1;;; avoid.el --- make mouse pointer stay out of the way of editing
2
3;; Copyright (C) 1993, 1994, 2000, 2001, 2002, 2003, 2004,
4;;   2005, 2006, 2007 Free Software Foundation, Inc.
5
6;; Author: Boris Goldowsky <boris@gnu.org>
7;; Keywords: mouse
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 2, or (at your option)
14;; 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; see the file COPYING.  If not, write to the
23;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
24;; Boston, MA 02110-1301, USA.
25
26;;; Commentary:
27
28;; For those who are annoyed by the mouse pointer obscuring text,
29;; this mode moves the mouse pointer - either just a little out of
30;; the way, or all the way to the corner of the frame.
31;; To use, load or evaluate this file and type M-x mouse-avoidance-mode .
32;; To set up permanently, put the following in your .emacs:
33;;
34;; (if (display-mouse-p) (mouse-avoidance-mode 'animate))
35;;
36;; Other legitimate alternatives include
37;; `banish', `exile', `jump', `cat-and-mouse', and `proteus'.
38;; They do somewhat different things.
39;; See the documentation for function `mouse-avoidance-mode' for
40;; details of the different modes.
41;;
42;; For added silliness, make the animatee animate...
43;; put something similar to the following into your .emacs:
44;;
45;; (if (eq window-system 'x)
46;;     (mouse-avoidance-set-pointer-shape
47;;	     (eval (nth (random 4)
48;;			'(x-pointer-man x-pointer-spider
49;;			  x-pointer-gobbler x-pointer-gumby)))))
50;;
51;; For completely random pointer shape, replace the setq above with:
52;; (setq x-pointer-shape (mouse-avoidance-random-shape))
53;;
54;; Bugs / Warnings / To-Do:
55;;
56;; - Using this code does slow Emacs down.  "banish" mode shouldn't
57;;   be too bad, and on my workstation even "animate" is reasonable.
58;;
59;; - It ought to find out where any overlapping frames are and avoid them,
60;;   rather than always raising the frame.
61
62;; Credits:
63;; This code was helped by all those who contributed suggestions,
64;;   fixes, and additions
65;; Joe Harrington (and his advisor), for the original inspiration.
66;; Ken Manheimer, for dreaming up the Protean mode.
67;; Richard Stallman, for the awful cat-and-mouse pun, among other things.
68;; Mike Williams, Denis Howe, Bill Benedetto, Chris Moore, Don Morris,
69;; Simon Marshall, and M.S. Ashton, for their feedback.
70
71;;; Code:
72
73(provide 'avoid)
74
75(defgroup avoid nil
76  "Make mouse pointer stay out of the way of editing."
77  :prefix "mouse-avoidance-"
78  :group 'mouse)
79
80;;;###autoload
81(defcustom mouse-avoidance-mode nil
82  "Activate mouse avoidance mode.
83See function `mouse-avoidance-mode' for possible values.
84Setting this variable directly does not take effect;
85use either \\[customize] or the function `mouse-avoidance-mode'."
86  :set (lambda (symbol value)
87	 ;; 'none below prevents toggling when value is nil.
88	 (mouse-avoidance-mode (or value 'none)))
89  :initialize 'custom-initialize-default
90  :type '(choice (const :tag "none" nil) (const banish) (const jump)
91		 (const animate) (const exile) (const proteus)
92		 )
93  :group 'avoid
94  :require 'avoid
95  :version "20.3")
96
97
98(defcustom mouse-avoidance-nudge-dist 15
99  "*Average distance that mouse will be moved when approached by cursor.
100Only applies in Mouse-Avoidance mode `jump' and its derivatives.
101For best results make this larger than `mouse-avoidance-threshold'."
102  :type 'integer
103  :group 'avoid)
104
105(defcustom mouse-avoidance-nudge-var 10
106  "*Variability of `mouse-avoidance-nudge-dist' (which see)."
107  :type 'integer
108  :group 'avoid)
109
110(defcustom mouse-avoidance-animation-delay .01
111  "Delay between animation steps, in seconds."
112  :type 'number
113  :group 'avoid)
114
115(defcustom mouse-avoidance-threshold 5
116  "*Mouse-pointer's flight distance.
117If the cursor gets closer than this, the mouse pointer will move away.
118Only applies in mouse-avoidance-modes `animate' and `jump'."
119  :type 'integer
120  :group 'avoid)
121
122;; Internal variables
123(defvar mouse-avoidance-state nil)
124(defvar mouse-avoidance-pointer-shapes nil)
125(defvar mouse-avoidance-n-pointer-shapes 0)
126(defvar mouse-avoidance-old-pointer-shape nil)
127(defvar mouse-avoidance-animating-pointer nil)
128
129;; This timer is used to run something when Emacs is idle.
130(defvar mouse-avoidance-timer nil)
131
132;;; Functions:
133
134(defsubst mouse-avoidance-set-pointer-shape (shape)
135  "Set the shape of the mouse pointer to SHAPE."
136  (when (boundp 'x-pointer-shape)
137    (setq x-pointer-shape shape)
138    (set-mouse-color nil)))
139
140(defun mouse-avoidance-point-position ()
141  "Return the position of point as (FRAME X . Y).
142Analogous to `mouse-position'."
143  (let ((edges (window-inside-edges))
144	(x-y (posn-x-y (posn-at-point))))
145    (cons (selected-frame)
146	  (cons (+ (car edges)
147		   (/ (car x-y) (frame-char-width)))
148		(+ (car (cdr edges))
149		   (/ (cdr x-y) (frame-char-height)))))))
150
151;(defun mouse-avoidance-point-position-test ()
152;  (interactive)
153;  (message (format "point=%s mouse=%s"
154;		   (cdr (mouse-avoidance-point-position))
155;		   (cdr (mouse-position)))))
156
157(defun mouse-avoidance-set-mouse-position (pos)
158  ;; Carefully set mouse position to given position (X . Y)
159  ;; Ideally, should check if X,Y is in the current frame, and if not,
160  ;; leave the mouse where it was.  However, this is currently
161  ;; difficult to do, so we just raise the frame to avoid frame switches.
162  ;; Returns t if it moved the mouse.
163  (let ((f (selected-frame)))
164    (raise-frame f)
165    (set-mouse-position f (car pos) (cdr pos))
166    t))
167
168(defun mouse-avoidance-too-close-p (mouse)
169  "Return t if mouse pointer and point cursor are too close.
170MOUSE is the current mouse position as returned by `mouse-position'.
171Acceptable distance is defined by `mouse-avoidance-threshold'."
172  (let* ((frame (car mouse))
173	 (mouse-y (cdr (cdr mouse)))
174	 (tool-bar-lines (frame-parameter nil 'tool-bar-lines)))
175    (or tool-bar-lines
176	(setq tool-bar-lines 0))
177    (if (and mouse-y (< mouse-y tool-bar-lines))
178	nil
179      (let ((point (mouse-avoidance-point-position))
180	    (mouse-x (car (cdr mouse))))
181	(and (eq frame (car point))
182	     (not (null mouse-x))
183	     (< (abs (- mouse-x (car (cdr point))))
184		mouse-avoidance-threshold)
185	     (< (abs (- mouse-y (cdr (cdr point))))
186		mouse-avoidance-threshold))))))
187
188(defun mouse-avoidance-banish-destination ()
189  "The position to which Mouse-Avoidance mode `banish' moves the mouse.
190You can redefine this if you want the mouse banished to a different corner."
191  (let* ((pos (window-edges)))
192    (cons (- (nth 2 pos) 2)
193	  (nth 1 pos))))
194
195(defun mouse-avoidance-banish-mouse ()
196  ;; Put the mouse pointer in the upper-right corner of the current frame.
197  (mouse-avoidance-set-mouse-position (mouse-avoidance-banish-destination)))
198
199(defsubst mouse-avoidance-delta (cur delta dist var min max)
200  ;; Decide how far to move in either dimension.
201  ;; Args are the CURRENT location, the desired DELTA for
202  ;; warp-conservation, the DISTANCE we like to move, the VARIABILITY
203  ;; in distance allowed, and the MIN and MAX possible window positions.
204  ;; Returns something as close to DELTA as possible within the constraints.
205  (let ((L1 (max (- min cur) (+ (- dist) (- var))))
206	(R1                  (+ (- dist)    var ))
207	(L2                  (+    dist  (- var)))
208	(R2 (min (- max cur) (+    dist     var))))
209    (if (< R1 (- min cur)) (setq L1 nil R1 nil))
210    (if (> L2 (- max cur)) (setq L2 nil R2 nil))
211    (cond ((and L1 (< delta L1)) L1)
212	  ((and R1 (< delta R1)) delta)
213	  ((and R1 (< delta 0)) R1)
214	  ((and L2 (< delta L2)) L2)
215	  ((and R2 (< delta R2)) delta)
216	  (R2)
217	  ((or R1 L2))
218	  (t 0))))
219
220(defun mouse-avoidance-nudge-mouse ()
221  ;; Push the mouse a little way away, possibly animating the move.
222  ;; For these modes, state keeps track of the total offset that we've
223  ;; accumulated, and tries to keep it close to zero.
224  (let* ((cur (mouse-position))
225	 (cur-frame (car cur))
226	 (cur-pos (cdr cur))
227 	 (pos (window-edges))
228 	 (wleft (pop pos))
229 	 (wtop (pop pos))
230 	 (wright (pop pos))
231 	 (wbot (pop pos))
232	 (deltax (mouse-avoidance-delta
233		  (car cur-pos) (- (random mouse-avoidance-nudge-var)
234				   (car mouse-avoidance-state))
235		  mouse-avoidance-nudge-dist mouse-avoidance-nudge-var
236		  wleft (1- wright)))
237	 (deltay (mouse-avoidance-delta
238		  (cdr cur-pos) (- (random mouse-avoidance-nudge-var)
239				   (cdr mouse-avoidance-state))
240		  mouse-avoidance-nudge-dist mouse-avoidance-nudge-var
241		  wtop (1- wbot))))
242    (setq mouse-avoidance-state
243	  (cons (+ (car mouse-avoidance-state) deltax)
244		(+ (cdr mouse-avoidance-state) deltay)))
245    (if (or (eq mouse-avoidance-mode 'animate)
246	    (eq mouse-avoidance-mode 'proteus))
247	(let ((i 0.0)
248	      (incr (max .1 (/ 1.0 mouse-avoidance-nudge-dist))))
249	  (setq mouse-avoidance-animating-pointer t)
250	  (while (<= i 1)
251	    (mouse-avoidance-set-mouse-position
252	     (cons (+ (car cur-pos) (round (* i deltax)))
253		   (+ (cdr cur-pos) (round (* i deltay)))))
254    	    (setq i (+ i incr))
255	    (if (eq mouse-avoidance-mode 'proteus)
256		(mouse-avoidance-set-pointer-shape
257		 (mouse-avoidance-random-shape)))
258	    (sit-for mouse-avoidance-animation-delay))
259	  (setq mouse-avoidance-animating-pointer nil))
260      (mouse-avoidance-set-mouse-position (cons (+ (car (cdr cur)) deltax)
261						(+ (cdr (cdr cur)) deltay))))))
262
263(defun mouse-avoidance-random-shape ()
264  "Return a random cursor shape.
265This assumes that any variable whose name begins with x-pointer- and
266has an integer value is a valid cursor shape.  You might want to
267redefine this function to suit your own tastes."
268  (if (null mouse-avoidance-pointer-shapes)
269      (progn
270	(setq mouse-avoidance-pointer-shapes
271	      (mapcar (lambda (x) (symbol-value (intern x)))
272		      (all-completions "x-pointer-" obarray
273				       (lambda (x)
274					  (and (boundp x)
275					       (integerp (symbol-value x)))))))
276	(setq mouse-avoidance-n-pointer-shapes
277	      (length mouse-avoidance-pointer-shapes))))
278  (nth (random mouse-avoidance-n-pointer-shapes)
279       mouse-avoidance-pointer-shapes))
280
281(defun mouse-avoidance-ignore-p ()
282  (let ((mp (mouse-position)))
283    (or executing-kbd-macro	       ; don't check inside macro
284	(null (cadr mp))	       ; don't move unless in an Emacs frame
285	(not (eq (car mp) (selected-frame)))
286	;; Don't do anything if last event was a mouse event.
287	;; FIXME: this code fails in the case where the mouse was moved
288	;; since the last key-press but without generating any event.
289	(and (consp last-input-event)
290	     (symbolp (car last-input-event))
291	     (let ((modifiers (event-modifiers (car last-input-event))))
292	       (or (memq (car last-input-event)
293			 '(mouse-movement scroll-bar-movement
294			   select-window switch-frame))
295		   (memq 'click modifiers)
296		   (memq 'double modifiers)
297		   (memq 'triple modifiers)
298		   (memq 'drag modifiers)
299		   (memq 'down modifiers)))))))
300
301(defun mouse-avoidance-banish ()
302  (if (not (mouse-avoidance-ignore-p))
303      (mouse-avoidance-banish-mouse)))
304
305(defun mouse-avoidance-exile ()
306  ;; For exile mode, the state is nil when the mouse is in its normal
307  ;; position, and set to the old mouse-position when the mouse is in exile.
308  (if (not (mouse-avoidance-ignore-p))
309      (let ((mp (mouse-position)))
310	(cond ((and (not mouse-avoidance-state)
311		    (mouse-avoidance-too-close-p mp))
312	       (setq mouse-avoidance-state mp)
313	       (mouse-avoidance-banish-mouse))
314	      ((and mouse-avoidance-state
315		    (not (mouse-avoidance-too-close-p mouse-avoidance-state)))
316	       (if (and (eq (car mp) (selected-frame))
317			(equal (cdr mp) (mouse-avoidance-banish-destination)))
318		   (mouse-avoidance-set-mouse-position
319		    ;; move back only if user has not moved mouse
320		    (cdr mouse-avoidance-state)))
321	       ;; but clear state anyway, to be ready for another move
322	       (setq mouse-avoidance-state nil))))))
323
324(defun mouse-avoidance-fancy ()
325  ;; Used for the "fancy" modes, ie jump et al.
326  (if (and (not mouse-avoidance-animating-pointer)
327	   (not (mouse-avoidance-ignore-p))
328	   (mouse-avoidance-too-close-p (mouse-position)))
329      (let ((old-pos (mouse-position)))
330	(mouse-avoidance-nudge-mouse)
331	(if (not (eq (selected-frame) (car old-pos)))
332	    ;; This should never happen.
333	    (apply 'set-mouse-position old-pos)))))
334
335;;;###autoload
336(defun mouse-avoidance-mode (&optional mode)
337  "Set cursor avoidance mode to MODE.
338MODE should be one of the symbols `banish', `exile', `jump', `animate',
339`cat-and-mouse', `proteus', or `none'.
340
341If MODE is nil, toggle mouse avoidance between `none' and `banish'
342modes.  Positive numbers and symbols other than the above are treated
343as equivalent to `banish'; negative numbers and `-' are equivalent to `none'.
344
345Effects of the different modes:
346 * banish: Move the mouse to the upper-right corner on any keypress.
347 * exile: Move the mouse to the corner only if the cursor gets too close,
348     and allow it to return once the cursor is out of the way.
349 * jump: If the cursor gets too close to the mouse, displace the mouse
350     a random distance & direction.
351 * animate: As `jump', but shows steps along the way for illusion of motion.
352 * cat-and-mouse: Same as `animate'.
353 * proteus: As `animate', but changes the shape of the mouse pointer too.
354
355Whenever the mouse is moved, the frame is also raised.
356
357\(see `mouse-avoidance-threshold' for definition of \"too close\",
358and `mouse-avoidance-nudge-dist' and `mouse-avoidance-nudge-var' for
359definition of \"random distance\".)"
360  (interactive
361   (list (intern (completing-read
362		  "Select cursor avoidance technique (SPACE for list): "
363		  '(("banish") ("exile") ("jump") ("animate")
364		    ("cat-and-mouse") ("proteus") ("none"))
365		  nil t))))
366  (if (eq mode 'cat-and-mouse)
367      (setq mode 'animate))
368  (if mouse-avoidance-timer
369      (cancel-timer mouse-avoidance-timer))
370  (setq mouse-avoidance-timer nil)
371
372  ;; Restore pointer shape if necessary
373  (if (eq mouse-avoidance-mode 'proteus)
374      (mouse-avoidance-set-pointer-shape mouse-avoidance-old-pointer-shape))
375
376  ;; Do additional setup depending on version of mode requested
377  (cond	((eq mode 'none)
378	 (setq mouse-avoidance-mode nil))
379	((or (eq mode 'jump)
380	     (eq mode 'animate)
381	     (eq mode 'proteus))
382	 (setq mouse-avoidance-timer
383	       (run-with-idle-timer 0.1 t 'mouse-avoidance-fancy))
384	 (setq mouse-avoidance-mode mode
385	       mouse-avoidance-state (cons 0 0)
386	       mouse-avoidance-old-pointer-shape
387	       (and (boundp 'x-pointer-shape) x-pointer-shape)))
388	((eq mode 'exile)
389	 (setq mouse-avoidance-timer
390	       (run-with-idle-timer 0.1 t 'mouse-avoidance-exile))
391	 (setq mouse-avoidance-mode mode
392	       mouse-avoidance-state nil))
393	((or (eq mode 'banish)
394	     (eq mode t)
395	     (and (null mode) (null mouse-avoidance-mode))
396	     (and mode (> (prefix-numeric-value mode) 0)))
397	 (setq mouse-avoidance-timer
398	       (run-with-idle-timer 0.1 t 'mouse-avoidance-banish))
399	 (setq mouse-avoidance-mode 'banish))
400	(t (setq mouse-avoidance-mode nil)))
401  (force-mode-line-update))
402
403;; Most people who use avoid mode leave it on all the time, so it's not
404;; very informative to announce it in the mode line.
405;;(or (assq 'mouse-avoidance-mode minor-mode-alist)
406;;    (setq minor-mode-alist (cons '(mouse-avoidance-mode " Avoid")
407;;				 minor-mode-alist)))
408
409;; Needed for custom.
410(if mouse-avoidance-mode
411    (mouse-avoidance-mode mouse-avoidance-mode))
412
413;; arch-tag: 64ad4ef8-a870-4183-8d96-3aa93b7a6800
414;;; avoid.el ends here
415