[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..52170d6ed8d89463996cd068a270c36e497bb73f 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 hasMismatchedKeyframeProperty(Vector<RefPtr<MutableStylePropertySet> > propertySetVector)

[dstockwell, 2014/03/11 03:28:14]

Instead of doing the checks here, we might be able to add a method to
KeyframeEffectModel that just calls ensureKeyframeGroups and then checks that
none require composite: add.

eg. bool KeyframeEffectModel::isReplaceOnly()

+{
+    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;
+}
+
+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.
@@ -58,6 +74,9 @@ PassRefPtrWillBeRawPtr<AnimationEffect> EffectInput::convert(Element* element, c
     // FIXME: Move this code into KeyframeEffectModel, it will be used by the IDL constructor for that class.
     KeyframeEffectModel::KeyframeVector keyframes;
     Vector<RefPtr<MutableStylePropertySet> > propertySetVector;
+    bool hasOffsets = false;
+    bool hasOffsetZero = false;
+    bool hasOffsetOne = false;
 
     for (size_t i = 0; i < keyframeDictionaryVector.size(); ++i) {
         RefPtr<MutableStylePropertySet> propertySet = MutableStylePropertySet::create();
@@ -67,8 +86,14 @@ PassRefPtrWillBeRawPtr<AnimationEffect> EffectInput::convert(Element* element, c
         keyframes.append(keyframe);
 
         double offset;
-        if (keyframeDictionaryVector[i].get("offset", offset))
+        if (keyframeDictionaryVector[i].get("offset", offset)) {
             keyframe->setOffset(offset);
+            hasOffsets = true;
+            if (!offset)
+                hasOffsetZero = true;
+            if (offset == 1)
+                hasOffsetOne = true;
+        }
 
         String compositeString;
         keyframeDictionaryVector[i].get("composite", compositeString);
@@ -103,6 +128,17 @@ 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 input is added.
+    if (hasMismatchedKeyframeProperty(propertySetVector))
+        exceptionState.throwDOMException(NotSupportedError, "Keyframe effect contains properties that appear in only one keyframe.");
+    // FIXME: Web Animations can't yet handle keyframe sets which specify offsets and don't specify keyframes at offset: 0 and offset: 1.
+    // These checks can be removed once support for such input is added.
+    if (hasOffsets && !hasOffsetZero)
+        exceptionState.throwDOMException(NotSupportedError, "Keyframes specify offsets, but keyframe with offset: 0 is missing.");
+    if (hasOffsets && !hasOffsetOne)
+        exceptionState.throwDOMException(NotSupportedError, "Keyframes specify offsets, but keyframe with offset: 1 is missing.");
+
     // FIXME: Replace this with code that just parses, when that code is available.
     return StyleResolver::createKeyframeEffectModel(*element, propertySetVector, keyframes);
 }