X-Git-Url: https://code.delx.au/gnu-emacs-elpa/blobdiff_plain/19096a62529a75ea8999c3ee31babe097e3219b1..aaeb619f1ff57e666925bcef22bb3195c22d589e:/beacon.el

diff --git a/beacon.el b/beacon.el
index dd1976d5a..9a3edacb1 100644
--- a/beacon.el
+++ b/beacon.el
@@ -1,12 +1,12 @@
-;;; beacon.el --- Highlight the cursor whenever it moves long distances  -*- lexical-binding: t; -*-
+;;; beacon.el --- Highlight the cursor whenever the window scrolls  -*- lexical-binding: t; -*-
 
-;; Copyright (C) 2015  Artur Malabarba
+;; Copyright (C) 2015 Free Software Foundation, Inc.
 
 ;; Author: Artur Malabarba <emacs@endlessparentheses.com>
 ;; URL: https://github.com/Malabarba/beacon
 ;; Keywords: convenience
-;; Version: 0.1
-;; Package-Requires: ((cl-lib "0.5"))
+;; Version: 1.3.1
+;; Package-Requires: ((seq "2.14"))
 
 ;; 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
@@ -23,12 +23,39 @@
 
 ;;; Commentary:
 
-;; This is a global minor-mode.  Turn it on everywhere with
-;;     (beacon-mode 1)
+;; 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.
+;;
+;; See the accompanying Readme.org for configuration details.
 
 ;;; Code:
 
-(require 'cl-lib)
+(require 'seq)
+(require 'faces)
+(unless (fboundp 'seq-mapn)
+  ;; This is for people who are on outdated Emacs snapshots. Will be
+  ;; deleted in a couple of weeks.
+  (defun seq-mapn (function sequence &rest sequences)
+    "Like `seq-map' but FUNCTION is mapped over all SEQUENCES.
+The arity of FUNCTION must match the number of SEQUENCES, and the
+mapping stops on the shortest sequence.
+Return a list of the results.
+
+\(fn FUNCTION SEQUENCES...)"
+    (let ((result nil)
+          (sequences (seq-map (lambda (s) (seq-into s 'list))
+                            (cons sequence sequences))))
+      (while (not (memq nil sequences))
+        (push (apply function (seq-map #'car sequences)) result)
+        (setq sequences (seq-map #'cdr sequences)))
+      (nreverse result))))
 
 (defgroup beacon nil
   "Customization group for beacon."
@@ -37,20 +64,27 @@
 
 (defvar beacon--timer nil)
 
-(defcustom beacon-push-mark nil
+(defcustom beacon-push-mark 35
   "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.
+(defcustom beacon-blink-when-point-moves-vertically nil
+  "Should the beacon blink when moving a long distance vertically?
+If nil, don't blink due to vertical 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-point-moves-horizontally nil
+  "Should the beacon blink when moving a long distance horizontally?
+If nil, don't blink due to horizontal movement.
+If non-nil, this should be an integer, which is the minimum
+movement distance (in columns) 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)
@@ -59,6 +93,17 @@ movement distance (in lines) that triggers a beacon blink."
   "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-when-focused nil
+  "Should the beacon blink when Emacs gains focus?
+Note that, due to a limitation of `focus-in-hook', this might
+trigger false positives on some systems."
+  :type 'boolean
+  :package-version '(beacon . "0.2"))
+
 (defcustom beacon-blink-duration 0.3
   "Time, in seconds, that the blink should last."
   :type 'number)
@@ -83,46 +128,126 @@ If it is a string, it is a color name or specification,
 e.g. \"#666600\"."
   :type '(choice number color))
 
+(defface beacon-fallback-background
+  '((((class color) (background light)) (:background "black"))
+    (((class color) (background dark)) (:background "white")))
+  "Fallback beacon background color.
+Used in cases where the color can't be determined by Emacs.
+Only the background of this face is used.")
+
+(defvar 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.
+
+For instance, if you want to disable beacon on buffers where
+`hl-line-mode' is on, you can do:
+
+    (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 '(t magit-status-mode magit-popup-mode
+                                       inf-ruby-mode
+                                       gnus-summary-mode gnus-group-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))
+
+(defcustom beacon-dont-blink-commands '(next-line previous-line
+                                            forward-line)
+  "A list of commands that should not make the beacon blink.
+Use this for commands that scroll the window in very
+predictable ways, when the blink would be more distracting
+than helpful.."
+  :type '(repeat symbol))
+
+(defcustom beacon-before-blink-hook nil
+  "Hook run immediately before blinking the beacon."
+  :type 'hook)
+
+
+;;; Internal variables
+(defvar beacon--window-scrolled nil)
+(defvar beacon--previous-place nil)
+(defvar beacon--previous-mark-head nil)
+(defvar beacon--previous-window nil)
+(defvar beacon--previous-window-start 0)
+
+(defun beacon--record-vars ()
+  (unless (window-minibuffer-p)
+    (setq beacon--previous-mark-head (car mark-ring))
+    (setq beacon--previous-place (point-marker))
+    (setq beacon--previous-window (selected-window))
+    (setq beacon--previous-window-start (window-start))))
+
 
 ;;; Overlays
 (defvar beacon--ovs nil)
 
-(defun beacon--colored-overlay (color)
+(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) (1+ (point)))))
-    (overlay-put ov 'face (list :background color))
+  (let ((ov (make-overlay (point) (+ length (point)))))
     (overlay-put ov 'beacon t)
-    (push ov beacon--ovs)))
+    ;; 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."
-  (overlay-put overlay 'beacon-colors colors)
-  (overlay-put overlay 'after-string
-               (mapconcat (lambda (c) (propertize " " 'face (list :background c)))
-                          colors
-                          "")))
+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."
-  (let ((ov (make-overlay (point) (point))))
-    (beacon--ov-put-after-string ov colors)
-    (overlay-put ov 'beacon t)
-    (push ov beacon--ovs)))
+  ;; 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 (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 ()
+(defun beacon--vanish (&rest _)
   "Turn off the beacon."
-  (when (timerp beacon--timer)
-    (cancel-timer beacon--timer))
-  (mapc #'delete-overlay beacon--ovs)
-  (setq beacon--ovs nil))
+  (unless (string-match "\\` \\*\\(temp-buffer\\|Echo Area.*\\)\\*"
+                        (buffer-name))
+    (when (timerp beacon--timer)
+      (cancel-timer beacon--timer))
+    (mapc #'delete-overlay beacon--ovs)
+    (setq beacon--ovs nil)))
 
 
 ;;; Colors
@@ -137,14 +262,25 @@ Only returns `beacon-size' elements."
 
 (defun beacon--color-range ()
   "Return a list of background colors for the beacon."
-  (let* ((bg (color-values (face-attribute 'default :background)))
+  (let* ((default-bg (or (save-excursion
+                           (unless (eobp)
+                             (forward-line 1)
+                             (unless (or (bobp) (not (bolp)))
+                               (forward-char -1)))
+                           (background-color-at-point))
+                         (face-background 'default)))
+         (bg (color-values (if (or (not (stringp default-bg))
+                                   (string-match "\\`unspecified-" default-bg))
+                               (face-attribute 'beacon-fallback-background :background)
+                             default-bg)))
          (fg (cond
               ((stringp beacon-color) (color-values beacon-color))
-              ((< (color-distance "black" bg)
-                  (color-distance "white" bg))
+              ((and (stringp bg)
+                    (< (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))
+    (apply #'seq-mapn (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]))))
 
@@ -164,47 +300,85 @@ Only returns `beacon-size' elements."
 
 (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)))
-          (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))))))))
+  (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 (and (condition-case nil
+                       (progn (forward-char 1) t)
+                     (end-of-buffer nil))
+                   (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))))))))
 
+;;;###autoload
 (defun beacon-blink ()
-  "Blink the beacon at the position of the cursor."
+  "Blink the beacon at the position of the cursor.
+Unlike `beacon-blink-automated', the beacon will blink
+unconditionally (even if `beacon-mode' is disabled), and this can
+be invoked as a user command or called from lisp code."
   (interactive)
   (beacon--vanish)
+  (run-hooks 'beacon-before-blink-hook)
   (beacon--shine)
   (setq beacon--timer
         (run-at-time beacon-blink-delay
                      (/ beacon-blink-duration 1.0 beacon-size)
                      #'beacon--dec)))
 
+(defun beacon-blink-automated ()
+  "If appropriate, blink the beacon at the position of the cursor.
+Unlike `beacon-blink', the blinking is conditioned on a series of
+variables: `beacon-mode', `beacon-dont-blink-commands',
+`beacon-dont-blink-major-modes', and
+`beacon-dont-blink-predicates'."
+  ;; Record vars here in case something is blinking outside the
+  ;; command loop.
+  (beacon--record-vars)
+  (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)
+              (memq (or this-command last-command) beacon-dont-blink-commands))
+    (beacon-blink)))
+
 
 ;;; 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
+(defun beacon--movement-> (delta-y &optional delta-x)
+  "Return non-nil if latest vertical movement is > DELTA-Y.
+If DELTA-Y is nil, return nil.
+The same is true for DELTA-X and horizonta movement."
+  (and delta-y
+       (markerp beacon--previous-place)
        (equal (marker-buffer beacon--previous-place)
               (current-buffer))
+       ;; Quick check that prevents running the code below in very
+       ;; short movements (like typing).
        (> (abs (- (point) beacon--previous-place))
-          delta)
-       (> (count-screen-lines (min (point) beacon--previous-place)
-                              (max (point) beacon--previous-place))
-          delta)))
+          delta-y)
+       ;; Col movement.
+       (or (and delta-x
+                (> (abs (- (current-column)
+                           (save-excursion
+                             (goto-char beacon--previous-place)
+                             (current-column))))
+                   delta-x))
+           ;; Check if the movement was >= DELTA lines by moving DELTA
+           ;; lines. `count-screen-lines' is too slow if the movement had
+           ;; thousands of lines.
+           (save-excursion
+             (let ((p (point)))
+               (goto-char (min beacon--previous-place p))
+               (vertical-motion delta-y)
+               (> (max p beacon--previous-place)
+                  (line-beginning-position)))))))
 
 (defun beacon--maybe-push-mark ()
   "Push mark if it seems to be safe."
@@ -213,41 +387,62 @@ If DELTA is nil, return nil."
     (let ((head (car mark-ring)))
       (when (and (eq beacon--previous-mark-head head)
                  (not (equal head beacon--previous-place)))
-        (push-mark beacon--previous-place)))))
+        (push-mark beacon--previous-place 'silent)))))
 
 (defun beacon--post-command ()
   "Blink if point moved very far."
   (cond
-   ((not (markerp beacon--previous-place))
-    (beacon--vanish))
-   ;; Blink because we changed buffer.
-   ((not (equal (marker-buffer beacon--previous-place)
-                (current-buffer)))
-    (when beacon-blink-when-buffer-changes
-      (unless (window-minibuffer-p)
-        (beacon-blink))))
+   ;; Sanity check.
+   ((not (markerp beacon--previous-place)))
+   ;; Blink for switching buffers.
+   ((and beacon-blink-when-buffer-changes
+         (not (eq (marker-buffer beacon--previous-place)
+                  (current-buffer))))
+    (beacon-blink-automated))
+   ;; Blink for switching windows.
+   ((and beacon-blink-when-window-changes
+         (not (eq beacon--previous-window (selected-window))))
+    (beacon-blink-automated))
    ;; Blink for scrolling.
-   ((and beacon-blink-when-window-scrolls
-         (progn (redisplay)
-                (not (equal beacon--previous-window-start (window-start)))))
-    (beacon-blink))
+   ((and beacon--window-scrolled
+         (equal beacon--window-scrolled (selected-window)))
+    (beacon-blink-automated))
    ;; 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--movement-> beacon-blink-when-point-moves-vertically
+                  beacon-blink-when-point-moves-horizontally)
+    (beacon-blink-automated)))
   (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))))
+  (setq beacon--window-scrolled nil))
+
+(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."
+  (unless (or (and (equal beacon--previous-window-start start-pos)
+                   (equal beacon--previous-window win))
+              (not beacon-blink-when-window-scrolls))
+    (if this-command
+        (setq beacon--window-scrolled win)
+      (setq beacon--window-scrolled nil)
+      (beacon-blink-automated))))
+
+(defun beacon--blink-on-focus ()
+  "Blink if `beacon-blink-when-focused' is non-nil"
+  (when beacon-blink-when-focused
+    (beacon-blink-automated)))
 
 
 ;;; Minor-mode
-(defcustom beacon-lighter (cond
-                     ((char-displayable-p ?💡) "💡")
-                     ((char-displayable-p ?Λ) "Λ")
-                     (t "*"))
+(defcustom beacon-lighter
+  (cond
+   ;; ((char-displayable-p ?💡) " 💡")
+   ;; ((char-displayable-p ?Λ) " Λ")
+   (t " (*)"))
   "Lighter string used on the mode-line."
   :type 'string)
 
@@ -256,8 +451,23 @@ If DELTA is nil, return nil."
   nil nil beacon-lighter nil
   :global t
   (if beacon-mode
-      (add-hook 'post-command-hook #'beacon--post-command)
-    (remove-hook 'post-command-hook #'beacon--post-command)))
+      (progn
+        (add-hook 'window-scroll-functions #'beacon--window-scroll-function)
+        (add-hook 'focus-in-hook #'beacon--blink-on-focus)
+        (add-hook 'post-command-hook #'beacon--post-command)
+        (add-hook 'before-change-functions #'beacon--vanish)
+        (add-hook 'pre-command-hook #'beacon--record-vars)
+        (add-hook 'pre-command-hook #'beacon--vanish))
+    (remove-hook 'focus-in-hook #'beacon--blink-on-focus)
+    (remove-hook 'window-scroll-functions #'beacon--window-scroll-function)
+    (remove-hook 'post-command-hook #'beacon--post-command)
+    (remove-hook 'before-change-functions #'beacon--vanish)
+    (remove-hook 'pre-command-hook #'beacon--record-vars)
+    (remove-hook 'pre-command-hook #'beacon--vanish)))
 
 (provide 'beacon)
 ;;; beacon.el ends here
+
+;; Local Variables:
+;; indent-tabs-mode: nil
+;; End: