lisp/tooltip.el

   1 ;;; tooltip.el --- show tooltip windows
   2
   3 ;; Copyright (C) 1997, 1999, 2000, 2001 Free Software Foundation, Inc.
   4
   5 ;; Author: Gerd Moellmann <gerd@acm.org>
   6 ;; Keywords: help c mouse tools
   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 2, or (at your option)
  13 ;; 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; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 ;; Boston, MA 02111-1307, USA.
  24
  25 ;;; Commentary:
  26
  27 ;;; Code:
  28
  29 (eval-when-compile
  30   (require 'cl)
  31   (require 'comint)
  32   (require 'gud))
  33
  34 (provide 'tooltip)
  35
  36 \f
  37 ;;; Customizable settings
  38
  39 (defgroup tooltip nil
  40   "Customization group for the `tooltip' package."
  41   :group 'help
  42   :group 'gud
  43   :group 'mouse
  44   :group 'tools
  45   :version "21.1"
  46   :tag "Tool Tips")
  47
  48 (defvar tooltip-mode)
  49
  50 (defcustom tooltip-delay 0.7
  51   "Seconds to wait before displaying a tooltip the first time."
  52   :tag "Delay"
  53   :type 'number
  54   :group 'tooltip)
  55
  56
  57 (defcustom tooltip-short-delay 0.1
  58   "Seconds to wait between subsequent tooltips on different items."
  59   :tag "Short delay"
  60   :type 'number
  61   :group 'tooltip)
  62
  63
  64 (defcustom tooltip-recent-seconds 1
  65   "Display tooltips if changing tip items within this many seconds.
  66 Do so after `tooltip-short-delay'."
  67   :tag "Recent seconds"
  68   :type 'number
  69   :group 'tooltip)
  70
  71
  72 (defcustom tooltip-hide-delay 10
  73   "Hide tooltips automatically after this many seconds."
  74   :tag "Hide delay"
  75   :type 'number
  76   :group 'tooltip)
  77
  78
  79 (defcustom tooltip-x-offset nil
  80   "X offset, in pixels, for the display of tooltips.
  81 The offset is relative to the position of the mouse.  It must
  82 be chosen so that the tooltip window doesn't contain the mouse
  83 when it pops up.  If the value is nil, the default offset is 5
  84 pixels.
  85
  86 If `tooltip-frame-parameters' includes the `left' parameter,
  87 the value of `tooltip-x-offset' is ignored."
  88   :tag "X offset"
  89   :type '(choice (const :tag "Default" nil)
  90                  (integer :tag "Offset" :value 1))
  91   :group 'tooltip)
  92
  93
  94 (defcustom tooltip-y-offset nil
  95   "Y offset, in pixels, for the display of tooltips.
  96 The offset is relative to the position of the mouse.  It must
  97 be chosen so that the tooltip window doesn't contain the mouse
  98 when it pops up.  If the value is nil, the default offset is -10
  99 pixels.
 100
 101 If `tooltip-frame-parameters' includes the `top' parameter,
 102 the value of `tooltip-y-offset' is ignored."
 103   :tag "Y offset"
 104   :type '(choice (const :tag "Default" nil)
 105                  (integer :tag "Offset" :value 1))
 106   :group 'tooltip)
 107
 108
 109 (defcustom tooltip-frame-parameters
 110   '((name . "tooltip")
 111     (internal-border-width . 5)
 112     (border-width . 1))
 113   "Frame parameters used for tooltips.
 114
 115 If `left' or `top' parameters are included, they specify the absolute
 116 position to pop up the tooltip."
 117   :type 'sexp
 118   :tag "Frame Parameters"
 119   :group 'tooltip)
 120
 121
 122 (defface tooltip
 123   '((((class color))
 124      (:background "lightyellow" :foreground "black"))
 125     (t ()))
 126   "Face for tooltips."
 127   :group 'tooltip)
 128
 129
 130 (defcustom tooltip-gud-tips-p nil
 131   "*Non-nil means show tooltips in GUD sessions."
 132   :type 'boolean
 133   :tag "GUD"
 134   :set #'(lambda (symbol on)
 135            (setq tooltip-gud-tips-p on))
 136   :group 'tooltip)
 137
 138
 139 (defcustom tooltip-gud-modes '(gud-mode c-mode c++-mode)
 140   "List of modes for which to enable GUD tips."
 141   :type 'sexp
 142   :tag "GUD modes"
 143   :group 'tooltip)
 144
 145
 146 (defcustom tooltip-gud-display
 147   '((eq (tooltip-event-buffer tooltip-gud-event)
 148         (marker-buffer overlay-arrow-position)))
 149   "List of forms determining where GUD tooltips are displayed.
 150
 151 Forms in the list are combined with AND.  The default is to display
 152 only tooltips in the buffer containing the overlay arrow."
 153   :type 'sexp
 154   :tag "GUD buffers predicate"
 155   :group 'tooltip)
 156
 157
 158 (defcustom tooltip-use-echo-area nil
 159   "Use the echo area instead of tooltip frames.
 160 This is only relevant GUD display, since otherwise it is equivalent to
 161 turning off Tooltip mode."
 162   :type 'boolean
 163   :tag "Use echo area"
 164   :group 'tooltip)
 165
 166 \f
 167 ;;; Variables that are not customizable.
 168
 169 (defvar tooltip-hook nil
 170   "Functions to call to display tooltips.
 171 Each function is called with one argument EVENT which is a copy of
 172 the last mouse movement event that occurred.")
 173
 174
 175 (defvar tooltip-timeout-id nil
 176   "The id of the timeout started when Emacs becomes idle.")
 177
 178
 179 (defvar tooltip-last-mouse-motion-event nil
 180   "A copy of the last mouse motion event seen.")
 181
 182
 183 (defvar tooltip-hide-time nil
 184   "Time when the last tooltip was hidden.")
 185
 186
 187 \f
 188 ;;; Event accessors
 189
 190 (defun tooltip-event-buffer (event)
 191   "Return the buffer over which event EVENT occurred.
 192 This might return nil if the event did not occur over a buffer."
 193   (let ((window (posn-window (event-end event))))
 194     (and window (window-buffer window))))
 195
 196
 197 \f
 198 ;;; Switching tooltips on/off
 199
 200 ;; We don't set track-mouse globally because this is a big redisplay
 201 ;; problem in buffers having a pre-command-hook or such installed,
 202 ;; which does a set-buffer, like the summary buffer of Gnus.  Calling
 203 ;; set-buffer prevents redisplay optimizations, so every mouse motion
 204 ;; would be accompanied by a full redisplay.
 205
 206 ;;;###autoload
 207 (defun tooltip-mode (&optional arg)
 208   "Mode for tooltip display.
 209 With ARG, turn tooltip mode on if and only if ARG is positive."
 210   (interactive "P")
 211   (unless (fboundp 'x-show-tip)
 212     (error "Sorry, tooltips are not yet available on this system"))
 213   (let* ((on (if arg
 214                  (> (prefix-numeric-value arg) 0)
 215                (not tooltip-mode)))
 216          (hook-fn (if on 'add-hook 'remove-hook)))
 217     (setq tooltip-mode on)
 218     (funcall hook-fn 'change-major-mode-hook 'tooltip-change-major-mode)
 219     (tooltip-activate-mouse-motions-if-enabled)
 220     (funcall hook-fn 'pre-command-hook 'tooltip-hide)
 221     (funcall hook-fn 'tooltip-hook 'tooltip-gud-tips)
 222     (funcall hook-fn 'tooltip-hook 'tooltip-help-tips)
 223     (setq show-help-function (if on 'tooltip-show-help-function nil))
 224     ;; `ignore' is the default binding for mouse movements.
 225     (define-key global-map [mouse-movement]
 226       (if on 'tooltip-mouse-motion 'ignore))))
 227
 228
 229 \f
 230 ;;; Timeout for tooltip display
 231
 232 (defun tooltip-delay ()
 233   "Return the delay in seconds for the next tooltip."
 234   (let ((delay tooltip-delay)
 235         (now (float-time)))
 236     (when (and tooltip-hide-time
 237                (< (- now tooltip-hide-time) tooltip-recent-seconds))
 238       (setq delay tooltip-short-delay))
 239     delay))
 240
 241
 242 (defun tooltip-cancel-delayed-tip ()
 243   "Disable the tooltip timeout."
 244   (when tooltip-timeout-id
 245     (disable-timeout tooltip-timeout-id)
 246     (setq tooltip-timeout-id nil)))
 247
 248
 249 (defun tooltip-start-delayed-tip ()
 250   "Add a one-shot timeout to call function tooltip-timeout."
 251   (setq tooltip-timeout-id
 252         (add-timeout (tooltip-delay) 'tooltip-timeout nil)))
 253
 254
 255 (defun tooltip-timeout (object)
 256   "Function called when timer with id tooltip-timeout-id fires."
 257   (run-hook-with-args-until-success 'tooltip-hook
 258                                     tooltip-last-mouse-motion-event))
 259
 260
 261 \f
 262 ;;; Reacting on mouse movements
 263
 264 (defun tooltip-change-major-mode ()
 265   "Function added to `change-major-mode-hook' when tooltip mode is on."
 266   (add-hook 'post-command-hook 'tooltip-activate-mouse-motions-if-enabled))
 267
 268
 269 (defun tooltip-activate-mouse-motions-if-enabled ()
 270   "Reconsider for all buffers whether mouse motion events are desired."
 271   (remove-hook 'post-command-hook 'tooltip-activate-mouse-motions-if-enabled)
 272   (let ((buffers (buffer-list)))
 273     (save-excursion
 274       (while buffers
 275         (set-buffer (car buffers))
 276         (if (and tooltip-mode
 277                  tooltip-gud-tips-p
 278                  (memq major-mode tooltip-gud-modes))
 279             (tooltip-activate-mouse-motions t)
 280           (tooltip-activate-mouse-motions nil))
 281         (setq buffers (cdr buffers))))))
 282
 283 (defvar tooltip-mouse-motions-active nil
 284   "Locally t in a buffer if tooltip processing of mouse motion is enabled.")
 285
 286 (defun tooltip-activate-mouse-motions (activatep)
 287   "Activate/deactivate mouse motion events for the current buffer.
 288 ACTIVATEP non-nil means activate mouse motion events."
 289   (if activatep
 290       (progn
 291         (make-local-variable 'tooltip-mouse-motions-active)
 292         (setq tooltip-mouse-motions-active t)
 293         (make-local-variable 'track-mouse)
 294         (setq track-mouse t))
 295     (when tooltip-mouse-motions-active
 296       (kill-local-variable 'tooltip-mouse-motions-active)
 297       (kill-local-variable 'track-mouse))))
 298
 299 (defun tooltip-mouse-motion (event)
 300   "Command handler for mouse movement events in `global-map'."
 301   (interactive "e")
 302   (tooltip-hide)
 303   (when (car (mouse-pixel-position))
 304     (setq tooltip-last-mouse-motion-event (copy-sequence event))
 305     (tooltip-start-delayed-tip)))
 306
 307
 308 \f
 309 ;;; Displaying tips
 310
 311 (defun tooltip-set-param (alist key value)
 312   "Change the value of KEY in alist ALIST to VALUE.
 313 If there's no association for KEY in ALIST, add one, otherwise
 314 change the existing association.  Value is the resulting alist."
 315   (let ((param (assq key alist)))
 316     (if (consp param)
 317         (setcdr param value)
 318       (push (cons key value) alist))
 319     alist))
 320
 321
 322 (defun tooltip-show (text)
 323   "Show a tooltip window displaying TEXT.
 324
 325 Text larger than `x-max-tooltip-size' (which see) is clipped.
 326
 327 If the alist in `tooltip-frame-parameters' includes `left' and `top'
 328 parameters, they determine the x and y position where the tooltip
 329 is displayed.  Otherwise, the tooltip pops at offsets specified by
 330 `tooltip-x-offset' and `tooltip-y-offset' from the current mouse
 331 position."
 332   (if tooltip-use-echo-area
 333       (message "%s" text)
 334     (condition-case error
 335         (let ((params (copy-sequence tooltip-frame-parameters))
 336               (fg (face-attribute 'tooltip :foreground))
 337               (bg (face-attribute 'tooltip :background)))
 338           (when (stringp fg)
 339             (setq params (tooltip-set-param params 'foreground-color fg))
 340             (setq params (tooltip-set-param params 'border-color fg)))
 341           (when (stringp bg)
 342             (setq params (tooltip-set-param params 'background-color bg)))
 343           (x-show-tip (propertize text 'face 'tooltip)
 344                       (selected-frame)
 345                       params
 346                       tooltip-hide-delay
 347                       tooltip-x-offset
 348                       tooltip-y-offset))
 349       (error
 350        (message "Error while displaying tooltip: %s" error)
 351        (sit-for 1)
 352        (message "%s" text)))))
 353
 354
 355 (defun tooltip-hide (&optional ignored-arg)
 356   "Hide a tooltip, if one is displayed.
 357 Value is non-nil if tooltip was open."
 358   (tooltip-cancel-delayed-tip)
 359   (when (x-hide-tip)
 360     (setq tooltip-hide-time (float-time))))
 361
 362
 363 \f
 364 ;;; Debugger-related functions
 365
 366 (defun tooltip-identifier-from-point (point)
 367   "Extract the identifier at POINT, if any.
 368 Value is nil if no identifier exists at point.  Identifier extraction
 369 is based on the current syntax table."
 370   (save-excursion
 371     (goto-char point)
 372     (let ((start (progn (skip-syntax-backward "w_") (point))))
 373       (unless (looking-at "[0-9]")
 374         (skip-syntax-forward "w_")
 375         (when (> (point) start)
 376           (buffer-substring start (point)))))))
 377
 378
 379 (defmacro tooltip-region-active-p ()
 380   "Value is non-nil if the region is currently active."
 381   (if (string-match "^GNU" (emacs-version))
 382       `(and transient-mark-mode mark-active)
 383     `(region-active-p)))
 384
 385
 386 (defun tooltip-expr-to-print (event)
 387   "Return an expression that should be printed for EVENT.
 388 If a region is active and the mouse is inside the region, print
 389 the region.  Otherwise, figure out the identifier around the point
 390 where the mouse is."
 391   (save-excursion
 392     (set-buffer (tooltip-event-buffer event))
 393     (let ((point (posn-point (event-end event))))
 394       (if (tooltip-region-active-p)
 395           (when (and (<= (region-beginning) point) (<= point (region-end)))
 396             (buffer-substring (region-beginning) (region-end)))
 397         (tooltip-identifier-from-point point)))))
 398
 399
 400 (defun tooltip-process-prompt-regexp (process)
 401   "Return regexp matching the prompt of PROCESS at the end of a string.
 402 The prompt is taken from the value of COMINT-PROMPT-REGEXP in the buffer
 403 of PROCESS."
 404   (let ((prompt-regexp (save-excursion
 405                          (set-buffer (process-buffer process))
 406                          comint-prompt-regexp)))
 407     ;; Most start with `^' but the one for `sdb' cannot be easily
 408     ;; stripped.  Code the prompt for `sdb' fixed here.
 409     (if (= (aref prompt-regexp 0) ?^)
 410         (setq prompt-regexp (substring prompt-regexp 1))
 411       (setq prompt-regexp "\\*"))
 412     (concat "\n*" prompt-regexp "$")))
 413
 414
 415 (defun tooltip-strip-prompt (process output)
 416   "Return OUTPUT with any prompt of PROCESS stripped from its end."
 417   (let ((prompt-regexp (tooltip-process-prompt-regexp process)))
 418     (save-match-data
 419       (when (string-match prompt-regexp output)
 420         (setq output (substring output 0 (match-beginning 0)))))
 421     output))
 422
 423
 424 \f
 425 ;;; Tips for `gud'
 426
 427 (defvar tooltip-gud-original-filter nil
 428   "Process filter to restore after GUD output has been received.")
 429
 430
 431 (defvar tooltip-gud-dereference nil
 432   "Non-nil means print expressions with a `*' in front of them.
 433 For C this would dereference a pointer expression.")
 434
 435
 436 (defvar tooltip-gud-event nil
 437   "The mouse movement event that led to a tooltip display.
 438 This event can be examined by forms in TOOLTIP-GUD-DISPLAY.")
 439
 440
 441 (defun tooltip-gud-toggle-dereference ()
 442   "Toggle whether tooltips should show `* expr' or `expr'."
 443   (interactive)
 444   (setq tooltip-gud-dereference (not tooltip-gud-dereference))
 445   (when (interactive-p)
 446     (message "Dereferencing is now %s."
 447              (if tooltip-gud-dereference "on" "off"))))
 448
 449
 450 (defun tooltip-gud-process-output (process output)
 451   "Process debugger output and show it in a tooltip window."
 452   (set-process-filter process tooltip-gud-original-filter)
 453   (tooltip-show (tooltip-strip-prompt process output)))
 454
 455
 456 (defun tooltip-gud-print-command (expr)
 457   "Return a suitable command to print the expression EXPR.
 458 If TOOLTIP-GUD-DEREFERENCE is t, also prepend a `*' to EXPR."
 459   (when tooltip-gud-dereference
 460     (setq expr (concat "*" expr)))
 461   (case gud-minor-mode
 462     ((gdb gdba) (concat "server print " expr))
 463     (dbx (concat "print " expr))
 464     (xdb (concat "p " expr))
 465     (sdb (concat expr "/"))
 466     (perldb expr)))
 467
 468
 469 (defun tooltip-gud-tips (event)
 470   "Show tip for identifier or selection under the mouse.
 471 The mouse must either point at an identifier or inside a selected
 472 region for the tip window to be shown.  If tooltip-gud-dereference is t,
 473 add a `*' in front of the printed expression.
 474
 475 This function must return nil if it doesn't handle EVENT."
 476   (let (gud-buffer process)
 477     (when (and (eventp event)
 478                tooltip-gud-tips-p
 479                (boundp 'gud-comint-buffer)
 480                (setq gud-buffer gud-comint-buffer)
 481                (setq process (get-buffer-process gud-buffer))
 482                (posn-point (event-end event))
 483                (progn (setq tooltip-gud-event event)
 484                       (eval (cons 'and tooltip-gud-display))))
 485       (let ((expr (tooltip-expr-to-print event)))
 486         (when expr
 487           (let ((cmd (tooltip-gud-print-command expr)))
 488             (unless (null cmd)         ; CMD can be nil if unknown debugger
 489               (setq tooltip-gud-original-filter (process-filter process))
 490               (set-process-filter process 'tooltip-gud-process-output)
 491               (gud-basic-call cmd)
 492               expr)))))))
 493
 494 \f
 495 ;;; Tooltip help.
 496
 497 (defvar tooltip-help-message nil
 498   "The last help message received via `tooltip-show-help-function'.")
 499
 500
 501 (defun tooltip-show-help-function (msg)
 502   "Function installed as `show-help-function'.
 503 MSG is either a help string to display, or nil to cancel the display."
 504   (let ((previous-help tooltip-help-message))
 505     (setq tooltip-help-message msg)
 506     (cond ((null msg)
 507            ;; Cancel display.  This also cancels a delayed tip, if
 508            ;; there is one.
 509            (tooltip-hide))
 510           ((equal previous-help msg)
 511            ;; Same help as before (but possibly the mouse has moved).
 512            ;; Keep what we have.
 513            )
 514           (t
 515            ;; A different help.  Remove a previous tooltip, and
 516            ;; display a new one, with some delay.
 517            (tooltip-hide)
 518            (tooltip-start-delayed-tip)))))
 519
 520
 521 (defun tooltip-help-tips (event)
 522   "Hook function to display a help tooltip.
 523 This is installed on the hook `tooltip-hook', which is run when
 524 the timer with ID `tooltip-timeout-id' fires.
 525 Value is non-nil if this function handled the tip."
 526   (when (stringp tooltip-help-message)
 527     (tooltip-show tooltip-help-message)
 528     t))
 529
 530
 531 \f
 532 ;;; Do this after all functions have been defined that are called from
 533 ;;; `tooltip-mode'.  The actual default value of `tooltip-mode' is set
 534 ;;; in startup.el.
 535
 536 ;;;###autoload
 537 (defcustom tooltip-mode nil
 538   "Toggle tooltip-mode.
 539 Setting this variable directly does not take effect;
 540 use either \\[customize] or the function `tooltip-mode'."
 541   :set (lambda (symbol value)
 542          (tooltip-mode (or value 0)))
 543   :initialize 'custom-initialize-default
 544   :type 'boolean
 545   :require 'tooltip
 546   :group 'tooltip)
 547
 548
 549 ;;; tooltip.el ends here