+(defvar elmo-progress-counter-alist nil)
+
+(defmacro elmo-progress-counter-value (counter)
+ (` (aref (cdr (, counter)) 0)))
+
+(defmacro elmo-progress-counter-all-value (counter)
+ (` (aref (cdr (, counter)) 1)))
+
+(defmacro elmo-progress-counter-format (counter)
+ (` (aref (cdr (, counter)) 2)))
+
+(defmacro elmo-progress-counter-set-value (counter value)
+ (` (aset (cdr (, counter)) 0 (, value))))
+
+(defun elmo-progress-set (label all-value &optional format)
+ (unless (assq label elmo-progress-counter-alist)
+ (setq elmo-progress-counter-alist
+ (cons (cons label (vector 0 all-value (or format "")))
+ elmo-progress-counter-alist))))
+
+(defun elmo-progress-clear (label)
+ (let ((counter (assq label elmo-progress-counter-alist)))
+ (when counter
+ (elmo-display-progress label
+ (elmo-progress-counter-format counter)
+ 100)
+ (setq elmo-progress-counter-alist
+ (delq counter elmo-progress-counter-alist)))))
+
+(defun elmo-progress-notify (label &optional value op &rest args)
+ (let ((counter (assq label elmo-progress-counter-alist)))
+ (when counter
+ (let* ((value (or value 1))
+ (cur-value (elmo-progress-counter-value counter))
+ (all-value (elmo-progress-counter-all-value counter))
+ (new-value (if (eq op 'set) value (+ cur-value value)))
+ (cur-rate (/ (* cur-value 100) all-value))
+ (new-rate (/ (* new-value 100) all-value)))
+ (elmo-progress-counter-set-value counter new-value)
+ (unless (= cur-rate new-rate)
+ (apply 'elmo-display-progress
+ label
+ (elmo-progress-counter-format counter)
+ new-rate
+ args))
+ (when (>= new-rate 100)
+ (elmo-progress-clear label))))))
+
+(put 'elmo-with-progress-display 'lisp-indent-function '2)
+(def-edebug-spec elmo-with-progress-display
+ (form (symbolp form &optional form) &rest form))
+
+(defmacro elmo-with-progress-display (condition spec &rest body)
+ "Evaluate BODY with progress gauge if CONDITION is non-nil.
+SPEC is a list as followed (LABEL MAX-VALUE [FORMAT])."
+ (let ((label (car spec))
+ (max-value (cadr spec))
+ (fmt (caddr spec)))
+ `(unwind-protect
+ (progn
+ (when ,condition
+ (elmo-progress-set (quote ,label) ,max-value ,fmt))
+ ,@body)
+ (elmo-progress-clear (quote ,label)))))
+