-line'; the main difference is that whitespace at the end of the | |
807 | line is treated like ordinary characters." | |
808 | ||
809 | (interactive "P") | |
810 | (let* ((num (prefix-numeric-value arg)) | |
811 | (count (vcursor-get-char-count 'end-of-line num))) | |
812 | (vcursor-copy (if (or (= count 0) arg) (1+ count) count))) | |
813 | ) | |
814 | ||
815 | (defun vcursor-post-command () | |
816 | (and vcursor-auto-disable (not vcursor-last-command) | |
817 | vcursor-overlay (vcursor-disable)) | |
818 | (setq vcursor-last-command nil) | |
819 | ) | |
820 | ||
821 | (add-hook 'post-command-hook 'vcursor-post-command) | |
822 | ||
823 | (provide 'vcursor) | |
824 | ||
825 | ;; vcursor.el ends here |