code.delx.au - gnu-emacs-elpa/blob - company.el

   1 ;;; company.el --- extensible inline text completion mechanism
   2 ;;
   3 ;; Copyright (C) 2009 Nikolaj Schumacher
   4 ;;
   5 ;; Author: Nikolaj Schumacher <bugs * nschum de>
   6 ;; Version:
   7 ;; Keywords: abbrev, convenience, matchis
   8 ;; URL: http://nschum.de/src/emacs/company/
   9 ;; Compatibility: GNU Emacs 23.x
  10 ;;
  11 ;; This file is NOT part of GNU Emacs.
  12 ;;
  13 ;; This program is free software; you can redistribute it and/or
  14 ;; modify it under the terms of the GNU General Public License
  15 ;; as published by the Free Software Foundation; either version 2
  16 ;; of the License, or (at your option) any later version.
  17 ;;
  18 ;; This program is distributed in the hope that it will be useful,
  19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 ;; GNU General Public License for more details.
  22 ;;
  23 ;; You should have received a copy of the GNU General Public License
  24 ;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
  25 ;;
  26 ;;; Commentary:
  27 ;;
  28 ;;; Change Log:
  29 ;;
  30 ;;    Initial release.
  31 ;;
  32 ;;; Code:
  33
  34 (eval-when-compile (require 'cl))
  35
  36 (add-to-list 'debug-ignored-errors
  37              "^Pseudo tooltip frontend cannot be used twice$")
  38 (add-to-list 'debug-ignored-errors "^Preview frontend cannot be used twice$")
  39 (add-to-list 'debug-ignored-errors "^Echo area cannot be used twice$")
  40 (add-to-list 'debug-ignored-errors "^No documentation available$")
  41
  42 (defgroup company nil
  43   ""
  44   :group 'abbrev
  45   :group 'convenience
  46   :group 'maching)
  47
  48 (defface company-tooltip
  49   '((t :background "yellow"
  50        :foreground "black"))
  51   "*"
  52   :group 'company)
  53
  54 (defface company-tooltip-selection
  55   '((t :background "orange1"
  56        :foreground "black"))
  57   "*"
  58   :group 'company)
  59
  60 (defface company-tooltip-common
  61   '((t :inherit company-tooltip
  62        :foreground "red"))
  63   "*"
  64   :group 'company)
  65
  66 (defface company-tooltip-common-selection
  67   '((t :inherit company-tooltip-selection
  68        :foreground "red"))
  69   "*"
  70   :group 'company)
  71
  72 (defcustom company-tooltip-limit 10
  73   "*"
  74   :group 'company
  75   :type 'integer)
  76
  77 (defface company-preview
  78   '((t :background "blue4"
  79        :foreground "wheat"))
  80   "*"
  81   :group 'company)
  82
  83 (defface company-preview-common
  84   '((t :inherit company-preview
  85        :foreground "red"))
  86   "*"
  87   :group 'company)
  88
  89 (defface company-echo nil
  90   "*"
  91   :group 'company)
  92
  93 (defface company-echo-common
  94   '((((background dark)) (:foreground "firebrick1"))
  95     (((background light)) (:background "firebrick4")))
  96   "*"
  97   :group 'company)
  98
  99 (defun company-frontends-set (variable value)
 100   ;; uniquify
 101   (let ((remainder value))
 102     (setcdr remainder (delq (car remainder) (cdr remainder))))
 103   (and (memq 'company-pseudo-tooltip-unless-just-one-frontend value)
 104        (memq 'company-pseudo-tooltip-frontend value)
 105        (error "Pseudo tooltip frontend cannot be used twice"))
 106   (and (memq 'company-preview-if-just-one-frontend value)
 107        (memq 'company-preview-frontend value)
 108        (error "Preview frontend cannot be used twice"))
 109   (and (memq 'company-echo value)
 110        (memq 'company-echo-metadata-frontend value)
 111        (error "Echo area cannot be used twice"))
 112   ;; preview must come last
 113   (dolist (f '(company-preview-if-just-one-frontend company-preview-frontend))
 114     (when (memq f value)
 115       (setq value (append (delq f value) (list f)))))
 116   (set variable value))
 117
 118 (defcustom company-frontends '(company-pseudo-tooltip-unless-just-one-frontend
 119                                company-preview-if-just-one-frontend
 120                                company-echo-metadata-frontend)
 121   "*"
 122   :set 'company-frontends-set
 123   :group 'company
 124   :type '(repeat (choice (const :tag "echo" company-echo-frontend)
 125                          (const :tag "pseudo tooltip"
 126                                 company-pseudo-tooltip-frontend)
 127                          (const :tag "pseudo tooltip, multiple only"
 128                                 company-pseudo-tooltip-unless-just-one-frontend)
 129                          (const :tag "preview" company-preview-frontend)
 130                          (const :tag "preview, unique only"
 131                                 company-preview-if-just-one-frontend)
 132                          (function :tag "custom function" nil))))
 133
 134 (defcustom company-backends '(company-elisp company-nxml company-css
 135                               company-semantic company-oddmuse
 136                               company-dabbrev)
 137   "*"
 138   :group 'company
 139   :type '(repeat (function :tag "function" nil)))
 140
 141 (defcustom company-minimum-prefix-length 3
 142   "*"
 143   :group 'company
 144   :type '(integer :tag "prefix length"))
 145
 146 (defvar company-timer nil)
 147
 148 (defun company-timer-set (variable value)
 149   (set variable value)
 150   (when company-timer (cancel-timer company-timer))
 151   (when (numberp value)
 152     (setq company-timer (run-with-idle-timer value t 'company-idle-begin))))
 153
 154 (defcustom company-idle-delay .7
 155   "*"
 156   :set 'company-timer-set
 157   :group 'company
 158   :type '(choice (const :tag "never (nil)" nil)
 159                  (const :tag "immediate (t)" t)
 160                  (number :tag "seconds")))
 161
 162 ;;; mode ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 163
 164 (defvar company-mode-map
 165   (let ((keymap (make-sparse-keymap)))
 166     (define-key keymap (kbd "M-n") 'company-select-next)
 167     (define-key keymap (kbd "M-p") 'company-select-previous)
 168     (define-key keymap (kbd "M-<return>") 'company-complete-selection)
 169     (define-key keymap "\t" 'company-complete)
 170     (define-key keymap (kbd "<f1>") 'company-show-doc-buffer)
 171     keymap))
 172
 173 ;;;###autoload
 174 (define-minor-mode company-mode
 175   ""
 176   nil " comp" company-mode-map
 177   (if company-mode
 178       (progn
 179         (add-hook 'pre-command-hook 'company-pre-command nil t)
 180         (add-hook 'post-command-hook 'company-post-command nil t)
 181         (company-timer-set 'company-idle-delay
 182                            company-idle-delay))
 183     (remove-hook 'pre-command-hook 'company-pre-command t)
 184     (remove-hook 'post-command-hook 'company-post-command t)
 185     (company-cancel)
 186     (kill-local-variable 'company-point)))
 187
 188 ;;; backends ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 189
 190 (defun company-grab (regexp &optional expression)
 191   (when (looking-back regexp)
 192     (or (match-string-no-properties (or expression 0)) "")))
 193
 194 (defun company-in-string-or-comment (&optional point)
 195   (let ((pos (syntax-ppss)))
 196     (or (nth 3 pos) (nth 4 pos) (nth 7 pos))))
 197
 198 ;;; completion mechanism ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 199
 200 (defvar company-backend nil)
 201 (make-variable-buffer-local 'company-backend)
 202
 203 (defvar company-prefix nil)
 204 (make-variable-buffer-local 'company-prefix)
 205
 206 (defvar company-candidates nil)
 207 (make-variable-buffer-local 'company-candidates)
 208
 209 (defvar company-candidates-cache nil)
 210 (make-variable-buffer-local 'company-candidates-cache)
 211
 212 (defvar company-common nil)
 213 (make-variable-buffer-local 'company-common)
 214
 215 (defvar company-selection 0)
 216 (make-variable-buffer-local 'company-selection)
 217
 218 (defvar company-selection-changed nil)
 219 (make-variable-buffer-local 'company-selection-changed)
 220
 221 (defvar company-point nil)
 222 (make-variable-buffer-local 'company-point)
 223
 224 (defvar company-disabled-backends nil)
 225
 226 (defsubst company-strip-prefix (str)
 227   (substring str (length company-prefix)))
 228
 229 (defsubst company-reformat (candidate)
 230   ;; company-ispell needs this, because the results are always lower-case
 231   ;; It's mory efficient to fix it only when they are displayed.
 232   (concat company-prefix (substring candidate (length company-prefix))))
 233
 234 (defsubst company-should-complete (prefix)
 235   (and (eq company-idle-delay t)
 236        (>= (length prefix) company-minimum-prefix-length)))
 237
 238 (defsubst company-call-frontends (command)
 239   (dolist (frontend company-frontends)
 240     (funcall frontend command)))
 241
 242 (defsubst company-calculate-candidates (prefix)
 243   (or (setq company-candidates (cdr (assoc prefix company-candidates-cache)))
 244       (let ((len (length prefix))
 245             (completion-ignore-case (funcall company-backend 'ignore-case))
 246             prev)
 247         (dotimes (i len)
 248           (when (setq prev (cdr (assoc (substring prefix 0 (- len i))
 249                                        company-candidates-cache)))
 250             (setq company-candidates (all-completions prefix prev))
 251             (return t))))
 252       (progn
 253         (setq company-candidates (funcall company-backend 'candidates prefix))
 254         (unless (funcall company-backend 'sorted)
 255           (setq company-candidates (sort company-candidates 'string<)))))
 256   (unless (assoc prefix company-candidates-cache)
 257     (push (cons prefix company-candidates) company-candidates-cache))
 258   (setq company-selection 0
 259         company-prefix prefix)
 260   (let ((completion-ignore-case (funcall company-backend 'ignore-case)))
 261     (setq company-common (try-completion company-prefix company-candidates)))
 262   (when (eq company-common t)
 263     (setq company-candidates nil))
 264   company-candidates)
 265
 266 (defun company-idle-begin ()
 267   (and company-mode
 268        (not company-candidates)
 269        (not (equal (point) company-point))
 270        (let ((company-idle-delay t))
 271          (company-begin)
 272          (company-post-command))))
 273
 274 (defun company-manual-begin ()
 275   (and company-mode
 276        (not company-candidates)
 277        (let ((company-idle-delay t)
 278              (company-minimum-prefix-length 0))
 279          (company-begin)))
 280   ;; Return non-nil if active.
 281   company-candidates)
 282
 283 (defun company-continue ()
 284   (when company-candidates
 285     (let ((new-prefix (funcall company-backend 'prefix)))
 286       (unless (and (= (- (point) (length new-prefix))
 287                       (- company-point (length company-prefix)))
 288                    (or (equal company-prefix new-prefix)
 289                        (company-calculate-candidates new-prefix)))
 290         (setq company-candidates nil)))))
 291
 292 (defun company-begin ()
 293   (company-continue)
 294   (unless company-candidates
 295     (let (prefix)
 296       (dolist (backend company-backends)
 297         (unless (fboundp backend)
 298           (ignore-errors (require backend nil t)))
 299         (if (fboundp backend)
 300             (when (setq prefix (funcall backend 'prefix))
 301               (when (company-should-complete prefix)
 302                 (setq company-backend backend)
 303                 (company-calculate-candidates prefix))
 304               (return prefix))
 305           (unless (memq backend company-disabled-backends)
 306             (push backend company-disabled-backends)
 307             (message "Company back-end '%s' could not be initialized"
 308                      backend))))))
 309   (if company-candidates
 310       (progn
 311         (setq company-point (point))
 312         (company-call-frontends 'update))
 313     (company-cancel)))
 314
 315 (defun company-cancel ()
 316   (setq company-backend nil
 317         company-prefix nil
 318         company-candidates nil
 319         company-candidates-cache nil
 320         company-common nil
 321         company-selection 0
 322         company-selection-changed nil
 323         company-point nil)
 324   (company-call-frontends 'hide))
 325
 326 (defun company-abort ()
 327   (company-cancel)
 328   ;; Don't start again, unless started manually.
 329   (setq company-point (point)))
 330
 331 (defun company-pre-command ()
 332   (unless (eq this-command 'company-show-doc-buffer)
 333     (condition-case err
 334         (when company-candidates
 335           (company-call-frontends 'pre-command))
 336       (error (message "Company: An error occurred in pre-command")
 337              (message "%s" (error-message-string err))
 338              (company-cancel)))))
 339
 340 (defun company-post-command ()
 341   (unless (eq this-command 'company-show-doc-buffer)
 342     (condition-case err
 343         (progn
 344           (unless (equal (point) company-point)
 345             (company-begin))
 346           (when company-candidates
 347             (company-call-frontends 'post-command)))
 348       (error (message "Company: An error occurred in post-command")
 349              (message "%s" (error-message-string err))
 350              (company-cancel)))))
 351
 352 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 353
 354 (defun company-select-next ()
 355   (interactive)
 356   (when (company-manual-begin)
 357     (setq company-selection (min (1- (length company-candidates))
 358                                  (1+ company-selection))
 359           company-selection-changed t))
 360   (company-call-frontends 'update))
 361
 362 (defun company-select-previous ()
 363   (interactive)
 364   (when (company-manual-begin)
 365     (setq company-selection (max 0 (1- company-selection))
 366           company-selection-changed t))
 367   (company-call-frontends 'update))
 368
 369 (defun company-complete-selection ()
 370   (interactive)
 371   (when (company-manual-begin)
 372     (insert (company-strip-prefix (nth company-selection company-candidates)))
 373     (company-abort)))
 374
 375 (defun company-complete-common ()
 376   (interactive)
 377   (when (company-manual-begin)
 378     (insert (company-strip-prefix company-common))))
 379
 380 (defun company-complete ()
 381   (interactive)
 382   (when (company-manual-begin)
 383     (if (or company-selection-changed
 384             (eq last-command 'company-complete-common))
 385         (call-interactively 'company-complete-selection)
 386       (call-interactively 'company-complete-common)
 387       (setq this-command 'company-complete-common))))
 388
 389 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 390
 391 (defconst company-space-strings-limit 100)
 392
 393 (defconst company-space-strings
 394   (let (lst)
 395     (dotimes (i company-space-strings-limit)
 396       (push (make-string (- company-space-strings-limit 1 i) ?\  ) lst))
 397     (apply 'vector lst)))
 398
 399 (defsubst company-space-string (len)
 400   (if (< len company-space-strings-limit)
 401       (aref company-space-strings len)
 402     (make-string len ?\ )))
 403
 404 (defsubst company-safe-substring (str from &optional to)
 405   (let ((len (length str)))
 406     (if (> from len)
 407         ""
 408       (if (and to (> to len))
 409           (concat (substring str from)
 410                   (company-space-string (- to len)))
 411         (substring str from to)))))
 412
 413 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 414
 415 (defvar company-last-metadata nil)
 416 (make-variable-buffer-local 'company-last-metadata)
 417
 418 (defun company-fetch-metadata ()
 419   (let ((selected (nth company-selection company-candidates)))
 420     (unless (equal selected (car company-last-metadata))
 421       (setq company-last-metadata
 422             (cons selected (funcall company-backend 'meta selected))))
 423     (cdr company-last-metadata)))
 424
 425 (defun company-doc-buffer (&optional string)
 426   (with-current-buffer (get-buffer-create "*Company meta-data*")
 427     (erase-buffer)
 428     (current-buffer)))
 429
 430 (defun company-show-doc-buffer ()
 431   (interactive)
 432   (when company-candidates
 433     (save-window-excursion
 434       (let* ((selected (nth company-selection company-candidates))
 435              (buffer (funcall company-backend 'doc-buffer selected)))
 436         (if (not buffer)
 437             (error "No documentation available.")
 438           (display-buffer buffer)
 439           (read-event)
 440           (when last-input-event
 441             (clear-this-command-keys t)
 442             (setq unread-command-events (list last-input-event))))))))
 443
 444 ;;; pseudo-tooltip ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 445
 446 (defvar company-pseudo-tooltip-overlay nil)
 447 (make-variable-buffer-local 'company-pseudo-tooltip-overlay)
 448
 449 (defvar company-tooltip-offset 0)
 450 (make-variable-buffer-local 'company-tooltip-offset)
 451
 452 (defun company-pseudo-tooltip-update-offset (selection num-lines limit)
 453
 454   (decf limit 2)
 455   (setq company-tooltip-offset
 456         (max (min selection company-tooltip-offset)
 457              (- selection -1 limit)))
 458
 459   (when (<= company-tooltip-offset 1)
 460     (incf limit)
 461     (setq company-tooltip-offset 0))
 462
 463   (when (>= company-tooltip-offset (- num-lines limit 1))
 464     (incf limit)
 465     (when (= selection (1- num-lines))
 466       (setq company-tooltip-offset (max (1- company-tooltip-offset) 0))))
 467
 468   limit)
 469
 470 ;;; propertize
 471
 472 (defun company-fill-propertize (line width selected)
 473   (setq line (company-safe-substring line 0 width))
 474   (add-text-properties 0 width
 475                        (list 'face (if selected
 476                                        'company-tooltip-selection
 477                                      'company-tooltip)) line)
 478   (add-text-properties 0 (length company-common)
 479                        (list 'face (if selected
 480                                        'company-tooltip-common-selection
 481                                      'company-tooltip-common)) line)
 482   line)
 483
 484 ;;; replace
 485
 486 (defun company-buffer-lines (beg end)
 487   (goto-char beg)
 488   (let ((row (cdr (posn-col-row (posn-at-point))))
 489         lines)
 490     (while (< (point) end)
 491       (move-to-window-line (incf row))
 492       (push (buffer-substring beg (min end (1- (point)))) lines)
 493       (setq beg (point)))
 494     (nreverse lines)))
 495
 496 (defun company-modify-line (old new offset)
 497   (concat (company-safe-substring old 0 offset)
 498           new
 499           (company-safe-substring old (+ offset (length new)))))
 500
 501 (defun company-replacement-string (old lines column nl)
 502   (let (new)
 503     ;; Inject into old lines.
 504     (while old
 505       (push (company-modify-line (pop old) (pop lines) column) new))
 506     ;; Append whole new lines.
 507     (while lines
 508       (push (company-modify-line "" (pop lines) column) new))
 509     (concat (when nl "\n")
 510             (mapconcat 'identity (nreverse new) "\n")
 511             "\n")))
 512
 513 (defun company-create-lines (column lines selection)
 514
 515   (let ((limit (max company-tooltip-limit 3))
 516         (len (length lines))
 517         width
 518         lines-copy
 519         previous
 520         remainder
 521         new)
 522
 523     ;; Scroll to offset.
 524     (setq limit (company-pseudo-tooltip-update-offset selection len limit))
 525
 526     (when (> company-tooltip-offset 0)
 527       (setq previous (format "...(%d)" company-tooltip-offset)))
 528
 529     (setq remainder (- len limit company-tooltip-offset)
 530           remainder (when (> remainder 0)
 531                       (setq remainder (format "...(%d)" remainder))))
 532
 533     (decf selection company-tooltip-offset)
 534     (setq width (min (length previous) (length remainder))
 535           lines (nthcdr company-tooltip-offset lines)
 536           len (min limit (length lines))
 537           lines-copy lines)
 538
 539     (dotimes (i len)
 540       (setq width (max (length (pop lines-copy)) width)))
 541     (setq width (min width (- (window-width) column)))
 542
 543     (when previous
 544       (push (propertize (company-safe-substring previous 0 width)
 545                         'face 'company-tooltip)
 546             new))
 547
 548     (dotimes (i len)
 549       (push (company-fill-propertize (company-reformat (pop lines))
 550                                      width (equal i selection))
 551             new))
 552
 553     (when remainder
 554       (push (propertize (company-safe-substring remainder 0 width)
 555                         'face 'company-tooltip)
 556             new))
 557
 558     (setq lines (nreverse new))))
 559
 560 ;; show
 561
 562 (defun company-pseudo-tooltip-show (row column lines selection)
 563   (company-pseudo-tooltip-hide)
 564   (unless lines (error "No text provided"))
 565   (save-excursion
 566
 567     (move-to-column 0)
 568
 569     (let* ((lines (company-create-lines column lines selection))
 570            (nl (< (move-to-window-line row) row))
 571            (beg (point))
 572            (end (save-excursion
 573                   (move-to-window-line (min (window-height)
 574                                             (+ row company-tooltip-limit)))
 575                   (point)))
 576            (old-string (company-buffer-lines beg end))
 577            str)
 578
 579       (setq company-pseudo-tooltip-overlay (make-overlay beg end))
 580
 581       (overlay-put company-pseudo-tooltip-overlay 'company-old old-string)
 582       (overlay-put company-pseudo-tooltip-overlay 'company-column column)
 583       (overlay-put company-pseudo-tooltip-overlay 'company-nl nl)
 584       (overlay-put company-pseudo-tooltip-overlay 'company-before
 585                    (company-replacement-string old-string lines column nl))
 586
 587       (overlay-put company-pseudo-tooltip-overlay 'window (selected-window)))))
 588
 589 (defun company-pseudo-tooltip-show-at-point (pos)
 590   (let ((col-row (posn-col-row (posn-at-point pos))))
 591     (company-pseudo-tooltip-show (1+ (cdr col-row)) (car col-row)
 592                                  company-candidates company-selection)))
 593
 594 (defun company-pseudo-tooltip-edit (lines selection)
 595   (let* ((old-string (overlay-get company-pseudo-tooltip-overlay 'company-old))
 596          (column (overlay-get company-pseudo-tooltip-overlay 'company-column))
 597          (nl (overlay-get company-pseudo-tooltip-overlay 'company-nl))
 598          (lines (company-create-lines column lines selection)))
 599     (overlay-put company-pseudo-tooltip-overlay 'company-before
 600                  (company-replacement-string old-string lines column nl))))
 601
 602 (defun company-pseudo-tooltip-hide ()
 603   (when company-pseudo-tooltip-overlay
 604     (delete-overlay company-pseudo-tooltip-overlay)
 605     (setq company-pseudo-tooltip-overlay nil)))
 606
 607 (defun company-pseudo-tooltip-hide-temporarily ()
 608   (when (overlayp company-pseudo-tooltip-overlay)
 609     (overlay-put company-pseudo-tooltip-overlay 'invisible nil)
 610     (overlay-put company-pseudo-tooltip-overlay 'before-string nil)))
 611
 612 (defun company-pseudo-tooltip-unhide ()
 613   (when company-pseudo-tooltip-overlay
 614     (overlay-put company-pseudo-tooltip-overlay 'invisible t)
 615     (overlay-put company-pseudo-tooltip-overlay 'before-string
 616                  (overlay-get company-pseudo-tooltip-overlay 'company-before))))
 617
 618 (defun company-pseudo-tooltip-frontend (command)
 619   (case command
 620     ('pre-command (company-pseudo-tooltip-hide-temporarily))
 621     ('post-command
 622      (unless (overlayp company-pseudo-tooltip-overlay)
 623        (company-pseudo-tooltip-show-at-point (- (point)
 624                                                 (length company-prefix))))
 625      (company-pseudo-tooltip-unhide))
 626     ('hide (company-pseudo-tooltip-hide)
 627            (setq company-tooltip-offset 0))
 628     ('update (when (overlayp company-pseudo-tooltip-overlay)
 629                (company-pseudo-tooltip-edit company-candidates
 630                                             company-selection)))))
 631
 632 (defun company-pseudo-tooltip-unless-just-one-frontend (command)
 633   (unless (and (eq command 'post-command)
 634                (not (cdr company-candidates)))
 635     (company-pseudo-tooltip-frontend command)))
 636
 637 ;;; overlay ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 638
 639 (defvar company-preview-overlay nil)
 640 (make-variable-buffer-local 'company-preview-overlay)
 641
 642 (defun company-preview-show-at-point (pos)
 643   (company-preview-hide)
 644
 645   (setq company-preview-overlay (make-overlay pos pos))
 646
 647   (let ((completion (company-strip-prefix (nth company-selection
 648                                                company-candidates))))
 649     (and (equal pos (point))
 650          (not (equal completion ""))
 651          (add-text-properties 0 1 '(cursor t) completion))
 652
 653     (setq completion (propertize completion 'face 'company-preview))
 654     (add-text-properties 0 (- (length company-common) (length company-prefix))
 655                          '(face company-preview-common) completion)
 656
 657     (overlay-put company-preview-overlay 'after-string completion)
 658     (overlay-put company-preview-overlay 'window (selected-window))))
 659
 660 (defun company-preview-hide ()
 661   (when company-preview-overlay
 662     (delete-overlay company-preview-overlay)
 663     (setq company-preview-overlay nil)))
 664
 665 (defun company-preview-frontend (command)
 666   (case command
 667     ('pre-command (company-preview-hide))
 668     ('post-command (company-preview-show-at-point (point)))
 669     ('hide (company-preview-hide))))
 670
 671 (defun company-preview-if-just-one-frontend (command)
 672   (unless (and (eq command 'post-command)
 673                (cdr company-candidates))
 674     (company-preview-frontend command)))
 675
 676 ;;; echo ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 677
 678 (defvar company-echo-last-msg nil)
 679 (make-variable-buffer-local 'company-echo-last-msg)
 680
 681 (defun company-echo-refresh ()
 682   (let ((message-log-max nil))
 683     (if company-echo-last-msg
 684         (message "%s" company-echo-last-msg)
 685       (message ""))))
 686
 687 (defun company-echo-show (candidates)
 688
 689   ;; Roll to selection.
 690   (setq candidates (nthcdr company-selection candidates))
 691
 692   (let ((limit (window-width (minibuffer-window)))
 693         (len -1)
 694         comp msg)
 695     (while candidates
 696       (setq comp (company-reformat (pop candidates))
 697             len (+ len 1 (length comp)))
 698       (if (>= len limit)
 699           (setq candidates nil)
 700         (setq comp (propertize comp 'face 'company-echo))
 701         (add-text-properties 0 (length company-common)
 702                              '(face company-echo-common) comp)
 703         (push comp msg)))
 704
 705     (setq company-echo-last-msg (mapconcat 'identity (nreverse msg) " "))
 706     (company-echo-refresh)))
 707
 708 (defun company-echo-frontend (command)
 709   (case command
 710     ('pre-command (company-echo-refresh))
 711     ('post-command (company-echo-show company-candidates))
 712     ('hide (setq company-echo-last-msg nil))))
 713
 714 (defun company-echo-metadata-frontend (command)
 715   (case command
 716     ('pre-command (company-echo-refresh))
 717     ('post-command (setq company-echo-last-msg (company-fetch-metadata))
 718                    (company-echo-refresh))
 719     ('hide (setq company-echo-last-msg nil))))
 720
 721
 722 (provide 'company)
 723 ;;; company.el ends here