;; Copyright (C) 2015 Artur Malabarba
;; Author: Artur Malabarba <emacs@endlessparentheses.com>
+;; URL: https://github.com/Malabarba/beacon
;; Keywords: convenience
;; Version: 0.1
-;; Package-Requires: ((cl-lib "0.5"))
+;; Package-Requires: ((seq "1.9"))
;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;;; Code:
-(require 'cl-lib)
+(require 'seq)
(defgroup beacon nil
"Customization group for beacon."
(defvar beacon--timer nil)
-(defcustom beacon-minimum-distance 15
- "Minimum movement distance in lines to blink the beacon."
- :type 'integer)
-
(defcustom beacon-push-mark nil
- "Should the mark be pushed before long movements?"
- :type 'boolean)
+ "Should the mark be pushed before long movements?
+If nil, `beacon' will not push the mark.
+Otherwise this should be a number, and `beacon' will push the
+mark whenever point moves more than that many lines."
+ :type '(choice integer (const nil)))
+
+(defcustom beacon-blink-when-point-moves nil
+ "Should the beacon blink when moving a long distance?
+If nil, don't blink due to plain movement.
+If non-nil, this should be an integer, which is the minimum
+movement distance (in lines) that triggers a beacon blink."
+ :type '(choice integer (const nil)))
(defcustom beacon-blink-when-buffer-changes t
"Should the beacon blink when changing buffer?"
:type 'boolean)
+(defcustom beacon-blink-when-window-scrolls t
+ "Should the beacon blink when the window scrolls?"
+ :type 'boolean)
+
(defcustom beacon-blink-duration 0.3
"Time, in seconds, that the blink should last."
:type 'number)
"Time, in seconds, before starting to fade the beacon."
:type 'number)
-(defcustom beacon-size 30
+(defcustom beacon-size 40
"Size of the beacon in characters."
:type 'number)
-(defcustom beacon-brightness 0.5
- "Brightness as a float between 0 and 1."
- :type 'number)
+(defcustom beacon-color 0.5
+ "Color of the beacon.
+This can be a string or a number.
+
+If it is a number, the color is taken to be white or
+black (depending on the current theme's background) and this
+number is a float between 0 and 1 specifing the brightness.
+
+If it is a string, it is a color name or specification,
+e.g. \"#666600\"."
+ :type '(choice number color))
\f
;;; Overlays
(overlay-put ov 'beacon t)
(push ov beacon--ovs)))
+(defun beacon--ov-put-after-string (overlay colors)
+ "Add an after-string property to OVERLAY.
+The property's value is a string of spaces with background
+COLORS applied to each one."
+ (if (not colors)
+ (delete-overlay overlay)
+ (overlay-put overlay 'beacon-colors colors)
+ (overlay-put overlay 'after-string
+ (propertize
+ (mapconcat (lambda (c) (propertize " " 'face (list :background c)))
+ colors
+ "")
+ 'cursor 1000))))
+
+(defun beacon--after-string-overlay (colors)
+ "Put an overlay at point with an after-string property.
+The property's value is a string of spaces with background
+COLORS applied to each one."
+ (let ((ov (make-overlay (point) (point)))
+ ;; The after-string must not be longer than the remaining columns from
+ ;; point to right window-end else it will be wrapped around (assuming
+ ;; truncate-lines is nil) introducing an ugly wrap-around for a
+ ;; fraction of a second.
+ (colors (seq-take colors (- (window-width) (current-column)))))
+ (beacon--ov-put-after-string ov colors)
+ (overlay-put ov 'beacon t)
+ (push ov beacon--ovs)))
+
(defun beacon--ov-at-point ()
- (car (cl-member-if (lambda (o) (overlay-get o 'beacon))
- (overlays-at (point)))))
+ (car (or (seq-filter (lambda (o) (overlay-get o 'beacon))
+ (overlays-in (point) (point)))
+ (seq-filter (lambda (o) (overlay-get o 'beacon))
+ (overlays-at (point))))))
(defun beacon--vanish ()
"Turn off the beacon."
(defun beacon--color-range ()
"Return a list of background colors for the beacon."
- (let ((bg (color-values (face-attribute 'default :background))))
- (apply #'cl-mapcar (lambda (r g b) (format "#%04x%04x%04x" r g b))
- (if (< (color-distance "black" bg)
+ (let* ((bg (color-values (face-attribute 'default :background)))
+ (fg (cond
+ ((stringp beacon-color) (color-values beacon-color))
+ ((< (color-distance "black" bg)
(color-distance "white" bg))
- (mapcar (lambda (n) (butlast (beacon--int-range (* beacon-brightness 65535) n))) bg)
- (mapcar (lambda (n) (cdr (beacon--int-range (* (- 1 beacon-brightness) 65535) n))) bg)))))
+ (make-list 3 (* beacon-color 65535)))
+ (t (make-list 3 (* (- 1 beacon-color) 65535))))))
+ (apply #'cl-mapcar (lambda (r g b) (format "#%04x%04x%04x" r g b))
+ (mapcar (lambda (n) (butlast (beacon--int-range (elt fg n) (elt bg n))))
+ [0 1 2]))))
\f
;;; Blinking
(while colors
(if (looking-at "$")
(progn
- ;; (beacon--after-string)
+ (beacon--after-string-overlay colors)
(setq colors nil))
(beacon--colored-overlay (pop colors))
(forward-char 1))))))
(defun beacon--dec ()
"Decrease the beacon brightness by one."
- (let ((o (beacon--ov-at-point)))
- (if (not o)
- (beacon--vanish)
- (delete-overlay o)
- (save-excursion
- (while (progn (forward-char 1)
- (setq o (beacon--ov-at-point)))
- (move-overlay o (1- (point)) (point)))))))
+ (pcase (beacon--ov-at-point)
+ (`nil (beacon--vanish))
+ ((and o (let c (overlay-get o 'beacon-colors)) (guard c))
+ (beacon--ov-put-after-string o (cdr c)))
+ (o
+ (delete-overlay o)
+ (save-excursion
+ (while (progn (forward-char 1)
+ (setq o (beacon--ov-at-point)))
+ (let ((colors (overlay-get o 'beacon-colors)))
+ (if (not colors)
+ (move-overlay o (1- (point)) (point))
+ (forward-char -1)
+ (beacon--colored-overlay (pop colors))
+ (beacon--ov-put-after-string o colors)
+ (forward-char 1))))))))
(defun beacon-blink ()
"Blink the beacon at the position of the cursor."
(beacon--shine)
(setq beacon--timer
(run-at-time beacon-blink-delay
- (/ beacon-blink-duration 1.0 (length beacon--colors))
+ (/ beacon-blink-duration 1.0 beacon-size)
#'beacon--dec)))
\f
;;; Movement detection
(defvar beacon--previous-place nil)
+(defvar beacon--previous-window-start nil)
(defvar beacon--previous-mark-head nil)
+(defun beacon--movement-> (delta)
+ "Return non-nil if latest point movement is > DELTA.
+If DELTA is nil, return nil."
+ (and delta
+ (markerp beacon--previous-place)
+ (equal (marker-buffer beacon--previous-place)
+ (current-buffer))
+ (> (abs (- (point) beacon--previous-place))
+ delta)
+ (> (count-screen-lines (min (point) beacon--previous-place)
+ (max (point) beacon--previous-place))
+ delta)))
+
(defun beacon--maybe-push-mark ()
"Push mark if it seems to be safe."
- (when (and beacon-push-mark
- (not mark-active))
+ (when (and (not mark-active)
+ (beacon--movement-> beacon-push-mark))
(let ((head (car mark-ring)))
(when (and (eq beacon--previous-mark-head head)
(not (equal head beacon--previous-place)))
(when beacon-blink-when-buffer-changes
(unless (window-minibuffer-p)
(beacon-blink))))
- ;; Blink for distance movement
- ((and (> (abs (- (point) beacon--previous-place))
- beacon-minimum-distance)
- (> (count-screen-lines (min (point) beacon--previous-place)
- (max (point) beacon--previous-place))
- beacon-minimum-distance))
- (beacon--maybe-push-mark)
+ ;; Blink for scrolling.
+ ((and beacon-blink-when-window-scrolls
+ (progn (redisplay)
+ (not (equal beacon--previous-window-start (window-start)))))
+ (beacon-blink))
+ ;; Blink for movement
+ ((beacon--movement-> beacon-blink-when-point-moves)
(beacon-blink))
;; Even if we don't blink, vanish any previous beacon.
(t (beacon--vanish)))
+ (beacon--maybe-push-mark)
(unless (window-minibuffer-p)
+ (setq beacon--previous-window-start (window-start))
(setq beacon--previous-mark-head (car mark-ring))
(setq beacon--previous-place (point-marker))))
\f
;;; Minor-mode
(defcustom beacon-lighter (cond
- ((char-displayable-p ?💡) "💡")
- ((char-displayable-p ?Λ) "Λ")
- (t "*"))
+ ((char-displayable-p ?💡) " 💡")
+ ((char-displayable-p ?Λ) " Λ")
+ (t " *"))
"Lighter string used on the mode-line."
:type 'string)