Parsing CSS properties for scroll snap points

Source/core/css/resolver/StyleBuilderConverter.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
  * copyright notice, this list of conditions and the following disclaimer
  * in the documentation and/or other materials provided with the
  * distribution.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 41 matching lines @@
     if (primitiveValue->getValueID() == CSSValueMaxContent)
         return Length(MaxContent);
 
     // Fractional unit.
     if (primitiveValue->isFlex())
         return GridLength(primitiveValue->getDoubleValue());
 
     return StyleBuilderConverter::convertLengthOrAuto(state, primitiveValue);
 }
 
+template <CSSValueID cssValueFor0, CSSValueID cssValueFor100>
+static Length convertPositionLength(StyleResolverState& state, CSSPrimitiveValue* primitiveValue)
+{
+    if (Pair* pair = primitiveValue->getPairValue()) {
+        Length length = StyleBuilderConverter::convertLength(state, pair->second());
+        if (pair->first()->getValueID() == cssValueFor0)
+            return length;
+        ASSERT(pair->first()->getValueID() == cssValueFor100);
+        return length.subtractFromOneHundredPercent();
+    }
+
+    return StyleBuilderConverter::convertLength(state, primitiveValue);
+}
+
+static LengthSize convertSnapCoordinatePair(StyleResolverState& state, CSSValue* value)

[Timothy Loh, 2015/05/28 07:09:27]

I don't think anyone on Blink feels strongly about having static functions in
anonymous namespaces, I'd just have this next to the other snap-points
functions. Although if this is identical to convertObjectPosition, maybe we
should just rename that one to convertPosition and call it?

[majidvp, 2015/06/01 20:06:37]

Used convertPosition for both.

+{
+    CSSPrimitiveValue* primitiveValue = toCSSPrimitiveValue(value);
+    Pair* pair = primitiveValue->getPairValue();
+    return LengthSize(
+        convertPositionLength<CSSValueLeft, CSSValueRight>(state, pair->first()),
+        convertPositionLength<CSSValueTop, CSSValueBottom>(state, pair->second())
+    );
+}
+
+
 } // namespace
 
 PassRefPtr<StyleReflection> StyleBuilderConverter::convertBoxReflect(StyleResolverState& state, CSSValue* value)
 {
     if (value->isPrimitiveValue()) {
         ASSERT(toCSSPrimitiveValue(value)->getValueID() == CSSValueNone);
         return ComputedStyle::initialBoxReflect();
     }
 
     CSSReflectValue* reflectValue = toCSSReflectValue(value);
@@ skipping 556 matching lines @@
 
 float StyleBuilderConverter::convertNumberOrPercentage(StyleResolverState& state, CSSValue* value)
 {
     CSSPrimitiveValue* primitiveValue = toCSSPrimitiveValue(value);
     ASSERT(primitiveValue->isNumber() || primitiveValue->isPercentage());
     if (primitiveValue->isNumber())
         return primitiveValue->getFloatValue();
     return primitiveValue->getFloatValue() / 100.0f;
 }
 
-template <CSSValueID cssValueFor0, CSSValueID cssValueFor100>
-static Length convertPositionLength(StyleResolverState& state, CSSPrimitiveValue* primitiveValue)
-{
-    if (Pair* pair = primitiveValue->getPairValue()) {
-        Length length = StyleBuilderConverter::convertLength(state, pair->second());
-        if (pair->first()->getValueID() == cssValueFor0)
-            return length;
-        ASSERT(pair->first()->getValueID() == cssValueFor100);
-        return length.subtractFromOneHundredPercent();
-    }
-
-    return StyleBuilderConverter::convertLength(state, primitiveValue);
-}
-
 LengthPoint StyleBuilderConverter::convertObjectPosition(StyleResolverState& state, CSSValue* value)
 {
     CSSPrimitiveValue* primitiveValue = toCSSPrimitiveValue(value);
     Pair* pair = primitiveValue->getPairValue();
     return LengthPoint(
         convertPositionLength<CSSValueLeft, CSSValueRight>(state, pair->first()),
         convertPositionLength<CSSValueTop, CSSValueBottom>(state, pair->second())
     );
 }
 
@@ skipping 232 matching lines @@
     CSSPrimitiveValue* primitiveValueY = toCSSPrimitiveValue(list->item(1));
     CSSPrimitiveValue* primitiveValueZ = toCSSPrimitiveValue(list->item(2));
 
     return TransformOrigin(
         convertOriginLength<CSSValueLeft, CSSValueRight>(state, primitiveValueX),
         convertOriginLength<CSSValueTop, CSSValueBottom>(state, primitiveValueY),
         StyleBuilderConverter::convertComputedLength<float>(state, primitiveValueZ)
     );
 }
 
+ScrollSnapPoints StyleBuilderConverter::convertSnapPoints(StyleResolverState& state, CSSValue* value)
+{
+    // Handles: none | repeat(<length>)
+    ScrollSnapPoints points;
+    points.hasRepeat = false;
+
+    if (!value->isFunctionValue()) {
+        return points;
+    }

[Timothy Loh, 2015/05/28 07:09:27]

Nit: No need for braces on single-line ifs

[majidvp, 2015/06/01 20:06:37]

Done.

+
+    if (CSSFunctionValue* repeatFunction = toCSSFunctionValue(value)) {

[Timothy Loh, 2015/05/28 07:09:27]

I don't think the condition is ever false here?

[majidvp, 2015/06/01 20:06:37]

Done.

+        ASSERT_WITH_SECURITY_IMPLICATION(repeatFunction->length() == 1);
+        points.repeatOffset = convertLength(state, toCSSPrimitiveValue(repeatFunction->item(0)));
+        points.hasRepeat = true;
+    }
+
+    return points;
+}
+
+Vector<LengthSize> StyleBuilderConverter::convertSnapCoordinates(StyleResolverState& state, CSSValue* value)
+{
+    // Handles: none | <position>#
+    Vector<LengthSize> coordinates;
+
+    if (!value->isValueList())
+        return coordinates;
+
+    CSSValueList* valueList = toCSSValueList(value);
+    coordinates.reserveInitialCapacity(valueList->length());
+    for (auto& snapCoordinate : *valueList) {
+        coordinates.uncheckedAppend(convertSnapCoordinatePair(state, snapCoordinate.get()));
+    }
+
+    return coordinates;
+}
+
+LengthSize StyleBuilderConverter::convertSnapDestination(StyleResolverState& state, CSSValue* value)
+{
+    return convertSnapCoordinatePair(state, value);
+}
+
+
 } // namespace blink