1 ;;; pulse.el --- Pulsing Overlays
3 ;;; Copyright (C) 2007-2015 Free Software Foundation, Inc.
5 ;; Author: Eric M. Ludlam <eric@siege-engine.com>
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 3 of the License, or
13 ;; (at your option) 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. If not, see <http://www.gnu.org/licenses/>.
25 ;; Manage temporary pulsing of faces and overlays.
27 ;; This is a temporal decoration technique where something is to be
28 ;; highlighted briefly. This adds a gentle pulsing style to the text
29 ;; decorated this way.
31 ;; The following are useful entry points:
33 ;; `pulse' - Cause `pulse-highlight-face' to shift toward background color.
34 ;; Assumes you are using a version of Emacs that supports pulsing.
37 ;; `pulse-momentary-highlight-one-line' - Pulse a single line at POINT.
38 ;; `pulse-momentary-highlight-region' - Pulse a region.
39 ;; `pulse-momentary-highlight-overlay' - Pulse an overlay.
40 ;; These three functions will just blink the specified area if
41 ;; the version of Emacs you are using doesn't support pulsing.
43 ;; `pulse-line-hook-function' - A simple function that can be used in a
44 ;; hook that will pulse whatever line the cursor is on.
48 ;; The original pulse code was written for semantic tag highlighting.
49 ;; It has been extracted, and adapted for general purpose pulsing.
51 ;; Pulse is a part of CEDET. http://cedet.sf.net
53 (defun pulse-available-p ()
54 "Return non-nil if pulsing is available on the current frame."
56 (let ((v (color-values (face-background 'default
))))
57 (numberp (car-safe v
)))
60 (defcustom pulse-flag
(pulse-available-p)
61 "Whether to use pulsing for momentary highlighting.
62 Pulsing involves a bright highlight that slowly shifts to the
65 If the value is nil, highlight with an unchanging color until a
67 If the value is `never', do no coloring at all.
68 Any other value means to do the default pulsing behavior.
70 If `pulse-flag' is non-nil, but `pulse-available-p' is nil, then
71 this flag is ignored."
75 (defface pulse-highlight-start-face
76 '((((class color
) (background dark
))
77 (:background
"#AAAA33"))
78 (((class color
) (background light
))
79 (:background
"#FFFFAA")))
80 "Face used at beginning of a highlight."
83 (defface pulse-highlight-face
84 '((((class color
) (background dark
))
85 (:background
"#AAAA33"))
86 (((class color
) (background light
))
87 (:background
"#FFFFAA")))
88 "Face used during a pulse for display. *DO NOT CUSTOMIZE*
89 Face used for temporary highlighting of tags for effect."
94 (defun pulse-int-to-hex (int &optional nb-digits
)
95 "Convert integer argument INT to a #XXXXXXXXXXXX format hex string.
96 Each X in the output string is a hexadecimal digit.
97 NB-DIGITS is the number of hex digits. If INT is too large to be
98 represented with NB-DIGITS, then the result is truncated from the
99 left. So, for example, INT=256 and NB-DIGITS=2 returns \"00\", since
100 the hex equivalent of 256 decimal is 100, which is more than 2 digits.
102 This function was blindly copied from hexrgb.el by Drew Adams.
103 http://www.emacswiki.org/cgi-bin/wiki/hexrgb.el"
104 (setq nb-digits
(or nb-digits
4))
105 (substring (format (concat "%0" (int-to-string nb-digits
) "X") int
) (- nb-digits
)))
107 (defun pulse-color-values-to-hex (values)
108 "Convert list of rgb color VALUES to a hex string, #XXXXXXXXXXXX.
109 Each X in the string is a hexadecimal digit.
110 Input VALUES is as for the output of `x-color-values'.
112 This function was blindly copied from hexrgb.el by Drew Adams.
113 http://www.emacswiki.org/cgi-bin/wiki/hexrgb.el"
115 (pulse-int-to-hex (nth 0 values
) 4) ; red
116 (pulse-int-to-hex (nth 1 values
) 4) ; green
117 (pulse-int-to-hex (nth 2 values
) 4))) ; blue
119 (defcustom pulse-iterations
10
120 "Number of iterations in a pulse operation."
123 (defcustom pulse-delay
.03
124 "Delay between face lightening iterations, as used by `sit-for'."
128 (defun pulse-lighten-highlight ()
129 "Lighten the face by 1/`pulse-iterations' toward the background color.
130 Return t if there is more drift to do, nil if completed."
131 (if (>= (get 'pulse-highlight-face
:iteration
) pulse-iterations
)
133 (let* ((frame (color-values (face-background 'default
)))
134 (start (color-values (face-background
135 (get 'pulse-highlight-face
138 (frac (list (/ (- (nth 0 frame
) (nth 0 start
)) pulse-iterations
)
139 (/ (- (nth 1 frame
) (nth 1 start
)) pulse-iterations
)
140 (/ (- (nth 2 frame
) (nth 2 start
)) pulse-iterations
)))
141 (it (get 'pulse-highlight-face
:iteration
))
143 (set-face-background 'pulse-highlight-face
144 (pulse-color-values-to-hex
146 (+ (nth 0 start
) (* (nth 0 frac
) it
))
147 (+ (nth 1 start
) (* (nth 1 frac
) it
))
148 (+ (nth 2 start
) (* (nth 2 frac
) it
)))))
149 (put 'pulse-highlight-face
:iteration
(1+ it
))
150 (if (>= (1+ it
) pulse-iterations
)
154 (defun pulse-reset-face (&optional face
)
155 "Reset the pulse highlighting FACE."
156 (set-face-background 'pulse-highlight-face
158 (face-background face nil t
)
159 (face-background 'pulse-highlight-start-face
)
161 (put 'pulse-highlight-face
:startface
(or face
162 'pulse-highlight-start-face
))
163 (put 'pulse-highlight-face
:iteration
0))
165 (defun pulse (&optional face
)
166 "Pulse the colors on our highlight face.
167 If optional FACE is provided, reset the face to FACE color,
168 instead of `pulse-highlight-start-face'.
169 Be sure to call `pulse-reset-face' after calling pulse."
172 (pulse-reset-face face
)
173 (while (and (pulse-lighten-highlight)
174 (sit-for pulse-delay
))
177 ;;; Convenience Functions
179 (defvar pulse-momentary-overlay nil
180 "The current pulsing overlay.")
182 (defun pulse-momentary-highlight-overlay (o &optional face
)
183 "Pulse the overlay O, unhighlighting before next command.
184 Optional argument FACE specifies the face to do the highlighting."
185 (overlay-put o
'original-face
(overlay-get o
'face
))
186 (add-to-list 'pulse-momentary-overlay o
)
187 (if (eq pulse-flag
'never
)
189 (if (or (not pulse-flag
) (not (pulse-available-p)))
190 ;; Provide a face... clear on next command
192 (overlay-put o
'face
(or face
'pulse-highlight-start-face
))
193 (add-hook 'pre-command-hook
194 'pulse-momentary-unhighlight
))
198 (overlay-put o
'face
'pulse-highlight-face
)
199 ;; The pulse function puts FACE onto 'pulse-highlight-face.
200 ;; Thus above we put our face on the overlay, but pulse
201 ;; with a reference face needed for the color.
203 (pulse-momentary-unhighlight)))))
205 (defun pulse-momentary-unhighlight ()
206 "Unhighlight a line recently highlighted."
207 ;; If someone passes in an overlay, then pulse-momentary-overlay
208 ;; will still be nil, and won't need modifying.
209 (when pulse-momentary-overlay
210 ;; clear the starting face
213 (overlay-put ol
'face
(overlay-get ol
'original-face
))
214 (overlay-put ol
'original-face nil
)
215 ;; Clear the overlay if it needs deleting.
216 (when (overlay-get ol
'pulse-delete
) (delete-overlay ol
)))
217 pulse-momentary-overlay
)
219 ;; Clear the variable.
220 (setq pulse-momentary-overlay nil
))
222 ;; Reset the pulsing face.
226 (remove-hook 'pre-command-hook
'pulse-momentary-unhighlight
))
229 (defun pulse-momentary-highlight-one-line (point &optional face
)
230 "Highlight the line around POINT, unhighlighting before next command.
231 Optional argument FACE specifies the face to do the highlighting."
234 (let ((start (point-at-bol))
240 (pulse-momentary-highlight-region start end face
))))
243 (defun pulse-momentary-highlight-region (start end
&optional face
)
244 "Highlight between START and END, unhighlighting before next command.
245 Optional argument FACE specifies the face to do the highlighting."
246 (let ((o (make-overlay start end
)))
247 ;; Mark it for deletion
248 (overlay-put o
'pulse-delete t
)
249 (pulse-momentary-highlight-overlay o face
)))
251 ;;; Random integration with other tools
253 (defvar pulse-command-advice-flag nil
)
255 (defun pulse-line-hook-function ()
256 "Function used in hooks to pulse the current line.
257 Only pulses the line if `pulse-command-advice-flag' is non-nil."
258 (when pulse-command-advice-flag
259 (pulse-momentary-highlight-one-line (point))))
263 ;;; pulse.el ends here