[CSS Shapes] Implement BasicShapeInset blending

Source/core/rendering/style/BasicShapes.cpp

 /*
  * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above
  *    copyright notice, this list of conditions and the following
  *    disclaimer.
@@ skipping 223 matching lines @@
             std::max<float>(boundingBox.width() - left - floatValueForLength(m_right, boundingBox.width()), 0),
             std::max<float>(boundingBox.height() - top - floatValueForLength(m_bottom, boundingBox.height()), 0)
         ),
         floatSizeForLengthSize(m_topLeftRadius, boundingBox),
         floatSizeForLengthSize(m_topRightRadius, boundingBox),
         floatSizeForLengthSize(m_bottomLeftRadius, boundingBox),
         floatSizeForLengthSize(m_bottomRightRadius, boundingBox)
     );
 }
 
-PassRefPtr<BasicShape> BasicShapeInset::blend(const BasicShape* other, double) const
+static inline LengthSize blendLengthSize(const LengthSize& to, const LengthSize& from, double progress)
 {
-    ASSERT(type() == other->type());
-    // FIXME: Implement blend for BasicShapeInset (see: crbug.com/448295).
-    return nullptr;
+    return LengthSize(to.width().blend(from.width(), progress, ValueRangeAll),
+        to.height().blend(from.height(), progress, ValueRangeAll));
+}
+
+PassRefPtr<BasicShape> BasicShapeInset::blend(const BasicShape* other, double progress) const
+{
+    ASSERT(other && isSameType(*other));
+
+    const BasicShapeInset& otherInset = toBasicShapeInset(*other);
+    RefPtr<BasicShapeInset> result = BasicShapeInset::create();
+    result->setTop(m_top.blend(otherInset.top(), progress, ValueRangeAll));
+    result->setRight(m_right.blend(otherInset.right(), progress, ValueRangeAll));
+    result->setBottom(m_bottom.blend(otherInset.bottom(), progress, ValueRangeAll));
+    result->setLeft(m_left.blend(otherInset.left(), progress, ValueRangeAll));
+
+    result->setTopLeftRadius(blendLengthSize(m_topLeftRadius, otherInset.topLeftRadius(), progress));
+    result->setTopRightRadius(blendLengthSize(m_topRightRadius, otherInset.topRightRadius(), progress));
+    result->setBottomRightRadius(blendLengthSize(m_bottomRightRadius, otherInset.bottomRightRadius(), progress));
+    result->setBottomLeftRadius(blendLengthSize(m_bottomLeftRadius, otherInset.bottomLeftRadius(), progress));
+
+    return result.release();
 }
 
 bool BasicShapeInset::operator==(const BasicShape& o) const
 {
     if (!isSameType(o))
         return false;
     const BasicShapeInset& other = toBasicShapeInset(o);
     return m_right == other.m_right
         && m_top == other.m_top
         && m_bottom == other.m_bottom
         && m_left == other.m_left
         && m_topLeftRadius == other.m_topLeftRadius
         && m_topRightRadius == other.m_topRightRadius
         && m_bottomRightRadius == other.m_bottomRightRadius
         && m_bottomLeftRadius == other.m_bottomLeftRadius;
 }
 
 }