lisp/icomplete.el

   1 ;;; icomplete.el --- minibuffer completion incremental feedback
   2
   3 ;; Copyright (C) 1992-1994, 1997, 1999, 2001-2013 Free Software
   4 ;; Foundation, Inc.
   5
   6 ;; Author: Ken Manheimer <klm@i.am>
   7 ;; Maintainer: Ken Manheimer <klm@i.am>
   8 ;; Created: Mar 1993 Ken Manheimer, klm@nist.gov - first release to usenet
   9 ;; Last update: Ken Manheimer <klm@i.am>, 11/18/1999.
  10 ;; Keywords: help, abbrev
  11
  12 ;; This file is part of GNU Emacs.
  13
  14 ;; GNU Emacs is free software: you can redistribute it and/or modify
  15 ;; it under the terms of the GNU General Public License as published by
  16 ;; the Free Software Foundation, either version 3 of the License, or
  17 ;; (at your option) any later version.
  18
  19 ;; GNU Emacs is distributed in the hope that it will be useful,
  20 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 ;; GNU General Public License for more details.
  23
  24 ;; You should have received a copy of the GNU General Public License
  25 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  26
  27 ;;; Commentary:
  28
  29 ;; Loading this package implements a more fine-grained minibuffer
  30 ;; completion feedback scheme.  Prospective completions are concisely
  31 ;; indicated within the minibuffer itself, with each successive
  32 ;; keystroke.
  33
  34 ;; See `icomplete-completions' docstring for a description of the
  35 ;; icomplete display format.
  36
  37 ;; See the `icomplete-minibuffer-setup-hook' docstring for a means to
  38 ;; customize icomplete setup for interoperation with other
  39 ;; minibuffer-oriented packages.
  40
  41 ;; To activate icomplete mode, load the package and use the
  42 ;; `icomplete-mode' function.  You can subsequently deactivate it by
  43 ;; invoking the function icomplete-mode with a negative prefix-arg
  44 ;; (C-U -1 ESC-x icomplete-mode).  Also, you can prevent activation of
  45 ;; the mode during package load by first setting the variable
  46 ;; `icomplete-mode' to nil.  Icompletion can be enabled any time after
  47 ;; the package is loaded by invoking icomplete-mode without a prefix
  48 ;; arg.
  49
  50 ;; Thanks to everyone for their suggestions for refinements of this
  51 ;; package.  I particularly have to credit Michael Cook, who
  52 ;; implemented an incremental completion style in his 'iswitch'
  53 ;; functions that served as a model for icomplete.  Some other
  54 ;; contributors: Noah Friedman (restructuring as minor mode), Colin
  55 ;; Rafferty (lemacs reconciliation), Lars Lindberg, RMS, and others.
  56
  57 ;; klm.
  58
  59 ;;; Code:
  60
  61 ;;;_* Provide
  62 (provide 'icomplete)
  63
  64
  65 (defgroup icomplete nil
  66   "Show completions dynamically in minibuffer."
  67   :prefix "icomplete-"
  68   :group 'minibuffer)
  69
  70 (defvar icomplete-prospects-length 80)
  71 (make-obsolete-variable
  72  'icomplete-prospects-length 'icomplete-prospects-height "23.1")
  73
  74 (defcustom icomplete-separator " | "
  75   "String used by icomplete to separate alternatives in the minibuffer."
  76   :type 'string
  77   :version "24.4")
  78
  79 (defcustom icomplete-hide-common-prefix t
  80   "When non-nil, hide common prefix from completion candidates.
  81 When nil, show candidates in full."
  82   :type 'boolean
  83   :version "24.4"
  84   :group 'icomplete)
  85
  86 (defface icomplete-first-match  '((t :weight bold))
  87   "Face used by icomplete for highlighting first match."
  88   :version "24.4"
  89   :group 'icomplete)
  90
  91 ;;;_* User Customization variables
  92 (defcustom icomplete-prospects-height
  93   ;; 20 is an estimated common size for the prompt + minibuffer content, to
  94   ;; try to guess the number of lines used up by icomplete-prospects-length.
  95   (+ 1 (/ (+ icomplete-prospects-length 20) (window-width)))
  96   "Maximum number of lines to use in the minibuffer."
  97   :type 'integer
  98   :group 'icomplete
  99   :version "23.1")
 100
 101 (defcustom icomplete-compute-delay .3
 102   "Completions-computation stall, used only with large-number completions.
 103 See `icomplete-delay-completions-threshold'."
 104   :type 'number
 105   :group 'icomplete)
 106
 107 (defcustom icomplete-delay-completions-threshold 400
 108   "Pending-completions number over which to apply `icomplete-compute-delay'."
 109   :type 'integer
 110   :group 'icomplete)
 111
 112 (defcustom icomplete-max-delay-chars 3
 113   "Maximum number of initial chars to apply icomplete compute delay."
 114   :type 'integer
 115   :group 'icomplete)
 116
 117 (defcustom icomplete-minibuffer-setup-hook nil
 118   "Icomplete-specific customization of minibuffer setup.
 119
 120 This hook is run during minibuffer setup if icomplete is active.
 121 It is intended for use in customizing icomplete for interoperation
 122 with other features and packages.  For instance:
 123
 124   \(add-hook 'icomplete-minibuffer-setup-hook
 125             \(function
 126              \(lambda ()
 127                \(make-local-variable 'max-mini-window-height)
 128                \(setq max-mini-window-height 3))))
 129
 130 will constrain Emacs to a maximum minibuffer height of 3 lines when
 131 icompletion is occurring."
 132   :type 'hook
 133   :group 'icomplete)
 134
 135
 136 ;;;_* Initialization
 137
 138 ;;;_ + Internal Variables
 139 ;;;_  = icomplete-eoinput nil
 140 (defvar icomplete-overlay (make-overlay (point-min) (point-min) nil t t)
 141   "Overlay used to display the list of completions.")
 142
 143 ;;;_  = icomplete-pre-command-hook
 144 (defvar icomplete-pre-command-hook nil
 145   "Incremental-minibuffer-completion pre-command-hook.
 146
 147 Is run in minibuffer before user input when `icomplete-mode' is non-nil.
 148 Use `icomplete-mode' function to set it up properly for incremental
 149 minibuffer completion.")
 150 (add-hook 'icomplete-pre-command-hook 'icomplete-tidy)
 151 ;;;_  = icomplete-post-command-hook
 152 (defvar icomplete-post-command-hook nil
 153   "Incremental-minibuffer-completion post-command-hook.
 154
 155 Is run in minibuffer after user input when `icomplete-mode' is non-nil.
 156 Use `icomplete-mode' function to set it up properly for incremental
 157 minibuffer completion.")
 158 (add-hook 'icomplete-post-command-hook 'icomplete-exhibit)
 159
 160 ;;;_  = icomplete-with-completion-tables
 161 (defvar icomplete-with-completion-tables '(internal-complete-buffer)
 162   "Specialized completion tables with which icomplete should operate.
 163
 164 Icomplete does not operate with any specialized completion tables
 165 except those on this list.")
 166
 167 (defvar icomplete-minibuffer-map
 168   (let ((map (make-sparse-keymap)))
 169     (define-key map [?\M-\t] 'minibuffer-force-complete)
 170     (define-key map [?\C-j]  'minibuffer-force-complete-and-exit)
 171     (define-key map [?\C-.]  'icomplete-forward-completions)
 172     (define-key map [?\C-,]  'icomplete-backward-completions)
 173     map))
 174
 175 (defun icomplete-forward-completions ()
 176   "Step forward completions by one entry.
 177 Second entry becomes the first and can be selected with
 178 `minibuffer-force-complete-and-exit'."
 179   (interactive)
 180   (let* ((comps (completion-all-sorted-completions))
 181          (last (last comps)))
 182     (when comps
 183       (setcdr last (cons (car comps) (cdr last)))
 184       (completion--cache-all-sorted-completions (cdr comps)))))
 185
 186 (defun icomplete-backward-completions ()
 187   "Step backward completions by one entry.
 188 Last entry becomes the first and can be selected with
 189 `minibuffer-force-complete-and-exit'."
 190   (interactive)
 191   (let* ((comps (completion-all-sorted-completions))
 192          (last-but-one (last comps 2))
 193          (last (cdr last-but-one)))
 194     (when (consp last)                ; At least two elements in comps
 195       (setcdr last-but-one (cdr last))
 196       (push (car last) comps)
 197       (completion--cache-all-sorted-completions comps))))
 198
 199 ;;;_ > icomplete-mode (&optional prefix)
 200 ;;;###autoload
 201 (define-minor-mode icomplete-mode
 202   "Toggle incremental minibuffer completion (Icomplete mode).
 203 With a prefix argument ARG, enable Icomplete mode if ARG is
 204 positive, and disable it otherwise.  If called from Lisp, enable
 205 the mode if ARG is omitted or nil."
 206   :global t :group 'icomplete
 207   (if icomplete-mode
 208       ;; The following is not really necessary after first time -
 209       ;; no great loss.
 210       (add-hook 'minibuffer-setup-hook 'icomplete-minibuffer-setup)
 211     (remove-hook 'minibuffer-setup-hook 'icomplete-minibuffer-setup)))
 212
 213 ;;;_ > icomplete-simple-completing-p ()
 214 (defun icomplete-simple-completing-p ()
 215   "Non-nil if current window is minibuffer that's doing simple completion.
 216
 217 Conditions are:
 218    the selected window is a minibuffer,
 219    and not in the middle of macro execution,
 220    and `minibuffer-completion-table' is not a symbol (which would
 221        indicate some non-standard, non-simple completion mechanism,
 222        like file-name and other custom-func completions)."
 223
 224   (and (window-minibuffer-p (selected-window))
 225        (not executing-kbd-macro)
 226        minibuffer-completion-table
 227        (or (not (functionp minibuffer-completion-table))
 228            (eq icomplete-with-completion-tables t)
 229            (member minibuffer-completion-table
 230                    icomplete-with-completion-tables))))
 231
 232 ;;;_ > icomplete-minibuffer-setup ()
 233 (defun icomplete-minibuffer-setup ()
 234   "Run in minibuffer on activation to establish incremental completion.
 235 Usually run by inclusion in `minibuffer-setup-hook'."
 236   (when (and icomplete-mode (icomplete-simple-completing-p))
 237     (set (make-local-variable 'completion-show-inline-help) nil)
 238     (use-local-map (make-composed-keymap icomplete-minibuffer-map
 239                                          (current-local-map)))
 240     (add-hook 'pre-command-hook
 241               (lambda () (let ((non-essential t))
 242                       (run-hooks 'icomplete-pre-command-hook)))
 243               nil t)
 244     (add-hook 'post-command-hook
 245               (lambda () (let ((non-essential t)) ;E.g. don't prompt for password!
 246                       (run-hooks 'icomplete-post-command-hook)))
 247               nil t)
 248     (run-hooks 'icomplete-minibuffer-setup-hook)))
 249 ;\f
 250
 251
 252 ;;;_* Completion
 253
 254 ;;;_ > icomplete-tidy ()
 255 (defun icomplete-tidy ()
 256   "Remove completions display \(if any) prior to new user input.
 257 Should be run in on the minibuffer `pre-command-hook'.  See `icomplete-mode'
 258 and `minibuffer-setup-hook'."
 259   (delete-overlay icomplete-overlay))
 260
 261 ;;;_ > icomplete-exhibit ()
 262 (defun icomplete-exhibit ()
 263   "Insert icomplete completions display.
 264 Should be run via minibuffer `post-command-hook'.  See `icomplete-mode'
 265 and `minibuffer-setup-hook'."
 266   (when (and icomplete-mode (icomplete-simple-completing-p))
 267     (save-excursion
 268       (goto-char (point-max))
 269                                         ; Insert the match-status information:
 270       (if (and (> (point-max) (minibuffer-prompt-end))
 271                buffer-undo-list         ; Wait for some user input.
 272                (or
 273                 ;; Don't bother with delay after certain number of chars:
 274                 (> (- (point) (field-beginning)) icomplete-max-delay-chars)
 275                 ;; Don't delay if the completions are known.
 276                 completion-all-sorted-completions
 277                 ;; Don't delay if alternatives number is small enough:
 278                 (and (sequencep minibuffer-completion-table)
 279                      (< (length minibuffer-completion-table)
 280                         icomplete-delay-completions-threshold))
 281                 ;; Delay - give some grace time for next keystroke, before
 282                 ;; embarking on computing completions:
 283                 (sit-for icomplete-compute-delay)))
 284           (let ((text (while-no-input
 285                         (icomplete-completions
 286                          (field-string)
 287                          minibuffer-completion-table
 288                          minibuffer-completion-predicate
 289                          (not minibuffer-completion-confirm))))
 290                 (buffer-undo-list t)
 291                 deactivate-mark)
 292             ;; Do nothing if while-no-input was aborted.
 293             (when (stringp text)
 294               (move-overlay icomplete-overlay (point) (point) (current-buffer))
 295               ;; The current C cursor code doesn't know to use the overlay's
 296               ;; marker's stickiness to figure out whether to place the cursor
 297               ;; before or after the string, so let's spoon-feed it the pos.
 298               (put-text-property 0 1 'cursor t text)
 299               (overlay-put icomplete-overlay 'after-string text)))))))
 300
 301 ;;;_ > icomplete-completions (name candidates predicate require-match)
 302 (defun icomplete-completions (name candidates predicate require-match)
 303   "Identify prospective candidates for minibuffer completion.
 304
 305 The display is updated with each minibuffer keystroke during
 306 minibuffer completion.
 307
 308 Prospective completion suffixes (if any) are displayed, bracketed by
 309 one of \(), \[], or \{} pairs.  The choice of brackets is as follows:
 310
 311   \(...) - a single prospect is identified and matching is enforced,
 312   \[...] - a single prospect is identified but matching is optional, or
 313   \{...} - multiple prospects, separated by commas, are indicated, and
 314           further input is required to distinguish a single one.
 315
 316 The displays for unambiguous matches have ` [Matched]' appended
 317 \(whether complete or not), or ` \[No matches]', if no eligible
 318 matches exist.  \(Keybindings for uniquely matched commands
 319 are exhibited within the square braces.)"
 320
 321   (let* ((md (completion--field-metadata (field-beginning)))
 322          (comps (completion-all-sorted-completions))
 323          (last (if (consp comps) (last comps)))
 324          (base-size (cdr last))
 325          (open-bracket (if require-match "(" "["))
 326          (close-bracket (if require-match ")" "]")))
 327     ;; `concat'/`mapconcat' is the slow part.
 328     (if (not (consp comps))
 329         (format " %sNo matches%s" open-bracket close-bracket)
 330       (if last (setcdr last nil))
 331       (let* ((most-try
 332               (if (and base-size (> base-size 0))
 333                   (completion-try-completion
 334                    name candidates predicate (length name) md)
 335                 ;; If the `comps' are 0-based, the result should be
 336                 ;; the same with `comps'.
 337                 (completion-try-completion
 338                  name comps nil (length name) md)))
 339              (most (if (consp most-try) (car most-try)
 340                      (if most-try (car comps) "")))
 341              ;; Compare name and most, so we can determine if name is
 342              ;; a prefix of most, or something else.
 343              (compare (compare-strings name nil nil
 344                                        most nil nil completion-ignore-case))
 345              (determ (unless (or (eq t compare) (eq t most-try)
 346                                  (= (setq compare (1- (abs compare)))
 347                                     (length most)))
 348                        (concat open-bracket
 349                                (cond
 350                                 ((= compare (length name))
 351                                  ;; Typical case: name is a prefix.
 352                                  (substring most compare))
 353                                 ;; Don't bother truncating if it doesn't gain
 354                                 ;; us at least 2 columns.
 355                                 ((< compare 3) most)
 356                                 (t (concat "…" (substring most compare))))
 357                                close-bracket)))
 358              ;;"-prospects" - more than one candidate
 359              (prospects-len (+ (string-width
 360                                 (or determ (concat open-bracket close-bracket)))
 361                                (string-width icomplete-separator)
 362                                3 ;; take {…} into account
 363                                (string-width (buffer-string))))
 364              (prospects-max
 365               ;; Max total length to use, including the minibuffer content.
 366               (* (+ icomplete-prospects-height
 367                     ;; If the minibuffer content already uses up more than
 368                     ;; one line, increase the allowable space accordingly.
 369                     (/ prospects-len (window-width)))
 370                  (window-width)))
 371              (prefix (when icomplete-hide-common-prefix
 372                        (try-completion "" comps)))
 373              (prefix-len
 374               ;; Find the common prefix among `comps'.
 375               ;; We can't use the optimization below because its assumptions
 376               ;; aren't always true, e.g. when completion-cycling (bug#10850):
 377               ;; (if (eq t (compare-strings (car comps) nil (length most)
 378               ;;                         most nil nil completion-ignore-case))
 379               ;;     ;; Common case.
 380               ;;     (length most)
 381               ;; Else, use try-completion.
 382               (and (stringp prefix) (length prefix))) ;;)
 383              prospects comp limit)
 384         (if (eq most-try t) ;; (or (null (cdr comps))
 385             (setq prospects nil)
 386           (when (member name comps)
 387             ;; NAME is complete but not unique.  This scenario poses
 388             ;; following UI issues:
 389             ;;
 390             ;; - When `icomplete-hide-common-prefix' is non-nil, NAME
 391             ;;   is stripped empty.  This would make the entry
 392             ;;   inconspicuous.
 393             ;;
 394             ;; - Due to sorting of completions, NAME may not be the
 395             ;;   first of the prospects and could be hidden deep in
 396             ;;   the displayed string.
 397             ;;
 398             ;; - Because of `icomplete-prospects-height' , NAME may
 399             ;;   not even be displayed to the user.
 400             ;;
 401             ;; To circumvent all the above problems, provide a visual
 402             ;; cue to the user via an "empty string" in the try
 403             ;; completion field.
 404             (setq determ (concat open-bracket "" close-bracket)))
 405           ;; Compute prospects for display.
 406           (while (and comps (not limit))
 407             (setq comp
 408                   (if prefix-len (substring (car comps) prefix-len) (car comps))
 409                   comps (cdr comps))
 410             (setq prospects-len
 411                            (+ (string-width comp)
 412                               (string-width icomplete-separator)
 413                               prospects-len))
 414                      (if (< prospects-len prospects-max)
 415                          (push comp prospects)
 416               (setq limit t))))
 417         (setq prospects (nreverse prospects))
 418         ;; Decorate first of the prospects.
 419         (when prospects
 420           (let ((first (copy-sequence (pop prospects))))
 421             (put-text-property 0 (length first)
 422                                'face 'icomplete-first-match first)
 423             (push first prospects)))
 424         ;; Restore the base-size info, since completion-all-sorted-completions
 425         ;; is cached.
 426         (if last (setcdr last base-size))
 427         (if prospects
 428             (concat determ
 429                     "{"
 430                     (mapconcat 'identity prospects icomplete-separator)
 431                     (and limit (concat icomplete-separator "…"))
 432                     "}")
 433           (concat determ " [Matched]"))))))
 434
 435 ;;_* Local emacs vars.
 436 ;;Local variables:
 437 ;;allout-layout: (-2 :)
 438 ;;End:
 439
 440 ;;; icomplete.el ends here