CSS Motion Path: Support parsing of ray(<angle>) paths

third_party/WebKit/Source/core/css/properties/CSSPropertyOffsetPathUtils.cpp

Index: third_party/WebKit/Source/core/css/properties/CSSPropertyOffsetPathUtils.cpp
diff --git a/third_party/WebKit/Source/core/css/properties/CSSPropertyOffsetPathUtils.cpp b/third_party/WebKit/Source/core/css/properties/CSSPropertyOffsetPathUtils.cpp
index e129977ff7f7f2f7e03a435338a9af2cc6b13968..369ece4eceace380b6c2b53f0725f0578a569a93 100644
--- a/third_party/WebKit/Source/core/css/properties/CSSPropertyOffsetPathUtils.cpp
+++ b/third_party/WebKit/Source/core/css/properties/CSSPropertyOffsetPathUtils.cpp
@@ -4,7 +4,11 @@
 
 #include "core/css/properties/CSSPropertyOffsetPathUtils.h"
 
+#include "core/css/CSSIdentifierValue.h"
 #include "core/css/CSSPathValue.h"
+#include "core/css/CSSPrimitiveValue.h"
+#include "core/css/CSSRayValue.h"
+#include "core/css/CSSValueList.h"
 #include "core/css/parser/CSSParserContext.h"
 #include "core/css/parser/CSSPropertyParserHelpers.h"
 #include "core/svg/SVGPathByteStream.h"
@@ -41,12 +45,51 @@ CSSValue* ConsumePath(CSSParserTokenRange& range) {
   return CSSPathValue::Create(std::move(byte_stream));
 }
 
+CSSValue* ConsumeRay(CSSParserTokenRange& range) {
+  DCHECK(range.Peek().FunctionId() == CSSValueRay);
+  CSSParserTokenRange function_range = range;
+  CSSParserTokenRange function_args =
+      CSSPropertyParserHelpers::ConsumeFunction(function_range);
+  CSSValueList* arguments = CSSValueList::CreateSpaceSeparated();

[fs, 2017/05/15 09:18:14]

Rather than constructing a temporary list, could the three arguments be passed
to CSSRayValue::Create(...) instead? (Three is still not "too many" I think.)

[Eric Willigers, 2017/05/15 10:52:23]

Done.

+
+  CSSPrimitiveValue* angle = nullptr;
+  CSSIdentifierValue* size = nullptr;
+  CSSIdentifierValue* contain = nullptr;
+  while (!function_args.AtEnd()) {
+    if (!angle &&
+        (angle = CSSPropertyParserHelpers::ConsumeAngle(function_args)))
+      arguments->Append(*angle);
+    else if (!size && (size = CSSPropertyParserHelpers::ConsumeIdent<
+                           CSSValueClosestSide, CSSValueClosestCorner,
+                           CSSValueFarthestSide, CSSValueFarthestCorner,
+                           CSSValueSides, CSSValueCover>(function_args)))

[fs, 2017/05/15 09:18:14]

I didn't see 'cover' in <size>? C'n'P?

[Eric Willigers, 2017/05/15 10:52:23]

Oops. Fixed.

+      arguments->Append(*size);
+    else if (RuntimeEnabledFeatures::cssOffsetPathRayContainEnabled() &&
+             !contain &&
+             (contain = CSSPropertyParserHelpers::ConsumeIdent<CSSValueContain>(
+                  function_args)))
+      arguments->Append(*contain);
+    else
+      return nullptr;
+  }
+  if (!angle || !size)
+    return nullptr;
+  DCHECK_LE(arguments->length(), 3U);
+  range = function_range;
+  return CSSRayValue::Create(arguments);
+}
+
 }  // namespace
 
 CSSValue* CSSPropertyOffsetPathUtils::ConsumeOffsetPath(
     CSSParserTokenRange& range,
     const CSSParserContext* context) {
-  CSSValue* value = ConsumePathOrNone(range);
+  CSSValue* value = nullptr;
+  if (RuntimeEnabledFeatures::cssOffsetPathRayEnabled() &&
+      range.Peek().FunctionId() == CSSValueRay)
+    value = ConsumeRay(range);
+  else
+    value = ConsumePathOrNone(range);
 
   // Count when we receive a valid path other than 'none'.
   if (value && !value->IsIdentifierValue())