lisp/avoid.el

   1 ;;; avoid.el --- make mouse pointer stay out of the way of editing
   2
   3 ;; Copyright (C) 1993-1994, 2000-2017 Free Software Foundation, Inc.
   4
   5 ;; Author: Boris Goldowsky <boris@gnu.org>
   6 ;; Keywords: mouse
   7
   8 ;; This file is part of GNU Emacs.
   9
  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 3 of the License, or
  13 ;; (at your option) any later version.
  14
  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.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;; For those who are annoyed by the mouse pointer obscuring text,
  26 ;; this mode moves the mouse pointer - either just a little out of
  27 ;; the way, or all the way to the corner of the frame.
  28 ;; To use, load or evaluate this file and type M-x mouse-avoidance-mode .
  29 ;; To set up permanently, put the following in your .emacs:
  30 ;;
  31 ;; (if (display-mouse-p) (mouse-avoidance-mode 'animate))
  32 ;;
  33 ;; Other legitimate alternatives include
  34 ;; `banish', `exile', `jump', `cat-and-mouse', and `proteus'.
  35 ;; They do somewhat different things.
  36 ;; See the documentation for function `mouse-avoidance-mode' for
  37 ;; details of the different modes.
  38 ;;
  39 ;; For added silliness, make the animatee animate...
  40 ;; put something similar to the following into your .emacs:
  41 ;;
  42 ;; (if (eq window-system 'x)
  43 ;;     (mouse-avoidance-set-pointer-shape
  44 ;;           (nth (random 4)
  45 ;;                (list x-pointer-man x-pointer-spider
  46 ;;                      x-pointer-gobbler x-pointer-gumby))))
  47 ;;
  48 ;; For completely random pointer shape, replace the setq above with:
  49 ;; (setq x-pointer-shape (mouse-avoidance-random-shape))
  50 ;;
  51 ;; Bugs / Warnings / To-Do:
  52 ;;
  53 ;; - Using this code does slow Emacs down.  "banish" mode shouldn't
  54 ;;   be too bad, and on my workstation even "animate" is reasonable.
  55
  56 ;; Credits:
  57 ;; This code was helped by all those who contributed suggestions,
  58 ;;   fixes, and additions
  59 ;; Joe Harrington (and his advisor), for the original inspiration.
  60 ;; Ken Manheimer, for dreaming up the Protean mode.
  61 ;; Richard Stallman, for the awful cat-and-mouse pun, among other things.
  62 ;; Mike Williams, Denis Howe, Bill Benedetto, Chris Moore, Don Morris,
  63 ;; Simon Marshall, and M.S. Ashton, for their feedback.
  64
  65 ;;; Code:
  66
  67 (eval-when-compile (require 'cl-lib))
  68
  69 (defgroup avoid nil
  70   "Make mouse pointer stay out of the way of editing."
  71   :prefix "mouse-avoidance-"
  72   :group 'mouse)
  73
  74 ;;;###autoload
  75 (defcustom mouse-avoidance-mode nil
  76   "Activate Mouse Avoidance mode.
  77 See function `mouse-avoidance-mode' for possible values.
  78 Setting this variable directly does not take effect;
  79 use either \\[customize] or the function `mouse-avoidance-mode'."
  80   :set (lambda (_symbol value)
  81          ;; 'none below prevents toggling when value is nil.
  82          (mouse-avoidance-mode (or value 'none)))
  83   :initialize 'custom-initialize-default
  84   :type '(choice (const :tag "none" nil) (const banish) (const jump)
  85                  (const animate) (const exile) (const proteus))
  86   :group 'avoid
  87   :require 'avoid
  88   :version "20.3")
  89
  90
  91 (defcustom mouse-avoidance-nudge-dist 15
  92   "Average distance that mouse will be moved when approached by cursor.
  93 Only applies in Mouse Avoidance mode `jump' and its derivatives.
  94 For best results make this larger than `mouse-avoidance-threshold'."
  95   :type 'integer
  96   :group 'avoid)
  97
  98 (defcustom mouse-avoidance-nudge-var 10
  99   "Variability of `mouse-avoidance-nudge-dist' (which see)."
 100   :type 'integer
 101   :group 'avoid)
 102
 103 (defcustom mouse-avoidance-animation-delay .01
 104   "Delay between animation steps, in seconds."
 105   :type 'number
 106   :group 'avoid)
 107
 108 (defcustom mouse-avoidance-threshold 5
 109   "Mouse-pointer's flight distance.
 110 If the cursor gets closer than this, the mouse pointer will move away.
 111 Only applies in Mouse Avoidance modes `animate' and `jump'."
 112   :type 'integer
 113   :group 'avoid)
 114
 115 (defcustom mouse-avoidance-banish-position '((frame-or-window . frame)
 116                                              (side . right)
 117                                              (side-pos . 3)
 118                                              (top-or-bottom . top)
 119                                              (top-or-bottom-pos . 0))
 120   "Position to which Mouse Avoidance mode `banish' moves the mouse.
 121 An alist where keywords mean:
 122 FRAME-OR-WINDOW: banish the mouse to corner of frame or window.
 123 SIDE: banish the mouse on right or left corner of frame or window.
 124 SIDE-POS: Distance from right or left edge of frame or window.
 125 TOP-OR-BOTTOM: banish the mouse to top or bottom of frame or window.
 126 TOP-OR-BOTTOM-POS: Distance from top or bottom edge of frame or window."
 127   :group   'avoid
 128   :version "24.3"
 129   :type    '(alist :key-type symbol :value-type (choice symbol integer))
 130   :options '((frame-or-window symbol) (side symbol) (side-pos integer)
 131              (top-or-bottom symbol) (top-or-bottom-pos integer)))
 132
 133 ;; Internal variables
 134 (defvar mouse-avoidance-state nil)
 135 (defvar mouse-avoidance-pointer-shapes nil)
 136 (defvar mouse-avoidance-n-pointer-shapes 0)
 137 (defvar mouse-avoidance-old-pointer-shape nil)
 138 (defvar mouse-avoidance-animating-pointer nil)
 139
 140 ;; This timer is used to run something when Emacs is idle.
 141 (defvar mouse-avoidance-timer nil)
 142
 143 ;;; Functions:
 144
 145 (defsubst mouse-avoidance-set-pointer-shape (shape)
 146   "Set the shape of the mouse pointer to SHAPE."
 147   (when (boundp 'x-pointer-shape)
 148     (setq x-pointer-shape shape)
 149     (set-mouse-color nil)))
 150
 151 (defun mouse-avoidance-point-position ()
 152   "Return the position of point as (FRAME X . Y).
 153 Analogous to `mouse-position'."
 154   (let* ((edges (window-inside-edges))
 155          (posn-at-point (posn-at-point))
 156          (x-y (and posn-at-point (posn-x-y posn-at-point))))
 157     (when x-y
 158       (cons (selected-frame)
 159             (cons (+ (car edges)
 160                      (/ (car x-y) (frame-char-width)))
 161                   (+ (car (cdr edges))
 162                      (/ (cdr x-y) (frame-char-height))))))))
 163
 164 ;(defun mouse-avoidance-point-position-test ()
 165 ;  (interactive)
 166 ;  (message "point=%s mouse=%s"
 167 ;           (cdr (mouse-avoidance-point-position))
 168 ;           (cdr (mouse-position))))
 169
 170 (defun mouse-avoidance-set-mouse-position (pos)
 171   ;; Carefully set mouse position to given position (X . Y)
 172   ;; Returns t if it moved the mouse.
 173   (let ((f (selected-frame)))
 174     (set-mouse-position f (car pos) (cdr pos))
 175     t))
 176
 177 (defun mouse-avoidance-too-close-p (mouse)
 178   "Return t if mouse pointer and point cursor are too close.
 179 MOUSE is the current mouse position as returned by `mouse-position'.
 180 Acceptable distance is defined by `mouse-avoidance-threshold'."
 181   (let* ((frame (car mouse))
 182          (mouse-y (cdr (cdr mouse)))
 183          (tool-bar-lines (frame-parameter nil 'tool-bar-lines))
 184          point)
 185     (or tool-bar-lines
 186         (setq tool-bar-lines 0))
 187     (cond
 188      ((and mouse-y (< mouse-y tool-bar-lines))
 189       nil)
 190      ((setq point (mouse-avoidance-point-position))
 191       (let ((mouse-x (car (cdr mouse))))
 192         (and (eq frame (car point))
 193              (not (null mouse-x))
 194              (< (abs (- mouse-x (car (cdr point))))
 195                 mouse-avoidance-threshold)
 196              (< (abs (- mouse-y (cdr (cdr point))))
 197                 mouse-avoidance-threshold)))))))
 198
 199 (defun mouse-avoidance-banish-destination ()
 200   "The position to which Mouse Avoidance mode `banish' moves the mouse.
 201
 202 If you want the mouse banished to a different corner set
 203 `mouse-avoidance-banish-position' as you need."
 204   (let* ((fra-or-win         (assoc-default
 205                               'frame-or-window
 206                               mouse-avoidance-banish-position 'eq))
 207          (list-values        (pcase fra-or-win
 208                                (`frame (list 0 0 (frame-width) (frame-height)))
 209                                (`window (window-edges))))
 210          (alist              (cl-loop for v in list-values
 211                                       for k in '(left top right bottom)
 212                                       collect (cons k v)))
 213          (side               (assoc-default
 214                               'side
 215                               mouse-avoidance-banish-position #'eq))
 216          (side-dist          (assoc-default
 217                               'side-pos
 218                               mouse-avoidance-banish-position #'eq))
 219          (top-or-bottom      (assoc-default
 220                               'top-or-bottom
 221                               mouse-avoidance-banish-position #'eq))
 222          (top-or-bottom-dist (assoc-default
 223                               'top-or-bottom-pos
 224                               mouse-avoidance-banish-position #'eq))
 225          (side-fn            (pcase side
 226                                (`left '+)
 227                                (`right '-)))
 228          (top-or-bottom-fn   (pcase top-or-bottom
 229                                (`top '+)
 230                                (`bottom '-))))
 231     (cons (funcall side-fn                        ; -/+
 232                    (assoc-default side alist 'eq) ; right or left
 233                    side-dist)                     ; distance from side
 234           (funcall top-or-bottom-fn                        ; -/+
 235                    (assoc-default top-or-bottom alist 'eq) ; top/bottom
 236                    top-or-bottom-dist)))) ; distance from top/bottom
 237
 238 (defun mouse-avoidance-banish-mouse ()
 239   "Put the mouse pointer to `mouse-avoidance-banish-position'."
 240   (mouse-avoidance-set-mouse-position (mouse-avoidance-banish-destination)))
 241
 242 (defsubst mouse-avoidance-delta (cur delta dist var min max)
 243   ;; Decide how far to move in either dimension.
 244   ;; Args are the CURRENT location, the desired DELTA for
 245   ;; warp-conservation, the DISTANCE we like to move, the VARIABILITY
 246   ;; in distance allowed, and the MIN and MAX possible window positions.
 247   ;; Returns something as close to DELTA as possible within the constraints.
 248   (let ((L1 (max (- min cur) (+ (- dist) (- var))))
 249         (R1                  (+ (- dist)    var ))
 250         (L2                  (+    dist  (- var)))
 251         (R2 (min (- max cur) (+    dist     var))))
 252     (if (< R1 (- min cur)) (setq L1 nil R1 nil))
 253     (if (> L2 (- max cur)) (setq L2 nil R2 nil))
 254     (cond ((and L1 (< delta L1)) L1)
 255           ((and R1 (< delta R1)) delta)
 256           ((and R1 (< delta 0)) R1)
 257           ((and L2 (< delta L2)) L2)
 258           ((and R2 (< delta R2)) delta)
 259           (R2)
 260           ((or R1 L2))
 261           (t 0))))
 262
 263 (defun mouse-avoidance-nudge-mouse ()
 264   ;; Push the mouse a little way away, possibly animating the move.
 265   ;; For these modes, state keeps track of the total offset that we've
 266   ;; accumulated, and tries to keep it close to zero.
 267   (let* ((cur (mouse-position))
 268          (cur-pos (cdr cur))
 269          (pos (window-edges))
 270          (wleft (pop pos))
 271          (wtop (pop pos))
 272          (wright (pop pos))
 273          (wbot (pop pos))
 274          (deltax (mouse-avoidance-delta
 275                   (car cur-pos) (- (random mouse-avoidance-nudge-var)
 276                                    (car mouse-avoidance-state))
 277                   mouse-avoidance-nudge-dist mouse-avoidance-nudge-var
 278                   wleft (1- wright)))
 279          (deltay (mouse-avoidance-delta
 280                   (cdr cur-pos) (- (random mouse-avoidance-nudge-var)
 281                                    (cdr mouse-avoidance-state))
 282                   mouse-avoidance-nudge-dist mouse-avoidance-nudge-var
 283                   wtop (1- wbot))))
 284     (setq mouse-avoidance-state
 285           (cons (+ (car mouse-avoidance-state) deltax)
 286                 (+ (cdr mouse-avoidance-state) deltay)))
 287     (if (or (eq mouse-avoidance-mode 'animate)
 288             (eq mouse-avoidance-mode 'proteus))
 289         (let ((i 0.0)
 290               (incr (max .1 (/ 1.0 mouse-avoidance-nudge-dist))))
 291           (setq mouse-avoidance-animating-pointer t)
 292           (while (<= i 1)
 293             (mouse-avoidance-set-mouse-position
 294              (cons (+ (car cur-pos) (round (* i deltax)))
 295                    (+ (cdr cur-pos) (round (* i deltay)))))
 296             (setq i (+ i incr))
 297             (if (eq mouse-avoidance-mode 'proteus)
 298                 (mouse-avoidance-set-pointer-shape
 299                  (mouse-avoidance-random-shape)))
 300             (sit-for mouse-avoidance-animation-delay))
 301           (setq mouse-avoidance-animating-pointer nil))
 302       (mouse-avoidance-set-mouse-position (cons (+ (car (cdr cur)) deltax)
 303                                                 (+ (cdr (cdr cur)) deltay))))))
 304
 305 (defun mouse-avoidance-random-shape ()
 306   "Return a random cursor shape.
 307 This assumes that any variable whose name begins with x-pointer- and
 308 has an integer value is a valid cursor shape.  You might want to
 309 redefine this function to suit your own tastes."
 310   (if (null mouse-avoidance-pointer-shapes)
 311       (progn
 312         (setq mouse-avoidance-pointer-shapes
 313               (mapcar (lambda (x) (symbol-value (intern x)))
 314                       (all-completions "x-pointer-" obarray
 315                                        (lambda (x)
 316                                           (and (boundp x)
 317                                                (integerp (symbol-value x)))))))
 318         (setq mouse-avoidance-n-pointer-shapes
 319               (length mouse-avoidance-pointer-shapes))))
 320   (nth (random mouse-avoidance-n-pointer-shapes)
 321        mouse-avoidance-pointer-shapes))
 322
 323 (defun mouse-avoidance-ignore-p ()
 324   (let ((mp (mouse-position)))
 325     (or (not (frame-pointer-visible-p)) ; The pointer is hidden
 326         (not cursor-type)               ; There's no cursor
 327         executing-kbd-macro            ; don't check inside macro
 328         (null (cadr mp))               ; don't move unless in an Emacs frame
 329         (not (eq (car mp) (selected-frame)))
 330         ;; Don't do anything if last event was a mouse event.
 331         ;; FIXME: this code fails in the case where the mouse was moved
 332         ;; since the last key-press but without generating any event.
 333         (and (consp last-input-event)
 334              (symbolp (car last-input-event))
 335              (let ((modifiers (event-modifiers (car last-input-event))))
 336                (or (memq (car last-input-event)
 337                          '(mouse-movement scroll-bar-movement
 338                            select-window focus-out))
 339                    (memq 'click modifiers)
 340                    (memq 'double modifiers)
 341                    (memq 'triple modifiers)
 342                    (memq 'drag modifiers)
 343                    (memq 'down modifiers)
 344                    (memq 'meta modifiers)
 345                    (memq 'control modifiers)
 346                    (memq 'shift modifiers)
 347                    (memq 'hyper modifiers)
 348                    (memq 'super modifiers)
 349                    (memq 'alt modifiers)))))))
 350
 351 (defun mouse-avoidance-banish ()
 352   (if (not (mouse-avoidance-ignore-p))
 353       (mouse-avoidance-banish-mouse)))
 354
 355 (defun mouse-avoidance-exile ()
 356   ;; For exile mode, the state is nil when the mouse is in its normal
 357   ;; position, and set to the old mouse-position when the mouse is in exile.
 358   (if (not (mouse-avoidance-ignore-p))
 359       (let ((mp (mouse-position)))
 360         (cond ((and (not mouse-avoidance-state)
 361                     (mouse-avoidance-too-close-p mp))
 362                (setq mouse-avoidance-state mp)
 363                (mouse-avoidance-banish-mouse))
 364               ((and mouse-avoidance-state
 365                     (not (mouse-avoidance-too-close-p mouse-avoidance-state)))
 366                (if (and (eq (car mp) (selected-frame))
 367                         (equal (cdr mp) (mouse-avoidance-banish-destination)))
 368                    (mouse-avoidance-set-mouse-position
 369                     ;; move back only if user has not moved mouse
 370                     (cdr mouse-avoidance-state)))
 371                ;; but clear state anyway, to be ready for another move
 372                (setq mouse-avoidance-state nil))))))
 373
 374 (defun mouse-avoidance-fancy ()
 375   ;; Used for the "fancy" modes, ie jump et al.
 376   (if (and (not mouse-avoidance-animating-pointer)
 377            (not (mouse-avoidance-ignore-p))
 378            (mouse-avoidance-too-close-p (mouse-position)))
 379       (let ((old-pos (mouse-position)))
 380         (mouse-avoidance-nudge-mouse)
 381         (if (not (eq (selected-frame) (car old-pos)))
 382             ;; This should never happen.
 383             (apply 'set-mouse-position old-pos)))))
 384
 385 ;;;###autoload
 386 (defun mouse-avoidance-mode (&optional mode)
 387   "Set Mouse Avoidance mode to MODE.
 388 MODE should be one of the symbols `banish', `exile', `jump', `animate',
 389 `cat-and-mouse', `proteus', or `none'.
 390
 391 If MODE is nil, toggle mouse avoidance between `none' and `banish'
 392 modes.  Positive numbers and symbols other than the above are treated
 393 as equivalent to `banish'; negative numbers and `-' are equivalent to `none'.
 394
 395 Effects of the different modes:
 396  * banish: Move the mouse to the upper-right corner on any keypress.
 397  * exile: Move the mouse to the corner only if the cursor gets too close,
 398      and allow it to return once the cursor is out of the way.
 399  * jump: If the cursor gets too close to the mouse, displace the mouse
 400      a random distance & direction.
 401  * animate: As `jump', but shows steps along the way for illusion of motion.
 402  * cat-and-mouse: Same as `animate'.
 403  * proteus: As `animate', but changes the shape of the mouse pointer too.
 404
 405 \(See `mouse-avoidance-threshold' for definition of \"too close\",
 406 and `mouse-avoidance-nudge-dist' and `mouse-avoidance-nudge-var' for
 407 definition of \"random distance\".)"
 408   (interactive
 409    (list (intern (completing-read
 410                   "Select cursor avoidance technique (SPACE for list): "
 411                   '(("banish") ("exile") ("jump") ("animate")
 412                     ("cat-and-mouse") ("proteus") ("none"))
 413                   nil t))))
 414   (if (eq mode 'cat-and-mouse)
 415       (setq mode 'animate))
 416   (if mouse-avoidance-timer
 417       (cancel-timer mouse-avoidance-timer))
 418   (setq mouse-avoidance-timer nil)
 419
 420   ;; Restore pointer shape if necessary
 421   (if (eq mouse-avoidance-mode 'proteus)
 422       (mouse-avoidance-set-pointer-shape mouse-avoidance-old-pointer-shape))
 423
 424   ;; Do additional setup depending on version of mode requested
 425   (cond ((eq mode 'none)
 426          (setq mouse-avoidance-mode nil))
 427         ((or (eq mode 'jump)
 428              (eq mode 'animate)
 429              (eq mode 'proteus))
 430          (setq mouse-avoidance-timer
 431                (run-with-idle-timer 0.1 t 'mouse-avoidance-fancy))
 432          (setq mouse-avoidance-mode mode
 433                mouse-avoidance-state (cons 0 0)
 434                mouse-avoidance-old-pointer-shape
 435                (and (boundp 'x-pointer-shape) x-pointer-shape)))
 436         ((eq mode 'exile)
 437          (setq mouse-avoidance-timer
 438                (run-with-idle-timer 0.1 t 'mouse-avoidance-exile))
 439          (setq mouse-avoidance-mode mode
 440                mouse-avoidance-state nil))
 441         ((or (eq mode 'banish)
 442              (eq mode t)
 443              (and (null mode) (null mouse-avoidance-mode))
 444              (and mode (> (prefix-numeric-value mode) 0)))
 445          (setq mouse-avoidance-timer
 446                (run-with-idle-timer 0.1 t 'mouse-avoidance-banish))
 447          (setq mouse-avoidance-mode 'banish))
 448         (t (setq mouse-avoidance-mode nil)))
 449   (force-mode-line-update))
 450
 451 ;; Most people who use avoid mode leave it on all the time, so it's not
 452 ;; very informative to announce it in the mode line.
 453 ;;(or (assq 'mouse-avoidance-mode minor-mode-alist)
 454 ;;    (setq minor-mode-alist (cons '(mouse-avoidance-mode " Avoid")
 455 ;;                               minor-mode-alist)))
 456
 457 ;; Needed for custom.
 458 (if mouse-avoidance-mode
 459     (mouse-avoidance-mode mouse-avoidance-mode))
 460
 461 (provide 'avoid)
 462
 463 ;;; avoid.el ends here