summaryrefslogtreecommitdiff
path: root/lisp/tooltip.el
blob: 973e74bef3a780d0f721277ac6301be157777776 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
;;; tooltip.el --- show tooltip windows

;; Copyright (C) 1997, 1999-2014 Free Software Foundation, Inc.

;; Author: Gerd Moellmann <gerd@acm.org>
;; Keywords: help c mouse tools
;; Package: emacs

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;;; Code:

(require 'syntax)

(defvar comint-prompt-regexp)

(defgroup tooltip nil
  "Customization group for the `tooltip' package."
  :group 'help
  :group 'gud
  :group 'mouse
  :group 'tools
  :version "21.1"
  :tag "Tool Tips")

;;; Switching tooltips on/off

(define-minor-mode tooltip-mode
  "Toggle Tooltip mode.
With a prefix argument ARG, enable Tooltip mode if ARG is positive,
and disable it otherwise.  If called from Lisp, enable the mode
if ARG is omitted or nil.

When this global minor mode is enabled, Emacs displays help
text (e.g. for buttons and menu items that you put the mouse on)
in a pop-up window.

When Tooltip mode is disabled, Emacs displays help text in the
echo area, instead of making a pop-up window."
  :global t
  ;; Even if we start on a text-only terminal, make this non-nil by
  ;; default because we can open a graphical frame later (multi-tty).
  :init-value t
  :initialize 'custom-initialize-delay
  :group 'tooltip
  (if (and tooltip-mode (fboundp 'x-show-tip))
      (progn
	(add-hook 'pre-command-hook 'tooltip-hide)
	(add-hook 'tooltip-functions 'tooltip-help-tips))
    (unless (and (boundp 'gud-tooltip-mode) gud-tooltip-mode)
      (remove-hook 'pre-command-hook 'tooltip-hide))
    (remove-hook 'tooltip-functions 'tooltip-help-tips))
  (setq show-help-function
	(if tooltip-mode 'tooltip-show-help 'tooltip-show-help-non-mode)))


;;; Customizable settings

(defcustom tooltip-delay 0.7
  "Seconds to wait before displaying a tooltip the first time."
  :type 'number
  :group 'tooltip)

(defcustom tooltip-short-delay 0.1
  "Seconds to wait between subsequent tooltips on different items."
  :type 'number
  :group 'tooltip)

(defcustom tooltip-recent-seconds 1
  "Display tooltips if changing tip items within this many seconds.
Do so after `tooltip-short-delay'."
  :type 'number
  :group 'tooltip)

(defcustom tooltip-hide-delay 10
  "Hide tooltips automatically after this many seconds."
  :type 'number
  :group 'tooltip)

(defcustom tooltip-x-offset 5
  "X offset, in pixels, for the display of tooltips.
The offset is the distance between the X position of the mouse and
the left border of the tooltip window.  It must be chosen so that the
tooltip window doesn't contain the mouse when it pops up, or it may
interfere with clicking where you wish.

If `tooltip-frame-parameters' includes the `left' parameter,
the value of `tooltip-x-offset' is ignored."
  :type 'integer
  :group 'tooltip)

(defcustom tooltip-y-offset +20
  "Y offset, in pixels, for the display of tooltips.
The offset is the distance between the Y position of the mouse and
the top border of the tooltip window.  It must be chosen so that the
tooltip window doesn't contain the mouse when it pops up, or it may
interfere with clicking where you wish.

If `tooltip-frame-parameters' includes the `top' parameter,
the value of `tooltip-y-offset' is ignored."
  :type 'integer
  :group 'tooltip)

(defcustom tooltip-frame-parameters
  '((name . "tooltip")
    (internal-border-width . 2)
    (border-width . 1))
  "Frame parameters used for tooltips.

If `left' or `top' parameters are included, they specify the absolute
position to pop up the tooltip.

Note that font and color parameters are ignored, and the attributes
of the `tooltip' face are used instead."
  :type 'sexp
  :group 'tooltip)

(defface tooltip
  '((((class color))
     :background "lightyellow"
     :foreground "black"
     :inherit variable-pitch)
    (t
     :inherit variable-pitch))
  "Face for tooltips."
  :group 'tooltip
  :group 'basic-faces)

(defcustom tooltip-use-echo-area nil
  "Use the echo area instead of tooltip frames for help and GUD tooltips.
This variable is obsolete; instead of setting it to t, disable
`tooltip-mode' (which has a similar effect)."
  :type 'boolean
  :group 'tooltip)

(make-obsolete-variable 'tooltip-use-echo-area
			"disable Tooltip mode instead" "24.1" 'set)


;;; Variables that are not customizable.

(define-obsolete-variable-alias 'tooltip-hook 'tooltip-functions "23.1")

(defvar tooltip-functions nil
  "Functions to call to display tooltips.
Each function is called with one argument EVENT which is a copy
of the last mouse movement event that occurred.  If one of these
functions displays the tooltip, it should return non-nil and the
rest are not called.")

(defvar tooltip-timeout-id nil
  "The id of the timeout started when Emacs becomes idle.")

(defvar tooltip-last-mouse-motion-event nil
  "A copy of the last mouse motion event seen.")

(defvar tooltip-hide-time nil
  "Time when the last tooltip was hidden.")

(defvar gud-tooltip-mode) ;; Prevent warning.

;;; Event accessors

(defun tooltip-event-buffer (event)
  "Return the buffer over which event EVENT occurred.
This might return nil if the event did not occur over a buffer."
  (let ((window (posn-window (event-end event))))
    (and window (window-buffer window))))


;;; Timeout for tooltip display

(defun tooltip-delay ()
  "Return the delay in seconds for the next tooltip."
  (if (and tooltip-hide-time
           (< (- (float-time) tooltip-hide-time) tooltip-recent-seconds))
      tooltip-short-delay
    tooltip-delay))

(defun tooltip-cancel-delayed-tip ()
  "Disable the tooltip timeout."
  (when tooltip-timeout-id
    (disable-timeout tooltip-timeout-id)
    (setq tooltip-timeout-id nil)))

(defun tooltip-start-delayed-tip ()
  "Add a one-shot timeout to call function `tooltip-timeout'."
  (setq tooltip-timeout-id
	(add-timeout (tooltip-delay) 'tooltip-timeout nil)))

(defun tooltip-timeout (_object)
  "Function called when timer with id `tooltip-timeout-id' fires."
  (run-hook-with-args-until-success 'tooltip-functions
				    tooltip-last-mouse-motion-event))


;;; Displaying tips

(defun tooltip-set-param (alist key value)
  "Change the value of KEY in alist ALIST to VALUE.
If there's no association for KEY in ALIST, add one, otherwise
change the existing association.  Value is the resulting alist."
  (declare (obsolete "use (setf (alist-get ..) ..) instead" "25.1"))
  (setf (alist-get key alist) value)
  alist)

(declare-function x-show-tip "xfns.c"
		  (string &optional frame parms timeout dx dy))

(defun tooltip-show (text &optional use-echo-area)
  "Show a tooltip window displaying TEXT.

Text larger than `x-max-tooltip-size' is clipped.

If the alist in `tooltip-frame-parameters' includes `left' and `top'
parameters, they determine the x and y position where the tooltip
is displayed.  Otherwise, the tooltip pops at offsets specified by
`tooltip-x-offset' and `tooltip-y-offset' from the current mouse
position.

Optional second arg USE-ECHO-AREA non-nil means to show tooltip
in echo area."
  (if use-echo-area
      (tooltip-show-help-non-mode text)
    (condition-case error
	(let ((params (copy-sequence tooltip-frame-parameters))
	      (fg (face-attribute 'tooltip :foreground))
	      (bg (face-attribute 'tooltip :background)))
	  (when (stringp fg)
	    (setf (alist-get 'foreground-color params) fg)
	    (setf (alist-get 'border-color params) fg))
	  (when (stringp bg)
	    (setf (alist-get 'background-color params) bg))
	  (x-show-tip (propertize text 'face 'tooltip)
		      (selected-frame)
		      params
		      tooltip-hide-delay
		      tooltip-x-offset
		      tooltip-y-offset))
      (error
       (message "Error while displaying tooltip: %s" error)
       (sit-for 1)
       (message "%s" text)))))

(declare-function x-hide-tip "xfns.c" ())

(defun tooltip-hide (&optional _ignored-arg)
  "Hide a tooltip, if one is displayed.
Value is non-nil if tooltip was open."
  (tooltip-cancel-delayed-tip)
  (when (x-hide-tip)
    (setq tooltip-hide-time (float-time))))


;;; Debugger-related functions

(defun tooltip-identifier-from-point (point)
  "Extract the identifier at POINT, if any.
Value is nil if no identifier exists at point.  Identifier extraction
is based on the current syntax table."
  (save-excursion
    (goto-char point)
    (let* ((start (progn (skip-syntax-backward "w_") (point)))
	   (pstate (syntax-ppss)))
      (unless (or (looking-at "[0-9]")
		  (nth 3 pstate)
		  (nth 4 pstate))
	(skip-syntax-forward "w_")
	(when (> (point) start)
	  (buffer-substring start (point)))))))

(defun tooltip-expr-to-print (event)
  "Return an expression that should be printed for EVENT.
If a region is active and the mouse is inside the region, print
the region.  Otherwise, figure out the identifier around the point
where the mouse is."
  (with-current-buffer (tooltip-event-buffer event)
    (let ((point (posn-point (event-end event))))
      (if (use-region-p)
	  (when (and (<= (region-beginning) point) (<= point (region-end)))
	    (buffer-substring (region-beginning) (region-end)))
	(tooltip-identifier-from-point point)))))

(defun tooltip-process-prompt-regexp (process)
  "Return regexp matching the prompt of PROCESS at the end of a string.
The prompt is taken from the value of `comint-prompt-regexp' in
the buffer of PROCESS."
  (let ((prompt-regexp (with-current-buffer (process-buffer process)
			 comint-prompt-regexp)))
    (concat "\n*"
            ;; Most start with `^' but the one for `sdb' cannot be easily
            ;; stripped.  Code the prompt for `sdb' fixed here.
            (if (= (aref prompt-regexp 0) ?^)
                (substring prompt-regexp 1)
              "\\*")
            "$")))

(defun tooltip-strip-prompt (process output)
  "Return OUTPUT with any prompt of PROCESS stripped from its end."
  (save-match-data
    (if (string-match (tooltip-process-prompt-regexp process) output)
        (substring output 0 (match-beginning 0))
      output)))


;;; Tooltip help.

(defvar tooltip-help-message nil
  "The last help message received via `show-help-function'.
This is used by `tooltip-show-help' and
`tooltip-show-help-non-mode'.")

(defvar tooltip-previous-message nil
  "The previous content of the echo area.")

(defun tooltip-show-help-non-mode (help)
  "Function installed as `show-help-function' when Tooltip mode is off.
It is also called if Tooltip mode is on, for text-only displays."
  (when (and (not (window-minibuffer-p)) ;Don't overwrite minibuffer contents.
             (not cursor-in-echo-area))  ;Don't overwrite a prompt.
    (cond
     ((stringp help)
      (setq help (replace-regexp-in-string "\n" ", " help))
      (unless (or tooltip-previous-message
		  (equal-including-properties help (current-message))
		  (and (stringp tooltip-help-message)
		       (equal-including-properties tooltip-help-message
						   (current-message))))
        (setq tooltip-previous-message (current-message)))
      (setq tooltip-help-message help)
      (let ((message-truncate-lines t)
            (message-log-max nil))
        (message "%s" help)))
     ((stringp tooltip-previous-message)
      (let ((message-log-max nil))
        (message "%s" tooltip-previous-message)
        (setq tooltip-previous-message nil)))
     (t
      (message nil)))))

(defun tooltip-show-help (msg)
  "Function installed as `show-help-function'.
MSG is either a help string to display, or nil to cancel the display."
  (if (display-graphic-p)
      (let ((previous-help tooltip-help-message))
	(setq tooltip-help-message msg)
	(cond ((null msg)
	       ;; Cancel display.  This also cancels a delayed tip, if
	       ;; there is one.
	       (tooltip-hide))
	      ((equal-including-properties previous-help msg)
	       ;; Same help as before (but possibly the mouse has moved).
	       ;; Keep what we have.
	       )
	      (t
	       ;; A different help.  Remove a previous tooltip, and
	       ;; display a new one, with some delay.
	       (tooltip-hide)
	       (tooltip-start-delayed-tip))))
    ;; On text-only displays, try `tooltip-show-help-non-mode'.
    (tooltip-show-help-non-mode msg)))

(defun tooltip-help-tips (_event)
  "Hook function to display a help tooltip.
This is installed on the hook `tooltip-functions', which
is run when the timer with id `tooltip-timeout-id' fires.
Value is non-nil if this function handled the tip."
  (when (stringp tooltip-help-message)
    (tooltip-show tooltip-help-message tooltip-use-echo-area)
    t))

(provide 'tooltip)

;;; tooltip.el ends here