lisp/tooltip.el

   1 ;;; tooltip.el --- show tooltip windows
   2
   3 ;; Copyright (C) 1997, 1999-2012 Free Software Foundation, Inc.
   4
   5 ;; Author: Gerd Moellmann <gerd@acm.org>
   6 ;; Keywords: help c mouse tools
   7 ;; Package: emacs
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;;; Code:
  27
  28 (defvar comint-prompt-regexp)
  29
  30 (defgroup tooltip nil
  31   "Customization group for the `tooltip' package."
  32   :group 'help
  33   :group 'gud
  34   :group 'mouse
  35   :group 'tools
  36   :version "21.1"
  37   :tag "Tool Tips")
  38 \f
  39 ;;; Switching tooltips on/off
  40
  41 (define-minor-mode tooltip-mode
  42   "Toggle Tooltip mode.
  43 With ARG, turn Tooltip mode on if and only if ARG is positive.
  44
  45 When this global minor mode is enabled, Emacs displays help
  46 text (e.g. for buttons and menu items that you put the mouse on)
  47 in a pop-up window.
  48
  49 When Tooltip mode is disabled, Emacs displays help text in the
  50 echo area, instead of making a pop-up window."
  51   :global t
  52   ;; Even if we start on a text-only terminal, make this non-nil by
  53   ;; default because we can open a graphical frame later (multi-tty).
  54   :init-value t
  55   :initialize 'custom-initialize-delay
  56   :group 'tooltip
  57   (unless (or (null tooltip-mode) (fboundp 'x-show-tip))
  58     (error "Sorry, tooltips are not yet available on this system"))
  59   (if tooltip-mode
  60       (progn
  61         (add-hook 'pre-command-hook 'tooltip-hide)
  62         (add-hook 'tooltip-functions 'tooltip-help-tips))
  63     (unless (and (boundp 'gud-tooltip-mode) gud-tooltip-mode)
  64       (remove-hook 'pre-command-hook 'tooltip-hide))
  65     (remove-hook 'tooltip-functions 'tooltip-help-tips))
  66   (setq show-help-function
  67         (if tooltip-mode 'tooltip-show-help 'tooltip-show-help-non-mode)))
  68
  69 \f
  70 ;;; Customizable settings
  71
  72 (defcustom tooltip-delay 0.7
  73   "Seconds to wait before displaying a tooltip the first time."
  74   :type 'number
  75   :group 'tooltip)
  76
  77 (defcustom tooltip-short-delay 0.1
  78   "Seconds to wait between subsequent tooltips on different items."
  79   :type 'number
  80   :group 'tooltip)
  81
  82 (defcustom tooltip-recent-seconds 1
  83   "Display tooltips if changing tip items within this many seconds.
  84 Do so after `tooltip-short-delay'."
  85   :type 'number
  86   :group 'tooltip)
  87
  88 (defcustom tooltip-hide-delay 10
  89   "Hide tooltips automatically after this many seconds."
  90   :type 'number
  91   :group 'tooltip)
  92
  93 (defcustom tooltip-x-offset 5
  94   "X offset, in pixels, for the display of tooltips.
  95 The offset is the distance between the X position of the mouse and
  96 the left border of the tooltip window.  It must be chosen so that the
  97 tooltip window doesn't contain the mouse when it pops up, or it may
  98 interfere with clicking where you wish.
  99
 100 If `tooltip-frame-parameters' includes the `left' parameter,
 101 the value of `tooltip-x-offset' is ignored."
 102   :type 'integer
 103   :group 'tooltip)
 104
 105 (defcustom tooltip-y-offset +20
 106   "Y offset, in pixels, for the display of tooltips.
 107 The offset is the distance between the Y position of the mouse and
 108 the top border of the tooltip window.  It must be chosen so that the
 109 tooltip window doesn't contain the mouse when it pops up, or it may
 110 interfere with clicking where you wish.
 111
 112 If `tooltip-frame-parameters' includes the `top' parameter,
 113 the value of `tooltip-y-offset' is ignored."
 114   :type 'integer
 115   :group 'tooltip)
 116
 117 (defcustom tooltip-frame-parameters
 118   '((name . "tooltip")
 119     (internal-border-width . 2)
 120     (border-width . 1))
 121   "Frame parameters used for tooltips.
 122
 123 If `left' or `top' parameters are included, they specify the absolute
 124 position to pop up the tooltip.
 125
 126 Note that font and color parameters are ignored, and the attributes
 127 of the `tooltip' face are used instead."
 128   :type 'sexp
 129   :group 'tooltip)
 130
 131 (defface tooltip
 132   '((((class color))
 133      :background "lightyellow"
 134      :foreground "black"
 135      :inherit variable-pitch)
 136     (t
 137      :inherit variable-pitch))
 138   "Face for tooltips."
 139   :group 'tooltip
 140   :group 'basic-faces)
 141
 142 (defcustom tooltip-use-echo-area nil
 143   "Use the echo area instead of tooltip frames for help and GUD tooltips.
 144 This variable is obsolete; instead of setting it to t, disable
 145 `tooltip-mode' (which has a similar effect)."
 146   :type 'boolean
 147   :group 'tooltip)
 148
 149 (make-obsolete-variable 'tooltip-use-echo-area
 150                         "disable Tooltip mode instead" "24.1")
 151
 152 \f
 153 ;;; Variables that are not customizable.
 154
 155 (defvar tooltip-functions nil
 156   "Functions to call to display tooltips.
 157 Each function is called with one argument EVENT which is a copy
 158 of the last mouse movement event that occurred.  If one of these
 159 functions displays the tooltip, it should return non-nil and the
 160 rest are not called.")
 161
 162 (define-obsolete-variable-alias 'tooltip-hook 'tooltip-functions "23.1")
 163
 164 (defvar tooltip-timeout-id nil
 165   "The id of the timeout started when Emacs becomes idle.")
 166
 167 (defvar tooltip-last-mouse-motion-event nil
 168   "A copy of the last mouse motion event seen.")
 169
 170 (defvar tooltip-hide-time nil
 171   "Time when the last tooltip was hidden.")
 172
 173 (defvar gud-tooltip-mode) ;; Prevent warning.
 174
 175 ;;; Event accessors
 176
 177 (defun tooltip-event-buffer (event)
 178   "Return the buffer over which event EVENT occurred.
 179 This might return nil if the event did not occur over a buffer."
 180   (let ((window (posn-window (event-end event))))
 181     (and window (window-buffer window))))
 182
 183 \f
 184 ;;; Timeout for tooltip display
 185
 186 (defun tooltip-delay ()
 187   "Return the delay in seconds for the next tooltip."
 188   (if (and tooltip-hide-time
 189            (< (- (float-time) tooltip-hide-time) tooltip-recent-seconds))
 190       tooltip-short-delay
 191     tooltip-delay))
 192
 193 (defun tooltip-cancel-delayed-tip ()
 194   "Disable the tooltip timeout."
 195   (when tooltip-timeout-id
 196     (disable-timeout tooltip-timeout-id)
 197     (setq tooltip-timeout-id nil)))
 198
 199 (defun tooltip-start-delayed-tip ()
 200   "Add a one-shot timeout to call function `tooltip-timeout'."
 201   (setq tooltip-timeout-id
 202         (add-timeout (tooltip-delay) 'tooltip-timeout nil)))
 203
 204 (defun tooltip-timeout (_object)
 205   "Function called when timer with id `tooltip-timeout-id' fires."
 206   (run-hook-with-args-until-success 'tooltip-functions
 207                                     tooltip-last-mouse-motion-event))
 208
 209 \f
 210 ;;; Displaying tips
 211
 212 (defun tooltip-set-param (alist key value)
 213   "Change the value of KEY in alist ALIST to VALUE.
 214 If there's no association for KEY in ALIST, add one, otherwise
 215 change the existing association.  Value is the resulting alist."
 216   (let ((param (assq key alist)))
 217     (if (consp param)
 218         (setcdr param value)
 219       (push (cons key value) alist))
 220     alist))
 221
 222 (declare-function x-show-tip "xfns.c"
 223                   (string &optional frame parms timeout dx dy))
 224
 225 (defun tooltip-show (text &optional use-echo-area)
 226   "Show a tooltip window displaying TEXT.
 227
 228 Text larger than `x-max-tooltip-size' is clipped.
 229
 230 If the alist in `tooltip-frame-parameters' includes `left' and `top'
 231 parameters, they determine the x and y position where the tooltip
 232 is displayed.  Otherwise, the tooltip pops at offsets specified by
 233 `tooltip-x-offset' and `tooltip-y-offset' from the current mouse
 234 position.
 235
 236 Optional second arg USE-ECHO-AREA non-nil means to show tooltip
 237 in echo area."
 238   (if use-echo-area
 239       (tooltip-show-help-non-mode text)
 240     (condition-case error
 241         (let ((params (copy-sequence tooltip-frame-parameters))
 242               (fg (face-attribute 'tooltip :foreground))
 243               (bg (face-attribute 'tooltip :background)))
 244           (when (stringp fg)
 245             (setq params (tooltip-set-param params 'foreground-color fg))
 246             (setq params (tooltip-set-param params 'border-color fg)))
 247           (when (stringp bg)
 248             (setq params (tooltip-set-param params 'background-color bg)))
 249           (x-show-tip (propertize text 'face 'tooltip)
 250                       (selected-frame)
 251                       params
 252                       tooltip-hide-delay
 253                       tooltip-x-offset
 254                       tooltip-y-offset))
 255       (error
 256        (message "Error while displaying tooltip: %s" error)
 257        (sit-for 1)
 258        (message "%s" text)))))
 259
 260 (declare-function x-hide-tip "xfns.c" ())
 261
 262 (defun tooltip-hide (&optional _ignored-arg)
 263   "Hide a tooltip, if one is displayed.
 264 Value is non-nil if tooltip was open."
 265   (tooltip-cancel-delayed-tip)
 266   (when (x-hide-tip)
 267     (setq tooltip-hide-time (float-time))))
 268
 269 \f
 270 ;;; Debugger-related functions
 271
 272 (defun tooltip-identifier-from-point (point)
 273   "Extract the identifier at POINT, if any.
 274 Value is nil if no identifier exists at point.  Identifier extraction
 275 is based on the current syntax table."
 276   (save-excursion
 277     (goto-char point)
 278     (let ((start (progn (skip-syntax-backward "w_") (point))))
 279       (unless (looking-at "[0-9]")
 280         (skip-syntax-forward "w_")
 281         (when (> (point) start)
 282           (buffer-substring start (point)))))))
 283
 284 (defmacro tooltip-region-active-p ()
 285   "Value is non-nil if the region should override command actions."
 286   `(use-region-p))
 287
 288 (defun tooltip-expr-to-print (event)
 289   "Return an expression that should be printed for EVENT.
 290 If a region is active and the mouse is inside the region, print
 291 the region.  Otherwise, figure out the identifier around the point
 292 where the mouse is."
 293   (with-current-buffer (tooltip-event-buffer event)
 294     (let ((point (posn-point (event-end event))))
 295       (if (tooltip-region-active-p)
 296           (when (and (<= (region-beginning) point) (<= point (region-end)))
 297             (buffer-substring (region-beginning) (region-end)))
 298         (tooltip-identifier-from-point point)))))
 299
 300 (defun tooltip-process-prompt-regexp (process)
 301   "Return regexp matching the prompt of PROCESS at the end of a string.
 302 The prompt is taken from the value of `comint-prompt-regexp' in
 303 the buffer of PROCESS."
 304   (let ((prompt-regexp (with-current-buffer (process-buffer process)
 305                          comint-prompt-regexp)))
 306     (concat "\n*"
 307             ;; Most start with `^' but the one for `sdb' cannot be easily
 308             ;; stripped.  Code the prompt for `sdb' fixed here.
 309             (if (= (aref prompt-regexp 0) ?^)
 310                 (substring prompt-regexp 1)
 311               "\\*")
 312             "$")))
 313
 314 (defun tooltip-strip-prompt (process output)
 315   "Return OUTPUT with any prompt of PROCESS stripped from its end."
 316   (save-match-data
 317     (if (string-match (tooltip-process-prompt-regexp process) output)
 318         (substring output 0 (match-beginning 0))
 319       output)))
 320
 321 \f
 322 ;;; Tooltip help.
 323
 324 (defvar tooltip-help-message nil
 325   "The last help message received via `show-help-function'.
 326 This is used by `tooltip-show-help' and
 327 `tooltip-show-help-non-mode'.")
 328
 329 (defvar tooltip-previous-message nil
 330   "The previous content of the echo area.")
 331
 332 (defun tooltip-show-help-non-mode (help)
 333   "Function installed as `show-help-function' when Tooltip mode is off.
 334 It is also called if Tooltip mode is on, for text-only displays."
 335   (when (and (not (window-minibuffer-p)) ;Don't overwrite minibuffer contents.
 336              (not cursor-in-echo-area))  ;Don't overwrite a prompt.
 337     (cond
 338      ((stringp help)
 339       (setq help (replace-regexp-in-string "\n" ", " help))
 340       (unless (or tooltip-previous-message
 341                   (string-equal help (current-message))
 342                   (and (stringp tooltip-help-message)
 343                        (string-equal tooltip-help-message
 344                                      (current-message))))
 345         (setq tooltip-previous-message (current-message)))
 346       (setq tooltip-help-message help)
 347       (let ((message-truncate-lines t)
 348             (message-log-max nil))
 349         (message "%s" help)))
 350      ((stringp tooltip-previous-message)
 351       (let ((message-log-max nil))
 352         (message "%s" tooltip-previous-message)
 353         (setq tooltip-previous-message nil)))
 354      (t
 355       (message nil)))))
 356
 357 (defun tooltip-show-help (msg)
 358   "Function installed as `show-help-function'.
 359 MSG is either a help string to display, or nil to cancel the display."
 360   (if (display-graphic-p)
 361       (let ((previous-help tooltip-help-message))
 362         (setq tooltip-help-message msg)
 363         (cond ((null msg)
 364                ;; Cancel display.  This also cancels a delayed tip, if
 365                ;; there is one.
 366                (tooltip-hide))
 367               ((equal previous-help msg)
 368                ;; Same help as before (but possibly the mouse has moved).
 369                ;; Keep what we have.
 370                )
 371               (t
 372                ;; A different help.  Remove a previous tooltip, and
 373                ;; display a new one, with some delay.
 374                (tooltip-hide)
 375                (tooltip-start-delayed-tip))))
 376     ;; On text-only displays, try `tooltip-show-help-non-mode'.
 377     (tooltip-show-help-non-mode msg)))
 378
 379 (defun tooltip-help-tips (_event)
 380   "Hook function to display a help tooltip.
 381 This is installed on the hook `tooltip-functions', which
 382 is run when the timer with id `tooltip-timeout-id' fires.
 383 Value is non-nil if this function handled the tip."
 384   (when (stringp tooltip-help-message)
 385     (tooltip-show tooltip-help-message tooltip-use-echo-area)
 386     t))
 387
 388 (provide 'tooltip)
 389
 390 ;;; tooltip.el ends here