[WIP] Web Animations API: Constructing an Animation from partial keyframes throws a JS exception

Source/core/animation/EffectInput.cpp

Index: Source/core/animation/EffectInput.cpp
diff --git a/Source/core/animation/EffectInput.cpp b/Source/core/animation/EffectInput.cpp
index 2f87c28e668d7f864803948083a75f07a80e13f9..146d1ee5d6a709fa5305c2c8dd637cb5ffecd151 100644
--- a/Source/core/animation/EffectInput.cpp
+++ b/Source/core/animation/EffectInput.cpp
@@ -48,7 +48,23 @@ static bool checkDocumentAndRenderer(Element* element)
     return element->renderer();
 }
 
-PassRefPtrWillBeRawPtr<AnimationEffect> EffectInput::convert(Element* element, const Vector<Dictionary>& keyframeDictionaryVector, bool unsafe)
+static bool hasPartialKeyframe(Vector<RefPtr<MutableStylePropertySet> > propertySetVector)
+{
+    HashCountedSet<CSSPropertyID> counter;
+    for (size_t i = 0; i < propertySetVector.size(); ++i) {
+        for (size_t j = 0; j < propertySetVector[i]->propertyCount(); ++j) {
+            CSSPropertyID property = propertySetVector[i]->propertyAt(j).id();
+            counter.add(property);
+        }
+    }
+    for (HashCountedSet<CSSPropertyID>::iterator iterator = counter.begin(); iterator != counter.end(); ++iterator) {
+        if (iterator->value == 1)
+            return true;
+    }
+    return false;
+}

[shans, 2014/03/10 23:28:40]

This won't pick up cases like:
element.animate(
  [{opacity: '0', offset: 0},
   {opacity: '1', offset: 0.5}], 1);

[rjwright, 2014/03/10 23:35:37]

It is meant to?

[rjwright, 2014/03/11 01:48:42]

Done.

+
+PassRefPtrWillBeRawPtr<AnimationEffect> EffectInput::convert(Element* element, const Vector<Dictionary>& keyframeDictionaryVector,  ExceptionState& exceptionState, bool unsafe)
 {
     // FIXME: This test will not be neccessary once resolution of keyframe values occurs at
     // animation application time.
@@ -103,6 +119,11 @@ PassRefPtrWillBeRawPtr<AnimationEffect> EffectInput::convert(Element* element, c
         }
     }
 
+    // FIXME: Web Animations can't yet handle keyframe sets where a property appears in only one keyframe (called "partial keyframes").
+    // This check can be removed once support for such inputs is added.
+    if (hasPartialKeyframe(propertySetVector))
+        exceptionState.throwDOMException(NotSupportedError, "Keyframe effect contains properties that appear in only one keyframe.");
+
     // FIXME: Replace this with code that just parses, when that code is available.
     return StyleResolver::createKeyframeEffectModel(*element, propertySetVector, keyframes);
 }