diff -r 000000000000 -r 6474c204b198 accessible/src/base/StyleInfo.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/accessible/src/base/StyleInfo.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,126 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set expandtab shiftwidth=2 tabstop=2: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "StyleInfo.h"
+
+#include "mozilla/dom/Element.h"
+#include "nsComputedDOMStyle.h"
+#include "nsCSSProps.h"
+#include "nsIFrame.h"
+
+using namespace mozilla;
+using namespace mozilla::a11y;
+
+StyleInfo::StyleInfo(dom::Element* aElement, nsIPresShell* aPresShell) :
+  mElement(aElement)
+{
+  mStyleContext =
+    nsComputedDOMStyle::GetStyleContextForElementNoFlush(aElement,
+                                                         nullptr,
+                                                         aPresShell);
+}
+
+void
+StyleInfo::Display(nsAString& aValue)
+{
+  aValue.Truncate();
+  AppendASCIItoUTF16(
+    nsCSSProps::ValueToKeyword(mStyleContext->StyleDisplay()->mDisplay,
+                               nsCSSProps::kDisplayKTable), aValue);
+}
+
+void
+StyleInfo::TextAlign(nsAString& aValue)
+{
+  aValue.Truncate();
+  AppendASCIItoUTF16(
+    nsCSSProps::ValueToKeyword(mStyleContext->StyleText()->mTextAlign,
+                               nsCSSProps::kTextAlignKTable), aValue);
+}
+
+void
+StyleInfo::TextIndent(nsAString& aValue)
+{
+  aValue.Truncate();
+
+  const nsStyleCoord& styleCoord =
+    mStyleContext->StyleText()->mTextIndent;
+
+  nscoord coordVal = 0;
+  switch (styleCoord.GetUnit()) {
+    case eStyleUnit_Coord:
+      coordVal = styleCoord.GetCoordValue();
+      break;
+
+    case eStyleUnit_Percent:
+    {
+      nsIFrame* frame = mElement->GetPrimaryFrame();
+      nsIFrame* containerFrame = frame->GetContainingBlock();
+      nscoord percentageBase = containerFrame->GetContentRect().width;
+      coordVal = NSCoordSaturatingMultiply(percentageBase,
+                                           styleCoord.GetPercentValue());
+      break;
+    }
+
+    case eStyleUnit_Null:
+    case eStyleUnit_Normal:
+    case eStyleUnit_Auto:
+    case eStyleUnit_None:
+    case eStyleUnit_Factor:
+    case eStyleUnit_Degree:
+    case eStyleUnit_Grad:
+    case eStyleUnit_Radian:
+    case eStyleUnit_Turn:
+    case eStyleUnit_FlexFraction:
+    case eStyleUnit_Integer:
+    case eStyleUnit_Enumerated:
+    case eStyleUnit_Calc:
+      break;
+  }
+
+  aValue.AppendFloat(nsPresContext::AppUnitsToFloatCSSPixels(coordVal));
+  aValue.AppendLiteral("px");
+}
+
+void
+StyleInfo::Margin(css::Side aSide, nsAString& aValue)
+{
+  aValue.Truncate();
+
+  nscoord coordVal = mElement->GetPrimaryFrame()->GetUsedMargin().Side(aSide);
+  aValue.AppendFloat(nsPresContext::AppUnitsToFloatCSSPixels(coordVal));
+  aValue.AppendLiteral("px");
+}
+
+void
+StyleInfo::FormatColor(const nscolor& aValue, nsString& aFormattedValue)
+{
+  // Combine the string like rgb(R, G, B) from nscolor.
+  aFormattedValue.AppendLiteral("rgb(");
+  aFormattedValue.AppendInt(NS_GET_R(aValue));
+  aFormattedValue.AppendLiteral(", ");
+  aFormattedValue.AppendInt(NS_GET_G(aValue));
+  aFormattedValue.AppendLiteral(", ");
+  aFormattedValue.AppendInt(NS_GET_B(aValue));
+  aFormattedValue.Append(')');
+}
+
+void
+StyleInfo::FormatFontStyle(const nscoord& aValue, nsAString& aFormattedValue)
+{
+  nsCSSKeyword keyword =
+    nsCSSProps::ValueToKeywordEnum(aValue, nsCSSProps::kFontStyleKTable);
+  AppendUTF8toUTF16(nsCSSKeywords::GetStringValue(keyword), aFormattedValue);
+}
+
+void
+StyleInfo::FormatTextDecorationStyle(uint8_t aValue, nsAString& aFormattedValue)
+{
+  nsCSSKeyword keyword =
+    nsCSSProps::ValueToKeywordEnum(aValue,
+                                   nsCSSProps::kTextDecorationStyleKTable);
+  AppendUTF8toUTF16(nsCSSKeywords::GetStringValue(keyword), aFormattedValue);
+}