[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 isAngleValue(const CSSValue& value)
+{
+    if (!value.isPrimitiveValue())
+        return false;
+    return toCSSPrimitiveValue(value).isAngle();
+}
+
+bool isNumberValue(const CSSValue& value)
+{
+    if (!value.isPrimitiveValue())
+        return false;
+    return toCSSPrimitiveValue(value).isNumber();
+}
+
+} // namespace
+
+CSSRotation* CSSRotation::fromCSSValue(const CSSFunctionValue& value)
+{
+    if (value.functionType() == CSSValueRotate) {

[Timothy Loh, 2016/06/15 08:36:26]

This also needs to support rotatex/y/z, and test for these cases (you'd need to
set via old cssom since the typed om code below only outputs rotate/rotate3d).

[meade_UTC10, 2016/06/23 21:51:44]

Done.

+        if (value.length() != 1)

[Timothy Loh, 2016/06/15 08:36:26]

All of these checks should just be assertions because the parser never outputs
any other structures, e.g. 

DCHECK_EQ(value.length(), 1);
return ...;

computeDegrees will assert that we have a <angle> type.

[meade_UTC10, 2016/06/23 21:51:44]

Done.

+            return nullptr;
+        if (!isAngleValue(value.item(0)))
+            return nullptr;
+        return CSSRotation::create(toCSSPrimitiveValue(value.item(0)).computeDegrees());
+    }
+
+    if (value.functionType() == CSSValueRotate3d) {
+        if (value.length() != 4)
+            return nullptr;
+        if (!isNumberValue(value.item(0))
+            || !isNumberValue(value.item(1))
+            || !isNumberValue(value.item(2))
+            || !isAngleValue(value.item(3)))
+            return nullptr;
+        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);
+    }
+
+    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