Add support for UIA accessibility interfaces like IAccessibleEx and IRawElementProviderSimple.

ui/base/accessibility/accessible_text_utils.h

 // Copyright (c) 2011 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.
 
 #ifndef UI_BASE_ACCESSIBILITY_ACCESSIBLE_TEXT_UTILS_H_
 #define UI_BASE_ACCESSIBILITY_ACCESSIBLE_TEXT_UTILS_H_
 #pragma once
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/string16.h"
 #include "ui/base/ui_export.h"
 
+#if defined(OS_WIN)
+#include <atlbase.h>
+#include <atlcom.h>
+#include <UIAutomationCore.h>
+#endif  // OS_WIN
+
 namespace ui {
 
 // Boundaries that can be passed to FindAccessibleTextBoundary,
 // representing various visual boundaries in (potentially multi-line)
 // text. This is used by assistive technology in order to, for example,
 // retrieve the nearest word to the cursor, or retrieve all of the
 // text from the current cursor position to the end of the line.
 // These should be self-explanatory; "line" here refers to the visual
 // line as currently displayed (possibly affected by wrapping).
 enum UI_EXPORT TextBoundaryType {
@@ skipping 18 matching lines @@
 // (depending on |direction|) from the given |start_offset| until the
 // given boundary is found, and return the offset of that boundary,
 // using the vector of line break character offsets in |line_breaks|.
 size_t UI_EXPORT FindAccessibleTextBoundary(
     const string16& text,
     const std::vector<int>& line_breaks,
     TextBoundaryType boundary,
     size_t start_offset,
     TextBoundaryDirection direction);
 
+#if defined(OS_WIN)
+// UIA Text provider implementation for edit controls.
+class UI_EXPORT UIATextProvider

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

After looking at this, I think a better place for it would be base/win. It's
most similar to base/win/enum_variant.h, which implements a Windows-only helper
class used by accessibility code in both content/browser/accessibility and
ui/views/accessibility.

Perhaps at some point we may split these into base/win/accessibility.

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

Done. Moved the class to the new files accessibility_misc_utils.cc/.h under
base\win

+    : public CComObjectRootEx<CComMultiThreadModel>,
+      public IValueProvider,
+      public ITextProvider {
+ public:
+  BEGIN_COM_MAP(UIATextProvider)
+    COM_INTERFACE_ENTRY2(IUnknown, ITextProvider)
+    COM_INTERFACE_ENTRY(IValueProvider)
+    COM_INTERFACE_ENTRY(ITextProvider)
+  END_COM_MAP()
+
+  UIATextProvider();
+
+  // Creates an instance of the UIATextProvider class.
+  // Returns true on success
+  static bool CreateTextProvider(bool editable, IUnknown** provider);
+
+  void set_editable(bool editable) {
+    editable_ = editable;
+  }
+
+  // IValueProvider methods.
+  STDMETHOD(get_IsReadOnly)(BOOL* read_only);
+
+  // IValueProvider methods not implemented.
+  STDMETHOD(SetValue)(const wchar_t* val) {
+    return E_NOTIMPL;
+  }
+
+  STDMETHOD(get_Value)(BSTR* value) {
+    return E_NOTIMPL;
+  }
+
+  // ITextProvider methods not implemented.
+  STDMETHOD(GetSelection)(SAFEARRAY** ret) {
+    return E_NOTIMPL;
+  }
+
+  STDMETHOD(GetVisibleRanges)(SAFEARRAY** ret) {
+    return E_NOTIMPL;
+  }
+
+  STDMETHOD(RangeFromChild)(IRawElementProviderSimple* child,
+                            ITextRangeProvider** ret) {
+    return E_NOTIMPL;
+  }
+
+  STDMETHOD(RangeFromPoint)(struct UiaPoint point,
+                            ITextRangeProvider** ret) {
+    return E_NOTIMPL;
+  }
+
+  STDMETHOD(get_DocumentRange)(ITextRangeProvider** ret) {
+    return E_NOTIMPL;
+  }
+
+  STDMETHOD(get_SupportedTextSelection)(enum SupportedTextSelection* ret) {
+    return E_NOTIMPL;
+  }
+
+ private:
+  bool editable_;
+};
+#endif  // OS_WIN
+
 }  // namespace ui
 
 #endif  // UI_BASE_ACCESSIBILITY_ACCESSIBLE_TEXT_UTILS_H_