[Emacs-diffs] trunk r113912: Add functions to change the speed of animated images

[Glenn Morris]

------------------------------------------------------------
revno: 113912
revision-id: address@hidden
parent: address@hidden
committer: Glenn Morris <address@hidden>
branch nick: trunk
timestamp: Thu 2013-08-15 23:33:08 -0700
message:
  Add functions to change the speed of animated images
  
  * lisp/image-mode.el (image-mode-map): Add menu items to reverse,
  increase, decrease, reset animation speed.
  (image--set-speed, image-increase-speed, image-decrease-speed)
  (image-reverse-speed, image-reset-speed): New functions.
  (image-mode-map): Add bindings for speed commands.
  
  * lisp/image.el (image-animate-get-speed, image-animate-set-speed):
  New functions.
  (image-animate-timeout): Respect image :speed property.
  
  * etc/NEWS: Mention this.
modified:
  etc/NEWS                       news-20100311060928-aoit31wvzf25yr1z-1
  lisp/ChangeLog                 changelog-20091113204419-o5vbwnq5f7feedwu-1432
  lisp/image-mode.el             
imagemode.el-20091113204419-o5vbwnq5f7feedwu-3391
  lisp/image.el                  image.el-20091113204419-o5vbwnq5f7feedwu-1320

=== modified file 'etc/NEWS'
--- a/etc/NEWS  2013-08-13 20:13:02 +0000
+++ b/etc/NEWS  2013-08-16 06:33:08 +0000
@@ -347,6 +347,8 @@
 `f' (`image-next-frame') and `b' (`image-previous-frame') visit the
 next or previous frame.  `F' (`image-goto-frame') shows a specific frame.
 
+*** New commands to speed up, slow down, or reverse animation.
+
 ---
 *** The command `image-mode-fit-frame' deletes other windows.
 When toggling, it restores the frame's previous window configuration.
@@ -683,6 +685,8 @@
 *** New functions `image-current-frame' and `image-show-frame' for getting
 and setting the current frame of a multi-frame image.
 
+*** You can change the speed of animated images.
+
 ** Changes in encoding and decoding of text
 
 ---

=== modified file 'lisp/ChangeLog'
--- a/lisp/ChangeLog    2013-08-15 17:21:19 +0000
+++ b/lisp/ChangeLog    2013-08-16 06:33:08 +0000
@@ -1,3 +1,15 @@
+2013-08-16  Glenn Morris  <address@hidden>
+
+       * image-mode.el (image-mode-map): Add menu items to reverse,
+       increase, decrease, reset animation speed.
+       (image--set-speed, image-increase-speed, image-decrease-speed)
+       (image-reverse-speed, image-reset-speed): New functions.
+       (image-mode-map): Add bindings for speed commands.
+
+       * image.el (image-animate-get-speed, image-animate-set-speed):
+       New functions.
+       (image-animate-timeout): Respect image :speed property.
+
 2013-08-15  Stefan Monnier  <address@hidden>
 
        * emacs-lisp/debug.el (debugger-setup-buffer): Put point on the

=== modified file 'lisp/image-mode.el'
--- a/lisp/image-mode.el        2013-05-27 00:59:33 +0000
+++ b/lisp/image-mode.el        2013-08-16 06:33:08 +0000
@@ -354,6 +354,10 @@
     (define-key map "b" 'image-previous-frame)
     (define-key map "n" 'image-next-file)
     (define-key map "p" 'image-previous-file)
+    (define-key map "a+" 'image-increase-speed)
+    (define-key map "a-" 'image-decrease-speed)
+    (define-key map "a0" 'image-reset-speed)
+    (define-key map "ar" 'image-reverse-speed)
     (define-key map [remap forward-char] 'image-forward-hscroll)
     (define-key map [remap backward-char] 'image-backward-hscroll)
     (define-key map [remap right-char] 'image-forward-hscroll)
@@ -412,7 +416,23 @@
             (image-toggle-animation)))
         :style toggle :selected image-animate-loop
         :active image-multi-frame
-         :help "Animate images once, or forever?"]
+        :help "Animate images once, or forever?"]
+       ["Reverse Animation" image-reverse-speed
+        :style toggle :selected (let ((image (image-get-display-property)))
+                                  (and image (<
+                                              (image-animate-get-speed image)
+                                              0)))
+        :active image-multi-frame
+        :help "Reverse direction of this image's animation?"]
+       ["Speed Up Animation" image-increase-speed
+        :active image-multi-frame
+        :help "Speed up this image's animation"]
+       ["Slow Down Animation" image-decrease-speed
+        :active image-multi-frame
+        :help "Slow down this image's animation"]
+       ["Reset Animation Speed" image-reset-speed
+        :active image-multi-frame
+        :help "Reset the speed of this image's animation"]
        ["Next Frame" image-next-frame :active image-multi-frame
         :help "Show the next frame of this image"]
        ["Previous Frame" image-previous-frame :active image-multi-frame
@@ -437,7 +457,10 @@
 (defun image-mode ()
   "Major mode for image files.
 You can use \\<image-mode-map>\\[image-toggle-display]
-to toggle between display as an image and display as text."
+to toggle between display as an image and display as text.
+
+Key bindings:
+\\{image-mode-map}"
   (interactive)
   (condition-case err
       (progn
@@ -703,6 +726,48 @@
            (image-animate image index
                           (if image-animate-loop t)))))))))
 
+(defun image--set-speed (speed &optional multiply)
+  "Set speed of an animated image to SPEED.
+If MULTIPLY is non-nil, treat SPEED as a multiplication factor.
+If SPEED is `reset', reset the magnitude of the speed to 1."
+  (let ((image (image-get-display-property)))
+    (cond
+     ((null image)
+      (error "No image is present"))
+     ((null image-multi-frame)
+      (message "No image animation."))
+     (t
+      (if (eq speed 'reset)
+         (setq speed (if (< (image-animate-get-speed image) 0)
+                         -1 1)
+               multiply nil))
+      (image-animate-set-speed image speed multiply)
+      ;; FIXME Hack to refresh an active image.
+      (when (image-animate-timer image)
+       (image-toggle-animation)
+       (image-toggle-animation))
+      (message "Image speed is now %s" (image-animate-get-speed image))))))
+
+(defun image-increase-speed ()
+  "Increase the speed of current animated image by a factor of 2."
+  (interactive)
+  (image--set-speed 2 t))
+
+(defun image-decrease-speed ()
+  "Decrease the speed of current animated image by a factor of 2."
+  (interactive)
+  (image--set-speed 0.5 t))
+
+(defun image-reverse-speed ()
+  "Reverse the animation of the current image."
+  (interactive)
+  (image--set-speed -1 t))
+
+(defun image-reset-speed ()
+  "Reset the animation speed of the current image."
+  (interactive)
+  (image--set-speed 'reset))
+
 (defun image-goto-frame (n &optional relative)
   "Show frame N of a multi-frame image.
 Optional argument OFFSET non-nil means interpret N as relative to the

=== modified file 'lisp/image.el'
--- a/lisp/image.el     2013-08-13 20:13:02 +0000
+++ b/lisp/image.el     2013-08-16 06:33:08 +0000
@@ -687,6 +687,19 @@
   (plist-put (cdr image) :index n)
   (force-window-update))
 
+(defun image-animate-get-speed (image)
+  "Return the speed factor for animating IMAGE."
+  (or (plist-get (cdr image) :speed) 1))
+
+(defun image-animate-set-speed (image value &optional multiply)
+  "Set the speed factor for animating IMAGE to VALUE.
+With optional argument MULTIPLY non-nil, treat VALUE as a
+multiplication factor for the current value."
+  (plist-put (cdr image) :speed
+            (if multiply
+                (* value (image-animate-get-speed image))
+              value)))
+
 ;; FIXME? The delay may not be the same for different sub-images,
 ;; hence we need to call image-multi-frame-p to return it.
 ;; But it also returns count, so why do we bother passing that as an
@@ -700,21 +713,28 @@
 LIMIT determines when to stop.  If t, loop forever.  If nil, stop
  after displaying the last animation frame.  Otherwise, stop
  after LIMIT seconds have elapsed.
-The minimum delay between successive frames is `image-minimum-frame-delay'."
+The minimum delay between successive frames is `image-minimum-frame-delay'.
+
+If the image has a non-nil :speed property, it acts as a multiplier
+for the animation speed.  A negative value means to animate in reverse."
   (image-show-frame image n t)
-  (setq n (1+ n))
-  (let* ((time (float-time))
+  (let* ((speed (image-animate-get-speed image))
+        (time (float-time))
         (animation (image-multi-frame-p image))
         ;; Subtract off the time we took to load the image from the
         ;; stated delay time.
-        (delay (max (+ (or (cdr animation) image-default-frame-delay)
+        (delay (max (+ (* (or (cdr animation) image-default-frame-delay)
+                          (/ 1 (abs speed)))
                        time (- (float-time)))
                     image-minimum-frame-delay))
         done)
-    (if (>= n count)
-       (if limit
-           (setq n 0)
-         (setq done t)))
+    (setq n (if (< speed 0)
+               (1- n)
+             (1+ n)))
+    (if limit
+       (cond ((>= n count) (setq n 0))
+             ((< n 0) (setq n (1- count))))
+      (and (or (>= n count) (< n 0)) (setq done t)))
     (setq time-elapsed (+ delay time-elapsed))
     (if (numberp limit)
        (setq done (>= time-elapsed limit)))