Web Animations: Make AnimationPlayer an ActiveDOMObject

Source/core/animation/AnimationPlayer.h

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  * modification, are permitted provided that the following conditions are
  * met:
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  *     * Redistributions in binary form must reproduce the above
@@ skipping 14 matching lines @@
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  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef AnimationPlayer_h
 #define AnimationPlayer_h
 
 #include "core/animation/AnimationSource.h"
+#include "core/dom/ActiveDOMObject.h"
 #include "core/events/EventTarget.h"
 #include "wtf/RefPtr.h"
 
 namespace WebCore {
 
 class AnimationTimeline;
 class ExceptionState;
 
-class AnimationPlayer FINAL : public RefCountedWillBeRefCountedGarbageCollected<AnimationPlayer>, public EventTargetWithInlineData {
+class AnimationPlayer FINAL : public RefCountedWillBeRefCountedGarbageCollected<AnimationPlayer>
+    , public ActiveDOMObject
+    , public EventTargetWithInlineData {
     DEFINE_EVENT_TARGET_REFCOUNTING(RefCountedWillBeRefCountedGarbageCollected<AnimationPlayer>);
 public:
 
     ~AnimationPlayer();
     static PassRefPtrWillBeRawPtr<AnimationPlayer> create(AnimationTimeline&, AnimationSource*);
 
     // Returns whether the player is finished.
     bool update(TimingUpdateReason);
 
     // timeToEffectChange returns:
@@ skipping 17 matching lines @@
     void finish(ExceptionState&);
     bool finished() { return limited(currentTimeInternal()); }
     // FIXME: Resolve whether finished() should just return the flag, and
     // remove this method.
     bool finishedInternal() const { return m_finished; }
 
     DEFINE_ATTRIBUTE_EVENT_LISTENER(finish);
 
     virtual const AtomicString& interfaceName() const OVERRIDE;
     virtual ExecutionContext* executionContext() const OVERRIDE;
+    virtual bool hasPendingActivity() const OVERRIDE;

[haraken, 2014/05/23 07:15:05]

Don't we need to override ActiveDOMObject::stop()/resume()? I guess you need to
clear the event when the ActiveDOMObject is stopped, for example.

[dstockwell, 2014/05/26 00:47:50]

Yes, I suppose stop() is necessary. suspend/resume are handled by
ScriptedAnimationController.

[haraken, 2014/05/26 01:16:09]

Makes sense.

- I'm just curious, but why are suspend/resume handled by
ScriptedAnimationController instead of using the infrastructure of
ActiveDOMObject?

- ScriptedAnimationController's suspend/resume does nothing about
AnimationPlayer. This is expected, right? (For example, you don't need to clear
m_pendingFinishedEvent when the Document is suspended.)

[dstockwell, 2014/05/26 01:32:40]

There's nothing that we need to suspend here. Animation is not involved with
ActiveDOMObject, it's just the event dispatch that we need to be concerned with,
and it's the ScriptedAnimationController that does the event dispatch.
Right, we don't need to clear it on suspend. We're just using
m_pendingFinishedEvent to track the current event, it would still be dispatched
after suspend/resume for example.

+    virtual bool dispatchEvent(PassRefPtrWillBeRawPtr<Event>) OVERRIDE;
 
     double playbackRate() const { return m_playbackRate; }
     void setPlaybackRate(double);
     const AnimationTimeline* timeline() const { return m_timeline; }
     AnimationTimeline* timeline() { return m_timeline; }
 
 #if !ENABLE(OILPAN)
     void timelineDestroyed() { m_timeline = nullptr; }
 #endif
 
@@ skipping 79 matching lines @@
     // Reflects all pausing, including via pauseForTesting().
     bool m_paused;
     bool m_held;
     bool m_isPausedForTesting;
 
     // This indicates timing information relevant to the player has changed by
     // means other than the ordinary progression of time
     bool m_outdated;
 
     bool m_finished;
+    // Holds a 'finished' event queued for asynchronous dispatch via the
+    // ScriptedAnimationController. This object remains active until the
+    // event is actually dispatched.
+    RefPtrWillBeMember<Event> m_pendingFinishedEvent;
 };
 
 } // namespace
 
 #endif