From 50849ac1fdc7840cced9aa1730b5d3f7fd4d5d02 Mon Sep 17 00:00:00 2001
From: Elliot Smith <elliot.smith@intel.com>
Date: Tue, 30 Nov 2010 16:52:01 +0000
Subject: [PATCH] cookbook: Use new API to reverse timeline

clutter_timeline_set_reverse() can be used to
automatically reverse a timeline's direction each time
it completes, so use that in looping animation recipe and
examples.
---
 doc/cookbook/animations.xml                   | 25 +++++++++++++------
 .../examples/animations-looping-implicit.c    | 24 +-----------------
 2 files changed, 19 insertions(+), 30 deletions(-)

diff --git a/doc/cookbook/animations.xml b/doc/cookbook/animations.xml
index 95bb02975..628a57f35 100644
--- a/doc/cookbook/animations.xml
+++ b/doc/cookbook/animations.xml
@@ -2372,7 +2372,7 @@ clutter_actor_animate_with_timeline (actor,
           </programlisting>
         </informalexample>
 
-        <para>One further technique is to swop the timeline's
+        <para>One further technique is to repeatedly reverse the timeline's
         direction to create a "closed loop" animation (one which returns
         to its origin at the end of each iteration). See
         <link linkend="animations-looping-discussion-closed-loop">this
@@ -2655,12 +2655,23 @@ timeline_completed_cb (ClutterTimeline *timeline,
         animations, one the inverse of the other, and chaining them together.</para>
 
         <para>However, a simpler solution is to run forward through the timeline
-        once; then invert its direction when the end of timeline is reached.
-        The animation continues, but in reverse. Once the backward iteration
-        completes, set the timeline to run forward again. Keep changing the
-        timeline's direction each time it completes. This
-        is the approach used in <link linkend="animations-looping-example-1">the
-        example</link>, which results in a smooth, repeated right to left,
+        once, and have the timeline invert itself when its end is reached.
+        The animation then continues, but in reverse. Once the backward iteration
+        completes, the timeline sets itself to run forward again, etc.</para>
+
+        <para>To make a timeline reverse its direction each time it
+        completes, use the <function>clutter_timeline_set_reverse()</function>
+        function:</para>
+
+        <informalexample>
+          <programlisting>
+clutter_timeline_set_reverse (timeline, TRUE);
+          </programlisting>
+        </informalexample>
+
+        <para>This is the approach used in
+        <link linkend="animations-looping-example-1">the example</link>,
+        which results in a smooth, repeated right to left,
         left to right motion.</para>
 
         <para>See <link linkend="animations-inversion">this
diff --git a/doc/cookbook/examples/animations-looping-implicit.c b/doc/cookbook/examples/animations-looping-implicit.c
index 15eb00953..98bc58818 100644
--- a/doc/cookbook/examples/animations-looping-implicit.c
+++ b/doc/cookbook/examples/animations-looping-implicit.c
@@ -10,20 +10,6 @@ typedef struct
   ClutterTimeline *timeline;
 } State;
 
-static void
-invert_timeline_cb (ClutterTimeline *timeline,
-                    gpointer         user_data)
-{
-  ClutterTimelineDirection direction = clutter_timeline_get_direction (timeline);
-
-  if (direction == CLUTTER_TIMELINE_FORWARD)
-    direction = CLUTTER_TIMELINE_BACKWARD;
-  else
-    direction = CLUTTER_TIMELINE_FORWARD;
-
-  clutter_timeline_set_direction (timeline, direction);
-}
-
 static gboolean
 key_pressed_cb (ClutterActor *actor,
                 ClutterEvent *event,
@@ -63,21 +49,13 @@ main (int   argc,
 
   state->timeline = clutter_timeline_new (1000);
   clutter_timeline_set_loop (state->timeline, TRUE);
+  clutter_timeline_set_reverse (state->timeline, TRUE);
 
   g_signal_connect (stage,
                     "key-press-event",
                     G_CALLBACK (key_pressed_cb),
                     state);
 
-  /* the animation will not emit a "completed" signal,
-   * as it is set to loop; but the timeline emits "completed"
-   * at the end of each iteration of the loop
-   */
-  g_signal_connect (state->timeline,
-                    "completed",
-                    G_CALLBACK (invert_timeline_cb),
-                    NULL);
-
   clutter_container_add_actor (CLUTTER_CONTAINER (stage), state->actor);
 
   clutter_actor_show (stage);