lisp/term/xterm.el

   1 ;;; xterm.el --- define function key sequences and standard colors for xterm  -*- lexical-binding: t -*-
   2
   3 ;; Copyright (C) 1995, 2001-2013 Free Software Foundation, Inc.
   4
   5 ;; Author: FSF
   6 ;; Keywords: terminals
   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 <http://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;;; Code:
  26
  27 (defgroup xterm nil
  28   "XTerm support."
  29   :version "24.1"
  30   :group 'terminals)
  31
  32 (defcustom xterm-extra-capabilities 'check
  33   "Whether Xterm supports some additional, more modern, features.
  34 If nil, just assume that it does not.
  35 If `check', try to check if it does.
  36 If a list, assume that the listed features are supported, without checking.
  37
  38 The relevant features are:
  39   modifyOtherKeys  -- if supported, more key bindings work (e.g., \"\\C-,\")
  40   reportBackground -- if supported, Xterm reports its background color"
  41   :version "24.1"
  42   :group 'xterm
  43   :type '(choice (const :tag "No" nil)
  44                  (const :tag "Check" check)
  45                  ;; NOTE: If you add entries here, make sure to update
  46                  ;; `tocheck-capabilities' in `terminal-init-xterm' as well.
  47                  (set (const :tag "modifyOtherKeys support" modifyOtherKeys)
  48                       (const :tag "report background" reportBackground))))
  49
  50 (defvar xterm-function-map
  51   (let ((map (make-sparse-keymap)))
  52
  53     ;; xterm from X.org 6.8.2 uses these key definitions.
  54     (define-key map "\eOP" [f1])
  55     (define-key map "\eOQ" [f2])
  56     (define-key map "\eOR" [f3])
  57     (define-key map "\eOS" [f4])
  58     (define-key map "\e[15~" [f5])
  59     (define-key map "\e[17~" [f6])
  60     (define-key map "\e[18~" [f7])
  61     (define-key map "\e[19~" [f8])
  62     (define-key map "\e[20~" [f9])
  63     (define-key map "\e[21~" [f10])
  64     (define-key map "\e[23~" [f11])
  65     (define-key map "\e[24~" [f12])
  66
  67     (define-key map "\eO2P" [S-f1])
  68     (define-key map "\eO2Q" [S-f2])
  69     (define-key map "\eO2R" [S-f3])
  70     (define-key map "\eO2S" [S-f4])
  71     (define-key map "\e[1;2P" [S-f1])
  72     (define-key map "\e[1;2Q" [S-f2])
  73     (define-key map "\e[1;2R" [S-f3])
  74     (define-key map "\e[1;2S" [S-f4])
  75     (define-key map "\e[15;2~" [S-f5])
  76     (define-key map "\e[17;2~" [S-f6])
  77     (define-key map "\e[18;2~" [S-f7])
  78     (define-key map "\e[19;2~" [S-f8])
  79     (define-key map "\e[20;2~" [S-f9])
  80     (define-key map "\e[21;2~" [S-f10])
  81     (define-key map "\e[23;2~" [S-f11])
  82     (define-key map "\e[24;2~" [S-f12])
  83
  84     (define-key map "\eO5P" [C-f1])
  85     (define-key map "\eO5Q" [C-f2])
  86     (define-key map "\eO5R" [C-f3])
  87     (define-key map "\eO5S" [C-f4])
  88     (define-key map "\e[15;5~" [C-f5])
  89     (define-key map "\e[17;5~" [C-f6])
  90     (define-key map "\e[18;5~" [C-f7])
  91     (define-key map "\e[19;5~" [C-f8])
  92     (define-key map "\e[20;5~" [C-f9])
  93     (define-key map "\e[21;5~" [C-f10])
  94     (define-key map "\e[23;5~" [C-f11])
  95     (define-key map "\e[24;5~" [C-f12])
  96
  97     (define-key map "\eO6P" [C-S-f1])
  98     (define-key map "\eO6Q" [C-S-f2])
  99     (define-key map "\eO6R" [C-S-f3])
 100     (define-key map "\eO6S" [C-S-f4])
 101     (define-key map "\e[15;6~" [C-S-f5])
 102     (define-key map "\e[17;6~" [C-S-f6])
 103     (define-key map "\e[18;6~" [C-S-f7])
 104     (define-key map "\e[19;6~" [C-S-f8])
 105     (define-key map "\e[20;6~" [C-S-f9])
 106     (define-key map "\e[21;6~" [C-S-f10])
 107     (define-key map "\e[23;6~" [C-S-f11])
 108     (define-key map "\e[24;6~" [C-S-f12])
 109
 110     (define-key map "\eO3P" [M-f1])
 111     (define-key map "\eO3Q" [M-f2])
 112     (define-key map "\eO3R" [M-f3])
 113     (define-key map "\eO3S" [M-f4])
 114     (define-key map "\e[15;3~" [M-f5])
 115     (define-key map "\e[17;3~" [M-f6])
 116     (define-key map "\e[18;3~" [M-f7])
 117     (define-key map "\e[19;3~" [M-f8])
 118     (define-key map "\e[20;3~" [M-f9])
 119     (define-key map "\e[21;3~" [M-f10])
 120     (define-key map "\e[23;3~" [M-f11])
 121     (define-key map "\e[24;3~" [M-f12])
 122
 123     (define-key map "\eO4P" [M-S-f1])
 124     (define-key map "\eO4Q" [M-S-f2])
 125     (define-key map "\eO4R" [M-S-f3])
 126     (define-key map "\eO4S" [M-S-f4])
 127     (define-key map "\e[15;4~" [M-S-f5])
 128     (define-key map "\e[17;4~" [M-S-f6])
 129     (define-key map "\e[18;4~" [M-S-f7])
 130     (define-key map "\e[19;4~" [M-S-f8])
 131     (define-key map "\e[20;4~" [M-S-f9])
 132     (define-key map "\e[21;4~" [M-S-f10])
 133     (define-key map "\e[23;4~" [M-S-f11])
 134     (define-key map "\e[24;4~" [M-S-f12])
 135
 136     (define-key map "\eOA" [up])
 137     (define-key map "\eOB" [down])
 138     (define-key map "\eOC" [right])
 139     (define-key map "\eOD" [left])
 140     (define-key map "\eOF" [end])
 141     (define-key map "\eOH" [home])
 142
 143     (define-key map "\e[1;2A" [S-up])
 144     (define-key map "\e[1;2B" [S-down])
 145     (define-key map "\e[1;2C" [S-right])
 146     (define-key map "\e[1;2D" [S-left])
 147     (define-key map "\e[1;2F" [S-end])
 148     (define-key map "\e[1;2H" [S-home])
 149
 150     (define-key map "\e[1;4A" [M-S-up])
 151     (define-key map "\e[1;4B" [M-S-down])
 152     (define-key map "\e[1;4C" [M-S-right])
 153     (define-key map "\e[1;4D" [M-S-left])
 154     (define-key map "\e[1;4F" [M-S-end])
 155     (define-key map "\e[1;4H" [M-S-home])
 156
 157     (define-key map "\e[1;5A" [C-up])
 158     (define-key map "\e[1;5B" [C-down])
 159     (define-key map "\e[1;5C" [C-right])
 160     (define-key map "\e[1;5D" [C-left])
 161     (define-key map "\e[1;5F" [C-end])
 162     (define-key map "\e[1;5H" [C-home])
 163
 164     (define-key map "\e[1;6A" [C-S-up])
 165     (define-key map "\e[1;6B" [C-S-down])
 166     (define-key map "\e[1;6C" [C-S-right])
 167     (define-key map "\e[1;6D" [C-S-left])
 168     (define-key map "\e[1;6F" [C-S-end])
 169     (define-key map "\e[1;6H" [C-S-home])
 170
 171     (define-key map "\e[1;7A" [C-M-up])
 172     (define-key map "\e[1;7B" [C-M-down])
 173     (define-key map "\e[1;7C" [C-M-right])
 174     (define-key map "\e[1;7D" [C-M-left])
 175     (define-key map "\e[1;7F" [C-M-end])
 176     (define-key map "\e[1;7H" [C-M-home])
 177
 178     (define-key map "\e[1;8A" [C-M-S-up])
 179     (define-key map "\e[1;8B" [C-M-S-down])
 180     (define-key map "\e[1;8C" [C-M-S-right])
 181     (define-key map "\e[1;8D" [C-M-S-left])
 182     (define-key map "\e[1;8F" [C-M-S-end])
 183     (define-key map "\e[1;8H" [C-M-S-home])
 184
 185     (define-key map "\e[1;3A" [M-up])
 186     (define-key map "\e[1;3B" [M-down])
 187     (define-key map "\e[1;3C" [M-right])
 188     (define-key map "\e[1;3D" [M-left])
 189     (define-key map "\e[1;3F" [M-end])
 190     (define-key map "\e[1;3H" [M-home])
 191
 192     (define-key map "\e[2~" [insert])
 193     (define-key map "\e[3~" [delete])
 194     (define-key map "\e[5~" [prior])
 195     (define-key map "\e[6~" [next])
 196
 197     (define-key map "\e[2;2~" [S-insert])
 198     (define-key map "\e[3;2~" [S-delete])
 199     (define-key map "\e[5;2~" [S-prior])
 200     (define-key map "\e[6;2~" [S-next])
 201
 202     (define-key map "\e[2;4~" [M-S-insert])
 203     (define-key map "\e[3;4~" [M-S-delete])
 204     (define-key map "\e[5;4~" [M-S-prior])
 205     (define-key map "\e[6;4~" [M-S-next])
 206
 207     (define-key map "\e[2;5~" [C-insert])
 208     (define-key map "\e[3;5~" [C-delete])
 209     (define-key map "\e[5;5~" [C-prior])
 210     (define-key map "\e[6;5~" [C-next])
 211
 212     (define-key map "\e[2;6~" [C-S-insert])
 213     (define-key map "\e[3;6~" [C-S-delete])
 214     (define-key map "\e[5;6~" [C-S-prior])
 215     (define-key map "\e[6;6~" [C-S-next])
 216
 217     (define-key map "\e[2;7~" [C-M-insert])
 218     (define-key map "\e[3;7~" [C-M-delete])
 219     (define-key map "\e[5;7~" [C-M-prior])
 220     (define-key map "\e[6;7~" [C-M-next])
 221
 222     (define-key map "\e[2;8~" [C-M-S-insert])
 223     (define-key map "\e[3;8~" [C-M-S-delete])
 224     (define-key map "\e[5;8~" [C-M-S-prior])
 225     (define-key map "\e[6;8~" [C-M-S-next])
 226
 227     (define-key map "\e[2;3~" [M-insert])
 228     (define-key map "\e[3;3~" [M-delete])
 229     (define-key map "\e[5;3~" [M-prior])
 230     (define-key map "\e[6;3~" [M-next])
 231
 232     (define-key map "\e[4~" [select])
 233     (define-key map "\e[29~" [print])
 234
 235     (define-key map "\eOj" [kp-multiply])
 236     (define-key map "\eOk" [kp-add])
 237     (define-key map "\eOl" [kp-separator])
 238     (define-key map "\eOm" [kp-subtract])
 239     (define-key map "\eOo" [kp-divide])
 240     (define-key map "\eOp" [kp-0])
 241     (define-key map "\eOq" [kp-1])
 242     (define-key map "\eOr" [kp-2])
 243     (define-key map "\eOs" [kp-3])
 244     (define-key map "\eOt" [kp-4])
 245     (define-key map "\eOu" [kp-5])
 246     (define-key map "\eOv" [kp-6])
 247     (define-key map "\eOw" [kp-7])
 248     (define-key map "\eOx" [kp-8])
 249     (define-key map "\eOy" [kp-9])
 250
 251     ;; These keys are available in xterm starting from version 216
 252     ;; if the modifyOtherKeys resource is set to 1.
 253     (dolist (bind '((5 9   [C-tab])
 254                     (5 13  [C-return])
 255                     (5 39  [?\C-\'])
 256                     (5 44  [?\C-,])
 257                     (5 45  [?\C--])
 258                     (5 46  [?\C-.])
 259                     (5 47  [?\C-/])
 260                     (5 48  [?\C-0])
 261                     (5 49  [?\C-1])
 262                     ;; Not all C-DIGIT keys have a distinct binding.
 263                     (5 57  [?\C-9])
 264                     (5 59  [?\C-\;])
 265                     (5 61  [?\C-=])
 266                     (5 92  [?\C-\\])
 267
 268                     (6 33  [?\C-!])
 269                     (6 34  [?\C-\"])
 270                     (6 35  [?\C-#])
 271                     (6 36  [?\C-$])
 272                     (6 37  [?\C-%])
 273                     (6 38  [?\C-&])
 274                     (6 40  [?\C-\(])
 275                     (6 41  [?\C-\)])
 276                     (6 42  [?\C-*])
 277                     (6 43  [?\C-+])
 278                     (6 58  [?\C-:])
 279                     (6 60  [?\C-<])
 280                     (6 62  [?\C->])
 281                     (6 63  [(control ??)])
 282
 283                     ;; These are the strings emitted for various C-M-
 284                     ;; combinations for keyboards whose Meta and Alt
 285                     ;; modifiers are on the same key (usually labeled "Alt").
 286                     (13 9  [C-M-tab])
 287                     (13 13 [C-M-return])
 288
 289                     (13 39 [?\C-\M-\'])
 290                     (13 44 [?\C-\M-,])
 291                     (13 45 [?\C-\M--])
 292                     (13 46 [?\C-\M-.])
 293                     (13 47 [?\C-\M-/])
 294                     (13 48 [?\C-\M-0])
 295                     (13 49 [?\C-\M-1])
 296                     (13 50 [?\C-\M-2])
 297                     (13 51 [?\C-\M-3])
 298                     (13 52 [?\C-\M-4])
 299                     (13 53 [?\C-\M-5])
 300                     (13 54 [?\C-\M-6])
 301                     (13 55 [?\C-\M-7])
 302                     (13 56 [?\C-\M-8])
 303                     (13 57 [?\C-\M-9])
 304                     (13 59 [?\C-\M-\;])
 305                     (13 61 [?\C-\M-=])
 306                     (13 92 [?\C-\M-\\])
 307
 308                     (14 33  [?\C-\M-!])
 309                     (14 34  [?\C-\M-\"])
 310                     (14 35  [?\C-\M-#])
 311                     (14 36  [?\C-\M-$])
 312                     (14 37  [?\C-\M-%])
 313                     (14 38  [?\C-\M-&])
 314                     (14 40  [?\C-\M-\(])
 315                     (14 41  [?\C-\M-\)])
 316                     (14 42  [?\C-\M-*])
 317                     (14 43  [?\C-\M-+])
 318                     (14 58  [?\C-\M-:])
 319                     (14 60  [?\C-\M-<])
 320                     (14 62  [?\C-\M->])
 321                     (14 63  [(control meta ??)])
 322
 323                     (7 9  [C-M-tab])
 324                     (7 13 [C-M-return])
 325
 326                     (7 32 [?\C-\M-\s])
 327                     (7 39 [?\C-\M-\'])
 328                     (7 44 [?\C-\M-,])
 329                     (7 45 [?\C-\M--])
 330                     (7 46 [?\C-\M-.])
 331                     (7 47 [?\C-\M-/])
 332                     (7 48 [?\C-\M-0])
 333                     (7 49 [?\C-\M-1])
 334                     (7 50 [?\C-\M-2])
 335                     (7 51 [?\C-\M-3])
 336                     (7 52 [?\C-\M-4])
 337                     (7 53 [?\C-\M-5])
 338                     (7 54 [?\C-\M-6])
 339                     (7 55 [?\C-\M-7])
 340                     (7 56 [?\C-\M-8])
 341                     (7 57 [?\C-\M-9])
 342                     (7 59 [?\C-\M-\;])
 343                     (7 61 [?\C-\M-=])
 344                     (7 92 [?\C-\M-\\])
 345
 346                     (8 33  [?\C-\M-!])
 347                     (8 34  [?\C-\M-\"])
 348                     (8 35  [?\C-\M-#])
 349                     (8 36  [?\C-\M-$])
 350                     (8 37  [?\C-\M-%])
 351                     (8 38  [?\C-\M-&])
 352                     (8 40  [?\C-\M-\(])
 353                     (8 41  [?\C-\M-\)])
 354                     (8 42  [?\C-\M-*])
 355                     (8 43  [?\C-\M-+])
 356                     (8 58  [?\C-\M-:])
 357                     (8 60  [?\C-\M-<])
 358                     (8 62  [?\C-\M->])
 359                     (8 63  [(control meta ??)])
 360
 361                     (2 9   [S-tab])
 362                     (2 13  [S-return])
 363
 364                     (6 9   [C-S-tab])
 365                     (6 13  [C-S-return])))
 366       (define-key map
 367         (format "\e[27;%d;%d~" (nth 0 bind) (nth 1 bind)) (nth 2 bind))
 368       ;; For formatOtherKeys=1, the sequence is a bit shorter (bug#13839).
 369       (define-key map
 370         (format "\e[%d;%du" (nth 1 bind) (nth 0 bind)) (nth 2 bind)))
 371
 372     ;; Other versions of xterm might emit these.
 373     (define-key map "\e[A" [up])
 374     (define-key map "\e[B" [down])
 375     (define-key map "\e[C" [right])
 376     (define-key map "\e[D" [left])
 377     (define-key map "\e[1~" [home])
 378
 379     (define-key map "\eO2A" [S-up])
 380     (define-key map "\eO2B" [S-down])
 381     (define-key map "\eO2C" [S-right])
 382     (define-key map "\eO2D" [S-left])
 383     (define-key map "\eO2F" [S-end])
 384     (define-key map "\eO2H" [S-home])
 385
 386     (define-key map "\eO5A" [C-up])
 387     (define-key map "\eO5B" [C-down])
 388     (define-key map "\eO5C" [C-right])
 389     (define-key map "\eO5D" [C-left])
 390     (define-key map "\eO5F" [C-end])
 391     (define-key map "\eO5H" [C-home])
 392
 393     (define-key map "\e[11~" [f1])
 394     (define-key map "\e[12~" [f2])
 395     (define-key map "\e[13~" [f3])
 396     (define-key map "\e[14~" [f4])
 397     map)
 398   "Function key map overrides for xterm.")
 399
 400 (defvar xterm-alternatives-map
 401   (let ((map (make-sparse-keymap)))
 402     ;; The terminal initialization C code file might have initialized
 403     ;; function keys F13->F60 from the termcap/terminfo information.
 404     ;; On a PC-style keyboard these keys correspond to
 405     ;; MODIFIER-FUNCTION_KEY, where modifier is S-, C, A-, C-S-.  The code
 406     ;; here substitutes the corresponding definitions in function-key-map.
 407     ;; The mapping from escape sequences to Fn is done in input-decode-map
 408     ;; whereas this here mapping is done in local-function-key-map so that
 409     ;; bindings to f45 still work, in case your keyboard really has an f45
 410     ;; key rather than C-S-f9.
 411     (define-key map [f13] [S-f1])
 412     (define-key map [f14] [S-f2])
 413     (define-key map [f15] [S-f3])
 414     (define-key map [f16] [S-f4])
 415     (define-key map [f17] [S-f5])
 416     (define-key map [f18] [S-f6])
 417     (define-key map [f19] [S-f7])
 418     (define-key map [f20] [S-f8])
 419     (define-key map [f21] [S-f9])
 420     (define-key map [f22] [S-f10])
 421     (define-key map [f23] [S-f11])
 422     (define-key map [f24] [S-f12])
 423
 424     (define-key map [f25] [C-f1])
 425     (define-key map [f26] [C-f2])
 426     (define-key map [f27] [C-f3])
 427     (define-key map [f28] [C-f4])
 428     (define-key map [f29] [C-f5])
 429     (define-key map [f30] [C-f6])
 430     (define-key map [f31] [C-f7])
 431     (define-key map [f32] [C-f8])
 432     (define-key map [f33] [C-f9])
 433     (define-key map [f34] [C-f10])
 434     (define-key map [f35] [C-f11])
 435     (define-key map [f36] [C-f12])
 436
 437     (define-key map [f37] [C-S-f1])
 438     (define-key map [f38] [C-S-f2])
 439     (define-key map [f39] [C-S-f3])
 440     (define-key map [f40] [C-S-f4])
 441     (define-key map [f41] [C-S-f5])
 442     (define-key map [f42] [C-S-f6])
 443     (define-key map [f43] [C-S-f7])
 444     (define-key map [f44] [C-S-f8])
 445     (define-key map [f45] [C-S-f9])
 446     (define-key map [f46] [C-S-f10])
 447     (define-key map [f47] [C-S-f11])
 448     (define-key map [f48] [C-S-f12])
 449
 450     (define-key map [f49] [M-f1])
 451     (define-key map [f50] [M-f2])
 452     (define-key map [f51] [M-f3])
 453     (define-key map [f52] [M-f4])
 454     (define-key map [f53] [M-f5])
 455     (define-key map [f54] [M-f6])
 456     (define-key map [f55] [M-f7])
 457     (define-key map [f56] [M-f8])
 458     (define-key map [f57] [M-f9])
 459     (define-key map [f58] [M-f10])
 460     (define-key map [f59] [M-f11])
 461     (define-key map [f60] [M-f12])
 462
 463     map)
 464   "Keymap of possible alternative meanings for some keys.")
 465
 466 ;; List of terminals for which modify-other-keys has been turned on.
 467 (defvar xterm-modify-other-keys-terminal-list nil)
 468
 469 (defun xterm--report-background-handler ()
 470   (let ((str "")
 471         chr)
 472     ;; The reply should be: \e ] 11 ; rgb: NUMBER1 / NUMBER2 / NUMBER3 \e \\
 473     (while (and (setq chr (read-event nil nil 2)) (not (equal chr ?\\)))
 474       (setq str (concat str (string chr))))
 475     (when (string-match
 476            "rgb:\\([a-f0-9]+\\)/\\([a-f0-9]+\\)/\\([a-f0-9]+\\)" str)
 477       (let ((recompute-faces
 478              (xterm-maybe-set-dark-background-mode
 479               (string-to-number (match-string 1 str) 16)
 480               (string-to-number (match-string 2 str) 16)
 481               (string-to-number (match-string 3 str) 16))))
 482
 483         ;; Recompute faces here in case the background mode was
 484         ;; set to dark.  We used to call
 485         ;; `tty-set-up-initial-frame-faces' only once, but that
 486         ;; caused the light background faces to be computed
 487         ;; incorrectly.  See:
 488         ;; http://permalink.gmane.org/gmane.emacs.devel/119627
 489         (when recompute-faces
 490           (tty-set-up-initial-frame-faces))))))
 491
 492 (defun xterm--version-handler ()
 493   (let ((str "")
 494         chr)
 495     ;; The reply should be: \e [ > NUMBER1 ; NUMBER2 ; NUMBER3 c
 496     ;; If the timeout is completely removed for read-event, this
 497     ;; might hang for terminals that pretend to be xterm, but don't
 498     ;; respond to this escape sequence.  RMS' opinion was to remove
 499     ;; it completely.  That might be right, but let's first try to
 500     ;; see if by using a longer timeout we get rid of most issues.
 501     (while (and (setq chr (read-event nil nil 2)) (not (equal chr ?c)))
 502       (setq str (concat str (string chr))))
 503     (when (string-match "0;\\([0-9]+\\);0" str)
 504       (let ((version (string-to-number (match-string 1 str))))
 505         ;; If version is 242 or higher, assume the xterm supports
 506         ;; reporting the background color (TODO: maybe earlier
 507         ;; versions do too...)
 508         (when (>= version 242)
 509           (xterm--query "\e]11;?\e\\"
 510                         '(("\e]11;" .  xterm--report-background-handler))))
 511
 512         ;; If version is 216 (the version when modifyOtherKeys was
 513         ;; introduced) or higher, initialize the
 514         ;; modifyOtherKeys support.
 515         (when (>= version 216)
 516           (terminal-init-xterm-modify-other-keys))))))
 517
 518 (defun xterm--query (query handlers)
 519   ;; We used to query synchronously, but the need to use `discard-input' is
 520   ;; rather annoying (bug#6758).  Maybe we could always use the asynchronous
 521   ;; approach, but it's less tested.
 522   ;; FIXME: Merge the two branches.
 523   (if (input-pending-p)
 524       (progn
 525         (dolist (handler handlers)
 526           (define-key input-decode-map (car handler)
 527             (lambda (&optional _prompt)
 528               ;; Unregister the handler, since we don't expect further answers.
 529               (dolist (handler handlers)
 530                 (define-key input-decode-map (car handler) nil))
 531               (funcall (cdr handler))
 532               [])))
 533         (send-string-to-terminal query))
 534     ;; Pending input can be mistakenly returned by the calls to
 535     ;; read-event below.  Discard it.
 536     (send-string-to-terminal query)
 537     (while handlers
 538       (let ((handler (pop handlers))
 539             (i 0))
 540         (while (and (< i (length (car handler)))
 541                     (let ((evt (read-event nil nil 2)))
 542                       (or (eq evt (aref (car handler) i))
 543                           (progn (if evt (push evt unread-command-events))
 544                                  nil))))
 545           (setq i (1+ i)))
 546         (if (= i (length (car handler)))
 547             (funcall (cdr handler))
 548           (while (> i 0)
 549             (push (aref (car handler) (setq i (1- i)))
 550                   unread-command-events)))))))
 551
 552 (defun terminal-init-xterm ()
 553   "Terminal initialization function for xterm."
 554   ;; rxvt terminals sometimes set the TERM variable to "xterm", but
 555   ;; rxvt's keybindings are incompatible with xterm's. It is
 556   ;; better in that case to use rxvt's initialization function.
 557   (if (and (getenv "COLORTERM" (selected-frame))
 558            (string-match "\\`rxvt" (getenv "COLORTERM" (selected-frame))))
 559       (tty-run-terminal-initialization (selected-frame) "rxvt")
 560
 561     (let ((map (copy-keymap xterm-alternatives-map)))
 562       (set-keymap-parent map (keymap-parent local-function-key-map))
 563       (set-keymap-parent local-function-key-map map))
 564
 565     (let ((map (copy-keymap xterm-function-map)))
 566
 567       ;; Use inheritance to let the main keymap override those defaults.
 568       ;; This way we don't override terminfo-derived settings or settings
 569       ;; made in the init file.
 570       (set-keymap-parent map (keymap-parent input-decode-map))
 571       (set-keymap-parent input-decode-map map)))
 572
 573   (xterm-register-default-colors)
 574   (tty-set-up-initial-frame-faces)
 575
 576   (if (eq xterm-extra-capabilities 'check)
 577       ;; Try to find out the type of terminal by sending a "Secondary
 578       ;; Device Attributes (DA)" query.
 579       (xterm--query "\e[>0c"
 580                     ;; Some terminals (like OS X's Terminal.app) respond to
 581                     ;; this query as if it were a "Primary Device Attributes"
 582                     ;; query instead, so we should handle that too.
 583                     '(("\e[?" . xterm--version-handler)
 584                       ("\e[>" . xterm--version-handler)))
 585
 586     (when (memq 'reportBackground xterm-extra-capabilities)
 587       (xterm--query "\e]11;?\e\\"
 588                     '(("\e]11;" .  xterm--report-background-handler))))
 589
 590     (when (memq 'modifyOtherKeys xterm-extra-capabilities)
 591       (terminal-init-xterm-modify-other-keys)))
 592
 593   (run-hooks 'terminal-init-xterm-hook))
 594
 595 (defun terminal-init-xterm-modify-other-keys ()
 596   "Terminal initialization for xterm's modifyOtherKeys support."
 597   ;; Make sure that the modifyOtherKeys state is restored when
 598   ;; suspending, resuming and exiting.
 599   (add-hook 'suspend-hook 'xterm-turn-off-modify-other-keys)
 600   (add-hook 'suspend-resume-hook 'xterm-turn-on-modify-other-keys)
 601   (add-hook 'kill-emacs-hook 'xterm-remove-modify-other-keys)
 602   (add-hook 'delete-terminal-functions 'xterm-remove-modify-other-keys)
 603   ;; Add the selected frame to the list of frames that
 604   ;; need to deal with modify-other-keys.
 605   (push (frame-terminal (selected-frame))
 606       xterm-modify-other-keys-terminal-list)
 607   (xterm-turn-on-modify-other-keys))
 608
 609 ;; Set up colors, for those versions of xterm that support it.
 610 (defvar xterm-standard-colors
 611   ;; The names in the comments taken from XTerm-col.ad in the xterm
 612   ;; distribution, see ftp://dickey.his.com/xterm/.  RGB values are
 613   ;; from rgb.txt.
 614   '(("black"          0 (  0   0   0))  ; black
 615     ("red"            1 (205   0   0))  ; red3
 616     ("green"          2 (  0 205   0))  ; green3
 617     ("yellow"         3 (205 205   0))  ; yellow3
 618     ("blue"           4 (  0   0 238))  ; blue2
 619     ("magenta"        5 (205   0 205))  ; magenta3
 620     ("cyan"           6 (  0 205 205))  ; cyan3
 621     ("white"          7 (229 229 229))  ; gray90
 622     ("brightblack"    8 (127 127 127))  ; gray50
 623     ("brightred"      9 (255   0   0))  ; red
 624     ("brightgreen"   10 (  0 255   0))  ; green
 625     ("brightyellow"  11 (255 255   0))  ; yellow
 626     ("brightblue"    12 (92   92 255))  ; rgb:5c/5c/ff
 627     ("brightmagenta" 13 (255   0 255))  ; magenta
 628     ("brightcyan"    14 (  0 255 255))  ; cyan
 629     ("brightwhite"   15 (255 255 255))) ; white
 630   "Names of 16 standard xterm/aixterm colors, their numbers, and RGB values.")
 631
 632 (defun xterm-rgb-convert-to-16bit (prim)
 633   "Convert an 8-bit primary color value PRIM to a corresponding 16-bit value."
 634   (logior prim (lsh prim 8)))
 635
 636 (defun xterm-register-default-colors ()
 637   "Register the default set of colors for xterm or compatible emulator.
 638
 639 This function registers the number of colors returned by `display-color-cells'
 640 for the currently selected frame.  The first 16 colors are taken from
 641 `xterm-standard-colors', which see, while the rest are computed assuming
 642 either the 88- or 256-color standard color scheme supported by latest
 643 versions of xterm."
 644   (let* ((ncolors (display-color-cells (selected-frame)))
 645          (colors xterm-standard-colors)
 646          (color (car colors)))
 647     (if (> ncolors 0)
 648         ;; Clear the 8 default tty colors registered by startup.el
 649         (tty-color-clear))
 650     ;; Only register as many colors as are supported by the display.
 651     (while (and (> ncolors 0) colors)
 652       (tty-color-define (car color) (cadr color)
 653                         (mapcar 'xterm-rgb-convert-to-16bit
 654                                 (car (cddr color))))
 655       (setq colors (cdr colors)
 656             color (car colors)
 657             ncolors (1- ncolors)))
 658     ;; We've exhausted the colors from `xterm-standard-colors'.  If there
 659     ;; are more colors to support, compute them now.
 660     (when (> ncolors 0)
 661       (cond
 662        ((= ncolors 240) ; 256-color xterm
 663         ;; 216 non-gray colors first
 664         (let ((r 0) (g 0) (b 0))
 665           (while (> ncolors 24)
 666             ;; This and other formulas taken from 256colres.pl and
 667             ;; 88colres.pl in the xterm distribution.
 668             (tty-color-define (format "color-%d" (- 256 ncolors))
 669                               (- 256 ncolors)
 670                               (mapcar 'xterm-rgb-convert-to-16bit
 671                                       (list (if (zerop r) 0 (+ (* r 40) 55))
 672                                             (if (zerop g) 0 (+ (* g 40) 55))
 673                                             (if (zerop b) 0 (+ (* b 40) 55)))))
 674
 675             (setq b (1+ b))
 676             (if (> b 5)
 677                 (setq g (1+ g)
 678                       b 0))
 679             (if (> g 5)
 680                 (setq r (1+ r)
 681                       g 0))
 682             (setq ncolors (1- ncolors))))
 683         ;; Now the 24 gray colors
 684         (while (> ncolors 0)
 685           (setq color (xterm-rgb-convert-to-16bit (+ 8 (* (- 24 ncolors) 10))))
 686           (tty-color-define (format "color-%d" (- 256 ncolors))
 687                             (- 256 ncolors)
 688                             (list color color color))
 689           (setq ncolors (1- ncolors))))
 690        ((= ncolors 72)  ; 88-color xterm
 691         ;; 64 non-gray colors
 692         (let ((levels '(0 139 205 255))
 693               (r 0) (g 0) (b 0))
 694           (while (> ncolors 8)
 695             (tty-color-define (format "color-%d" (- 88 ncolors))
 696                               (- 88 ncolors)
 697                               (mapcar 'xterm-rgb-convert-to-16bit
 698                                       (list (nth r levels)
 699                                             (nth g levels)
 700                                             (nth b levels))))
 701             (setq b (1+ b))
 702             (if (> b 3)
 703                 (setq g (1+ g)
 704                       b 0))
 705             (if (> g 3)
 706                 (setq r (1+ r)
 707                       g 0))
 708             (setq ncolors (1- ncolors))))
 709         ;; Now the 8 gray colors
 710         (while (> ncolors 0)
 711           (setq color (xterm-rgb-convert-to-16bit
 712                        (floor
 713                         (if (= ncolors 8)
 714                             46.36363636
 715                           (+ (* (- 8 ncolors) 23.18181818) 69.54545454)))))
 716           (tty-color-define (format "color-%d" (- 88 ncolors))
 717                             (- 88 ncolors)
 718                             (list color color color))
 719           (setq ncolors (1- ncolors))))
 720        (t (error "Unsupported number of xterm colors (%d)" (+ 16 ncolors)))))
 721     ;; Modifying color mappings means realized faces don't use the
 722     ;; right colors, so clear them.
 723     (clear-face-cache)))
 724
 725 (defun xterm-turn-on-modify-other-keys ()
 726   "Turn the modifyOtherKeys feature of xterm back on."
 727   (let ((terminal (frame-terminal (selected-frame))))
 728     (when (and (terminal-live-p terminal)
 729                (memq terminal xterm-modify-other-keys-terminal-list))
 730       (send-string-to-terminal "\e[>4;1m" terminal))))
 731
 732 (defun xterm-turn-off-modify-other-keys (&optional frame)
 733   "Temporarily turn off the modifyOtherKeys feature of xterm."
 734   (let ((terminal (when frame (frame-terminal frame))))
 735     (when (and (terminal-live-p terminal)
 736                (memq terminal xterm-modify-other-keys-terminal-list))
 737       (send-string-to-terminal "\e[>4m" terminal))))
 738
 739 (defun xterm-remove-modify-other-keys (&optional terminal)
 740   "Turn off the modifyOtherKeys feature of xterm for good."
 741   (setq terminal (or terminal (frame-terminal (selected-frame))))
 742   (when (and (terminal-live-p terminal)
 743              (memq terminal xterm-modify-other-keys-terminal-list))
 744     (setq xterm-modify-other-keys-terminal-list
 745           (delq terminal xterm-modify-other-keys-terminal-list))
 746     (send-string-to-terminal "\e[>4m" terminal)))
 747
 748 (defun xterm-maybe-set-dark-background-mode (redc greenc bluec)
 749   ;; Use the heuristic in `frame-set-background-mode' to decide if a
 750   ;; frame is dark.
 751   (when (< (+ redc greenc bluec) (* .6 (+ 65535 65535 65535)))
 752     (set-terminal-parameter nil 'background-mode 'dark)
 753     t))
 754
 755 (provide 'xterm)
 756
 757 ;;; xterm.el ends here