views/accessibility/view_accessibility.cc - chromium/src.git - Git at Google

 // Copyright (c) 2006-2008 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.

 #include "views/accessibility/view_accessibility.h"

 #include "views/accessibility/view_accessibility_wrapper.h"
 #include "views/widget/widget.h"

 HRESULT ViewAccessibility::Initialize(views::View* view) {
   if (!view) {
     return E_INVALIDARG;
   }

   view_ = view;
   return S_OK;
 }

 // TODO(klink): Handle case where child View is not contained by parent.
 STDMETHODIMP ViewAccessibility::accHitTest(LONG x_left, LONG y_top,
                                            VARIANT* child) {
   if (!child) {
     return E_INVALIDARG;
   }

   gfx::Point pt(x_left, y_top);
   views::View::ConvertPointToView(NULL, view_, &pt);

   if (!view_->HitTest(pt)) {
     // If containing parent is not hit, return with failure.
     child->vt = VT_EMPTY;
     return S_FALSE;
   }

   int child_count = view_->GetChildViewCount();
   bool child_hit = false;
   views::View* child_view = NULL;
   for (int child_id = 0; child_id < child_count; ++child_id) {
     // Search for hit within any of the children.
     child_view = view_->GetChildViewAt(child_id);
     views::View::ConvertPointToView(view_, child_view, &pt);
     if (child_view->HitTest(pt)) {
       // Store child_id (adjusted with +1 to convert to MSAA indexing).
       child->lVal = child_id + 1;
       child_hit = true;
       break;
     }
     // Convert point back to parent view to test next child.
     views::View::ConvertPointToView(child_view, view_, &pt);
   }

   child->vt = VT_I4;

   if (!child_hit) {
     // No child hit, return parent id.
     child->lVal = CHILDID_SELF;
   } else {
     if (child_view == NULL) {
       return E_FAIL;
     } else if (child_view->GetChildViewCount() != 0) {
       // Retrieve IDispatch for child, if it is not a leaf.
       child->vt = VT_DISPATCH;
       if ((GetViewAccessibilityWrapper(child_view))->
           GetInstance(IID_IAccessible,
                       reinterpret_cast<void**>(&child->pdispVal)) == S_OK) {
         // Increment the reference count for the retrieved interface.
         child->pdispVal->AddRef();
         return S_OK;
       } else {
         return E_NOINTERFACE;
       }
     }
   }

   return S_OK;
 }

 STDMETHODIMP ViewAccessibility::accLocation(LONG* x_left, LONG* y_top,
                                             LONG* width, LONG* height,
                                             VARIANT var_id) {
   if (var_id.vt != VT_I4 || !x_left || !y_top || !width || !height) {
     return E_INVALIDARG;
   }

   gfx::Rect view_bounds;
   // Retrieving the parent View to be used for converting from view-to-screen
   // coordinates.
   views::View* parent = view_->GetParent();

   if (parent == NULL) {
     // If no parent, remain within the same View.
     parent = view_;
   }

   if (var_id.lVal == CHILDID_SELF) {
     // Retrieve active View's bounds.
     view_bounds = view_->bounds();
   } else {
     // Check to see if child is out-of-bounds.
     if (!IsValidChild((var_id.lVal - 1), view_)) {
       return E_INVALIDARG;
     }
     // Retrieve child bounds.
     view_bounds = view_->GetChildViewAt(var_id.lVal - 1)->bounds();
     // Parent View is current View.
     parent = view_;
   }

   if (!view_bounds.IsEmpty()) {
     *width  = view_bounds.width();
     *height = view_bounds.height();

     gfx::Point topleft(view_bounds.origin());
     views::View::ConvertPointToScreen(parent, &topleft);
     *x_left = topleft.x();
     *y_top  = topleft.y();
   } else {
     return E_FAIL;
   }
   return S_OK;
 }

 STDMETHODIMP ViewAccessibility::accNavigate(LONG nav_dir, VARIANT start,
                                             VARIANT* end) {
   if (start.vt != VT_I4 || !end) {
     return E_INVALIDARG;
   }

   switch (nav_dir) {
     case NAVDIR_FIRSTCHILD:
     case NAVDIR_LASTCHILD: {
       if (start.lVal != CHILDID_SELF) {
         // Start of navigation must be on the View itself.
         return E_INVALIDARG;
       } else if (view_->GetChildViewCount() == 0) {
         // No children found.
         return S_FALSE;
       }

       // Set child_id based on first or last child.
       int child_id = 0;
       if (nav_dir == NAVDIR_LASTCHILD) {
         child_id = view_->GetChildViewCount() - 1;
       }

       views::View* child = view_->GetChildViewAt(child_id);

       if (child->GetChildViewCount() != 0) {
         end->vt = VT_DISPATCH;
         if ((GetViewAccessibilityWrapper(child))->
             GetInstance(IID_IAccessible,
                         reinterpret_cast<void**>(&end->pdispVal)) == S_OK) {
           // Increment the reference count for the retrieved interface.
           end->pdispVal->AddRef();
           return S_OK;
         } else {
           return E_NOINTERFACE;
         }
       } else {
         end->vt = VT_I4;
         // Set return child lVal, adjusted for MSAA indexing. (MSAA
         // child indexing starts with 1, whereas View indexing starts with 0).
         end->lVal = child_id + 1;
       }
       break;
     }
     case NAVDIR_LEFT:
     case NAVDIR_UP:
     case NAVDIR_PREVIOUS:
     case NAVDIR_RIGHT:
     case NAVDIR_DOWN:
     case NAVDIR_NEXT: {
       // Retrieve parent to access view index and perform bounds checking.
       views::View* parent = view_->GetParent();
       if (!parent) {
         return E_FAIL;
       }

       if (start.lVal == CHILDID_SELF) {
         int view_index = parent->GetChildIndex(view_);
         // Check navigation bounds, adjusting for View child indexing (MSAA
         // child indexing starts with 1, whereas View indexing starts with 0).
         if (!IsValidNav(nav_dir, view_index, -1,
                         parent->GetChildViewCount())) {
           // Navigation attempted to go out-of-bounds.
           end->vt = VT_EMPTY;
           return S_FALSE;
         } else {
           if (IsNavDirNext(nav_dir)) {
             view_index += 1;
           } else {
             view_index -=1;
           }
         }

         views::View* child = parent->GetChildViewAt(view_index);
         if (child->GetChildViewCount() != 0) {
           end->vt = VT_DISPATCH;
           // Retrieve IDispatch for non-leaf child.
           if ((GetViewAccessibilityWrapper(child))->
               GetInstance(IID_IAccessible,
                           reinterpret_cast<void**>(&end->pdispVal)) == S_OK) {
             // Increment the reference count for the retrieved interface.
             end->pdispVal->AddRef();
             return S_OK;
           } else {
             return E_NOINTERFACE;
           }
         } else {
           end->vt = VT_I4;
           // Modifying view_index to give lVal correct MSAA-based value. (MSAA
           // child indexing starts with 1, whereas View indexing starts with 0).
           end->lVal = view_index + 1;
         }
       } else {
         // Check navigation bounds, adjusting for MSAA child indexing (MSAA
         // child indexing starts with 1, whereas View indexing starts with 0).
         if (!IsValidNav(nav_dir, start.lVal, 0,
                         parent->GetChildViewCount() + 1)) {
             // Navigation attempted to go out-of-bounds.
             end->vt = VT_EMPTY;
             return S_FALSE;
           } else {
             if (IsNavDirNext(nav_dir)) {
               start.lVal += 1;
             } else {
               start.lVal -= 1;
             }
         }

         HRESULT result = this->get_accChild(start, &end->pdispVal);
         if (result == S_FALSE) {
           // Child is a leaf.
           end->vt = VT_I4;
           end->lVal = start.lVal;
         } else if (result == E_INVALIDARG) {
           return E_INVALIDARG;
         } else {
           // Child is not a leaf.
           end->vt = VT_DISPATCH;
         }
       }
       break;
     }
     default:
       return E_INVALIDARG;
   }
   // Navigation performed correctly. Global return for this function, if no
   // error triggered an escape earlier.
   return S_OK;
 }

 STDMETHODIMP ViewAccessibility::get_accChild(VARIANT var_child,
                                              IDispatch** disp_child) {
   if (var_child.vt != VT_I4 || !disp_child) {
     return E_INVALIDARG;
   }

   // If var_child is the parent, remain with the same IDispatch.
   if (var_child.lVal == CHILDID_SELF) {
     return S_OK;
   }

   views::View* child_view = NULL;
   bool get_iaccessible = false;

   // Check to see if child is out-of-bounds.
   if (IsValidChild((var_child.lVal - 1), view_)) {
     child_view = view_->GetChildViewAt(var_child.lVal - 1);
   } else {
     // Child is located elsewhere in the hierarchy, get ID and adjust for MSAA.
     child_view = view_->GetViewByID(static_cast<int>(var_child.lVal));
     get_iaccessible = true;
   }

   if (!child_view) {
     // No child found.
     *disp_child = NULL;
     return E_FAIL;
   }

   if (get_iaccessible || child_view->GetChildViewCount() != 0) {
     // Retrieve the IUnknown interface for the requested child view, and
     // assign the IDispatch returned.
     if ((GetViewAccessibilityWrapper(child_view))->
         GetInstance(IID_IAccessible,
                     reinterpret_cast<void**>(disp_child)) == S_OK) {
       // Increment the reference count for the retrieved interface.
       (*disp_child)->AddRef();
       return S_OK;
     } else {
       // No interface, return failure.
       return E_NOINTERFACE;
     }
   } else {
     // When at a leaf, children are handled by the parent object.
     *disp_child = NULL;
     return S_FALSE;
   }
 }

 STDMETHODIMP ViewAccessibility::get_accChildCount(LONG* child_count) {
   if (!child_count || !view_) {
     return E_INVALIDARG;
   }

   *child_count = view_->GetChildViewCount();
   return S_OK;
 }

 STDMETHODIMP ViewAccessibility::get_accDefaultAction(VARIANT var_id,
                                                      BSTR* def_action) {
   if (var_id.vt != VT_I4 || !def_action) {
     return E_INVALIDARG;
   }

   std::wstring temp_action;

   if (var_id.lVal == CHILDID_SELF) {
     view_->GetAccessibleDefaultAction(&temp_action);
   } else {
     if (!IsValidChild((var_id.lVal - 1), view_)) {
       return E_INVALIDARG;
     }
     view_->GetChildViewAt(var_id.lVal - 1)->
         GetAccessibleDefaultAction(&temp_action);
   }
   if (!temp_action.empty()) {
     *def_action = SysAllocString(temp_action.c_str());
   } else {
     return S_FALSE;
   }

   return S_OK;
 }

 STDMETHODIMP ViewAccessibility::get_accDescription(VARIANT var_id, BSTR* desc) {
   if (var_id.vt != VT_I4 || !desc) {
     return E_INVALIDARG;
   }

   std::wstring temp_desc;

   if (var_id.lVal == CHILDID_SELF) {
     view_->GetTooltipText(0, 0, &temp_desc);
   } else {
     if (!IsValidChild((var_id.lVal - 1), view_)) {
       return E_INVALIDARG;
     }
     view_->GetChildViewAt(var_id.lVal - 1)->GetTooltipText(0, 0, &temp_desc);
   }
   if (!temp_desc.empty()) {
     *desc = SysAllocString(temp_desc.c_str());
   } else {
     return S_FALSE;
   }

   return S_OK;
 }

 STDMETHODIMP ViewAccessibility::get_accFocus(VARIANT* focus_child) {
   if (!focus_child) {
     return E_INVALIDARG;
   }

   if (view_->GetChildViewCount() == 0 && view_->HasFocus()) {
     // Parent view has focus.
     focus_child->vt = VT_I4;
     focus_child->lVal = CHILDID_SELF;
   } else {
     bool has_focus = false;
     int child_count = view_->GetChildViewCount();
     // Search for child view with focus.
     for (int child_id = 0; child_id < child_count; ++child_id) {
       if (view_->GetChildViewAt(child_id)->HasFocus()) {
         focus_child->vt = VT_I4;
         focus_child->lVal = child_id + 1;

         // If child view is no leaf, retrieve IDispatch.
         if (view_->GetChildViewAt(child_id)->GetChildViewCount() != 0) {
           focus_child->vt = VT_DISPATCH;
           this->get_accChild(*focus_child, &focus_child->pdispVal);
         }
         has_focus = true;
         break;
       }
     }
     // No current focus on any of the children.
     if (!has_focus) {
       focus_child->vt = VT_EMPTY;
       return S_FALSE;
     }
   }

   return S_OK;
 }

 STDMETHODIMP ViewAccessibility::get_accKeyboardShortcut(VARIANT var_id,
                                                         BSTR* acc_key) {
   if (var_id.vt != VT_I4 || !acc_key) {
     return E_INVALIDARG;
   }

   std::wstring temp_key;

   if (var_id.lVal == CHILDID_SELF) {
     view_->GetAccessibleKeyboardShortcut(&temp_key);
   } else {
     if (!IsValidChild((var_id.lVal - 1), view_)) {
       return E_INVALIDARG;
     }
     view_->GetChildViewAt(var_id.lVal - 1)->
         GetAccessibleKeyboardShortcut(&temp_key);
   }
   if (!temp_key.empty()) {
     *acc_key = SysAllocString(temp_key.c_str());
   } else {
     return S_FALSE;
   }

   return S_OK;
 }

 STDMETHODIMP ViewAccessibility::get_accName(VARIANT var_id, BSTR* name) {
   if (var_id.vt != VT_I4 || !name) {
     return E_INVALIDARG;
   }

   std::wstring temp_name;

   if (var_id.lVal == CHILDID_SELF) {
     // Retrieve the parent view's name.
     view_->GetAccessibleName(&temp_name);
   } else {
     if (!IsValidChild((var_id.lVal - 1), view_)) {
       return E_INVALIDARG;
     }
     // Retrieve the child view's name.
     view_->GetChildViewAt(var_id.lVal - 1)->GetAccessibleName(&temp_name);
   }
   if (!temp_name.empty()) {
     // Return name retrieved.
     *name = SysAllocString(temp_name.c_str());
   } else {
     // If view has no name, return S_FALSE.
     return S_FALSE;
   }

   return S_OK;
 }

 STDMETHODIMP ViewAccessibility::get_accParent(IDispatch** disp_parent) {
   if (!disp_parent) {
     return E_INVALIDARG;
   }

   views::View* parent_view = view_->GetParent();

   if (!parent_view) {
     // This function can get called during teardown of WidetWin so we
     // should bail out if we fail to get the HWND.
     if (!view_->GetWidget() || !view_->GetWidget()->GetNativeView()) {
       *disp_parent = NULL;
       return S_FALSE;
     }

     // For a View that has no parent (e.g. root), point the accessible parent to
     // the default implementation, to interface with Windows' hierarchy and to
     // support calls from e.g. WindowFromAccessibleObject.
     HRESULT hr =
         ::AccessibleObjectFromWindow(view_->GetWidget()->GetNativeView(),
                                      OBJID_WINDOW, IID_IAccessible,
                                      reinterpret_cast<void**>(disp_parent));

     if (!SUCCEEDED(hr)) {
       *disp_parent = NULL;
       return S_FALSE;
     }

     return S_OK;
   }

   // Retrieve the IUnknown interface for the parent view, and assign the
   // IDispatch returned.
   if ((GetViewAccessibilityWrapper(parent_view))->
       GetInstance(IID_IAccessible,
                   reinterpret_cast<void**>(disp_parent)) == S_OK) {
     // Increment the reference count for the retrieved interface.
     (*disp_parent)->AddRef();
     return S_OK;
   } else {
     return E_NOINTERFACE;
   }
 }

 STDMETHODIMP ViewAccessibility::get_accRole(VARIANT var_id, VARIANT* role) {
   if (var_id.vt != VT_I4 || !role) {
     return E_INVALIDARG;
   }

   AccessibilityTypes::Role acc_role;

   if (var_id.lVal == CHILDID_SELF) {
     // Retrieve parent role.
     if (!view_->GetAccessibleRole(&acc_role)) {
       return E_FAIL;
     }
   } else {
     if (!IsValidChild((var_id.lVal - 1), view_)) {
       return E_INVALIDARG;
     }
     // Retrieve child role.
     if (!view_->GetChildViewAt(var_id.lVal - 1)->GetAccessibleRole(&acc_role)) {
       role->vt = VT_EMPTY;
       return E_FAIL;
     }
   }

   role->vt = VT_I4;
   role->lVal = MSAARole(acc_role);
   return S_OK;
 }

 STDMETHODIMP ViewAccessibility::get_accState(VARIANT var_id, VARIANT* state) {
   if (var_id.vt != VT_I4 || !state) {
     return E_INVALIDARG;
   }

   state->vt = VT_I4;

   if (var_id.lVal == CHILDID_SELF) {
     // Retrieve all currently applicable states of the parent.
     this->SetState(state, view_);
   } else {
     if (!IsValidChild((var_id.lVal - 1), view_)) {
       return E_INVALIDARG;
     }
     // Retrieve all currently applicable states of the child.
     this->SetState(state, view_->GetChildViewAt(var_id.lVal - 1));
   }

   // Make sure that state is not empty, and has the proper type.
   if (state->vt == VT_EMPTY)
     return E_FAIL;

   return S_OK;
 }

 // Helper functions.

 bool ViewAccessibility::IsValidChild(int child_id, views::View* view) const {
   if (((child_id) < 0) ||
       ((child_id) >= view->GetChildViewCount())) {
     return false;
   }
   return true;
 }

 bool ViewAccessibility::IsNavDirNext(int nav_dir) const {
   if (nav_dir == NAVDIR_RIGHT || nav_dir == NAVDIR_DOWN ||
       nav_dir == NAVDIR_NEXT) {
       return true;
   }
   return false;
 }

 bool ViewAccessibility::IsValidNav(int nav_dir, int start_id, int lower_bound,
                                    int upper_bound) const {
   if (IsNavDirNext(nav_dir)) {
     if ((start_id + 1) > upper_bound) {
       return false;
     }
   } else {
     if ((start_id - 1) <= lower_bound) {
       return false;
     }
   }
   return true;
 }

 void ViewAccessibility::SetState(VARIANT* msaa_state, views::View* view) {
   // Default state; all views can have accessibility focus.
   msaa_state->lVal |= STATE_SYSTEM_FOCUSABLE;

   if (!view)
     return;

   if (!view->IsEnabled()) {
     msaa_state->lVal |= STATE_SYSTEM_UNAVAILABLE;
   }
   if (!view->IsVisible()) {
     msaa_state->lVal |= STATE_SYSTEM_INVISIBLE;
   }
   if (view->IsHotTracked()) {
     msaa_state->lVal |= STATE_SYSTEM_HOTTRACKED;
   }
   if (view->IsPushed()) {
     msaa_state->lVal |= STATE_SYSTEM_PRESSED;
   }
   // Check both for actual View focus, as well as accessibility focus.
   views::View* parent = view->GetParent();

   if (view->HasFocus() ||
       (parent && parent->GetAccFocusedChildView() == view)) {
     msaa_state->lVal |= STATE_SYSTEM_FOCUSED;
   }

   // Add on any view-specific states.
   AccessibilityTypes::State state;
   view->GetAccessibleState(&state);

   msaa_state->lVal |= MSAAState(state);
 }

 long ViewAccessibility::MSAARole(AccessibilityTypes::Role role) {
   switch (role) {
     case AccessibilityTypes::ROLE_APPLICATION:
       return ROLE_SYSTEM_APPLICATION;
     case AccessibilityTypes::ROLE_BUTTONDROPDOWN:
       return ROLE_SYSTEM_BUTTONDROPDOWN;
     case AccessibilityTypes::ROLE_BUTTONMENU:
       return ROLE_SYSTEM_BUTTONMENU;
     case AccessibilityTypes::ROLE_GRAPHIC:
       return ROLE_SYSTEM_GRAPHIC;
     case AccessibilityTypes::ROLE_GROUPING:
       return ROLE_SYSTEM_GROUPING;
     case AccessibilityTypes::ROLE_PAGETAB:
       return ROLE_SYSTEM_PAGETAB;
     case AccessibilityTypes::ROLE_PAGETABLIST:
       return ROLE_SYSTEM_PAGETABLIST;
     case AccessibilityTypes::ROLE_PUSHBUTTON:
       return ROLE_SYSTEM_PUSHBUTTON;
     case AccessibilityTypes::ROLE_SEPARATOR:
       return ROLE_SYSTEM_SEPARATOR;
     case AccessibilityTypes::ROLE_TEXT:
       return ROLE_SYSTEM_TEXT;
     case AccessibilityTypes::ROLE_TITLEBAR:
       return ROLE_SYSTEM_TITLEBAR;
     case AccessibilityTypes::ROLE_TOOLBAR:
       return ROLE_SYSTEM_TOOLBAR;
     case AccessibilityTypes::ROLE_WINDOW:
       return ROLE_SYSTEM_WINDOW;
     case AccessibilityTypes::ROLE_CLIENT:
     default:
       // This is the default role for MSAA.
       return ROLE_SYSTEM_CLIENT;
   }
 }

 long ViewAccessibility::MSAAState(AccessibilityTypes::State state) {
   switch (state) {
     case AccessibilityTypes::STATE_HASPOPUP :
       return STATE_SYSTEM_HASPOPUP;
     case AccessibilityTypes::STATE_READONLY :
       return STATE_SYSTEM_READONLY;
     default :
       // No default state in MSAA.
       return 0;
   }
 }

 // IAccessible functions not supported.

 HRESULT ViewAccessibility::accDoDefaultAction(VARIANT var_id) {
   return E_NOTIMPL;
 }

 STDMETHODIMP ViewAccessibility::get_accValue(VARIANT var_id, BSTR* value) {
   if (value)
     *value = NULL;
   return E_NOTIMPL;
 }

 STDMETHODIMP ViewAccessibility::get_accSelection(VARIANT* selected) {
   if (selected)
     selected->vt = VT_EMPTY;
   return E_NOTIMPL;
 }

 STDMETHODIMP ViewAccessibility::accSelect(LONG flagsSelect, VARIANT var_id) {
   return E_NOTIMPL;
 }

 STDMETHODIMP ViewAccessibility::get_accHelp(VARIANT var_id, BSTR* help) {
   if (help)
     *help = NULL;
   return E_NOTIMPL;
 }

 STDMETHODIMP ViewAccessibility::get_accHelpTopic(BSTR* help_file,
                                                  VARIANT var_id,
                                                  LONG* topic_id) {
   if (help_file) {
     *help_file = NULL;
   }
   if (topic_id) {
     *topic_id = static_cast<LONG>(-1);
   }
   return E_NOTIMPL;
 }

 STDMETHODIMP ViewAccessibility::put_accName(VARIANT var_id, BSTR put_name) {
   // Deprecated.
   return E_NOTIMPL;
 }

 STDMETHODIMP ViewAccessibility::put_accValue(VARIANT var_id, BSTR put_val) {
   // Deprecated.
   return E_NOTIMPL;
 }
	// Copyright (c) 2006-2008 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.

	#include "views/accessibility/view_accessibility.h"

	#include "views/accessibility/view_accessibility_wrapper.h"
	#include "views/widget/widget.h"

	HRESULT ViewAccessibility::Initialize(views::View* view) {
	if (!view) {
	return E_INVALIDARG;
	}

	view_ = view;
	return S_OK;
	}

	// TODO(klink): Handle case where child View is not contained by parent.
	STDMETHODIMP ViewAccessibility::accHitTest(LONG x_left, LONG y_top,
	VARIANT* child) {
	if (!child) {
	return E_INVALIDARG;
	}

	gfx::Point pt(x_left, y_top);
	views::View::ConvertPointToView(NULL, view_, &pt);

	if (!view_->HitTest(pt)) {
	// If containing parent is not hit, return with failure.
	child->vt = VT_EMPTY;
	return S_FALSE;
	}

	int child_count = view_->GetChildViewCount();
	bool child_hit = false;
	views::View* child_view = NULL;
	for (int child_id = 0; child_id < child_count; ++child_id) {
	// Search for hit within any of the children.
	child_view = view_->GetChildViewAt(child_id);
	views::View::ConvertPointToView(view_, child_view, &pt);
	if (child_view->HitTest(pt)) {
	// Store child_id (adjusted with +1 to convert to MSAA indexing).
	child->lVal = child_id + 1;
	child_hit = true;
	break;
	}
	// Convert point back to parent view to test next child.
	views::View::ConvertPointToView(child_view, view_, &pt);
	}

	child->vt = VT_I4;

	if (!child_hit) {
	// No child hit, return parent id.
	child->lVal = CHILDID_SELF;
	} else {
	if (child_view == NULL) {
	return E_FAIL;
	} else if (child_view->GetChildViewCount() != 0) {
	// Retrieve IDispatch for child, if it is not a leaf.
	child->vt = VT_DISPATCH;
	if ((GetViewAccessibilityWrapper(child_view))->
	GetInstance(IID_IAccessible,
	reinterpret_cast<void**>(&child->pdispVal)) == S_OK) {
	// Increment the reference count for the retrieved interface.
	child->pdispVal->AddRef();
	return S_OK;
	} else {
	return E_NOINTERFACE;
	}
	}
	}

	return S_OK;
	}

	STDMETHODIMP ViewAccessibility::accLocation(LONG* x_left, LONG* y_top,
	LONG* width, LONG* height,
	VARIANT var_id) {
	if (var_id.vt != VT_I4 \|\| !x_left \|\| !y_top \|\| !width \|\| !height) {
	return E_INVALIDARG;
	}

	gfx::Rect view_bounds;
	// Retrieving the parent View to be used for converting from view-to-screen
	// coordinates.
	views::View* parent = view_->GetParent();

	if (parent == NULL) {
	// If no parent, remain within the same View.
	parent = view_;
	}

	if (var_id.lVal == CHILDID_SELF) {
	// Retrieve active View's bounds.
	view_bounds = view_->bounds();
	} else {
	// Check to see if child is out-of-bounds.
	if (!IsValidChild((var_id.lVal - 1), view_)) {
	return E_INVALIDARG;
	}
	// Retrieve child bounds.
	view_bounds = view_->GetChildViewAt(var_id.lVal - 1)->bounds();
	// Parent View is current View.
	parent = view_;
	}

	if (!view_bounds.IsEmpty()) {
	*width = view_bounds.width();
	*height = view_bounds.height();

	gfx::Point topleft(view_bounds.origin());
	views::View::ConvertPointToScreen(parent, &topleft);
	*x_left = topleft.x();
	*y_top = topleft.y();
	} else {
	return E_FAIL;
	}
	return S_OK;
	}

	STDMETHODIMP ViewAccessibility::accNavigate(LONG nav_dir, VARIANT start,
	VARIANT* end) {
	if (start.vt != VT_I4 \|\| !end) {
	return E_INVALIDARG;
	}

	switch (nav_dir) {
	case NAVDIR_FIRSTCHILD:
	case NAVDIR_LASTCHILD: {
	if (start.lVal != CHILDID_SELF) {
	// Start of navigation must be on the View itself.
	return E_INVALIDARG;
	} else if (view_->GetChildViewCount() == 0) {
	// No children found.
	return S_FALSE;
	}

	// Set child_id based on first or last child.
	int child_id = 0;
	if (nav_dir == NAVDIR_LASTCHILD) {
	child_id = view_->GetChildViewCount() - 1;
	}

	views::View* child = view_->GetChildViewAt(child_id);

	if (child->GetChildViewCount() != 0) {
	end->vt = VT_DISPATCH;
	if ((GetViewAccessibilityWrapper(child))->
	GetInstance(IID_IAccessible,
	reinterpret_cast<void**>(&end->pdispVal)) == S_OK) {
	// Increment the reference count for the retrieved interface.
	end->pdispVal->AddRef();
	return S_OK;
	} else {
	return E_NOINTERFACE;
	}
	} else {
	end->vt = VT_I4;
	// Set return child lVal, adjusted for MSAA indexing. (MSAA
	// child indexing starts with 1, whereas View indexing starts with 0).
	end->lVal = child_id + 1;
	}
	break;
	}
	case NAVDIR_LEFT:
	case NAVDIR_UP:
	case NAVDIR_PREVIOUS:
	case NAVDIR_RIGHT:
	case NAVDIR_DOWN:
	case NAVDIR_NEXT: {
	// Retrieve parent to access view index and perform bounds checking.
	views::View* parent = view_->GetParent();
	if (!parent) {
	return E_FAIL;
	}

	if (start.lVal == CHILDID_SELF) {
	int view_index = parent->GetChildIndex(view_);
	// Check navigation bounds, adjusting for View child indexing (MSAA
	// child indexing starts with 1, whereas View indexing starts with 0).
	if (!IsValidNav(nav_dir, view_index, -1,
	parent->GetChildViewCount())) {
	// Navigation attempted to go out-of-bounds.
	end->vt = VT_EMPTY;
	return S_FALSE;
	} else {
	if (IsNavDirNext(nav_dir)) {
	view_index += 1;
	} else {
	view_index -=1;
	}
	}

	views::View* child = parent->GetChildViewAt(view_index);
	if (child->GetChildViewCount() != 0) {
	end->vt = VT_DISPATCH;
	// Retrieve IDispatch for non-leaf child.
	if ((GetViewAccessibilityWrapper(child))->
	GetInstance(IID_IAccessible,
	reinterpret_cast<void**>(&end->pdispVal)) == S_OK) {
	// Increment the reference count for the retrieved interface.
	end->pdispVal->AddRef();
	return S_OK;
	} else {
	return E_NOINTERFACE;
	}
	} else {
	end->vt = VT_I4;
	// Modifying view_index to give lVal correct MSAA-based value. (MSAA
	// child indexing starts with 1, whereas View indexing starts with 0).
	end->lVal = view_index + 1;
	}
	} else {
	// Check navigation bounds, adjusting for MSAA child indexing (MSAA
	// child indexing starts with 1, whereas View indexing starts with 0).
	if (!IsValidNav(nav_dir, start.lVal, 0,
	parent->GetChildViewCount() + 1)) {
	// Navigation attempted to go out-of-bounds.
	end->vt = VT_EMPTY;
	return S_FALSE;
	} else {
	if (IsNavDirNext(nav_dir)) {
	start.lVal += 1;
	} else {
	start.lVal -= 1;
	}
	}

	HRESULT result = this->get_accChild(start, &end->pdispVal);
	if (result == S_FALSE) {
	// Child is a leaf.
	end->vt = VT_I4;
	end->lVal = start.lVal;
	} else if (result == E_INVALIDARG) {
	return E_INVALIDARG;
	} else {
	// Child is not a leaf.
	end->vt = VT_DISPATCH;
	}
	}
	break;
	}
	default:
	return E_INVALIDARG;
	}
	// Navigation performed correctly. Global return for this function, if no
	// error triggered an escape earlier.
	return S_OK;
	}

	STDMETHODIMP ViewAccessibility::get_accChild(VARIANT var_child,
	IDispatch** disp_child) {
	if (var_child.vt != VT_I4 \|\| !disp_child) {
	return E_INVALIDARG;
	}

	// If var_child is the parent, remain with the same IDispatch.
	if (var_child.lVal == CHILDID_SELF) {
	return S_OK;
	}

	views::View* child_view = NULL;
	bool get_iaccessible = false;

	// Check to see if child is out-of-bounds.
	if (IsValidChild((var_child.lVal - 1), view_)) {
	child_view = view_->GetChildViewAt(var_child.lVal - 1);
	} else {
	// Child is located elsewhere in the hierarchy, get ID and adjust for MSAA.
	child_view = view_->GetViewByID(static_cast<int>(var_child.lVal));
	get_iaccessible = true;
	}

	if (!child_view) {
	// No child found.
	*disp_child = NULL;
	return E_FAIL;
	}

	if (get_iaccessible \|\| child_view->GetChildViewCount() != 0) {
	// Retrieve the IUnknown interface for the requested child view, and
	// assign the IDispatch returned.
	if ((GetViewAccessibilityWrapper(child_view))->
	GetInstance(IID_IAccessible,
	reinterpret_cast<void**>(disp_child)) == S_OK) {
	// Increment the reference count for the retrieved interface.
	(*disp_child)->AddRef();
	return S_OK;
	} else {
	// No interface, return failure.
	return E_NOINTERFACE;
	}
	} else {
	// When at a leaf, children are handled by the parent object.
	*disp_child = NULL;
	return S_FALSE;
	}
	}

	STDMETHODIMP ViewAccessibility::get_accChildCount(LONG* child_count) {
	if (!child_count \|\| !view_) {
	return E_INVALIDARG;
	}

	*child_count = view_->GetChildViewCount();
	return S_OK;
	}

	STDMETHODIMP ViewAccessibility::get_accDefaultAction(VARIANT var_id,
	BSTR* def_action) {
	if (var_id.vt != VT_I4 \|\| !def_action) {
	return E_INVALIDARG;
	}

	std::wstring temp_action;

	if (var_id.lVal == CHILDID_SELF) {
	view_->GetAccessibleDefaultAction(&temp_action);
	} else {
	if (!IsValidChild((var_id.lVal - 1), view_)) {
	return E_INVALIDARG;
	}
	view_->GetChildViewAt(var_id.lVal - 1)->
	GetAccessibleDefaultAction(&temp_action);
	}
	if (!temp_action.empty()) {
	*def_action = SysAllocString(temp_action.c_str());
	} else {
	return S_FALSE;
	}

	return S_OK;
	}

	STDMETHODIMP ViewAccessibility::get_accDescription(VARIANT var_id, BSTR* desc) {
	if (var_id.vt != VT_I4 \|\| !desc) {
	return E_INVALIDARG;
	}

	std::wstring temp_desc;

	if (var_id.lVal == CHILDID_SELF) {
	view_->GetTooltipText(0, 0, &temp_desc);
	} else {
	if (!IsValidChild((var_id.lVal - 1), view_)) {
	return E_INVALIDARG;
	}
	view_->GetChildViewAt(var_id.lVal - 1)->GetTooltipText(0, 0, &temp_desc);
	}
	if (!temp_desc.empty()) {
	*desc = SysAllocString(temp_desc.c_str());
	} else {
	return S_FALSE;
	}

	return S_OK;
	}

	STDMETHODIMP ViewAccessibility::get_accFocus(VARIANT* focus_child) {
	if (!focus_child) {
	return E_INVALIDARG;
	}

	if (view_->GetChildViewCount() == 0 && view_->HasFocus()) {
	// Parent view has focus.
	focus_child->vt = VT_I4;
	focus_child->lVal = CHILDID_SELF;
	} else {
	bool has_focus = false;
	int child_count = view_->GetChildViewCount();
	// Search for child view with focus.
	for (int child_id = 0; child_id < child_count; ++child_id) {
	if (view_->GetChildViewAt(child_id)->HasFocus()) {
	focus_child->vt = VT_I4;
	focus_child->lVal = child_id + 1;

	// If child view is no leaf, retrieve IDispatch.
	if (view_->GetChildViewAt(child_id)->GetChildViewCount() != 0) {
	focus_child->vt = VT_DISPATCH;
	this->get_accChild(*focus_child, &focus_child->pdispVal);
	}
	has_focus = true;
	break;
	}
	}
	// No current focus on any of the children.
	if (!has_focus) {
	focus_child->vt = VT_EMPTY;
	return S_FALSE;
	}
	}

	return S_OK;
	}

	STDMETHODIMP ViewAccessibility::get_accKeyboardShortcut(VARIANT var_id,
	BSTR* acc_key) {
	if (var_id.vt != VT_I4 \|\| !acc_key) {
	return E_INVALIDARG;
	}

	std::wstring temp_key;

	if (var_id.lVal == CHILDID_SELF) {
	view_->GetAccessibleKeyboardShortcut(&temp_key);
	} else {
	if (!IsValidChild((var_id.lVal - 1), view_)) {
	return E_INVALIDARG;
	}
	view_->GetChildViewAt(var_id.lVal - 1)->
	GetAccessibleKeyboardShortcut(&temp_key);
	}
	if (!temp_key.empty()) {
	*acc_key = SysAllocString(temp_key.c_str());
	} else {
	return S_FALSE;
	}

	return S_OK;
	}

	STDMETHODIMP ViewAccessibility::get_accName(VARIANT var_id, BSTR* name) {
	if (var_id.vt != VT_I4 \|\| !name) {
	return E_INVALIDARG;
	}

	std::wstring temp_name;

	if (var_id.lVal == CHILDID_SELF) {
	// Retrieve the parent view's name.
	view_->GetAccessibleName(&temp_name);
	} else {
	if (!IsValidChild((var_id.lVal - 1), view_)) {
	return E_INVALIDARG;
	}
	// Retrieve the child view's name.
	view_->GetChildViewAt(var_id.lVal - 1)->GetAccessibleName(&temp_name);
	}
	if (!temp_name.empty()) {
	// Return name retrieved.
	*name = SysAllocString(temp_name.c_str());
	} else {
	// If view has no name, return S_FALSE.
	return S_FALSE;
	}

	return S_OK;
	}

	STDMETHODIMP ViewAccessibility::get_accParent(IDispatch** disp_parent) {
	if (!disp_parent) {
	return E_INVALIDARG;
	}

	views::View* parent_view = view_->GetParent();

	if (!parent_view) {
	// This function can get called during teardown of WidetWin so we
	// should bail out if we fail to get the HWND.
	if (!view_->GetWidget() \|\| !view_->GetWidget()->GetNativeView()) {
	*disp_parent = NULL;
	return S_FALSE;
	}

	// For a View that has no parent (e.g. root), point the accessible parent to
	// the default implementation, to interface with Windows' hierarchy and to
	// support calls from e.g. WindowFromAccessibleObject.
	HRESULT hr =
	::AccessibleObjectFromWindow(view_->GetWidget()->GetNativeView(),
	OBJID_WINDOW, IID_IAccessible,
	reinterpret_cast<void**>(disp_parent));

	if (!SUCCEEDED(hr)) {
	*disp_parent = NULL;
	return S_FALSE;
	}

	return S_OK;
	}

	// Retrieve the IUnknown interface for the parent view, and assign the
	// IDispatch returned.
	if ((GetViewAccessibilityWrapper(parent_view))->
	GetInstance(IID_IAccessible,
	reinterpret_cast<void**>(disp_parent)) == S_OK) {
	// Increment the reference count for the retrieved interface.
	(*disp_parent)->AddRef();
	return S_OK;
	} else {
	return E_NOINTERFACE;
	}
	}

	STDMETHODIMP ViewAccessibility::get_accRole(VARIANT var_id, VARIANT* role) {
	if (var_id.vt != VT_I4 \|\| !role) {
	return E_INVALIDARG;
	}

	AccessibilityTypes::Role acc_role;

	if (var_id.lVal == CHILDID_SELF) {
	// Retrieve parent role.
	if (!view_->GetAccessibleRole(&acc_role)) {
	return E_FAIL;
	}
	} else {
	if (!IsValidChild((var_id.lVal - 1), view_)) {
	return E_INVALIDARG;
	}
	// Retrieve child role.
	if (!view_->GetChildViewAt(var_id.lVal - 1)->GetAccessibleRole(&acc_role)) {
	role->vt = VT_EMPTY;
	return E_FAIL;
	}
	}

	role->vt = VT_I4;
	role->lVal = MSAARole(acc_role);
	return S_OK;
	}

	STDMETHODIMP ViewAccessibility::get_accState(VARIANT var_id, VARIANT* state) {
	if (var_id.vt != VT_I4 \|\| !state) {
	return E_INVALIDARG;
	}

	state->vt = VT_I4;

	if (var_id.lVal == CHILDID_SELF) {
	// Retrieve all currently applicable states of the parent.
	this->SetState(state, view_);
	} else {
	if (!IsValidChild((var_id.lVal - 1), view_)) {
	return E_INVALIDARG;
	}
	// Retrieve all currently applicable states of the child.
	this->SetState(state, view_->GetChildViewAt(var_id.lVal - 1));
	}

	// Make sure that state is not empty, and has the proper type.
	if (state->vt == VT_EMPTY)
	return E_FAIL;

	return S_OK;
	}

	// Helper functions.

	bool ViewAccessibility::IsValidChild(int child_id, views::View* view) const {
	if (((child_id) < 0) \|\|
	((child_id) >= view->GetChildViewCount())) {
	return false;
	}
	return true;
	}

	bool ViewAccessibility::IsNavDirNext(int nav_dir) const {
	if (nav_dir == NAVDIR_RIGHT \|\| nav_dir == NAVDIR_DOWN \|\|
	nav_dir == NAVDIR_NEXT) {
	return true;
	}
	return false;
	}

	bool ViewAccessibility::IsValidNav(int nav_dir, int start_id, int lower_bound,
	int upper_bound) const {
	if (IsNavDirNext(nav_dir)) {
	if ((start_id + 1) > upper_bound) {
	return false;
	}
	} else {
	if ((start_id - 1) <= lower_bound) {
	return false;
	}
	}
	return true;
	}

	void ViewAccessibility::SetState(VARIANT* msaa_state, views::View* view) {
	// Default state; all views can have accessibility focus.
	msaa_state->lVal \|= STATE_SYSTEM_FOCUSABLE;

	if (!view)
	return;

	if (!view->IsEnabled()) {
	msaa_state->lVal \|= STATE_SYSTEM_UNAVAILABLE;
	}
	if (!view->IsVisible()) {
	msaa_state->lVal \|= STATE_SYSTEM_INVISIBLE;
	}
	if (view->IsHotTracked()) {
	msaa_state->lVal \|= STATE_SYSTEM_HOTTRACKED;
	}
	if (view->IsPushed()) {
	msaa_state->lVal \|= STATE_SYSTEM_PRESSED;
	}
	// Check both for actual View focus, as well as accessibility focus.
	views::View* parent = view->GetParent();

	if (view->HasFocus() \|\|
	(parent && parent->GetAccFocusedChildView() == view)) {
	msaa_state->lVal \|= STATE_SYSTEM_FOCUSED;
	}

	// Add on any view-specific states.
	AccessibilityTypes::State state;
	view->GetAccessibleState(&state);

	msaa_state->lVal \|= MSAAState(state);
	}

	long ViewAccessibility::MSAARole(AccessibilityTypes::Role role) {
	switch (role) {
	case AccessibilityTypes::ROLE_APPLICATION:
	return ROLE_SYSTEM_APPLICATION;
	case AccessibilityTypes::ROLE_BUTTONDROPDOWN:
	return ROLE_SYSTEM_BUTTONDROPDOWN;
	case AccessibilityTypes::ROLE_BUTTONMENU:
	return ROLE_SYSTEM_BUTTONMENU;
	case AccessibilityTypes::ROLE_GRAPHIC:
	return ROLE_SYSTEM_GRAPHIC;
	case AccessibilityTypes::ROLE_GROUPING:
	return ROLE_SYSTEM_GROUPING;
	case AccessibilityTypes::ROLE_PAGETAB:
	return ROLE_SYSTEM_PAGETAB;
	case AccessibilityTypes::ROLE_PAGETABLIST:
	return ROLE_SYSTEM_PAGETABLIST;
	case AccessibilityTypes::ROLE_PUSHBUTTON:
	return ROLE_SYSTEM_PUSHBUTTON;
	case AccessibilityTypes::ROLE_SEPARATOR:
	return ROLE_SYSTEM_SEPARATOR;
	case AccessibilityTypes::ROLE_TEXT:
	return ROLE_SYSTEM_TEXT;
	case AccessibilityTypes::ROLE_TITLEBAR:
	return ROLE_SYSTEM_TITLEBAR;
	case AccessibilityTypes::ROLE_TOOLBAR:
	return ROLE_SYSTEM_TOOLBAR;
	case AccessibilityTypes::ROLE_WINDOW:
	return ROLE_SYSTEM_WINDOW;
	case AccessibilityTypes::ROLE_CLIENT:
	default:
	// This is the default role for MSAA.
	return ROLE_SYSTEM_CLIENT;
	}
	}

	long ViewAccessibility::MSAAState(AccessibilityTypes::State state) {
	switch (state) {
	case AccessibilityTypes::STATE_HASPOPUP :
	return STATE_SYSTEM_HASPOPUP;
	case AccessibilityTypes::STATE_READONLY :
	return STATE_SYSTEM_READONLY;
	default :
	// No default state in MSAA.
	return 0;
	}
	}

	// IAccessible functions not supported.

	HRESULT ViewAccessibility::accDoDefaultAction(VARIANT var_id) {
	return E_NOTIMPL;
	}

	STDMETHODIMP ViewAccessibility::get_accValue(VARIANT var_id, BSTR* value) {
	if (value)
	*value = NULL;
	return E_NOTIMPL;
	}

	STDMETHODIMP ViewAccessibility::get_accSelection(VARIANT* selected) {
	if (selected)
	selected->vt = VT_EMPTY;
	return E_NOTIMPL;
	}

	STDMETHODIMP ViewAccessibility::accSelect(LONG flagsSelect, VARIANT var_id) {
	return E_NOTIMPL;
	}

	STDMETHODIMP ViewAccessibility::get_accHelp(VARIANT var_id, BSTR* help) {
	if (help)
	*help = NULL;
	return E_NOTIMPL;
	}

	STDMETHODIMP ViewAccessibility::get_accHelpTopic(BSTR* help_file,
	VARIANT var_id,
	LONG* topic_id) {
	if (help_file) {
	*help_file = NULL;
	}
	if (topic_id) {
	*topic_id = static_cast<LONG>(-1);
	}
	return E_NOTIMPL;
	}

	STDMETHODIMP ViewAccessibility::put_accName(VARIANT var_id, BSTR put_name) {
	// Deprecated.
	return E_NOTIMPL;
	}

	STDMETHODIMP ViewAccessibility::put_accValue(VARIANT var_id, BSTR put_val) {
	// Deprecated.
	return E_NOTIMPL;
	}