[Typed OM] Implement CSSValue->CSSRotation conversion

third_party/WebKit/Source/core/css/cssom/CSSRotation.cpp

 // Copyright 2016 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/css/cssom/CSSRotation.h"
 
+#include "core/css/CSSFunctionValue.h"
 #include "core/css/CSSPrimitiveValue.h"
 
 namespace blink {
 
+namespace {
+
+bool isNumberValue(const CSSValue& value)
+{
+    return value.isPrimitiveValue() && toCSSPrimitiveValue(value).isNumber();
+}
+
+CSSRotation* fromCSSRotate(const CSSFunctionValue& value)
+{
+    DCHECK_EQ(value.length(), 1UL);
+    return CSSRotation::create(toCSSPrimitiveValue(value.item(0)).computeDegrees());
+}
+
+CSSRotation* fromCSSRotate3d(const CSSFunctionValue& value)
+{
+    DCHECK_EQ(value.length(), 4UL);
+    DCHECK(isNumberValue(value.item(0)));
+    DCHECK(isNumberValue(value.item(1)));
+    DCHECK(isNumberValue(value.item(2)));
+    // computeDegrees asserts that value.item(3) is an angle.
+
+    double x = toCSSPrimitiveValue(value.item(0)).getDoubleValue();
+    double y = toCSSPrimitiveValue(value.item(1)).getDoubleValue();
+    double z = toCSSPrimitiveValue(value.item(2)).getDoubleValue();
+    double angle = toCSSPrimitiveValue(value.item(3)).computeDegrees();
+    return CSSRotation::create(x, y, z, angle);
+}
+
+CSSRotation* fromCSSRotateXYZ(const CSSFunctionValue& value)
+{
+    DCHECK_EQ(value.length(), 1UL);
+    double angle = toCSSPrimitiveValue(value.item(0)).computeDegrees();
+
+    switch (value.functionType()) {
+    case CSSValueRotateX:
+        return CSSRotation::create(1, 0, 0, angle);
+    case CSSValueRotateY:
+        return CSSRotation::create(0, 1, 0, angle);
+    case CSSValueRotateZ:
+        return CSSRotation::create(0, 0, 1, angle);
+    default:
+        NOTREACHED();
+        return nullptr;
+    }
+}
+
+} // namespace
+
+CSSRotation* CSSRotation::fromCSSValue(const CSSFunctionValue& value)
+{
+    switch (value.functionType()) {
+    case CSSValueRotate:
+        return fromCSSRotate(value);
+    case CSSValueRotate3d:
+        return fromCSSRotate3d(value);
+    case CSSValueRotateX:
+    case CSSValueRotateY:
+    case CSSValueRotateZ:
+        return fromCSSRotateXYZ(value);
+    default:
+        NOTREACHED();
+        return nullptr;
+    }
+}
+
 CSSFunctionValue* CSSRotation::toCSSValue() const
 {
     CSSFunctionValue* result = CSSFunctionValue::create(m_is2D ? CSSValueRotate : CSSValueRotate3d);
     if (!m_is2D) {
         result->append(*CSSPrimitiveValue::create(m_x, CSSPrimitiveValue::UnitType::Number));
         result->append(*CSSPrimitiveValue::create(m_y, CSSPrimitiveValue::UnitType::Number));
         result->append(*CSSPrimitiveValue::create(m_z, CSSPrimitiveValue::UnitType::Number));
     }
     result->append(*CSSPrimitiveValue::create(m_angle, CSSPrimitiveValue::UnitType::Degrees));
     return result;
 }
 
 } // namespace blink