lisp/tooltip.el

   1 ;;; tooltip.el --- show tooltip windows
   2
   3 ;; Copyright (C) 1997, 1999, 2000, 2001, 2002, 2003, 2004,
   4 ;;   2005 Free Software Foundation, Inc.
   5
   6 ;; Author: Gerd Moellmann <gerd@acm.org>
   7 ;; Keywords: help c mouse tools
   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 2, or (at your option)
  14 ;; 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; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  24 ;; Boston, MA 02110-1301, USA.
  25
  26 ;;; Commentary:
  27
  28 ;;; Code:
  29
  30 (defvar comint-prompt-regexp)
  31
  32 (defgroup tooltip nil
  33   "Customization group for the `tooltip' package."
  34   :group 'help
  35   :group 'gud
  36   :group 'mouse
  37   :group 'tools
  38   :version "21.1"
  39   :tag "Tool Tips")
  40 \f
  41 ;;; Switching tooltips on/off
  42
  43 ;; We don't set track-mouse globally because this is a big redisplay
  44 ;; problem in buffers having a pre-command-hook or such installed,
  45 ;; which does a set-buffer, like the summary buffer of Gnus.  Calling
  46 ;; set-buffer prevents redisplay optimizations, so every mouse motion
  47 ;; would be accompanied by a full redisplay.
  48
  49 (define-minor-mode tooltip-mode
  50   "Toggle Tooltip display.
  51 With ARG, turn tooltip mode on if and only if ARG is positive."
  52   :global t
  53   :init-value (not (or noninteractive
  54                        emacs-basic-display
  55                        (not (display-graphic-p))
  56                        (not (fboundp 'x-show-tip))))
  57   :initialize 'custom-initialize-safe-default
  58   :group 'tooltip
  59   (unless (or (null tooltip-mode) (fboundp 'x-show-tip))
  60     (error "Sorry, tooltips are not yet available on this system"))
  61   (if tooltip-mode
  62       (progn
  63         (add-hook 'pre-command-hook 'tooltip-hide)
  64         (add-hook 'tooltip-hook 'tooltip-help-tips))
  65     (unless (and (boundp 'gud-tooltip-mode) gud-tooltip-mode)
  66       (remove-hook 'pre-command-hook 'tooltip-hide))
  67     (remove-hook 'tooltip-hook 'tooltip-help-tips))
  68   (setq show-help-function
  69         (if tooltip-mode 'tooltip-show-help nil)))
  70
  71 \f
  72 ;;; Customizable settings
  73
  74 (defcustom tooltip-delay 0.7
  75   "Seconds to wait before displaying a tooltip the first time."
  76   :type 'number
  77   :group 'tooltip)
  78
  79 (defcustom tooltip-short-delay 0.1
  80   "Seconds to wait between subsequent tooltips on different items."
  81   :type 'number
  82   :group 'tooltip)
  83
  84 (defcustom tooltip-recent-seconds 1
  85   "Display tooltips if changing tip items within this many seconds.
  86 Do so after `tooltip-short-delay'."
  87   :type 'number
  88   :group 'tooltip)
  89
  90 (defcustom tooltip-hide-delay 10
  91   "Hide tooltips automatically after this many seconds."
  92   :type 'number
  93   :group 'tooltip)
  94
  95 (defcustom tooltip-x-offset 5
  96   "X offset, in pixels, for the display of tooltips.
  97 The offset is the distance between the X position of the mouse and
  98 the left border of the tooltip window.  It must be chosen so that the
  99 tooltip window doesn't contain the mouse when it pops up, or it may
 100 interfere with clicking where you wish.
 101
 102 If `tooltip-frame-parameters' includes the `left' parameter,
 103 the value of `tooltip-x-offset' is ignored."
 104   :type 'integer
 105   :group 'tooltip)
 106
 107 (defcustom tooltip-y-offset +20
 108   "Y offset, in pixels, for the display of tooltips.
 109 The offset is the distance between the Y position of the mouse and
 110 the top border of the tooltip window.  It must be chosen so that the
 111 tooltip window doesn't contain the mouse when it pops up, or it may
 112 interfere with clicking where you wish.
 113
 114 If `tooltip-frame-parameters' includes the `top' parameter,
 115 the value of `tooltip-y-offset' is ignored."
 116   :type 'integer
 117   :group 'tooltip)
 118
 119 (defcustom tooltip-frame-parameters
 120   '((name . "tooltip")
 121     (internal-border-width . 2)
 122     (border-width . 1))
 123   "Frame parameters used for tooltips.
 124
 125 If `left' or `top' parameters are included, they specify the absolute
 126 position to pop up the tooltip."
 127   :type 'sexp
 128   :group 'tooltip)
 129
 130 (defface tooltip
 131   '((((class color))
 132      :background "lightyellow"
 133      :foreground "black"
 134      :inherit variable-pitch)
 135     (t
 136      :inherit variable-pitch))
 137   "Face for tooltips."
 138   :group 'tooltip
 139   :group 'basic-faces)
 140
 141 (defcustom tooltip-use-echo-area nil
 142   "Use the echo area instead of tooltip frames for help and GUD tooltips."
 143   :type 'boolean
 144   :group 'tooltip)
 145
 146 \f
 147 ;;; Variables that are not customizable.
 148
 149 (defvar tooltip-hook nil
 150   "Functions to call to display tooltips.
 151 Each function is called with one argument EVENT which is a copy of
 152 the last mouse movement event that occurred.")
 153
 154 (defvar tooltip-timeout-id nil
 155   "The id of the timeout started when Emacs becomes idle.")
 156
 157 (defvar tooltip-last-mouse-motion-event nil
 158   "A copy of the last mouse motion event seen.")
 159
 160 (defvar tooltip-hide-time nil
 161   "Time when the last tooltip was hidden.")
 162
 163 (defvar gud-tooltip-mode) ;; Prevent warning.
 164
 165 ;;; Event accessors
 166
 167 (defun tooltip-event-buffer (event)
 168   "Return the buffer over which event EVENT occurred.
 169 This might return nil if the event did not occur over a buffer."
 170   (let ((window (posn-window (event-end event))))
 171     (and window (window-buffer window))))
 172
 173 \f
 174 ;;; Timeout for tooltip display
 175
 176 (defun tooltip-delay ()
 177   "Return the delay in seconds for the next tooltip."
 178   (let ((delay tooltip-delay)
 179         (now (float-time)))
 180     (when (and tooltip-hide-time
 181                (< (- now tooltip-hide-time) tooltip-recent-seconds))
 182       (setq delay tooltip-short-delay))
 183     delay))
 184
 185 (defun tooltip-cancel-delayed-tip ()
 186   "Disable the tooltip timeout."
 187   (when tooltip-timeout-id
 188     (disable-timeout tooltip-timeout-id)
 189     (setq tooltip-timeout-id nil)))
 190
 191 (defun tooltip-start-delayed-tip ()
 192   "Add a one-shot timeout to call function `tooltip-timeout'."
 193   (setq tooltip-timeout-id
 194         (add-timeout (tooltip-delay) 'tooltip-timeout nil)))
 195
 196 (defun tooltip-timeout (object)
 197   "Function called when timer with id `tooltip-timeout-id' fires."
 198   (run-hook-with-args-until-success 'tooltip-hook
 199                                     tooltip-last-mouse-motion-event))
 200
 201 \f
 202 ;;; Displaying tips
 203
 204 (defun tooltip-set-param (alist key value)
 205   "Change the value of KEY in alist ALIST to VALUE.
 206 If there's no association for KEY in ALIST, add one, otherwise
 207 change the existing association.  Value is the resulting alist."
 208   (let ((param (assq key alist)))
 209     (if (consp param)
 210         (setcdr param value)
 211       (push (cons key value) alist))
 212     alist))
 213
 214 (defun tooltip-show (text &optional use-echo-area)
 215   "Show a tooltip window displaying TEXT.
 216
 217 Text larger than `x-max-tooltip-size' is clipped.
 218
 219 If the alist in `tooltip-frame-parameters' includes `left' and `top'
 220 parameters, they determine the x and y position where the tooltip
 221 is displayed.  Otherwise, the tooltip pops at offsets specified by
 222 `tooltip-x-offset' and `tooltip-y-offset' from the current mouse
 223 position.
 224
 225 Optional second arg USE-ECHO-AREA non-nil means to show tooltip
 226 in echo area."
 227   (if use-echo-area
 228       (message "%s" text)
 229     (condition-case error
 230         (let ((params (copy-sequence tooltip-frame-parameters))
 231               (fg (face-attribute 'tooltip :foreground))
 232               (bg (face-attribute 'tooltip :background)))
 233           (when (stringp fg)
 234             (setq params (tooltip-set-param params 'foreground-color fg))
 235             (setq params (tooltip-set-param params 'border-color fg)))
 236           (when (stringp bg)
 237             (setq params (tooltip-set-param params 'background-color bg)))
 238           (x-show-tip (propertize text 'face 'tooltip)
 239                       (selected-frame)
 240                       params
 241                       tooltip-hide-delay
 242                       tooltip-x-offset
 243                       tooltip-y-offset))
 244       (error
 245        (message "Error while displaying tooltip: %s" error)
 246        (sit-for 1)
 247        (message "%s" text)))))
 248
 249 (defun tooltip-hide (&optional ignored-arg)
 250   "Hide a tooltip, if one is displayed.
 251 Value is non-nil if tooltip was open."
 252   (tooltip-cancel-delayed-tip)
 253   (when (x-hide-tip)
 254     (setq tooltip-hide-time (float-time))))
 255
 256 \f
 257 ;;; Debugger-related functions
 258
 259 (defun tooltip-identifier-from-point (point)
 260   "Extract the identifier at POINT, if any.
 261 Value is nil if no identifier exists at point.  Identifier extraction
 262 is based on the current syntax table."
 263   (save-excursion
 264     (goto-char point)
 265     (let ((start (progn (skip-syntax-backward "w_") (point))))
 266       (unless (looking-at "[0-9]")
 267         (skip-syntax-forward "w_")
 268         (when (> (point) start)
 269           (buffer-substring start (point)))))))
 270
 271 (defmacro tooltip-region-active-p ()
 272   "Value is non-nil if the region is currently active."
 273   (if (string-match "^GNU" (emacs-version))
 274       `(and transient-mark-mode mark-active)
 275     `(region-active-p)))
 276
 277 (defun tooltip-expr-to-print (event)
 278   "Return an expression that should be printed for EVENT.
 279 If a region is active and the mouse is inside the region, print
 280 the region.  Otherwise, figure out the identifier around the point
 281 where the mouse is."
 282   (save-excursion
 283     (set-buffer (tooltip-event-buffer event))
 284     (let ((point (posn-point (event-end event))))
 285       (if (tooltip-region-active-p)
 286           (when (and (<= (region-beginning) point) (<= point (region-end)))
 287             (buffer-substring (region-beginning) (region-end)))
 288         (tooltip-identifier-from-point point)))))
 289
 290 (defun tooltip-process-prompt-regexp (process)
 291   "Return regexp matching the prompt of PROCESS at the end of a string.
 292 The prompt is taken from the value of `comint-prompt-regexp' in
 293 the buffer of PROCESS."
 294   (let ((prompt-regexp (save-excursion
 295                          (set-buffer (process-buffer process))
 296                          comint-prompt-regexp)))
 297     ;; Most start with `^' but the one for `sdb' cannot be easily
 298     ;; stripped.  Code the prompt for `sdb' fixed here.
 299     (if (= (aref prompt-regexp 0) ?^)
 300         (setq prompt-regexp (substring prompt-regexp 1))
 301       (setq prompt-regexp "\\*"))
 302     (concat "\n*" prompt-regexp "$")))
 303
 304 (defun tooltip-strip-prompt (process output)
 305   "Return OUTPUT with any prompt of PROCESS stripped from its end."
 306   (let ((prompt-regexp (tooltip-process-prompt-regexp process)))
 307     (save-match-data
 308       (when (string-match prompt-regexp output)
 309         (setq output (substring output 0 (match-beginning 0)))))
 310     output))
 311
 312 \f
 313 ;;; Tooltip help.
 314
 315 (defvar tooltip-help-message nil
 316   "The last help message received via `tooltip-show-help'.")
 317
 318 (defun tooltip-show-help (msg)
 319   "Function installed as `show-help-function'.
 320 MSG is either a help string to display, or nil to cancel the display."
 321   (let ((previous-help tooltip-help-message))
 322     (setq tooltip-help-message msg)
 323     (cond ((null msg)
 324            ;; Cancel display.  This also cancels a delayed tip, if
 325            ;; there is one.
 326            (tooltip-hide))
 327           ((equal previous-help msg)
 328            ;; Same help as before (but possibly the mouse has moved).
 329            ;; Keep what we have.
 330            )
 331           (t
 332            ;; A different help.  Remove a previous tooltip, and
 333            ;; display a new one, with some delay.
 334            (tooltip-hide)
 335            (tooltip-start-delayed-tip)))))
 336
 337 (defun tooltip-help-tips (event)
 338   "Hook function to display a help tooltip.
 339 This is installed on the hook `tooltip-hook', which is run when
 340 the timer with id `tooltip-timeout-id' fires.
 341 Value is non-nil if this function handled the tip."
 342   (when (stringp tooltip-help-message)
 343     (tooltip-show tooltip-help-message tooltip-use-echo-area)
 344     t))
 345
 346 (provide 'tooltip)
 347
 348 ;; arch-tag: 3d61135e-4618-4a78-af28-183f6df5636f
 349 ;;; tooltip.el ends here