(defvar beacon--previous-mark-head nil)
(defvar beacon--previous-window nil)
-(defun beacon--pos-on-current-line-p (pos)
- "Return non-nil if POS is on the current line."
- (and (<= (save-excursion (beginning-of-line) (point)) pos)
- (<= pos (save-excursion (end-of-line) (point)))))
-
(defun beacon--movement-> (delta)
"Return non-nil if latest point movement is > DELTA.
If DELTA is nil, return nil."
(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)
- ;; Check if the movement was larger than DELTA lines by testing if
- ;; `point' is still on the same line or on any line DELTA lines up or
- ;; down. This is much cheaper than computing the actual number of lines
- ;; moved using `count-screen-lines'.
- (let ((prev-pos (marker-position beacon--previous-place)))
- (catch 'movement
- (when (beacon--pos-on-current-line-p prev-pos)
- (throw 'movement nil))
- (dolist (inc '(1 -1))
- (save-excursion
- (dotimes (i delta)
- (vertical-motion inc)
- (when (beacon--pos-on-current-line-p prev-pos)
- (throw 'movement nil)))))
- (throw 'movement t)))))
+ ;; 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
+ (goto-char (min beacon--previous-place (point)))
+ (vertical-motion delta)
+ (> (max (point) beacon--previous-place)
+ (line-beginning-position)))))
(defun beacon--maybe-push-mark ()
"Push mark if it seems to be safe."