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, 2008 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 3, 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 (define-key function-key-map "\e[M" 'xterm-mouse-translate)
  47
  48 (defvar xterm-mouse-last)
  49
  50 ;; Mouse events symbols must have an 'event-kind property with
  51 ;; the value 'mouse-click.
  52 (dolist (event-type '(mouse-1 mouse-2 mouse-3
  53                               M-down-mouse-1 M-down-mouse-2 M-down-mouse-3))
  54   (put event-type 'event-kind 'mouse-click))
  55
  56 (defun xterm-mouse-translate (event)
  57   "Read a click and release event from XTerm."
  58   (save-excursion
  59     (save-window-excursion
  60       (deactivate-mark)
  61       (let* ((xterm-mouse-last)
  62              (down (xterm-mouse-event))
  63              (down-command (nth 0 down))
  64              (down-data (nth 1 down))
  65              (down-where (nth 1 down-data))
  66              (down-binding (key-binding (if (symbolp down-where)
  67                                             (vector down-where down-command)
  68                                           (vector down-command))))
  69              (is-click (string-match "^mouse" (symbol-name (car down)))))
  70
  71         (unless is-click
  72           (unless (and (eq (read-char) ?\e)
  73                        (eq (read-char) ?\[)
  74                        (eq (read-char) ?M))
  75             (error "Unexpected escape sequence from XTerm")))
  76
  77         (let* ((click (if is-click down (xterm-mouse-event)))
  78                (click-command (nth 0 click))
  79                (click-data (nth 1 click))
  80                (click-where (nth 1 click-data)))
  81           (if (memq down-binding '(nil ignore))
  82               (if (and (symbolp click-where)
  83                        (consp click-where))
  84                   (vector (list click-where click-data) click)
  85                 (vector click))
  86             (setq unread-command-events
  87                   (if (eq down-where click-where)
  88                       (list click)
  89                     (list
  90                      ;; Cheat `mouse-drag-region' with move event.
  91                      (list 'mouse-movement click-data)
  92                      ;; Generate a drag event.
  93                      (if (symbolp down-where)
  94                          0
  95                        (list (intern (format "drag-mouse-%d"
  96                                              (+ 1 xterm-mouse-last)))
  97                              down-data click-data)))))
  98             (if (and (symbolp down-where)
  99                      (consp down-where))
 100                 (vector (list down-where down-data) down)
 101               (vector down))))))))
 102
 103 (defvar xterm-mouse-x 0
 104   "Position of last xterm mouse event relative to the frame.")
 105
 106 (defvar xterm-mouse-y 0
 107   "Position of last xterm mouse event relative to the frame.")
 108
 109 (defvar xt-mouse-epoch nil)
 110
 111 ;; Indicator for the xterm-mouse mode.
 112
 113 (defun xterm-mouse-position-function (pos)
 114   "Bound to `mouse-position-function' in XTerm mouse mode."
 115   (setcdr pos (cons xterm-mouse-x xterm-mouse-y))
 116   pos)
 117
 118 ;; read xterm sequences above ascii 127 (#x7f)
 119 (defun xterm-mouse-event-read ()
 120   (let ((c (read-char)))
 121     (if (< c 0)
 122         (+ c #x8000000 128)
 123       c)))
 124
 125 (defun xterm-mouse-truncate-wrap (f)
 126   "Truncate with wrap-around."
 127   (condition-case nil
 128       ;; First try the built-in truncate, in case there's no overflow.
 129       (truncate f)
 130     ;; In case of overflow, do wraparound by hand.
 131     (range-error
 132      ;; In our case, we wrap around every 3 days or so, so if we assume
 133      ;; a maximum of 65536 wraparounds, we're safe for a couple years.
 134      ;; Using a power of 2 makes rounding errors less likely.
 135      (let* ((maxwrap (* 65536 2048))
 136             (dbig (truncate (/ f maxwrap)))
 137             (fdiff (- f (* 1.0 maxwrap dbig))))
 138        (+ (truncate fdiff) (* maxwrap dbig))))))
 139
 140
 141 (defun xterm-mouse-event ()
 142   "Convert XTerm mouse event to Emacs mouse event."
 143   (let* ((type (- (xterm-mouse-event-read) #o40))
 144          (x (- (xterm-mouse-event-read) #o40 1))
 145          (y (- (xterm-mouse-event-read) #o40 1))
 146          ;; Emulate timestamp information.  This is accurate enough
 147          ;; for default value of mouse-1-click-follows-link (450msec).
 148          (timestamp (xterm-mouse-truncate-wrap
 149                      (* 1000
 150                         (- (float-time)
 151                            (or xt-mouse-epoch
 152                                (setq xt-mouse-epoch (float-time)))))))
 153          (mouse (intern
 154                  ;; For buttons > 3, the release-event looks
 155                  ;; differently (see xc/programs/xterm/button.c,
 156                  ;; function EditorButton), and there seems to come in
 157                  ;; a release-event only, no down-event.
 158                  (cond ((>= type 64)
 159                         (format "mouse-%d" (- type 60)))
 160                        ((memq type '(8 9 10))
 161                         (setq xterm-mouse-last type)
 162                         (format "M-down-mouse-%d" (- type 7)))
 163                        ((= type 11)
 164                         (format "mouse-%d" (- xterm-mouse-last 7)))
 165                        ((= type 3)
 166                         (format "mouse-%d" (+ 1 xterm-mouse-last)))
 167                        (t
 168                         (setq xterm-mouse-last type)
 169                         (format "down-mouse-%d" (+ 1 type))))))
 170          (w (window-at x y))
 171          (ltrb (window-edges w))
 172          (left (nth 0 ltrb))
 173          (top (nth 1 ltrb)))
 174
 175     (setq xterm-mouse-x x
 176           xterm-mouse-y y)
 177     (setq
 178      last-input-event
 179      (list mouse
 180            (let ((event (if w
 181                             (posn-at-x-y (- x left) (- y top) w t)
 182                           (append (list nil 'menu-bar)
 183                                   (nthcdr 2 (posn-at-x-y x y))))))
 184              (setcar (nthcdr 3 event) timestamp)
 185              event)))))
 186
 187 ;;;###autoload
 188 (define-minor-mode xterm-mouse-mode
 189   "Toggle XTerm mouse mode.
 190 With prefix arg, turn XTerm mouse mode on if arg is positive, otherwise turn
 191 it off.
 192
 193 Turn it on to use Emacs mouse commands, and off to use xterm mouse commands.
 194 This works in terminal emulators compatible with xterm.  It only
 195 works for simple uses of the mouse.  Basically, only non-modified
 196 single clicks are supported.  When turned on, the normal xterm
 197 mouse functionality for such clicks is still available by holding
 198 down the SHIFT key while pressing the mouse button."
 199   :global t :group 'mouse
 200   (if xterm-mouse-mode
 201       ;; Turn it on
 202       (unless window-system
 203         (setq mouse-position-function #'xterm-mouse-position-function)
 204         (turn-on-xterm-mouse-tracking))
 205     ;; Turn it off
 206     (turn-off-xterm-mouse-tracking 'force)
 207     (setq mouse-position-function nil)))
 208
 209 (defun turn-on-xterm-mouse-tracking ()
 210   "Enable Emacs mouse tracking in xterm."
 211   (if xterm-mouse-mode
 212       (send-string-to-terminal "\e[?1000h")))
 213
 214 (defun turn-off-xterm-mouse-tracking (&optional force)
 215   "Disable Emacs mouse tracking in xterm."
 216   (if (or force xterm-mouse-mode)
 217       (send-string-to-terminal "\e[?1000l")))
 218
 219 ;; Restore normal mouse behaviour outside Emacs.
 220 (add-hook 'suspend-hook 'turn-off-xterm-mouse-tracking)
 221 (add-hook 'suspend-resume-hook 'turn-on-xterm-mouse-tracking)
 222 (add-hook 'kill-emacs-hook 'turn-off-xterm-mouse-tracking)
 223
 224 (provide 'xt-mouse)
 225
 226 ;; arch-tag: 84962d4e-fae9-4c13-a9d7-ef4925a4ac03
 227 ;;; xt-mouse.el ends here