Web Animations: Support animation of SVG number attributes

Source/core/animation/NumberSVGInterpolation.h

+// Copyright 2015 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.
+
+#ifndef NumberSVGInterpolation_h
+#define NumberSVGInterpolation_h
+
+#include "core/animation/SVGInterpolation.h"
+#include "core/svg/SVGNumber.h"
+#include "core/svg/SVGNumberList.h"
+
+namespace blink {
+
+enum SVGNumberNegativeValuesMode {
+    AllowNegativeNumbers,
+    ForbidNegativeNumbers
+};
+
+class NumberSVGInterpolation : public SVGInterpolation {
+public:
+    typedef SVGNumberList ListType;
+    typedef void NonInterpolableType;
+
+    static PassRefPtrWillBeRawPtr<NumberSVGInterpolation> create(SVGPropertyBase* start, SVGPropertyBase* end, PassRefPtrWillBeRawPtr<SVGAnimatedPropertyBase> attribute);
+
+    static bool canCreateFrom(SVGPropertyBase* value)
+    {
+        return true;
+    }
+
+    virtual PassRefPtrWillBeRawPtr<SVGPropertyBase> interpolatedValue(SVGElement&) const override final
+    {
+        return fromInterpolableValue(*m_cachedValue, m_negativeValuesMode);
+    }
+
+    DEFINE_INLINE_VIRTUAL_TRACE()
+    {
+        SVGInterpolation::trace(visitor);
+    }
+
+    static PassOwnPtrWillBeRawPtr<InterpolableNumber> toInterpolableValue(SVGPropertyBase* value)
+    {
+        return InterpolableNumber::create(toSVGNumber(value)->value());
+    }
+
+    static PassRefPtrWillBeRawPtr<SVGNumber> fromInterpolableValue(const InterpolableValue&, SVGNumberNegativeValuesMode = AllowNegativeNumbers);
+
+private:
+    NumberSVGInterpolation(PassOwnPtrWillBeRawPtr<InterpolableValue> start, PassOwnPtrWillBeRawPtr<InterpolableValue> end, PassRefPtrWillBeRawPtr<SVGAnimatedPropertyBase> attribute, SVGNumberNegativeValuesMode negativeValuesMode)
+        : SVGInterpolation(start, end, attribute)
+        , m_negativeValuesMode(negativeValuesMode)
+    {
+    }
+
+    const SVGNumberNegativeValuesMode m_negativeValuesMode;
+};
+
+}
+
+#endif // NumberSVGInterpolation_h