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

third_party/WebKit/Source/core/style/StyleRay.cpp

Index: third_party/WebKit/Source/core/style/StyleRay.cpp
diff --git a/third_party/WebKit/Source/core/style/StyleRay.cpp b/third_party/WebKit/Source/core/style/StyleRay.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..9be76673fbe5655d77a52db169092138948bc7db
--- /dev/null
+++ b/third_party/WebKit/Source/core/style/StyleRay.cpp
@@ -0,0 +1,92 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/style/StyleRay.h"
+
+#include "core/css/CSSIdentifierValue.h"
+#include "core/css/CSSPrimitiveValue.h"
+#include "core/css/CSSRayValue.h"
+#include "core/css/CSSValueList.h"
+
+namespace blink {
+
+namespace {
+
+StyleRay::RaySize KeywordToRaySize(CSSValueID id) {
+  switch (id) {
+    case CSSValueClosestSide:
+      return StyleRay::RaySize::kClosestSide;
+    case CSSValueClosestCorner:
+      return StyleRay::RaySize::kClosestCorner;
+    case CSSValueFarthestSide:
+      return StyleRay::RaySize::kFarthestSide;
+    case CSSValueFarthestCorner:
+      return StyleRay::RaySize::kFarthestCorner;
+    case CSSValueSides:
+      return StyleRay::RaySize::kSides;
+    default:
+      NOTREACHED();
+      return StyleRay::RaySize::kClosestSide;
+  }
+}
+
+CSSValueID RaySizeToKeyword(StyleRay::RaySize size) {
+  switch (size) {
+    case StyleRay::RaySize::kClosestSide:
+      return CSSValueClosestSide;
+    case StyleRay::RaySize::kClosestCorner:
+      return CSSValueClosestCorner;
+    case StyleRay::RaySize::kFarthestSide:
+      return CSSValueFarthestSide;
+    case StyleRay::RaySize::kFarthestCorner:
+      return CSSValueFarthestCorner;
+    case StyleRay::RaySize::kSides:
+      return CSSValueSides;
+  }
+  NOTREACHED();
+  return CSSValueInvalid;
+}
+
+}  // anonymous namespace
+
+PassRefPtr<StyleRay> StyleRay::Create(const CSSRayValue& value) {

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

Could we have this just take the three values, and let the style converter do
the work?

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

Done.

+  return AdoptRef(new StyleRay(value));
+}
+
+StyleRay::StyleRay(const CSSRayValue& value) {
+  angle_ = value.Angle()->ComputeDegrees();
+  size_ = KeywordToRaySize(value.Size()->GetValueID());
+  contain_ = !!value.Contain();
+}
+
+CSSRayValue* StyleRay::ComputedCSSValue() const {

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

I think this might as well go in ValueForBasicShape (the major reason StylePath
has this is to allow sharing of the path-data - something that isn't needed
here.)

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

Done.

+  CSSValueList* arguments = CSSValueList::CreateSpaceSeparated();
+  arguments->Append(*CSSPrimitiveValue::Create(
+      Angle(), CSSPrimitiveValue::UnitType::kDegrees));
+  arguments->Append(*CSSIdentifierValue::Create(RaySizeToKeyword(Size())));
+  if (Contain())
+    arguments->Append(*CSSIdentifierValue::Create(CSSValueContain));
+  return CSSRayValue::Create(arguments);
+}
+
+bool StyleRay::operator==(const BasicShape& o) const {
+  if (!IsSameType(o))
+    return false;
+  const StyleRay& other = ToStyleRay(o);
+  return angle_ == other.angle_;

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

Should also check size_ and contain_?

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

Done.

+}
+
+void StyleRay::GetPath(Path&, const FloatRect&) {
+  // ComputedStyle::ApplyMotionPathTransform cannot call GetPath
+  // for rays as they may have infinite length.

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

This is kind of an indication that ray(...) isn't a great match for
<basic-shape> in general. Doesn't prevent treating it as such internally of
course.

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

Acknowledged.

+  NOTREACHED();
+}
+
+PassRefPtr<BasicShape> StyleRay::Blend(const BasicShape*, double) const {
+  // FIXME(ericwilligers): Implement animation for offset-path.

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

TODO

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

Done.

+  NOTREACHED();
+  return nullptr;
+}
+
+}  // namespace blink