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emacs/lisp/cedet/pulse.el

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9.0 KiB
EmacsLisp

;;; pulse.el --- Pulsing Overlays
;;; Copyright (C) 2007-2014 Free Software Foundation, Inc.
;; Author: Eric M. Ludlam <eric@siege-engine.com>
;; Version: 1.0
;; 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:
;;
;; Manage temporary pulsing of faces and overlays.
;;
;; This is a temporal decoration technique where something is to be
;; highlighted briefly. This adds a gentle pulsing style to the text
;; decorated this way.
;;
;; The following are useful entry points:
;;
;; `pulse' - Cause `pulse-highlight-face' to shift toward background color.
;; Assumes you are using a version of Emacs that supports pulsing.
;;
;;
;; `pulse-momentary-highlight-one-line' - Pulse a single line at POINT.
;; `pulse-momentary-highlight-region' - Pulse a region.
;; `pulse-momentary-highlight-overlay' - Pulse an overlay.
;; These three functions will just blink the specified area if
;; the version of Emacs you are using doesn't support pulsing.
;;
;; `pulse-line-hook-function' - A simple function that can be used in a
;; hook that will pulse whatever line the cursor is on.
;;
;;; History:
;;
;; The original pulse code was written for semantic tag highlighting.
;; It has been extracted, and adapted for general purpose pulsing.
;;
;; Pulse is a part of CEDET. http://cedet.sf.net
(defun pulse-available-p ()
"Return non-nil if pulsing is available on the current frame."
(condition-case nil
(let ((v (color-values (face-background 'default))))
(numberp (car-safe v)))
(error nil)))
(defcustom pulse-flag (pulse-available-p)
"Whether to use pulsing for momentary highlighting.
Pulsing involves a bright highlight that slowly shifts to the
background color.
If the value is nil, highlight with an unchanging color until a
key is pressed.
If the value is `never', do no coloring at all.
Any other value means to do the default pulsing behavior.
If `pulse-flag' is non-nil, but `pulse-available-p' is nil, then
this flag is ignored."
:group 'pulse
:type 'boolean)
(defface pulse-highlight-start-face
'((((class color) (background dark))
(:background "#AAAA33"))
(((class color) (background light))
(:background "#FFFFAA")))
"Face used at beginning of a highlight."
:group 'pulse)
(defface pulse-highlight-face
'((((class color) (background dark))
(:background "#AAAA33"))
(((class color) (background light))
(:background "#FFFFAA")))
"Face used during a pulse for display. *DO NOT CUSTOMIZE*
Face used for temporary highlighting of tags for effect."
:group 'pulse)
;;; Code:
;;
(defun pulse-int-to-hex (int &optional nb-digits)
"Convert integer argument INT to a #XXXXXXXXXXXX format hex string.
Each X in the output string is a hexadecimal digit.
NB-DIGITS is the number of hex digits. If INT is too large to be
represented with NB-DIGITS, then the result is truncated from the
left. So, for example, INT=256 and NB-DIGITS=2 returns \"00\", since
the hex equivalent of 256 decimal is 100, which is more than 2 digits.
This function was blindly copied from hexrgb.el by Drew Adams.
http://www.emacswiki.org/cgi-bin/wiki/hexrgb.el"
(setq nb-digits (or nb-digits 4))
(substring (format (concat "%0" (int-to-string nb-digits) "X") int) (- nb-digits)))
(defun pulse-color-values-to-hex (values)
"Convert list of rgb color VALUES to a hex string, #XXXXXXXXXXXX.
Each X in the string is a hexadecimal digit.
Input VALUES is as for the output of `x-color-values'.
This function was blindly copied from hexrgb.el by Drew Adams.
http://www.emacswiki.org/cgi-bin/wiki/hexrgb.el"
(concat "#"
(pulse-int-to-hex (nth 0 values) 4) ; red
(pulse-int-to-hex (nth 1 values) 4) ; green
(pulse-int-to-hex (nth 2 values) 4))) ; blue
(defcustom pulse-iterations 10
"Number of iterations in a pulse operation."
:group 'pulse
:type 'number)
(defcustom pulse-delay .03
"Delay between face lightening iterations, as used by `sit-for'."
:group 'pulse
:type 'number)
(defun pulse-lighten-highlight ()
"Lighten the face by 1/`pulse-iterations' toward the background color.
Return t if there is more drift to do, nil if completed."
(if (>= (get 'pulse-highlight-face :iteration) pulse-iterations)
nil
(let* ((frame (color-values (face-background 'default)))
(start (color-values (face-background
(get 'pulse-highlight-face
:startface))))
(frac (list (/ (- (nth 0 frame) (nth 0 start)) pulse-iterations)
(/ (- (nth 1 frame) (nth 1 start)) pulse-iterations)
(/ (- (nth 2 frame) (nth 2 start)) pulse-iterations)))
(it (get 'pulse-highlight-face :iteration))
)
(set-face-background 'pulse-highlight-face
(pulse-color-values-to-hex
(list
(+ (nth 0 start) (* (nth 0 frac) it))
(+ (nth 1 start) (* (nth 1 frac) it))
(+ (nth 2 start) (* (nth 2 frac) it)))))
(put 'pulse-highlight-face :iteration (1+ it))
(if (>= (1+ it) pulse-iterations)
nil
t))))
(defun pulse-reset-face (&optional face)
"Reset the pulse highlighting FACE."
(set-face-background 'pulse-highlight-face
(if face
(face-background face)
(face-background 'pulse-highlight-start-face)
))
(put 'pulse-highlight-face :startface (or face
'pulse-highlight-start-face))
(put 'pulse-highlight-face :iteration 0))
(defun pulse (&optional face)
"Pulse the colors on our highlight face.
If optional FACE is provided, reset the face to FACE color,
instead of `pulse-highlight-start-face'.
Be sure to call `pulse-reset-face' after calling pulse."
(unwind-protect
(progn
(pulse-reset-face face)
(while (and (pulse-lighten-highlight)
(sit-for pulse-delay))
nil))))
;;; Convenience Functions
;;
(defvar pulse-momentary-overlay nil
"The current pulsing overlay.")
(defun pulse-momentary-highlight-overlay (o &optional face)
"Pulse the overlay O, unhighlighting before next command.
Optional argument FACE specifies the face to do the highlighting."
(overlay-put o 'original-face (overlay-get o 'face))
(add-to-list 'pulse-momentary-overlay o)
(if (eq pulse-flag 'never)
nil
(if (or (not pulse-flag) (not (pulse-available-p)))
;; Provide a face... clear on next command
(progn
(overlay-put o 'face (or face 'pulse-highlight-start-face))
(add-hook 'pre-command-hook
'pulse-momentary-unhighlight))
;; pulse it.
(unwind-protect
(progn
(overlay-put o 'face 'pulse-highlight-face)
;; The pulse function puts FACE onto 'pulse-highlight-face.
;; Thus above we put our face on the overlay, but pulse
;; with a reference face needed for the color.
(pulse face))
(pulse-momentary-unhighlight)))))
(defun pulse-momentary-unhighlight ()
"Unhighlight a line recently highlighted."
;; If someone passes in an overlay, then pulse-momentary-overlay
;; will still be nil, and won't need modifying.
(when pulse-momentary-overlay
;; clear the starting face
(mapc
(lambda (ol)
(overlay-put ol 'face (overlay-get ol 'original-face))
(overlay-put ol 'original-face nil)
;; Clear the overlay if it needs deleting.
(when (overlay-get ol 'pulse-delete) (delete-overlay ol)))
pulse-momentary-overlay)
;; Clear the variable.
(setq pulse-momentary-overlay nil))
;; Reset the pulsing face.
(pulse-reset-face)
;; Remove this hook.
(remove-hook 'pre-command-hook 'pulse-momentary-unhighlight))
(defun pulse-momentary-highlight-one-line (point &optional face)
"Highlight the line around POINT, unhighlighting before next command.
Optional argument FACE specifies the face to do the highlighting."
(let ((start (point-at-bol))
(end (save-excursion
(end-of-line)
(when (not (eobp))
(forward-char 1))
(point))))
(pulse-momentary-highlight-region start end face)))
(defun pulse-momentary-highlight-region (start end &optional face)
"Highlight between START and END, unhighlighting before next command.
Optional argument FACE specifies the face to do the highlighting."
(let ((o (make-overlay start end)))
;; Mark it for deletion
(overlay-put o 'pulse-delete t)
(pulse-momentary-highlight-overlay o face)))
;;; Random integration with other tools
(defvar pulse-command-advice-flag nil)
(defun pulse-line-hook-function ()
"Function used in hooks to pulse the current line.
Only pulses the line if `pulse-command-advice-flag' is non-nil."
(when pulse-command-advice-flag
(pulse-momentary-highlight-one-line (point))))
(provide 'pulse)
;;; pulse.el ends here