volatile-highlight.el

volatile-highlight.el

;; (c) 2011 sonota486 <[email protected]>
;; license: GPL


;; ;; .emacs.el example
;; (require 'volatile-highlight)
;; (set-face-background 'volatile-highlight-face "#ffff00") ; optional


(copy-face 'highlight 'volatile-highlight-face)
(defvar volatile-highlight:timer nil)
(defvar volatile-highlight:default-duration-sec 0.1)

;; オーバーレイ管理用
;; expire-time: オーバーレイが消えるべき時刻、unix time 
;; ((expire-time1 . overlay1)
;;  (expire-time2 . overlay2)
;;  ;; ...
;;  )
(defvar volatile-highlight:overlay-list '())


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;


(defun volatile-highlight:add-to-list (overlay duration-sec)
  (setq volatile-highlight:overlay-list
          (cons (cons (+ (time-to-seconds (current-time)) duration-sec)
                      overlay)
                volatile-highlight:overlay-list)))

(defun volatile-highlight:remove-from-list (pair-to-remove)
  (setq volatile-highlight:overlay-list
        (seq-remove (lambda (pair)
                     (equal (car pair)
                            (car pair-to-remove)))
                   volatile-highlight:overlay-list)))


(defun volatile-highlight:delete-overlay (pair-to-remove)
  (let (overlay)
    (setq overlay (cdr pair-to-remove))
    
    ;; オーバーレイを削除
    (delete-overlay overlay)
    (setq overlay nil)

    ;; リストから除去
    (volatile-highlight:remove-from-list pair-to-remove)))


(defun volatile-highlight:expired-p (pair)
  (let ((now (time-to-seconds (current-time))))
    (<= (car pair) now)))


(defun volatile-highlight:delete-expired ()
  (let (now
        expired-pairs)

    (setq expired-pairs
          (seq-filter
           (lambda (pair)
             (volatile-highlight:expired-p pair))
           volatile-highlight:overlay-list))
    
    (dolist (pair expired-pairs)
      (volatile-highlight:delete-overlay pair))))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;


(defun volatile-highlight (beg end &optional duration-sec)
  (let (overlay)

    (setq duration-sec
          (or duration-sec
              volatile-highlight:default-duration-sec))

    (setq overlay
          (make-overlay beg end))
    (overlay-put overlay
                 'font-lock-face 'volatile-highlight-face)

    ;; リストに追加
    (volatile-highlight:add-to-list overlay duration-sec)
    
    (run-with-timer duration-sec
                    nil
                    'volatile-highlight:delete-expired)))


(provide 'volatile-highlight)


;; for test
;; (setq volatile-highlight:overlay-list '())
;; (progn (volatile-highlight 10 20 2.5)
;;        (sit-for 0.51) (volatile-highlight 30 40 1.5)
;;        (sit-for 0.51) (volatile-highlight 50 60 0.5)
;;        )