diff -r 000000000000 -r 6474c204b198 accessible/src/windows/ia2/ia2AccessibleValue.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/accessible/src/windows/ia2/ia2AccessibleValue.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,137 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: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 "ia2AccessibleValue.h"
+
+#include "AccessibleValue_i.c"
+
+#include "AccessibleWrap.h"
+#include "Accessible-inl.h"
+#include "IUnknownImpl.h"
+
+#include "mozilla/FloatingPoint.h"
+
+using namespace mozilla::a11y;
+
+// IUnknown
+
+STDMETHODIMP
+ia2AccessibleValue::QueryInterface(REFIID iid, void** ppv)
+{
+  if (!ppv)
+    return E_INVALIDARG;
+
+  *ppv = nullptr;
+
+  if (IID_IAccessibleValue == iid) {
+    AccessibleWrap* valueAcc = static_cast<AccessibleWrap*>(this);
+    if (valueAcc->HasNumericValue()) {
+      *ppv = static_cast<IAccessibleValue*>(this);
+      valueAcc->AddRef();
+      return S_OK;
+    }
+
+    return E_NOINTERFACE;
+  }
+
+  return E_NOINTERFACE;
+}
+
+// IAccessibleValue
+
+STDMETHODIMP
+ia2AccessibleValue::get_currentValue(VARIANT* aCurrentValue)
+{
+  A11Y_TRYBLOCK_BEGIN
+
+  if (!aCurrentValue)
+    return E_INVALIDARG;
+
+  VariantInit(aCurrentValue);
+
+  AccessibleWrap* valueAcc = static_cast<AccessibleWrap*>(this);
+  if (valueAcc->IsDefunct())
+    return CO_E_OBJNOTCONNECTED;
+
+  double currentValue = valueAcc->CurValue();
+  if (IsNaN(currentValue))
+    return S_FALSE;
+
+  aCurrentValue->vt = VT_R8;
+  aCurrentValue->dblVal = currentValue;
+  return S_OK;
+
+  A11Y_TRYBLOCK_END
+}
+
+STDMETHODIMP
+ia2AccessibleValue::setCurrentValue(VARIANT aValue)
+{
+  A11Y_TRYBLOCK_BEGIN
+
+  AccessibleWrap* valueAcc = static_cast<AccessibleWrap*>(this);
+  if (valueAcc->IsDefunct())
+    return CO_E_OBJNOTCONNECTED;
+
+  if (aValue.vt != VT_R8)
+    return E_INVALIDARG;
+
+  return valueAcc->SetCurValue(aValue.dblVal) ? S_OK : E_FAIL;
+
+  A11Y_TRYBLOCK_END
+}
+
+STDMETHODIMP
+ia2AccessibleValue::get_maximumValue(VARIANT* aMaximumValue)
+{
+  A11Y_TRYBLOCK_BEGIN
+
+  if (!aMaximumValue)
+    return E_INVALIDARG;
+
+  VariantInit(aMaximumValue);
+
+  AccessibleWrap* valueAcc = static_cast<AccessibleWrap*>(this);
+  if (valueAcc->IsDefunct())
+    return CO_E_OBJNOTCONNECTED;
+
+  double maximumValue = valueAcc->MaxValue();
+  if (IsNaN(maximumValue))
+    return S_FALSE;
+
+  aMaximumValue->vt = VT_R8;
+  aMaximumValue->dblVal = maximumValue;
+  return S_OK;
+
+  A11Y_TRYBLOCK_END
+}
+
+STDMETHODIMP
+ia2AccessibleValue::get_minimumValue(VARIANT* aMinimumValue)
+{
+  A11Y_TRYBLOCK_BEGIN
+
+  if (!aMinimumValue)
+    return E_INVALIDARG;
+
+  VariantInit(aMinimumValue);
+
+  AccessibleWrap* valueAcc = static_cast<AccessibleWrap*>(this);
+  if (valueAcc->IsDefunct())
+    return CO_E_OBJNOTCONNECTED;
+
+  double minimumValue = valueAcc->MinValue();
+  if (IsNaN(minimumValue))
+    return S_FALSE;
+
+  aMinimumValue->vt = VT_R8;
+  aMinimumValue->dblVal = minimumValue;
+  return S_OK;
+
+  A11Y_TRYBLOCK_END
+}
+