lisp/xt-mouse.el

   1 ;;; xt-mouse.el --- support the mouse when emacs run in an xterm
   2
   3 ;; Copyright (C) 1994, 2000, 2001, 2002, 2003,
   4 ;;   2004, 2005, 2006, 2007 Free Software Foundation, Inc.
   5
   6 ;; Author: Per Abrahamsen <abraham@dina.kvl.dk>
   7 ;; Keywords: mouse, terminals
   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 ;; Enable mouse support when running inside an xterm.
  29
  30 ;; This is actually useful when you are running X11 locally, but is
  31 ;; working on remote machine over a modem line or through a gateway.
  32
  33 ;; It works by translating xterm escape codes into generic emacs mouse
  34 ;; events so it should work with any package that uses the mouse.
  35
  36 ;; You don't have to turn off xterm mode to use the normal xterm mouse
  37 ;; functionality, it is still available by holding down the SHIFT key
  38 ;; when you press the mouse button.
  39
  40 ;;; Todo:
  41
  42 ;; Support multi-click -- somehow.
  43
  44 ;;; Code:
  45
  46 (defvar xterm-mouse-debug-buffer nil)
  47
  48 (define-key function-key-map "\e[M" 'xterm-mouse-translate)
  49
  50 (defvar xterm-mouse-last)
  51
  52 ;; Mouse events symbols must have an 'event-kind property with
  53 ;; the value 'mouse-click.
  54 (dolist (event-type '(mouse-1 mouse-2 mouse-3
  55                               M-down-mouse-1 M-down-mouse-2 M-down-mouse-3))
  56   (put event-type 'event-kind 'mouse-click))
  57
  58 (defun xterm-mouse-translate (event)
  59   "Read a click and release event from XTerm."
  60   (save-excursion
  61     (save-window-excursion
  62       (deactivate-mark)
  63       (let* ((xterm-mouse-last)
  64              (down (xterm-mouse-event))
  65              (down-command (nth 0 down))
  66              (down-data (nth 1 down))
  67              (down-where (nth 1 down-data))
  68              (down-binding (key-binding (if (symbolp down-where)
  69                                             (vector down-where down-command)
  70                                           (vector down-command))))
  71              (is-click (string-match "^mouse" (symbol-name (car down)))))
  72
  73         (unless is-click
  74           (unless (and (eq (read-char) ?\e)
  75                        (eq (read-char) ?\[)
  76                        (eq (read-char) ?M))
  77             (error "Unexpected escape sequence from XTerm")))
  78
  79         (let* ((click (if is-click down (xterm-mouse-event)))
  80                (click-command (nth 0 click))
  81                (click-data (nth 1 click))
  82                (click-where (nth 1 click-data)))
  83           (if (memq down-binding '(nil ignore))
  84               (if (and (symbolp click-where)
  85                        (consp click-where))
  86                   (vector (list click-where click-data) click)
  87                 (vector click))
  88             (setq unread-command-events
  89                   (if (eq down-where click-where)
  90                       (list click)
  91                     (list
  92                      ;; Cheat `mouse-drag-region' with move event.
  93                      (list 'mouse-movement click-data)
  94                      ;; Generate a drag event.
  95                      (if (symbolp down-where)
  96                          0
  97                        (list (intern (format "drag-mouse-%d"
  98                                              (+ 1 xterm-mouse-last)))
  99                              down-data click-data)))))
 100             (if xterm-mouse-debug-buffer
 101                 (print unread-command-events xterm-mouse-debug-buffer))
 102             (if (and (symbolp down-where)
 103                      (consp down-where))
 104                 (vector (list down-where down-data) down)
 105               (vector down))))))))
 106
 107 (defvar xterm-mouse-x 0
 108   "Position of last xterm mouse event relative to the frame.")
 109
 110 (defvar xterm-mouse-y 0
 111   "Position of last xterm mouse event relative to the frame.")
 112
 113 (defvar xt-mouse-epoch nil)
 114
 115 ;; Indicator for the xterm-mouse mode.
 116
 117 (defun xterm-mouse-position-function (pos)
 118   "Bound to `mouse-position-function' in XTerm mouse mode."
 119   (setcdr pos (cons xterm-mouse-x xterm-mouse-y))
 120   pos)
 121
 122 ;; read xterm sequences above ascii 127 (#x7f)
 123 (defun xterm-mouse-event-read ()
 124   (let ((c (read-char)))
 125     (if (< c 0)
 126         (+ c #x8000000 128)
 127       c)))
 128
 129 (defun xterm-mouse-truncate-wrap (f)
 130   "Truncate with wrap-around."
 131   (condition-case nil
 132       ;; First try the built-in truncate, in case there's no overflow.
 133       (truncate f)
 134     ;; In case of overflow, do wraparound by hand.
 135     (range-error
 136      ;; In our case, we wrap around every 3 days or so, so if we assume
 137      ;; a maximum of 65536 wraparounds, we're safe for a couple years.
 138      ;; Using a power of 2 makes rounding errors less likely.
 139      (let* ((maxwrap (* 65536 2048))
 140             (dbig (truncate (/ f maxwrap)))
 141             (fdiff (- f (* 1.0 maxwrap dbig))))
 142        (+ (truncate fdiff) (* maxwrap dbig))))))
 143
 144 (defun xterm-mouse-event ()
 145   "Convert XTerm mouse event to Emacs mouse event."
 146   (let* ((type (- (xterm-mouse-event-read) #o40))
 147          (x (- (xterm-mouse-event-read) #o40 1))
 148          (y (- (xterm-mouse-event-read) #o40 1))
 149          ;; Emulate timestamp information.  This is accurate enough
 150          ;; for default value of mouse-1-click-follows-link (450msec).
 151          (timestamp (xterm-mouse-truncate-wrap
 152                      (* 1000
 153                         (- (float-time)
 154                            (or xt-mouse-epoch
 155                                (setq xt-mouse-epoch (float-time)))))))
 156          (mouse (intern
 157                  ;; For buttons > 3, the release-event looks
 158                  ;; differently (see xc/programs/xterm/button.c,
 159                  ;; function EditorButton), and there seems to come in
 160                  ;; a release-event only, no down-event.
 161                  (cond ((>= type 64)
 162                         (format "mouse-%d" (- type 60)))
 163                        ((memq type '(8 9 10))
 164                         (setq xterm-mouse-last type)
 165                         (format "M-down-mouse-%d" (- type 7)))
 166                        ((= type 11)
 167                         (format "mouse-%d" (- xterm-mouse-last 7)))
 168                        ((= type 3)
 169                         (format "mouse-%d" (+ 1 xterm-mouse-last)))
 170                        (t
 171                         (setq xterm-mouse-last type)
 172                         (format "down-mouse-%d" (+ 1 type))))))
 173          (w (window-at x y))
 174          (ltrb (window-edges w))
 175          (left (nth 0 ltrb))
 176          (top (nth 1 ltrb)))
 177
 178     (setq xterm-mouse-x x
 179           xterm-mouse-y y)
 180     (setq
 181      last-input-event
 182      (list mouse
 183            (let ((event (if w
 184                             (posn-at-x-y (- x left) (- y top) w t)
 185                           (append (list nil 'menu-bar)
 186                                   (nthcdr 2 (posn-at-x-y x y))))))
 187              (setcar (nthcdr 3 event) timestamp)
 188              event)))))
 189
 190 ;;;###autoload
 191 (define-minor-mode xterm-mouse-mode
 192   "Toggle XTerm mouse mode.
 193 With prefix arg, turn XTerm mouse mode on iff arg is positive.
 194
 195 Turn it on to use Emacs mouse commands, and off to use xterm mouse commands.
 196 This works in terminal emulators compatible with xterm.  It only
 197 works for simple uses of the mouse.  Basically, only non-modified
 198 single clicks are supported.  When turned on, the normal xterm
 199 mouse functionality for such clicks is still available by holding
 200 down the SHIFT key while pressing the mouse button."
 201   :global t :group 'mouse
 202   (if xterm-mouse-mode
 203       ;; Turn it on
 204       (unless window-system
 205         (setq mouse-position-function #'xterm-mouse-position-function)
 206         (turn-on-xterm-mouse-tracking))
 207     ;; Turn it off
 208     (turn-off-xterm-mouse-tracking 'force)
 209     (setq mouse-position-function nil)))
 210
 211 (defun turn-on-xterm-mouse-tracking ()
 212   "Enable Emacs mouse tracking in xterm."
 213   (if xterm-mouse-mode
 214       (send-string-to-terminal "\e[?1000h")))
 215
 216 (defun turn-off-xterm-mouse-tracking (&optional force)
 217   "Disable Emacs mouse tracking in xterm."
 218   (if (or force xterm-mouse-mode)
 219       (send-string-to-terminal "\e[?1000l")))
 220
 221 ;; Restore normal mouse behaviour outside Emacs.
 222 (add-hook 'suspend-hook 'turn-off-xterm-mouse-tracking)
 223 (add-hook 'suspend-resume-hook 'turn-on-xterm-mouse-tracking)
 224 (add-hook 'kill-emacs-hook 'turn-off-xterm-mouse-tracking)
 225
 226 (provide 'xt-mouse)
 227
 228 ;; arch-tag: 84962d4e-fae9-4c13-a9d7-ef4925a4ac03
 229 ;;; xt-mouse.el ends here