[elpa] master 2eb4c54 34/34: Add 'packages/beacon/' from commit 'bccd3de53787c996f9a90bcb5d541252deda01e1'

[Artur Malabarba]

branch: master
commit 2eb4c540640a91d153a93fd7df3e26c7f22799c8
Merge: 6578236 bccd3de
Author: Artur Malabarba <address@hidden>
Commit: Artur Malabarba <address@hidden>

    Add 'packages/beacon/' from commit 
'bccd3de53787c996f9a90bcb5d541252deda01e1'
    
    git-subtree-dir: packages/beacon
    git-subtree-mainline: 6578236b45ab6d68749e2430c73660d5a03c2e22
    git-subtree-split: bccd3de53787c996f9a90bcb5d541252deda01e1
---
 packages/beacon/Readme.org         |   40 ++++
 packages/beacon/beacon.el          |  362 ++++++++++++++++++++++++++++++++++++
 packages/beacon/example-beacon.gif |  Bin 0 -> 2578269 bytes
 3 files changed, 402 insertions(+), 0 deletions(-)

diff --git a/packages/beacon/Readme.org b/packages/beacon/Readme.org
new file mode 100644
index 0000000..1f20527
--- /dev/null
+++ b/packages/beacon/Readme.org
@@ -0,0 +1,40 @@
+#+TITLE: Beacon --- Never lose your cursor again
+
+This is a global minor-mode.  Turn it on everywhere with:
+#+BEGIN_SRC emacs-lisp
+(beacon-mode 1)
+#+END_SRC
+
+[[file:example-beacon.gif]]
+
+Whenever the window scrolls a light will shine on top of your cursor
+so you know where it is.
+
+That’s it.
+
+** Customizations
+
+- The appearance of the beacon is configured by ~beacon-size~ and
+  ~beacon-color~.
+
+- The duration is configured by ~beacon-blink-duration~ and
+  ~beacon-blink-delay~.
+
+- To customize /when/ the beacon should blink at all, configure
+  ~beacon-blink-when-window-scrolls~,
+  ~beacon-blink-when-window-changes~, and
+  ~beacon-blink-when-point-moves~.
+
+- To prevent the beacon from blinking only on some major-modes,
+  configure ~beacon-dont-blink-major-modes~. For specific buffers, you
+  can do ~(setq-local beacon-mode nil)~. For even more refined
+  control, configure ~beacon-dont-blink-predicates~
+
+- Beacon can also push the mark for you whenever point moves a long
+  distance. For this, configure ~beacon-push-mark~.
+
+** Contributors
+
+- [[https://github.com/tsdh][Tassilo Horn]]
+
+If you’d like to help too, just open a PR.
diff --git a/packages/beacon/beacon.el b/packages/beacon/beacon.el
new file mode 100644
index 0000000..290054e
--- /dev/null
+++ b/packages/beacon/beacon.el
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+;;; beacon.el --- Highlight the cursor whenever the window scrolls  -*- 
lexical-binding: t; -*-
+
+;; Copyright (C) 2015 Free Software Foundation, Inc.
+
+;; Author: Artur Malabarba <address@hidden>
+;; URL: https://github.com/Malabarba/beacon
+;; Keywords: convenience
+;; Version: 0.1
+;; 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
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This is a global minor-mode. Turn it on everywhere with:
+;; ┌────
+;; │ (beacon-mode 1)
+;; └────
+;;
+;; Whenever the window scrolls a light will shine on top of your cursor so
+;; you know where it is.
+;;
+;; That’s it.
+;;
+;;
+;; 1 Customizations
+;; ════════════════
+;;
+;;   • The appearance of the beacon is configured by `beacon-size' and
+;;     `beacon-color'.
+;;
+;;   • The duration is configured by `beacon-blink-duration' and
+;;     `beacon-blink-delay'.
+;;
+;;   • To customize /when/ the beacon should blink at all, configure
+;;     `beacon-blink-when-window-scrolls',
+;;     `beacon-blink-when-window-changes', and
+;;     `beacon-blink-when-point-moves'.
+;;
+;;   • To prevent the beacon from blinking only on some major-modes,
+;;     configure `beacon-dont-blink-major-modes'. For specific buffers, you
+;;     can do `(setq-local beacon-mode nil)'. For even more refined
+;;     control, configure `beacon-dont-blink-predicates'
+;;
+;;   • Beacon can also push the mark for you whenever point moves a long
+;;     distance. For this, configure `beacon-push-mark'.
+
+;;; Code:
+
+(require 'seq)
+
+(defgroup beacon nil
+  "Customization group for beacon."
+  :group 'emacs
+  :prefix "beacon-")
+
+(defvar beacon--timer nil)
+
+(defcustom beacon-push-mark nil
+  "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-when-window-changes t
+  "Should the beacon blink when the window changes?"
+  :type 'boolean)
+
+(defcustom beacon-blink-duration 0.3
+  "Time, in seconds, that the blink should last."
+  :type 'number)
+
+(defcustom beacon-blink-delay 0.3
+  "Time, in seconds, before starting to fade the beacon."
+  :type 'number)
+
+(defcustom beacon-size 40
+  "Size of the beacon in characters."
+  :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))
+
+(defcustom beacon-dont-blink-predicates nil
+  "A list of predicates that prevent the beacon blink.
+These predicate functions are called in order, with no
+arguments, before blinking the beacon.  If any returns
+non-nil, the beacon will not blink."
+  :type 'hook)
+
+(add-hook 'beacon-dont-blink-predicates (lambda () (bound-and-true-p 
hl-line-mode)))
+(add-hook 'beacon-dont-blink-predicates #'window-minibuffer-p)
+
+(defcustom beacon-dont-blink-major-modes '(magit-status-mode)
+  "A list of major-modes where the beacon won't blink.
+Whenever the current buffer satisfies `derived-mode-p' for
+one of the major-modes on this list, the beacon will not
+blink."
+  :type '(repeat symbol))
+
+
+;;; Overlays
+(defvar beacon--ovs nil)
+
+(defconst beacon-overlay-priority (/ most-positive-fixnum 2)
+  "Priotiy used on all of our overlays.")
+
+(defun beacon--make-overlay (length &rest properties)
+  "Put an overlay at point with background COLOR."
+  (let ((ov (make-overlay (point) (+ length (point)))))
+    (overlay-put ov 'beacon t)
+    ;; Our overlay is very temporary, so we take the liberty of giving
+    ;; it a high priority.
+    (overlay-put ov 'priority beacon-overlay-priority)
+    (overlay-put ov 'window (selected-window))
+    (while properties
+      (overlay-put ov (pop properties) (pop properties)))
+    (push ov beacon--ovs)
+    ov))
+
+(defun beacon--colored-overlay (color)
+  "Put an overlay at point with background COLOR."
+  (beacon--make-overlay 1 'face (list :background color)))
+
+(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 COLORS is nil, OVERLAY is deleted!"
+  (if (not colors)
+      (when (overlayp overlay)
+        (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."
+  ;; The after-string must not be longer than the remaining columns
+  ;; from point to right window-end else it will be wrapped around.
+  (let ((colors (seq-take colors (- (window-width) (current-column)))))
+    (beacon--ov-put-after-string (beacon--make-overlay 0) colors)))
+
+(defun beacon--ov-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."
+  (when (timerp beacon--timer)
+    (cancel-timer beacon--timer))
+  (mapc #'delete-overlay beacon--ovs)
+  (setq beacon--ovs nil))
+
+
+;;; Colors
+(defun beacon--int-range (a b)
+  "Return a list of integers between A inclusive and B exclusive.
+Only returns `beacon-size' elements."
+  (let ((d (/ (- b a) beacon-size))
+        (out (list a)))
+    (dotimes (_ (1- beacon-size))
+      (push (+ (car out) d) out))
+    (nreverse out)))
+
+(defun beacon--color-range ()
+  "Return a list of background colors for the beacon."
+  (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))
+               (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]))))
+
+
+;;; Blinking
+(defun beacon--shine ()
+  "Shine a beacon at point."
+  (let ((colors (beacon--color-range)))
+    (save-excursion
+      (while colors
+        (if (looking-at "$")
+            (progn
+              (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."
+  (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."
+  (interactive)
+  (beacon--vanish)
+  (unless (or (not beacon-mode)
+              (run-hook-with-args-until-success 'beacon-dont-blink-predicates)
+              (seq-find #'derived-mode-p beacon-dont-blink-major-modes))
+    (beacon--shine)
+    (setq beacon--timer
+          (run-at-time beacon-blink-delay
+                       (/ beacon-blink-duration 1.0 beacon-size)
+                       #'beacon--dec))))
+
+
+;;; Movement detection
+(defvar beacon--window-scrolled nil)
+(defvar beacon--previous-place nil)
+(defvar beacon--previous-mark-head nil)
+(defvar beacon--previous-window 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 (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)))
+        (push-mark beacon--previous-place)))))
+
+(defun beacon--post-command ()
+  "Blink if point moved very far."
+  (cond
+   ((not (markerp beacon--previous-place))
+    (beacon--vanish))
+   ;; Blink for switching windows.
+   ((and beacon-blink-when-window-changes
+        (not (eq beacon--previous-window (selected-window))))
+    (beacon-blink))
+   ;; Blink for scrolling.
+   ((and beacon-blink-when-window-scrolls
+         beacon--window-scrolled
+         (equal beacon--window-scrolled (selected-window)))
+    (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)
+  (setq beacon--window-scrolled nil)
+  (unless (window-minibuffer-p)
+    (setq beacon--previous-mark-head (car mark-ring))
+    (setq beacon--previous-place (point-marker))
+    (setq beacon--previous-window (selected-window))))
+
+(defun beacon--window-scroll-function (win _start-pos)
+  "Blink the beacon or record that window has been scrolled.
+If invoked during the command loop, record the current window so
+that it may be blinked on post-command.  This is because the
+scrolled window might not be active, but we only know that at
+`post-command-hook'.
+
+If invoked outside the command loop, `post-command-hook' would be
+unreliable, so just blink immediately."
+  (if this-command
+      (setq beacon--window-scrolled win)
+    (setq beacon--window-scrolled nil)
+    (beacon-blink)))
+
+
+;;; Minor-mode
+(defcustom beacon-lighter
+  (cond
+   ((char-displayable-p ?💡) " 💡")
+   ((char-displayable-p ?Λ) " Λ")
+   (t " *"))
+  "Lighter string used on the mode-line."
+  :type 'string)
+
+;;;###autoload
+(define-minor-mode beacon-mode
+  nil nil beacon-lighter nil
+  :global t
+  (if beacon-mode
+      (progn
+        (add-hook 'window-scroll-functions #'beacon--window-scroll-function)
+        (add-hook 'post-command-hook #'beacon--post-command)
+        (add-hook 'pre-command-hook #'beacon--vanish))
+    (remove-hook 'window-scroll-functions #'beacon--window-scroll-function)
+    (remove-hook 'post-command-hook #'beacon--post-command)
+    (remove-hook 'pre-command-hook #'beacon--vanish)))
+
+(provide 'beacon)
+;;; beacon.el ends here
diff --git a/packages/beacon/example-beacon.gif 
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