Support keywords in LengthStyleInterpolation

Source/core/animation/LengthStyleInterpolation.cpp

Index: Source/core/animation/LengthStyleInterpolation.cpp
diff --git a/Source/core/animation/LengthStyleInterpolation.cpp b/Source/core/animation/LengthStyleInterpolation.cpp
index effaf43168f31f34598aba819483a4db8969647f..7379c1f049dc84a1dd6d77c195ffa276c3c5d245 100644
--- a/Source/core/animation/LengthStyleInterpolation.cpp
+++ b/Source/core/animation/LengthStyleInterpolation.cpp
@@ -10,13 +10,24 @@
 
 namespace blink {
 
-bool LengthStyleInterpolation::canCreateFrom(const CSSValue& value)
+bool LengthStyleInterpolation::canCreateFrom(const CSSValue& value, CSSPropertyID id)

[alancutter (OOO until 2018), 2015/03/05 23:38:49]

Nit: I think we should name our CSSPropertyID variables "property" instead of
"id".

[Eric Willigers, 2015/03/07 23:58:21]

Done.

 {
     if (value.isPrimitiveValue()) {
         const CSSPrimitiveValue& primitiveValue = blink::toCSSPrimitiveValue(value);
         if (primitiveValue.cssCalcValue())
             return true;
 
+        if (primitiveValue.isValueID()) {

[alancutter (OOO until 2018), 2015/03/05 23:38:49]

You should only enter this branch if the property has been specified.

[Eric Willigers, 2015/03/07 23:58:21]

Acknowledged.

+            CSSValueID valueID = primitiveValue.getValueID();
+
+            // border-*-width column-rule-width, outline-width support thin, medium, thick.
+            return valueID == CSSValueThin
+                || valueID == CSSValueMedium
+                || valueID == CSSValueThick
+                || (id == CSSPropertyLetterSpacing && valueID == CSSValueNormal)
+                || (id == CSSPropertyPerspective && valueID == CSSValueNone);

[alancutter (OOO until 2018), 2015/03/05 23:38:50]

The properties should be called out in code, a comment is hard to test.
I'd pull this out into a single switch as bool pixelsForKeyword(CSSPropertyID,
CSSValueID, double& result).

[Eric Willigers, 2015/03/07 23:58:22]

Done.

+        }
+
         CSSPrimitiveValue::LengthUnitType type;
         // Only returns true if the type is a primitive length unit.
         return CSSPrimitiveValue::unitTypeToLengthUnitType(primitiveValue.primitiveType(), type);
@@ -24,12 +35,9 @@ bool LengthStyleInterpolation::canCreateFrom(const CSSValue& value)
     return value.isCalcValue();
 }
 
-PassOwnPtrWillBeRawPtr<InterpolableValue> LengthStyleInterpolation::toInterpolableValue(const CSSValue& value)
+PassOwnPtrWillBeRawPtr<InterpolableValue> LengthStyleInterpolation::toInterpolableValue(const CSSValue& value, CSSPropertyID id)
 {
-    ASSERT(canCreateFrom(value));
-    OwnPtrWillBeRawPtr<InterpolableList> listOfValuesAndTypes = InterpolableList::create(2);
-    OwnPtrWillBeRawPtr<InterpolableList> listOfValues = InterpolableList::create(CSSPrimitiveValue::LengthUnitTypeCount);
-    OwnPtrWillBeRawPtr<InterpolableList> listOfTypes = InterpolableList::create(CSSPrimitiveValue::LengthUnitTypeCount);

[alancutter (OOO until 2018), 2015/03/05 23:38:50]

Do these need to move? I think the original placement made it more obvious what
the shape of the IV is.

[Eric Willigers, 2015/03/07 23:58:22]

Acknowledged.

+    ASSERT(canCreateFrom(value, id));
 
     const CSSPrimitiveValue& primitive = toCSSPrimitiveValue(value);
 
@@ -39,13 +47,31 @@ PassOwnPtrWillBeRawPtr<InterpolableValue> LengthStyleInterpolation::toInterpolab
         arrayOfValues.append(0);
 
     arrayOfTypes.ensureSize(CSSPrimitiveValue::LengthUnitTypeCount);
-    primitive.accumulateLengthArray(arrayOfValues, arrayOfTypes);
+    if (primitive.isValueID()) {
+        CSSValueID valueID = primitive.getValueID();
+
+        arrayOfTypes.set(0);
+        if (valueID == CSSValueThin)
+            arrayOfValues[0] = 1;

[alancutter (OOO until 2018), 2015/03/05 23:38:50]

Don't index by 0, use CSSPrimitiveValue::UnitTypePixels.

[Eric Willigers, 2015/03/07 23:58:21]

Done.

+        if (valueID == CSSValueMedium)
+            arrayOfValues[0] = 3;
+        if (valueID == CSSValueThick)
+            arrayOfValues[0] = 5;
+
+        // letter-spacing 'normal' corresponds to 0
+        // perspective 'none' corresponds to 0
+    } else {
+        primitive.accumulateLengthArray(arrayOfValues, arrayOfTypes);
+    }
 
+    OwnPtrWillBeRawPtr<InterpolableList> listOfValues = InterpolableList::create(CSSPrimitiveValue::LengthUnitTypeCount);
+    OwnPtrWillBeRawPtr<InterpolableList> listOfTypes = InterpolableList::create(CSSPrimitiveValue::LengthUnitTypeCount);
     for (size_t i = 0; i < CSSPrimitiveValue::LengthUnitTypeCount; i++) {
         listOfValues->set(i, InterpolableNumber::create(arrayOfValues.at(i)));
         listOfTypes->set(i, InterpolableNumber::create(arrayOfTypes.get(i)));
     }
 
+    OwnPtrWillBeRawPtr<InterpolableList> listOfValuesAndTypes = InterpolableList::create(2);
     listOfValuesAndTypes->set(0, listOfValues.release());
     listOfValuesAndTypes->set(1, listOfTypes.release());