Add support for UIA accessibility interfaces like IAccessibleEx and IRawElementProviderSimple.

ui/views/accessibility/native_view_accessibility_win.cc

 // Copyright (c) 2012 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.
 
+#define _ATL_DEBUG_QI

[dmazzoni, 2012/04/04 06:02:00]

Delete this before checking in?

[ananta, 2012/04/04 19:23:00]

Done.

 #include "ui/views/accessibility/native_view_accessibility_win.h"
 
 #include <atlbase.h>
 #include <atlcom.h>
 
+#include <UIAutomationClient.h>

[dmazzoni, 2012/04/04 06:02:00]

Nit: group above

[ananta, 2012/04/04 19:23:00]

Done.

 #include <vector>
 
+#include "base/win/windows_version.h"
 #include "third_party/iaccessible2/ia2_api_all.h"
 #include "ui/base/accessibility/accessible_text_utils.h"
 #include "ui/base/accessibility/accessible_view_state.h"
 #include "ui/base/view_prop.h"
 #include "ui/base/win/atl_module.h"
 #include "ui/views/widget/native_widget_win.h"
 #include "ui/views/widget/widget.h"
 
 using ui::AccessibilityTypes;
 
@@ skipping 755 matching lines @@
 
 //
 // IServiceProvider methods.
 //
 
 STDMETHODIMP NativeViewAccessibilityWin::QueryService(
     REFGUID guidService, REFIID riid, void** object) {
   if (!view_)
     return E_FAIL;
 
-  if (guidService == IID_IAccessible ||
-      guidService == IID_IAccessible2 ||
-      guidService == IID_IAccessibleText) {
+  if (riid == IID_IAccessible ||
+      riid == IID_IAccessible2 ||
+      riid == IID_IAccessibleText)  {
+    return QueryInterface(riid, object);
+  }
+
+  // We only support the IAccessibleEx interface on Windows 8 and above. This
+  // is needed for the On screen Keyboard to show up in metro mode, when the
+  // user taps an editable region in the window.
+  // All methods in the IAccessibleEx interface are unimplemented.
+  if (riid == IID_IAccessibleEx &&
+      base::win::GetVersion() >= base::win::VERSION_WIN8) {
     return QueryInterface(riid, object);
   }
 
   *object = NULL;
   return E_FAIL;
 }
 
+STDMETHODIMP NativeViewAccessibilityWin::GetPatternProvider(
+    PATTERNID id, IUnknown** provider) {
+  DVLOG(1) << "In Function: "
+           << __FUNCTION__
+           << " for pattern id: "
+           << id;
+  if (id == UIA_ValuePatternId || id == UIA_TextPatternId) {
+    ui::AccessibleViewState state;
+    view_->GetAccessibleState(&state);
+    long role = MSAARole(state.role);
+
+    if (role == ROLE_SYSTEM_TEXT) {
+      DVLOG(1) << "Returning UIA text provider";
+      ui::UIATextProvider::CreateTextProvider(true, provider);
+      return S_OK;
+    }
+  }
+  return E_NOTIMPL;
+}
+
+STDMETHODIMP NativeViewAccessibilityWin::GetPropertyValue(PROPERTYID id,
+                                                           VARIANT* ret) {
+  DVLOG(1) << "In Function: "
+           << __FUNCTION__
+           << " for property id: "
+           << id;
+  if (id == UIA_ControlTypePropertyId) {
+    ui::AccessibleViewState state;
+    view_->GetAccessibleState(&state);
+    long role = MSAARole(state.role);
+    if (role == ROLE_SYSTEM_TEXT) {
+      V_VT(ret) = VT_I4;
+      ret->lVal = UIA_EditControlTypeId;
+      DVLOG(1) << "Returning Edit control type";
+    } else {
+      DVLOG(1) << "Returning empty control type";
+      V_VT(ret) = VT_EMPTY;
+    }
+  } else {
+    V_VT(ret) = VT_EMPTY;
+  }
+  return S_OK;
+}
+
 //
 // Static methods.
 //
 
 int32 NativeViewAccessibilityWin::MSAAEvent(AccessibilityTypes::Event event) {
   switch (event) {
     case AccessibilityTypes::EVENT_ALERT:
       return EVENT_SYSTEM_ALERT;
     case AccessibilityTypes::EVENT_FOCUS:
       return EVENT_OBJECT_FOCUS;
@@ skipping 220 matching lines @@
     const string16& text,
     IA2TextBoundaryType ia2_boundary,
     LONG start_offset,
     ui::TextBoundaryDirection direction) {
   HandleSpecialTextOffset(text, &start_offset);
   ui::TextBoundaryType boundary = IA2TextBoundaryToTextBoundary(ia2_boundary);
   std::vector<int32> line_breaks;
   return ui::FindAccessibleTextBoundary(
       text, line_breaks, boundary, start_offset, direction);
 }