Display a mode-line frame counter for animated images

* lisp/image.el (image-current-frame): New variable.
(image-animate-timeout): Set image-current-frame.

* lisp/image-mode.el (image-mode): For animated images,
display a frame counter via mode-line-process.

1 files changed, 4 insertions, 0 deletions

diff --git a/lisp/image.el b/lisp/image.el
index 73b25f6da67..e0521ad065a 100644
--- a/lisp/image.el
+++ b/lisp/image.el
@@ -657,6 +657,9 @@ number, play until that number of seconds has elapsed."
         (setq timer nil)))
     timer))
 
+(defvar-local image-current-frame nil
+  "The frame index of the current animated image.")
+
 ;; FIXME? The delay may not be the same for different sub-images,
 ;; hence we need to call image-animated-p to return it.
 ;; But it also returns count, so why do we bother passing that as an
@@ -672,6 +675,7 @@ LIMIT determines when to stop.  If t, loop forever.  If nil, stop
  after LIMIT seconds have elapsed.
 The minimum delay between successive frames is 0.01s."
   (plist-put (cdr image) :index n)
+  (setq image-current-frame n)
   (force-window-update)
   (setq n (1+ n))
   (let* ((time (float-time))