[CSS Typed OM] Implement FromCSSValue and AsMatrix for CSSTranslation

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

Index: third_party/WebKit/Source/core/css/cssom/CSSTranslation.cpp
diff --git a/third_party/WebKit/Source/core/css/cssom/CSSTranslation.cpp b/third_party/WebKit/Source/core/css/cssom/CSSTranslation.cpp
index 7948a0d3c782639172897ca405924f8b57fd416a..1df7c3b63a74d4cd739609264a79471cefa64102 100644
--- a/third_party/WebKit/Source/core/css/cssom/CSSTranslation.cpp
+++ b/third_party/WebKit/Source/core/css/cssom/CSSTranslation.cpp
@@ -8,16 +8,98 @@
 #include "core/css/CSSPrimitiveValue.h"
 #include "core/css/cssom/CSSNumericValue.h"
 #include "core/css/cssom/CSSStyleValue.h"
+#include "core/geometry/DOMMatrix.h"
 
 namespace blink {
 
+namespace {
+
+bool IsLengthOrPercent(const CSSNumericValue* value) {
+  return (value->GetType() == CSSStyleValue::StyleValueType::kLengthType ||
+          value->GetType() == CSSStyleValue::StyleValueType::kPercentType);
+}
+
+bool IsLengthValue(const CSSValue& value) {
+  return value.IsPrimitiveValue() && ToCSSPrimitiveValue(value).IsLength();
+}
+
+CSSTranslation* FromCSSTranslate(const CSSFunctionValue& value) {
+  DCHECK_GT(value.length(), 0UL);
+  DCHECK(IsLengthValue(value.Item(0)));
+
+  CSSNumericValue* x =
+      CSSNumericValue::FromCSSValue(ToCSSPrimitiveValue(value.Item(0)));
+  if (!x)
+    return nullptr;
+
+  if (value.length() == 1) {
+    return CSSTranslation::Create(
+        x, CSSUnitValue::Create(0, CSSPrimitiveValue::UnitType::kPixels));
+  }
+
+  DCHECK_EQ(value.length(), 2UL);
+  DCHECK(IsLengthValue(value.Item(1)));
+
+  CSSNumericValue* y =
+      CSSNumericValue::FromCSSValue(ToCSSPrimitiveValue(value.Item(1)));
+  if (!y)
+    return nullptr;
+  return CSSTranslation::Create(x, y);
+}
+
+CSSTranslation* FromCSSTranslateXYZ(const CSSFunctionValue& value) {
+  DCHECK_EQ(value.length(), 1UL);
+  DCHECK(IsLengthValue(value.Item(0)));
+
+  CSSNumericValue* length =
+      CSSNumericValue::FromCSSValue(ToCSSPrimitiveValue(value.Item(0)));
+  if (!length)
+    return nullptr;
+
+  switch (value.FunctionType()) {
+    case CSSValueTranslateX:
+      return CSSTranslation::Create(
+          length,
+          CSSUnitValue::Create(0, CSSPrimitiveValue::UnitType::kPixels));
+    case CSSValueTranslateY:
+      return CSSTranslation::Create(
+          CSSUnitValue::Create(0, CSSPrimitiveValue::UnitType::kPixels),
+          length);
+    case CSSValueTranslateZ:
+      return CSSTranslation::Create(
+          CSSUnitValue::Create(0, CSSPrimitiveValue::UnitType::kPixels),
+          CSSUnitValue::Create(0, CSSPrimitiveValue::UnitType::kPixels),
+          length);
+    default:
+      NOTREACHED();
+      return nullptr;
+  }
+}
+
+CSSTranslation* FromCSSTranslate3D(const CSSFunctionValue& value) {
+  DCHECK_EQ(value.length(), 3UL);
+  DCHECK(IsLengthValue(value.Item(0)));
+  DCHECK(IsLengthValue(value.Item(1)));
+  DCHECK(IsLengthValue(value.Item(2)));
+
+  CSSNumericValue* x =
+      CSSNumericValue::FromCSSValue(ToCSSPrimitiveValue(value.Item(0)));
+  CSSNumericValue* y =
+      CSSNumericValue::FromCSSValue(ToCSSPrimitiveValue(value.Item(1)));
+  CSSNumericValue* z =
+      CSSNumericValue::FromCSSValue(ToCSSPrimitiveValue(value.Item(2)));
+  if (!x || !y || !z)
+    return nullptr;
+
+  return CSSTranslation::Create(x, y, z);
+}
+
+}  // namespace
+
 CSSTranslation* CSSTranslation::Create(CSSNumericValue* x,
                                        CSSNumericValue* y,
                                        ExceptionState& exception_state) {
-  if ((x->GetType() != CSSStyleValue::StyleValueType::kLengthType &&
-       x->GetType() != CSSStyleValue::StyleValueType::kPercentType) ||
-      (y->GetType() != CSSStyleValue::StyleValueType::kLengthType &&
-       y->GetType() != CSSStyleValue::StyleValueType::kPercentType)) {
+  if (!IsLengthOrPercent(x) || !IsLengthOrPercent(y)) {
     exception_state.ThrowTypeError(
         "Must pass length or percentage to X and Y of CSSTranslation");
     return nullptr;
@@ -31,10 +113,7 @@ CSSTranslation* CSSTranslation::Create(CSSNumericValue* x,
                                        CSSNumericValue* y,
                                        CSSNumericValue* z,
                                        ExceptionState& exception_state) {
-  if ((x->GetType() != CSSStyleValue::StyleValueType::kLengthType &&
-       x->GetType() != CSSStyleValue::StyleValueType::kPercentType) ||
-      (y->GetType() != CSSStyleValue::StyleValueType::kLengthType &&
-       y->GetType() != CSSStyleValue::StyleValueType::kPercentType)) {
+  if (!IsLengthOrPercent(x) || !IsLengthOrPercent(y)) {
     exception_state.ThrowTypeError(
         "Must pass length or percentage to X and Y of CSSTranslation");
     return nullptr;
@@ -51,6 +130,40 @@ CSSTranslation* CSSTranslation::Create(CSSNumericValue* x,
   return new CSSTranslation(x, y, z, false /* is2D */);
 }
 
+CSSTranslation* CSSTranslation::Create(CSSNumericValue* x, CSSNumericValue* y) {
+  DCHECK(IsLengthOrPercent(x));
+  DCHECK(IsLengthOrPercent(y));
+  return new CSSTranslation(
+      x, y, CSSUnitValue::Create(0, CSSPrimitiveValue::UnitType::kPixels),
+      true /* is2D */);
+}
+
+CSSTranslation* CSSTranslation::Create(CSSNumericValue* x,
+                                       CSSNumericValue* y,
+                                       CSSNumericValue* z) {
+  DCHECK(IsLengthOrPercent(x));
+  DCHECK(IsLengthOrPercent(y));
+  DCHECK_EQ(z->GetType(), CSSStyleValue::StyleValueType::kLengthType);
+  DCHECK(!z->ContainsPercent());
+  return new CSSTranslation(x, y, z, false /* is2D */);
+}
+
+CSSTranslation* CSSTranslation::FromCSSValue(const CSSFunctionValue& value) {
+  switch (value.FunctionType()) {
+    case CSSValueTranslateX:
+    case CSSValueTranslateY:
+    case CSSValueTranslateZ:
+      return FromCSSTranslateXYZ(value);
+    case CSSValueTranslate:
+      return FromCSSTranslate(value);
+    case CSSValueTranslate3d:
+      return FromCSSTranslate3D(value);
+    default:
+      NOTREACHED();
+      return nullptr;
+  }
+}
+
 void CSSTranslation::setX(CSSNumericValue* x, ExceptionState& exception_state) {
   if (x->GetType() != CSSStyleValue::StyleValueType::kLengthType &&
       x->GetType() != CSSStyleValue::StyleValueType::kPercentType) {
@@ -72,11 +185,11 @@ void CSSTranslation::setY(CSSNumericValue* y, ExceptionState& exception_state) {
 }
 
 void CSSTranslation::setZ(CSSNumericValue* z, ExceptionState& exception_state) {
-  if (z && z->GetType() != CSSStyleValue::StyleValueType::kLengthType) {
+  if (z->GetType() != CSSStyleValue::StyleValueType::kLengthType) {
     exception_state.ThrowTypeError("Must pass length to Z of CSSTranslation");
     return;
   }
-  if (z && z->ContainsPercent()) {
+  if (z->ContainsPercent()) {
     exception_state.ThrowTypeError(
         "CSSTranslation does not support z CSSNumericValue with percent units");
     return;
@@ -84,6 +197,20 @@ void CSSTranslation::setZ(CSSNumericValue* z, ExceptionState& exception_state) {
   z_ = z;
 }
 
+DOMMatrix* CSSTranslation::AsMatrix() const {
+  CSSUnitValue* x = x_->to(CSSPrimitiveValue::UnitType::kPixels);
+  CSSUnitValue* y = y_->to(CSSPrimitiveValue::UnitType::kPixels);
+  CSSUnitValue* z = z_->to(CSSPrimitiveValue::UnitType::kPixels);
+  // TODO(meade): What should happen when the translation contains relative
+  // lengths here?
+  // https://github.com/w3c/css-houdini-drafts/issues/421
+  if (!x || !y || !z)
+    return nullptr;
+
+  DOMMatrix* matrix = DOMMatrix::Create();
+  return matrix->translate(x->value(), y->value(), z->value());
+}
+
 CSSFunctionValue* CSSTranslation::ToCSSValue() const {
   CSSFunctionValue* result = CSSFunctionValue::Create(
       is2D() ? CSSValueTranslate : CSSValueTranslate3d);