[elpa] externals/greader 160ce3d5bb 1/2: First draft on reading estimated time facility.

[ELPA Syncer]

branch: externals/greader
commit 160ce3d5bb505d2d614a51e9ef0ebf3e955d3480
Author: Michelangelo Rodriguez <michelangelo.rodriguez@gmail.com>
Commit: Michelangelo Rodriguez <michelangelo.rodriguez@gmail.com>

    First draft on reading estimated time facility.
    
    The entry-point for this functionality is
    `greader-estimated-time-update' that updates the mode line with the
    estimated remaining time in "hh:mm:ss" format.
    If emacspeak is loaded, remaining time is also spoken.
---
 greader.el | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/greader.el b/greader.el
index d0ec4626b7..7055bd1411 100644
--- a/greader.el
+++ b/greader.el
@@ -1749,5 +1749,65 @@ If `greader-region-mode' is enabled, restart will behave 
accordingly."
     (remove-hook 'greader-before-finish-functions
                 #'greader-study-restart t)))
 
+;; Estimated reading time calculation.
+(defvar-local greader--buffer-words nil
+  "Total buffer words.")
+(defun greader--estimated-reading-time (&optional start end)
+  "Calculate the estimated reading time between START and END, based
+on your reading speed in WPM (words per minute).
+The selected back-end must support `rate' command.
+If START or END is not provided, consider the entire buffer."
+  (if-let* ((wpm (and (numberp (greader-get-rate))
+                      (greader-get-rate))))
+      (progn
+       (setq greader--buffer-words (if greader--buffer-words
+                                       greader--buffer-words (count-words (or 
start (point-min))
+                                                                          (or 
end (point-max)))))
+       (let* ((total-minutes (/ (* 1.0 greader--buffer-words) wpm))
+               (total-seconds (round (* total-minutes 60)))
+               (hours (/ total-seconds 3600))
+             (minutes (/ (% total-seconds 3600) 60))
+             (seconds (% total-seconds 60)))
+          ;; (message "%02d:%02d:%02d" hours minutes seconds)
+         (list (propertize (format "%02d:%02d:%02d" hours minutes
+                                   seconds) 'greader-estimated-time t)
+               `(,hours ,minutes ,seconds))))
+    nil))
+
+(defun greader--estimated-reading-time-remove ()
+  "Remove estimated-time banner from the mode line."
+  (catch 'banner-found
+    (dolist (elt mode-line-misc-info)
+      (if (listp elt)
+         (let ((line (cadr elt)))
+           (and
+            (equal (car elt) :propertize)
+            (text-property-any 0 (- (length line) 1)
+                               'greader-estimated-time t line)
+            (setq-local mode-line-misc-info (delete elt
+                                              mode-line-misc-info))))
+       (throw 'banner-found t))
+      nil)))
+
+(defun greader-estimated-time-update ()
+  "update of estimated reading time.
+new data is stored in the mode-line.
+The calculation is made from point to end of the buffer.
+If the region is active, use it."
+  (interactive)
+  (setq greader--buffer-words nil)
+  (greader--estimated-reading-time-remove)
+  (let ((region-beginning
+        (if (region-active-p) (region-beginning) (point)))
+       (region-end
+        (if (region-active-p) (region-end) (point-max))))
+    (add-to-list 'mode-line-misc-info (list :propertize (car 
(greader--estimated-reading-time
+                                                        region-beginning 
region-end))
+                                                  'greader-estimated-time
+                                                  t))
+      (when (and (featurep 'emacspeak) (called-interactively-p 'any))
+       (dtk-speak (car (greader--estimated-reading-time)))))
+  (force-mode-line-update))
+
 (provide 'greader)
 ;;; greader.el ends here