;;; avoid.el --- make mouse pointer stay out of the way of editing
;;; Copyright (C) 1993, 1994 Free Software Foundation, Inc.
;; Author: Boris Goldowsky <firstname.lastname@example.org>
;; Keywords: mouse
;; This file is part of GNU Emacs.
;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.
;; For those who are annoyed by the mouse pointer obscuring text,
;; this mode moves the mouse pointer - either just a little out of
;; the way, or all the way to the corner of the frame.
;; To use, load or evaluate this file and type M-x mouse-avoidance-mode .
;; To set up permanently, put the following in your .emacs:
;; (if window-system (mouse-avoidance-mode 'animate))
;; The 'animate can be 'jump or 'banish or 'exile or 'protean if you prefer.
;; See the documentation for function `mouse-avoidance-mode' for
;; details of the different modes.
;; For added silliness, make the animatee animate...
;; put something similar to the following into your .emacs:
;; (if window-system
;; (eval (nth (random 4)
;; '(x-pointer-man x-pointer-spider
;; x-pointer-gobbler x-pointer-gumby)))))
;; For completely random pointer shape, replace the setq above with:
;; (setq x-pointer-shape (mouse-avoidance-random-shape))
;; Bugs / Warnings / To-Do:
;; - Using this code does slow emacs down. "banish" mode shouldn't
;; be too bad, and on my workstation even "animate" is reasonable.
;; - It ought to find out where any overlapping frames are and avoid them,
;; rather than always raising the frame.
;; This code was helped by all those who contributed suggestions,
;; fixes, and additions
;; Joe Harrington (and his advisor), for the original inspiration.
;; Ken Manheimer, for dreaming up the Protean mode.
;; Richard Stallman, for the awful cat-and-mouse pun, among other things.
;; Mike Williams, Denis Howe, Bill Benedetto, Chris Moore, Don Morris,
;; Simon Marshall, and M.S. Ashton, for their feedback.
(defvar mouse-avoidance-mode nil
"Value is t or a symbol if the mouse pointer should avoid the cursor.
See function `mouse-avoidance-mode' for possible values. Changing this
variable is NOT the recommended way to change modes; use that function
(defvar mouse-avoidance-nudge-dist 15
"*Average distance that mouse will be moved when approached by cursor.
Only applies in mouse-avoidance-mode `jump' and its derivatives.
For best results make this larger than `mouse-avoidance-threshold'.")
(defvar mouse-avoidance-nudge-var 10
"*Variability of `mouse-avoidance-nudge-dist' (which see).")
(defvar mouse-avoidance-animation-delay .01
"Delay between animation steps, in seconds.")
(defvar mouse-avoidance-threshold 5
"*Mouse-pointer's flight distance.
If the cursor gets closer than this, the mouse pointer will move away.
Only applies in mouse-avoidance-modes `animate' and `jump'.")
;; Internal variables
(defvar mouse-avoidance-state nil)
(defvar mouse-avoidance-pointer-shapes nil)
(defvar mouse-avoidance-n-pointer-shapes 0)
(defsubst mouse-avoidance-set-pointer-shape (shape)
"Set the shape of the mouse pointer to SHAPE."
(setq x-pointer-shape shape)
(defun mouse-avoidance-point-position ()
"Return the position of point as (FRAME X . Y).
Analogous to mouse-position."
(let* ((w (selected-window))
(edges (window-edges w))
(compute-motion (max (window-start w) (point-min)) ; start pos
;; window-start can be < point-min if the
;; latter has changed since the last redisplay
'(0 . 0) ; start XY
(point) ; stop pos
(cons (window-width) (window-height)); stop XY: none
(1- (window-width)) ; width
(cons (window-hscroll w) 0) ; 0 may not be right?
;; compute-motion returns (pos HPOS VPOS prevhpos contin)
;; we want: (frame hpos . vpos)
(cons (+ (car edges) (car (cdr list)))
(+ (car (cdr edges)) (car (cdr (cdr list))))))))
;(defun mouse-avoidance-point-position-test ()
; (message (format "point=%s mouse=%s"
; (cdr (mouse-avoidance-point-position))
; (cdr (mouse-position)))))
(defun mouse-avoidance-set-mouse-position (pos)
;; Carefully set mouse position to given position (X . Y)
;; Ideally, should check if X,Y is in the current frame, and if not,
;; leave the mouse where it was. However, this is currently
;; difficult to do, so we just raise the frame to avoid frame switches.
;; Returns t if it moved the mouse.
(let ((f (selected-frame)))
(set-mouse-position f (car pos) (cdr pos))
(defun mouse-avoidance-too-close-p (mouse)
;; Return t if mouse pointer and point cursor are too close.
;; Acceptable distance is defined by mouse-avoidance-threshold.
(let ((point (mouse-avoidance-point-position)))
(and (eq (car mouse) (car point))
(car (cdr mouse))
(< (abs (- (car (cdr mouse)) (car (cdr point))))
(< (abs (- (cdr (cdr mouse)) (cdr (cdr point))))
(defun mouse-avoidance-banish-destination ()
"The position to which mouse-avoidance-mode `banish' moves the mouse.
You can redefine this if you want the mouse banished to a different corner."
(cons (1- (frame-width))
(defun mouse-avoidance-banish-mouse ()
;; Put the mouse pointer in the upper-right corner of the current frame.
(defsubst mouse-avoidance-delta (cur delta dist var min max)
;; Decide how far to move in either dimension.
;; Args are the CURRENT location, the desired DELTA for
;; warp-conservation, the DISTANCE we like to move, the VARIABILITY
;; in distance allowed, and the MIN and MAX possible window positions.
;; Returns something as close to DELTA as possible within the constraints.
(let ((L1 (max (- min cur) (+ (- dist) (- var))))
(R1 (+ (- dist) var ))
(L2 (+ dist (- var)))
(R2 (min (- max cur) (+ dist var))))
(if (< R1 (- min cur)) (setq L1 nil R1 nil))
(if (> L2 (- max cur)) (setq L2 nil R2 nil))
(cond ((and L1 (< delta L1)) L1)
((and R1 (< delta R1)) delta)
((and R1 (< delta 0)) R1)
((and L2 (< delta L2)) L2)
((and R2 (< delta R2)) delta)
((or R1 L2))
(defun mouse-avoidance-nudge-mouse ()
;; Push the mouse a little way away, possibly animating the move
;; For these modes, state keeps track of the total offset that we've
;; accumulated, and tries to keep it close to zero.
(let* ((cur (mouse-position))
(cur-frame (car cur))
(cur-pos (cdr cur))
(car cur-pos) (- (random mouse-avoidance-nudge-var)
(cdr cur-pos) (- (random mouse-avoidance-nudge-var)
(cons (+ (car mouse-avoidance-state) deltax)
(+ (cdr mouse-avoidance-state) deltay)))
(if (or (eq mouse-avoidance-mode 'animate)
(eq mouse-avoidance-mode 'proteus))
(let ((i 0.0))
(while (<= i 1)
(cons (+ (car cur-pos) (round (* i deltax)))
(+ (cdr cur-pos) (round (* i deltay)))))
(setq i (+ i (max .1 (/ 1.0 mouse-avoidance-nudge-dist))))
(if (eq mouse-avoidance-mode 'proteus)
(mouse-avoidance-set-mouse-position (cons (+ (car (cdr cur)) deltax)
(+ (cdr (cdr cur)) deltay))))))
(defun mouse-avoidance-random-shape ()
"Return a random cursor shape.
This assumes that any variable whose name begins with x-pointer- and
has an integer value is a valid cursor shape. You might want to
redefine this function to suit your own tastes."
(if (null mouse-avoidance-pointer-shapes)
(mapcar '(lambda (x) (symbol-value (intern x)))
(all-completions "x-pointer-" obarray
(and (boundp x)
(integerp (symbol-value x)))))))
(nth (random mouse-avoidance-n-pointer-shapes)
(defun mouse-avoidance-banish-hook ()
(if (and (not executing-kbd-macro) ; don't check inside macro
(defun mouse-avoidance-exile-hook ()
;; For exile mode, the state is nil when the mouse is in its normal
;; position, and set to the old mouse-position when the mouse is in exile.
(if (and (not executing-kbd-macro)
(let ((mp (mouse-position)))
(cond ((and (not mouse-avoidance-state)
(setq mouse-avoidance-state mp)
(not (mouse-avoidance-too-close-p mouse-avoidance-state)))
(if (and (eq (car mp) (selected-frame))
(equal (cdr mp) (mouse-avoidance-banish-destination)))
;; move back only if user has not moved mouse
;; but clear state anyway, to be ready for another move
(setq mouse-avoidance-state nil))))))
(defun mouse-avoidance-fancy-hook ()
;; Used for the "fancy" modes, ie jump et al.
(if (and (not executing-kbd-macro) ; don't check inside macro
(let ((old-pos (mouse-position)))
(if (not (eq (selected-frame) (car old-pos)))
;; This should never happen.
(apply 'set-mouse-position old-pos)))))
(defun mouse-avoidance-kbd-command (key)
"Return t if the KEYSEQENCE is composed of keyboard events only.
Return nil if there are any lists in the key sequence."
(cond ((null key) nil) ; Null event seems to be
; returned occasionally.
((not (vectorp key)) t) ; Strings are keyboard events.
(let ((i 0)
(l (length key)))
(while (< i l)
(if (listp (aref key i))
(throw 'done nil))
(setq i (1+ i))))
(defun mouse-avoidance-mode (&optional mode)
"Set cursor avoidance mode to MODE.
MODE should be one of the symbols `banish', `exile', `jump', `animate',
`cat-and-mouse', `proteus', or `none'.
If MODE is nil, toggle mouse avoidance between `none` and `banish'
modes. Positive numbers and symbols other than the above are treated
as equivalent to `banish'; negative numbers and `-' are equivalent to `none'.
Effects of the different modes:
* banish: Move the mouse to the upper-right corner on any keypress.
* exile: Move the mouse to the corner only if the cursor gets too close,
and allow it to return once the cursor is out of the way.
* jump: If the cursor gets too close to the mouse, displace the mouse
a random distance & direction.
* animate: As `jump', but shows steps along the way for illusion of motion.
* cat-and-mouse: Same as `animate'.
* proteus: As `animate', but changes the shape of the mouse pointer too.
Whenever the mouse is moved, the frame is also raised.
\(see `mouse-avoidance-threshold' for definition of \"too close\",
and `mouse-avoidance-nudge-dist' and `mouse-avoidance-nudge-var' for
definition of \"random distance\".)"
(list (intern (completing-read
"Select cursor avoidance technique (SPACE for list): "
'(("banish") ("exile") ("jump") ("animate")
("cat-and-mouse") ("proteus") ("none"))
(if (eq mode 'cat-and-mouse)
(setq mode 'animate))
(remove-hook 'post-command-idle-hook 'mouse-avoidance-banish-hook)
(remove-hook 'post-command-idle-hook 'mouse-avoidance-exile-hook)
(remove-hook 'post-command-idle-hook 'mouse-avoidance-fancy-hook)
(cond ((eq mode 'none)
(setq mouse-avoidance-mode nil))
((or (eq mode 'jump)
(eq mode 'animate)
(eq mode 'proteus))
(add-hook 'post-command-idle-hook 'mouse-avoidance-fancy-hook)
(setq mouse-avoidance-mode mode
mouse-avoidance-state (cons 0 0)))
((eq mode 'exile)
(add-hook 'post-command-idle-hook 'mouse-avoidance-exile-hook)
(setq mouse-avoidance-mode mode
((or (eq mode 'banish)
(eq mode t)
(and (null mode) (null mouse-avoidance-mode))
(and mode (> (prefix-numeric-value mode) 0)))
(add-hook 'post-command-idle-hook 'mouse-avoidance-banish-hook)
(setq mouse-avoidance-mode 'banish))
(t (setq mouse-avoidance-mode nil)))
(or (assq 'mouse-avoidance-mode minor-mode-alist)
(setq minor-mode-alist (cons '(mouse-avoidance-mode " Avoid")
;;; End of avoid.el