| 1 | ;;; mwheel.el --- Mouse support for MS intelli-mouse type mice |
| 2 | |
| 3 | ;; Copyright (C) 1998, Free Software Foundation, Inc. |
| 4 | ;; Maintainer: William M. Perry <wmperry@gnu.org> |
| 5 | ;; Keywords: mouse |
| 6 | |
| 7 | ;; This file is part of GNU Emacs. |
| 8 | |
| 9 | ;; GNU Emacs is free software; you can redistribute it and/or modify |
| 10 | ;; it under the terms of the GNU General Public License as published by |
| 11 | ;; the Free Software Foundation; either version 2, or (at your option) |
| 12 | ;; any later version. |
| 13 | |
| 14 | ;; GNU Emacs is distributed in the hope that it will be useful, |
| 15 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | ;; GNU General Public License for more details. |
| 18 | |
| 19 | ;; You should have received a copy of the GNU General Public License |
| 20 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
| 21 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| 22 | ;; Boston, MA 02111-1307, USA. |
| 23 | |
| 24 | ;;; Commentary: |
| 25 | |
| 26 | ;; This code will enable the use of the infamous 'wheel' on the new |
| 27 | ;; crop of mice. Under XFree86 and the XSuSE X Servers, the wheel |
| 28 | ;; events are sent as button4/button5 events. |
| 29 | |
| 30 | ;; I for one would prefer some way of converting the button4/button5 |
| 31 | ;; events into different event types, like 'mwheel-up' or |
| 32 | ;; 'mwheel-down', but I cannot find a way to do this very easily (or |
| 33 | ;; portably), so for now I just live with it. |
| 34 | |
| 35 | ;; To enable this code, simply put this at the top of your .emacs |
| 36 | ;; file: |
| 37 | ;; |
| 38 | ;; (mwheel-install) |
| 39 | |
| 40 | ;;; Code: |
| 41 | |
| 42 | (require 'custom) |
| 43 | |
| 44 | (defcustom mwheel-scroll-amount '(5 . 1) |
| 45 | "Amount to scroll windows by when spinning the mouse wheel. |
| 46 | This is actually a cons cell, where the first item is the amount to scroll |
| 47 | on a normal wheel event, and the second is the amount to scroll when the |
| 48 | wheel is moved with the shift key depressed. |
| 49 | |
| 50 | Each item should be the number of lines to scroll, or `nil' for near |
| 51 | full screen. |
| 52 | A near full screen is `next-screen-context-lines' less than a full screen." |
| 53 | :group 'mouse |
| 54 | :type '(cons |
| 55 | (choice :tag "Normal" |
| 56 | (const :tag "Full screen" :value nil) |
| 57 | (integer :tag "Specific # of lines")) |
| 58 | (choice :tag "Shifted" |
| 59 | (const :tag "Full screen" :value nil) |
| 60 | (integer :tag "Specific # of lines")))) |
| 61 | |
| 62 | (defcustom mwheel-follow-mouse nil |
| 63 | "Whether the mouse wheel should scroll the window that the mouse is over. |
| 64 | This can be slightly disconcerting, but some people may prefer it." |
| 65 | :group 'mouse |
| 66 | :type 'boolean) |
| 67 | |
| 68 | (if (not (fboundp 'event-button)) |
| 69 | (defun mwheel-event-button (event) |
| 70 | (let ((x (symbol-name (event-basic-type event)))) |
| 71 | (if (not (string-match "^mouse-\\([0-9]+\\)" x)) |
| 72 | (error "Not a button event: %S" event)) |
| 73 | (string-to-int (substring x (match-beginning 1) (match-end 1))))) |
| 74 | (fset 'mwheel-event-button 'event-button)) |
| 75 | |
| 76 | (if (not (fboundp 'event-window)) |
| 77 | (defun mwheel-event-window (event) |
| 78 | (posn-window (event-start event))) |
| 79 | (fset 'mwheel-event-window 'event-window)) |
| 80 | |
| 81 | (defun mwheel-scroll (event) |
| 82 | (interactive "e") |
| 83 | (let ((curwin (if mwheel-follow-mouse |
| 84 | (prog1 |
| 85 | (selected-window) |
| 86 | (select-window (mwheel-event-window event))))) |
| 87 | (amt (if (memq 'shift (event-modifiers event)) |
| 88 | (cdr mwheel-scroll-amount) |
| 89 | (car mwheel-scroll-amount)))) |
| 90 | (unwind-protect |
| 91 | (let ((button (mwheel-event-button event))) |
| 92 | (cond ((= button 4) (scroll-down amt)) |
| 93 | ((= button 5) (scroll-up amt)) |
| 94 | (t (error "Bad binding in mwheel-scroll")))) |
| 95 | (if curwin (select-window curwin))))) |
| 96 | |
| 97 | |
| 98 | ;;; Note this definition must be at the end of the file, because |
| 99 | ;;; `define-minor-mode' actually calls the mode-function if the |
| 100 | ;;; associated variable is non-nil, which requires that all needed |
| 101 | ;;; functions be already defined. [This is arguably a bug in d-m-m] |
| 102 | ;;;###autoload |
| 103 | (define-minor-mode mouse-wheel-mode |
| 104 | "Toggle mouse wheel support. |
| 105 | With prefix argument ARG, turn on if positive, otherwise off. |
| 106 | Returns non-nil if the new state is enabled." |
| 107 | nil nil nil |
| 108 | :global t |
| 109 | :group 'mouse |
| 110 | ;; In the latest versions of XEmacs, we could just use |
| 111 | ;; (S-)*mouse-[45], since those are aliases for the button |
| 112 | ;; equivalents in XEmacs, but I want this to work in as many |
| 113 | ;; versions of XEmacs as it can. |
| 114 | (let* ((mwheel-running-xemacs (string-match "XEmacs" (emacs-version))) |
| 115 | (keys (if mwheel-running-xemacs |
| 116 | '(button4 [(shift button4)] button5 [(shift button5)]) |
| 117 | '([mouse-4] [S-mouse-4] [mouse-5] [S-mouse-5])))) |
| 118 | ;; This condition-case is here because Emacs 19 will throw an error |
| 119 | ;; if you try to define a key that it does not know about. I for one |
| 120 | ;; prefer to just unconditionally do a mwheel-install in my .emacs, so |
| 121 | ;; that if the wheeled-mouse is there, it just works, and this way it |
| 122 | ;; doesn't yell at me if I'm on my laptop or another machine, etc. |
| 123 | (condition-case () |
| 124 | (dolist (key keys) |
| 125 | (cond (mouse-wheel-mode |
| 126 | (define-key global-map key 'mwheel-scroll)) |
| 127 | ((eq (lookup-key global-map key) 'mwheel-scroll) |
| 128 | (define-key global-map key nil)))) |
| 129 | (error nil)))) |
| 130 | |
| 131 | ;;; Compatibility entry point |
| 132 | ;;;###autoload |
| 133 | (defun mwheel-install (&optional uninstall) |
| 134 | "Enable mouse wheel support." |
| 135 | (mouse-wheel-mode t)) |
| 136 | |
| 137 | |
| 138 | (provide 'mwheel) |
| 139 | |
| 140 | ;;; mwheel.el ends here |