[GeometryInterface] Add setMatrixValue(transfromList) function.

third_party/WebKit/Source/core/dom/DOMMatrix.cpp

Index: third_party/WebKit/Source/core/dom/DOMMatrix.cpp
diff --git a/third_party/WebKit/Source/core/dom/DOMMatrix.cpp b/third_party/WebKit/Source/core/dom/DOMMatrix.cpp
index eed0a170ce5864c208fa5ca308ce09205b8d3bba..f084a536466988ca065787eacdf492e0d530c6c9 100644
--- a/third_party/WebKit/Source/core/dom/DOMMatrix.cpp
+++ b/third_party/WebKit/Source/core/dom/DOMMatrix.cpp
@@ -4,6 +4,14 @@
 
 #include "core/dom/DOMMatrix.h"
 
+#include "core/css/CSSIdentifierValue.h"
+#include "core/css/CSSToLengthConversionData.h"
+#include "core/css/CSSValueList.h"
+#include "core/css/parser/CSSParser.h"
+#include "core/css/resolver/TransformBuilder.h"
+#include "core/layout/api/LayoutViewItem.h"
+#include "core/style/ComputedStyle.h"
+
 namespace blink {
 
 DOMMatrix* DOMMatrix::create(ExceptionState& exceptionState) {
@@ -211,4 +219,65 @@ DOMMatrix* DOMMatrix::invertSelf() {
   return this;
 }
 
+static inline PassRefPtr<ComputedStyle> createInitialStyle() {

[Timothy Loh, 2016/10/19 02:59:08]

Just use ComputedStyle::initialStyle() instead of creating a new one.

[Hwanseung Lee, 2016/10/22 14:44:56]

Done.

[Timothy Loh, 2016/10/24 04:18:30]

I meant that we shouldn't need a createInitialStyle() function at all, can't we
call ComputedStyle::initialStyle() where you're currently calling
createInitialStyle()?

[Hwanseung Lee, 2016/10/24 13:23:37]

Done.

+  RefPtr<ComputedStyle> initialStyle = ComputedStyle::create();
+  initialStyle->font().update(nullptr);
+  return initialStyle;
+}
+
+DOMMatrix* DOMMatrix::setMatrixValue(const String& string,
+                                     ExceptionState& exceptionState) {
+  DEFINE_STATIC_LOCAL(String, identityMatrix2D, ("matrix(1, 0, 0, 1, 0, 0)"));
+  String inputString = string;

[Timothy Loh, 2016/10/19 02:59:08]

This naming is weird, if you have inputString and string I would expect the
argument to be inputString.

[Hwanseung Lee, 2016/10/22 14:44:56]

Done.

+  if (string.isEmpty())
+    inputString = identityMatrix2D;
+
+  const CSSValue* value =
+      CSSParser::parseSingleValue(CSSPropertyTransform, inputString);
+
+  if (!value) {  // There is something there but parsing failed.
+    exceptionState.throwDOMException(SyntaxError,
+                                     "Failed to parse '" + string + "'.");
+    return nullptr;
+  }
+
+  if (value->isIdentifierValue() &&
+      (toCSSIdentifierValue(value))->getValueID() == CSSValueNone) {
+    exceptionState.throwDOMException(SyntaxError,
+                                     "Failed to parse '" + string + "'.");
+    return nullptr;
+  }
+
+  DEFINE_STATIC_REF(ComputedStyle, initialStyle, createInitialStyle());
+
+  if (TransformBuilder::hasRelativeLengths(toCSSValueList(*value))) {
+    exceptionState.throwDOMException(SyntaxError,
+                                     "Relative lengths not supported.");
+    return nullptr;
+  }
+
+  TransformOperations operations;
+  TransformBuilder::createTransformOperations(
+      *value, CSSToLengthConversionData(initialStyle, initialStyle,
+                                        LayoutViewItem(nullptr), 1.0f),
+      operations);
+
+  // Convert transform operations to a TransformationMatrix. This can fail

[Timothy Loh, 2016/10/19 02:59:08]

This comment is misplaced, the conversion is 12 lines below, and also incorrect
because the conversion doesn't actually fail.

[Hwanseung Lee, 2016/10/22 14:44:56]

Done.

+  // if a param has a percentage ('%')
+  if (operations.dependsOnBoxSize()) {
+    exceptionState.throwDOMException(SyntaxError,
+                                     "The transformation depends on the box "
+                                     "size, which is not supported.");
+    return nullptr;
+  }
+
+  if (operations.has3DOperation())
+    m_is2D = false;

[Timothy Loh, 2016/10/19 02:59:08]

Shouldn't this be

m_is2D = !operations.has3DOperation();

Because otherwise if you have a 3d matrix and call setMatrixValue with a 2d
transform list the flag won't be correctly set. Please have some sort of test
for this.

[Hwanseung Lee, 2016/10/22 14:44:57]

Done.

+
+  m_matrix = TransformationMatrix::create();
+  operations.apply(FloatSize(0, 0), *m_matrix);
+
+  return this;
+}
+
 }  // namespace blink