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