Re-land: Implement NativeViewAccessibilityWin using AXPlatformNodeWin.

ui/accessibility/platform/ax_platform_node_win.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright 2015 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_VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_WIN_H_
-#define UI_VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_WIN_H_
+#ifndef UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_WIN_H_
+#define UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_WIN_H_
 
 #include <atlbase.h>
 #include <atlcom.h>
 #include <oleacc.h>
 
-#include <UIAutomationCore.h>
-
-#include <set>
-#include <vector>
-
 #include "third_party/iaccessible2/ia2_api_all.h"
-#include "ui/accessibility/ax_view_state.h"
-#include "ui/views/accessibility/native_view_accessibility.h"
-#include "ui/views/controls/native/native_view_host.h"
-#include "ui/views/view.h"
+#include "ui/accessibility/platform/ax_platform_node_base.h"
 
 namespace ui {
-enum TextBoundaryDirection;
-enum TextBoundaryType;
-}
 
-namespace views {
-
-////////////////////////////////////////////////////////////////////////////////
-//
-// NativeViewAccessibilityWin
-//
-// Class implementing the MSAA IAccessible COM interface for a generic View,
-// providing accessibility to be used by screen readers and other assistive
-// technology (AT).
-//
-////////////////////////////////////////////////////////////////////////////////
 class __declspec(uuid("26f5641a-246d-457b-a96d-07f3fae6acf2"))
-NativeViewAccessibilityWin
-  : public CComObjectRootEx<CComMultiThreadModel>,
-    public IDispatchImpl<IAccessible2_2, &IID_IAccessible2_2,
-                           &LIBID_IAccessible2Lib>,
+AXPlatformNodeWin
+: public CComObjectRootEx<CComMultiThreadModel>,
+    public IDispatchImpl<IAccessible2_2, &IID_IAccessible2,
+                         &LIBID_IAccessible2Lib>,
     public IAccessibleText,
     public IServiceProvider,
-    public IAccessibleEx,
-    public IRawElementProviderSimple,
-    public NativeViewAccessibility {
+    public AXPlatformNodeBase {
  public:
-  BEGIN_COM_MAP(NativeViewAccessibilityWin)
+  BEGIN_COM_MAP(AXPlatformNodeWin)
     COM_INTERFACE_ENTRY2(IDispatch, IAccessible2_2)
+    COM_INTERFACE_ENTRY(AXPlatformNodeWin)
     COM_INTERFACE_ENTRY(IAccessible)
     COM_INTERFACE_ENTRY(IAccessible2)
     COM_INTERFACE_ENTRY(IAccessible2_2)
-    COM_INTERFACE_ENTRY(IAccessibleEx)
     COM_INTERFACE_ENTRY(IAccessibleText)
-    COM_INTERFACE_ENTRY(IRawElementProviderSimple)
     COM_INTERFACE_ENTRY(IServiceProvider)
   END_COM_MAP()
 
-  virtual ~NativeViewAccessibilityWin();
+  virtual ~AXPlatformNodeWin();
 
-  // NativeViewAccessibility.
+  // AXPlatformNode overrides.
+  void Destroy() override;
+  gfx::NativeViewAccessible GetNativeViewAccessible() override;
   void NotifyAccessibilityEvent(ui::AXEvent event_type) override;
-  gfx::NativeViewAccessible GetNativeObject() override;
-  void Destroy() override;
 
-  // Supported IAccessible methods.
+  //
+  // IAccessible methods.
+  //
 
   // Retrieves the child element or child object at a given point on the screen.
-  STDMETHODIMP accHitTest(LONG x_left, LONG y_top, VARIANT* child) override;
+  virtual STDMETHODIMP accHitTest(LONG x_left, LONG y_top, VARIANT* child);
 
   // Performs the object's default action.
-  STDMETHODIMP accDoDefaultAction(VARIANT var_id) override;
+  STDMETHODIMP accDoDefaultAction(VARIANT var_id);
 
   // Retrieves the specified object's current screen location.
   STDMETHODIMP accLocation(LONG* x_left,
                            LONG* y_top,
                            LONG* width,
                            LONG* height,
-                           VARIANT var_id) override;
+                           VARIANT var_id);
 
   // Traverses to another UI element and retrieves the object.
-  STDMETHODIMP accNavigate(LONG nav_dir, VARIANT start, VARIANT* end) override;
+  STDMETHODIMP accNavigate(LONG nav_dir, VARIANT start, VARIANT* end);
 
   // Retrieves an IDispatch interface pointer for the specified child.
-  STDMETHODIMP get_accChild(VARIANT var_child, IDispatch** disp_child) override;
+  virtual STDMETHODIMP get_accChild(VARIANT var_child, IDispatch** disp_child);
 
   // Retrieves the number of accessible children.
-  STDMETHODIMP get_accChildCount(LONG* child_count) override;
+  virtual STDMETHODIMP get_accChildCount(LONG* child_count);
 
   // Retrieves a string that describes the object's default action.
-  STDMETHODIMP get_accDefaultAction(VARIANT var_id,
-                                    BSTR* default_action) override;
+  STDMETHODIMP get_accDefaultAction(VARIANT var_id, BSTR* default_action);
 
   // Retrieves the tooltip description.
-  STDMETHODIMP get_accDescription(VARIANT var_id, BSTR* desc) override;
+  STDMETHODIMP get_accDescription(VARIANT var_id, BSTR* desc);
 
   // Retrieves the object that has the keyboard focus.
-  STDMETHODIMP get_accFocus(VARIANT* focus_child) override;
+  STDMETHODIMP get_accFocus(VARIANT* focus_child);
 
   // Retrieves the specified object's shortcut.
-  STDMETHODIMP get_accKeyboardShortcut(VARIANT var_id,
-                                       BSTR* access_key) override;
+  STDMETHODIMP get_accKeyboardShortcut(VARIANT var_id, BSTR* access_key);
 
   // Retrieves the name of the specified object.
-  STDMETHODIMP get_accName(VARIANT var_id, BSTR* name) override;
+  STDMETHODIMP get_accName(VARIANT var_id, BSTR* name);
 
   // Retrieves the IDispatch interface of the object's parent.
-  STDMETHODIMP get_accParent(IDispatch** disp_parent) override;
+  STDMETHODIMP get_accParent(IDispatch** disp_parent);
 
   // Retrieves information describing the role of the specified object.
-  STDMETHODIMP get_accRole(VARIANT var_id, VARIANT* role) override;
+  STDMETHODIMP get_accRole(VARIANT var_id, VARIANT* role);
 
   // Retrieves the current state of the specified object.
-  STDMETHODIMP get_accState(VARIANT var_id, VARIANT* state) override;
+  STDMETHODIMP get_accState(VARIANT var_id, VARIANT* state);
+
+  // Gets the help string for the specified object.
+  STDMETHODIMP get_accHelp(VARIANT var_id, BSTR* help);
 
   // Retrieve or set the string value associated with the specified object.
   // Setting the value is not typically used by screen readers, but it's
   // used frequently by automation software.
-  STDMETHODIMP get_accValue(VARIANT var_id, BSTR* value) override;
-  STDMETHODIMP put_accValue(VARIANT var_id, BSTR new_value) override;
+  STDMETHODIMP get_accValue(VARIANT var_id, BSTR* value);
+  STDMETHODIMP put_accValue(VARIANT var_id, BSTR new_value);
 
-  // Selections not applicable to views.
-  STDMETHODIMP get_accSelection(VARIANT* selected) override;
-  STDMETHODIMP accSelect(LONG flags_sel, VARIANT var_id) override;
-
-  // Help functions not supported.
-  STDMETHODIMP get_accHelp(VARIANT var_id, BSTR* help) override;
+  // IAccessible methods not implemented.
+  STDMETHODIMP get_accSelection(VARIANT* selected);
+  STDMETHODIMP accSelect(LONG flags_sel, VARIANT var_id);
   STDMETHODIMP get_accHelpTopic(BSTR* help_file,
                                 VARIANT var_id,
-                                LONG* topic_id) override;
-
-  // Deprecated functions, not implemented here.
-  STDMETHODIMP put_accName(VARIANT var_id, BSTR put_name) override;
+                                LONG* topic_id);
+  STDMETHODIMP put_accName(VARIANT var_id, BSTR put_name);
 
   //
-  // IAccessible2
+  // IAccessible2 methods.
   //
 
   STDMETHODIMP role(LONG* role) override;
 
   STDMETHODIMP get_states(AccessibleStates* states) override;
 
   STDMETHODIMP get_uniqueID(LONG* unique_id) override;
 
   STDMETHODIMP get_windowHandle(HWND* window_handle) override;
 
@@ skipping 151 matching lines @@
                                       enum IA2CoordinateType coordinate_type,
                                       LONG x,
                                       LONG y) override {
     return E_NOTIMPL;
   }
 
   //
   // IServiceProvider methods.
   //
 
-  STDMETHODIMP QueryService(REFGUID guidService,
-                            REFIID riid,
-                            void** object) override;
-
-  //
-  // IAccessibleEx methods not implemented.
-  //
-  STDMETHODIMP GetObjectForChild(long child_id, IAccessibleEx** ret) override {
-    return E_NOTIMPL;
-  }
-
-  STDMETHODIMP GetIAccessiblePair(IAccessible** acc, long* child_id) override {
-    return E_NOTIMPL;
-  }
-
-  STDMETHODIMP GetRuntimeId(SAFEARRAY** runtime_id) override {
-    return E_NOTIMPL;
-  }
-
-  STDMETHODIMP ConvertReturnedElement(IRawElementProviderSimple* element,
-                                      IAccessibleEx** acc) override {
-    return E_NOTIMPL;
-  }
-
-  //
-  // IRawElementProviderSimple methods.
-  //
-  // The GetPatternProvider/GetPropertyValue methods need to be implemented for
-  // the on-screen keyboard to show up in Windows 8 metro.
-  STDMETHODIMP GetPatternProvider(PATTERNID id, IUnknown** provider) override;
-  STDMETHODIMP GetPropertyValue(PROPERTYID id, VARIANT* ret) override;
-
-  //
-  // IRawElementProviderSimple methods not implemented.
-  //
-  STDMETHODIMP get_ProviderOptions(enum ProviderOptions* ret) override {
-    return E_NOTIMPL;
-  }
-
-  STDMETHODIMP get_HostRawElementProvider(
-      IRawElementProviderSimple** provider) override {
-    return E_NOTIMPL;
-  }
-
-  // Static methods
-
-  // Returns a conversion from the event (as defined in ax_enums.idl)
-  // to an MSAA event.
-  static int32 MSAAEvent(ui::AXEvent event);
-
-  // Returns a conversion from the Role (as defined in ax_enums.idl)
-  // to an MSAA role.
-  static int32 MSAARole(ui::AXRole role);
-
-  // Returns a conversion from the State (as defined in ax_enums.idl)
-  // to MSAA states set.
-  static int32 MSAAState(const ui::AXViewState& state);
+  STDMETHODIMP QueryService(REFGUID guidService, REFIID riid, void** object);
 
  protected:
-  NativeViewAccessibilityWin();
+  AXPlatformNodeWin();
 
  private:
-  // Determines navigation direction for accNavigate, based on left, up and
-  // previous being mapped all to previous and right, down, next being mapped
-  // to next. Returns true if navigation direction is next, false otherwise.
-  bool IsNavDirNext(int nav_dir) const;
+  bool IsValidId(const VARIANT& child) const;
+  int MSAARole();
+  int MSAAState();
+  int MSAAEvent(ui::AXEvent event);
 
-  // Determines if the navigation target is within the allowed bounds. Returns
-  // true if it is, false otherwise.
-  bool IsValidNav(int nav_dir,
-                  int start_id,
-                  int lower_bound,
-                  int upper_bound) const;
+  HRESULT GetStringAttributeAsBstr(
+      ui::AXStringAttribute attribute,
+      BSTR* value_bstr) const;
 
-  // Determines if the child id variant is valid.
-  bool IsValidId(const VARIANT& child) const;
-
-  // Helper function which sets applicable states of view.
-  void SetState(VARIANT* msaa_state, View* view);
+  void AddAlertTarget();
+  void RemoveAlertTarget();
 
   // Return the text to use for IAccessibleText.
   base::string16 TextForIAccessibleText();
 
   // If offset is a member of IA2TextSpecialOffsets this function updates the
   // value of offset and returns, otherwise offset remains unchanged.
   void HandleSpecialTextOffset(const base::string16& text, LONG* offset);
 
   // Convert from a IA2TextBoundaryType to a ui::TextBoundaryType.
   ui::TextBoundaryType IA2TextBoundaryToTextBoundary(IA2TextBoundaryType type);
 
   // Search forwards (direction == 1) or backwards (direction == -1)
   // from the given offset until the given boundary is found, and
   // return the offset of that boundary.
   LONG FindBoundary(const base::string16& text,
                     IA2TextBoundaryType ia2_boundary,
                     LONG start_offset,
                     ui::TextBoundaryDirection direction);
 
-  // Populates the given vector with all widgets that are either a child
-  // or are owned by this view's widget, and who are not contained in a
-  // NativeViewHost.
-  void PopulateChildWidgetVector(std::vector<Widget*>* child_widgets);
-
-  // Adds this view to alert_target_view_storage_ids_.
-  void AddAlertTarget();
-
-  // Removes this view from alert_target_view_storage_ids_.
-  void RemoveAlertTarget();
-
-  // Give CComObject access to the class constructor.
-  template <class Base> friend class CComObject;
-
-  // A unique id for each object, needed for IAccessible2.
-  long unique_id_;
-
-  // Next unique id to assign.
-  static long next_unique_id_;
-
-  // Circular queue size.
-  static const int kMaxViewStorageIds = 20;
-
-  // Circular queue of view storage ids corresponding to child ids
-  // used to post notifications using NotifyWinEvent.
-  static int view_storage_ids_[kMaxViewStorageIds];
-
-  // Next index into |view_storage_ids_| to use.
-  static int next_view_storage_id_index_;
-
-  // A vector of view storage ids of views that have been the target of
-  // an alert event, in order to provide an api to quickly identify all
-  // open alerts.
-  static std::vector<int> alert_target_view_storage_ids_;
-
-  DISALLOW_COPY_AND_ASSIGN(NativeViewAccessibilityWin);
+  // A windows-specific unique ID for this object. It's returned in
+  // IAccessible2::get_uniqueID, but more importantly it's used for
+  // firing events. On Windows, we fire events on the nearest parent HWND
+  // and pass the unique ID as the child id parameter. When the client
+  // wants to retrieve the object the event was fired on, it calls
+  // get_accChild and passes the child ID. We use negative IDs for the unique
+  // ID so we can distinguish a request for an arbitrary child from a request
+  // for an immediate child of an object by its 0-based index.
+  LONG unique_id_win_;
 };
 
-}  // namespace views
+}  // namespace ui
 
-#endif  // UI_VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_WIN_H_
+#endif  // UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_WIN_H_