X-Git-Url: https://code.delx.au/gnu-emacs-elpa/blobdiff_plain/729472997f2a86eb14277c1f0c2fc94709ff8cb9..3e1defba2d847bec0f67570c3f8d9148823b1703:/beacon.el

diff --git a/beacon.el b/beacon.el
index 76d7652de..290054eb0 100644
--- a/beacon.el
+++ b/beacon.el
@@ -1,4 +1,4 @@
-;;; 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 Free Software Foundation, Inc.
 
@@ -28,8 +28,8 @@
 ;; │ (beacon-mode 1)
 ;; └────
 ;;
-;; Whenever the window scrolls or the buffer changes a light will shine on
-;; top of your cursor so you know where it is.
+;; Whenever the window scrolls a light will shine on top of your cursor so
+;; you know where it is.
 ;;
 ;; That’s it.
 ;;
@@ -37,16 +37,24 @@
 ;; 1 Customizations
 ;; ════════════════
 ;;
-;;   • To customize the appearance of the beacon, configure `beacon-size'
-;;     and `beacon-color'.
+;;   • The appearance of the beacon is configured by `beacon-size' and
+;;     `beacon-color'.
 ;;
-;;   • To customize how long it lasts, configure `beacon-blink-duration'
-;;       and `beacon-blink-delay'.
+;;   • The duration is configured by `beacon-blink-duration' and
+;;     `beacon-blink-delay'.
 ;;
-;;   • To customize /when/ it is used at all, configure
+;;   • To customize /when/ the beacon should blink at all, configure
 ;;     `beacon-blink-when-window-scrolls',
-;;     `beacon-blink-when-buffer-changes', and
+;;     `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:
 
@@ -81,6 +89,10 @@ 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-duration 0.3
   "Time, in seconds, that the blink should last."
   :type 'number)
@@ -105,23 +117,55 @@ 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)
 
-(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."
+COLORS applied to each one.
+If COLORS is nil, OVERLAY is deleted!"
   (if (not colors)
-      (delete-overlay overlay)
+      (when (overlayp overlay)
+        (delete-overlay overlay))
     (overlay-put overlay 'beacon-colors colors)
     (overlay-put overlay 'after-string
                  (propertize
@@ -134,15 +178,10 @@ COLORS applied to each one."
   "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)))
+  ;; 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))
@@ -218,7 +257,9 @@ Only returns `beacon-size' elements."
   "Blink the beacon at the position of the cursor."
   (interactive)
   (beacon--vanish)
-  (unless (window-minibuffer-p)
+  (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
@@ -230,6 +271,7 @@ Only returns `beacon-size' elements."
 (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.
@@ -258,26 +300,26 @@ If DELTA is nil, return nil."
   (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
-      (beacon-blink)))
+   ;; 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)
-    (setq beacon--window-scrolled nil))
+    (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-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.
@@ -290,6 +332,7 @@ 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)))
 
 
@@ -309,9 +352,11 @@ unreliable, so just blink immediately."
   (if beacon-mode
       (progn
         (add-hook 'window-scroll-functions #'beacon--window-scroll-function)
-        (add-hook 'post-command-hook #'beacon--post-command))
+        (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 'post-command-hook #'beacon--post-command)
+    (remove-hook 'pre-command-hook #'beacon--vanish)))
 
 (provide 'beacon)
 ;;; beacon.el ends here