Devtools Animations: Update transition timing on timeline interaction

Source/core/inspector/InspectorAnimationAgent.cpp

Index: Source/core/inspector/InspectorAnimationAgent.cpp
diff --git a/Source/core/inspector/InspectorAnimationAgent.cpp b/Source/core/inspector/InspectorAnimationAgent.cpp
index 2e0da3629ea6ca071ffd763925a88fd6675fd592..35bb33b61fde80fae200fd41eb16281014201737 100644
--- a/Source/core/inspector/InspectorAnimationAgent.cpp
+++ b/Source/core/inspector/InspectorAnimationAgent.cpp
@@ -246,17 +246,37 @@ void InspectorAnimationAgent::setCurrentTime(ErrorString*, double currentTime)
     m_pageAgent->inspectedFrame()->document()->timeline().setCurrentTime(currentTime);
 }
 
-void InspectorAnimationAgent::setTiming(ErrorString* errorString, const String& playerId, double duration, double delay)
+void InspectorAnimationAgent::setTiming(ErrorString* errorString, const String& playerId, double duration, double delay, bool isTransition)
 {
     AnimationPlayer* player = assertAnimationPlayer(errorString, playerId);
     if (!player)
         return;
 
-    RefPtrWillBeRawPtr<AnimationNodeTiming> timing = player->source()->timing();
-    UnrestrictedDoubleOrString unrestrictedDuration;
-    unrestrictedDuration.setUnrestrictedDouble(duration);
-    timing->setDuration(unrestrictedDuration);
-    timing->setDelay(delay);
+    if (isTransition) {
+        Animation* animation = toAnimation(player->source());
+        KeyframeEffectModelBase* effect = toKeyframeEffectModelBase(animation->effect());

[dgozman, 2015/03/30 10:38:58]

Can we assert before calling |toKeyframeEffectModelBase| that effect is indeed
keyframe effect?

[samli, 2015/03/30 23:14:17]

Done.

+        ASSERT(effect->isAnimatableValueKeyframeEffectModel());
+        const AnimatableValueKeyframeEffectModel* oldEffect = toAnimatableValueKeyframeEffectModel(effect);
+        const KeyframeVector& frames = oldEffect->getFrames();
+        ASSERT(frames.size() == 3);

[dgozman, 2015/03/30 10:38:58]

Is there any documentation/explanation about the design of transition (being 3
keyframes)? Let's point there in the comment, otherwise this code is too
cryptic.

[samli, 2015/03/30 23:14:17]

Done. There isn't really much to it, except for the fact that delay is
represented by a keyframe instead of "delay" timing parameter in the web
animations API. We have an internal doc discussing why we needed to do this in
the first place, but that isn't necessary for the comprehension of this code.

+        KeyframeVector newFrames;
+        for (int i = 0; i < 3; i++)
+            newFrames.append(toAnimatableValueKeyframe(frames[i]->clone().get()));
+        // Update delay, represented by the distance between the first two keyframes

[dgozman, 2015/03/30 10:38:58]

nit: full stop please.

[samli, 2015/03/30 23:14:17]

Done.

+        newFrames[1]->setOffset(delay / (delay + duration));
+        effect->setFrames(newFrames);
+
+        RefPtrWillBeRawPtr<AnimationNodeTiming> timing = player->source()->timing();
+        UnrestrictedDoubleOrString unrestrictedDuration;
+        unrestrictedDuration.setUnrestrictedDouble(duration + delay);
+        timing->setDuration(unrestrictedDuration);
+    } else {
+        RefPtrWillBeRawPtr<AnimationNodeTiming> timing = player->source()->timing();
+        UnrestrictedDoubleOrString unrestrictedDuration;
+        unrestrictedDuration.setUnrestrictedDouble(duration);
+        timing->setDuration(unrestrictedDuration);
+        timing->setDelay(delay);
+    }
 }
 
 void InspectorAnimationAgent::didCreateAnimationPlayer(AnimationPlayer* player)