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      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "ui/views/accessibility/native_view_accessibility_win.h"
      6 
      7 #include <oleacc.h>
      8 #include <UIAutomationClient.h>
      9 
     10 #include <set>
     11 #include <vector>
     12 
     13 #include "base/memory/singleton.h"
     14 #include "base/strings/utf_string_conversions.h"
     15 #include "base/win/scoped_comptr.h"
     16 #include "base/win/windows_version.h"
     17 #include "third_party/iaccessible2/ia2_api_all.h"
     18 #include "ui/accessibility/ax_enums.h"
     19 #include "ui/accessibility/ax_text_utils.h"
     20 #include "ui/accessibility/ax_view_state.h"
     21 #include "ui/base/win/accessibility_ids_win.h"
     22 #include "ui/base/win/accessibility_misc_utils.h"
     23 #include "ui/base/win/atl_module.h"
     24 #include "ui/views/controls/button/custom_button.h"
     25 #include "ui/views/focus/focus_manager.h"
     26 #include "ui/views/focus/view_storage.h"
     27 #include "ui/views/widget/widget.h"
     28 #include "ui/views/win/hwnd_util.h"
     29 
     30 namespace views {
     31 namespace {
     32 
     33 class AccessibleWebViewRegistry {
     34  public:
     35   static AccessibleWebViewRegistry* GetInstance();
     36 
     37   void RegisterWebView(View* web_view);
     38 
     39   void UnregisterWebView(View* web_view);
     40 
     41   // Given the view that received the request for the accessible
     42   // id in |top_view|, and the child id requested, return the native
     43   // accessible object with that child id from one of the WebViews in
     44   // |top_view|'s view hierarchy, if any.
     45   IAccessible* GetAccessibleFromWebView(View* top_view, long child_id);
     46 
     47   // The system uses IAccessible APIs for many purposes, but only
     48   // assistive technology like screen readers uses IAccessible2.
     49   // Call this method to note that the IAccessible2 interface was queried and
     50   // that WebViews should be proactively notified that this interface will be
     51   // used. If this is enabled for the first time, this will explicitly call
     52   // QueryService with an argument of IAccessible2 on all WebViews, otherwise
     53   // it will just do it from now on.
     54   void EnableIAccessible2Support();
     55 
     56  private:
     57   friend struct DefaultSingletonTraits<AccessibleWebViewRegistry>;
     58   AccessibleWebViewRegistry();
     59   ~AccessibleWebViewRegistry() {}
     60 
     61   IAccessible* AccessibleObjectFromChildId(View* web_view, long child_id);
     62 
     63   void QueryIAccessible2Interface(View* web_view);
     64 
     65   // Set of all web views. We check whether each one is contained in a
     66   // top view dynamically rather than keeping track of a map.
     67   std::set<View*> web_views_;
     68 
     69   // The most recent top view used in a call to GetAccessibleFromWebView.
     70   View* last_top_view_;
     71 
     72   // The most recent web view where an accessible object was found,
     73   // corresponding to |last_top_view_|.
     74   View* last_web_view_;
     75 
     76   // If IAccessible2 support is enabled, we query the IAccessible2 interface
     77   // of WebViews proactively when they're registered, so that they are
     78   // aware that they need to support this interface.
     79   bool iaccessible2_support_enabled_;
     80 
     81   DISALLOW_COPY_AND_ASSIGN(AccessibleWebViewRegistry);
     82 };
     83 
     84 AccessibleWebViewRegistry::AccessibleWebViewRegistry()
     85     : last_top_view_(NULL),
     86       last_web_view_(NULL),
     87       iaccessible2_support_enabled_(false) {
     88 }
     89 
     90 AccessibleWebViewRegistry* AccessibleWebViewRegistry::GetInstance() {
     91   return Singleton<AccessibleWebViewRegistry>::get();
     92 }
     93 
     94 void AccessibleWebViewRegistry::RegisterWebView(View* web_view) {
     95   DCHECK(web_views_.find(web_view) == web_views_.end());
     96   web_views_.insert(web_view);
     97 
     98   if (iaccessible2_support_enabled_)
     99     QueryIAccessible2Interface(web_view);
    100 }
    101 
    102 void AccessibleWebViewRegistry::UnregisterWebView(View* web_view) {
    103   DCHECK(web_views_.find(web_view) != web_views_.end());
    104   web_views_.erase(web_view);
    105   if (last_web_view_ == web_view) {
    106     last_top_view_ = NULL;
    107     last_web_view_ = NULL;
    108   }
    109 }
    110 
    111 IAccessible* AccessibleWebViewRegistry::GetAccessibleFromWebView(
    112     View* top_view, long child_id) {
    113   // This function gets called frequently, so try to avoid searching all
    114   // of the web views if the notification is on the same web view that
    115   // sent the last one.
    116   if (last_top_view_ == top_view) {
    117     IAccessible* accessible =
    118         AccessibleObjectFromChildId(last_web_view_, child_id);
    119     if (accessible)
    120       return accessible;
    121   }
    122 
    123   // Search all web views. For each one, first ensure it's a descendant
    124   // of this view where the event was posted - and if so, see if it owns
    125   // an accessible object with that child id. If so, save the view to speed
    126   // up the next notification.
    127   for (std::set<View*>::iterator iter = web_views_.begin();
    128        iter != web_views_.end(); ++iter) {
    129     View* web_view = *iter;
    130     if (top_view == web_view || !top_view->Contains(web_view))
    131       continue;
    132     IAccessible* accessible = AccessibleObjectFromChildId(web_view, child_id);
    133     if (accessible) {
    134       last_top_view_ = top_view;
    135       last_web_view_ = web_view;
    136       return accessible;
    137     }
    138   }
    139 
    140   return NULL;
    141 }
    142 
    143 void AccessibleWebViewRegistry::EnableIAccessible2Support() {
    144   if (iaccessible2_support_enabled_)
    145     return;
    146   iaccessible2_support_enabled_ = true;
    147   for (std::set<View*>::iterator iter = web_views_.begin();
    148        iter != web_views_.end(); ++iter) {
    149     QueryIAccessible2Interface(*iter);
    150   }
    151 }
    152 
    153 IAccessible* AccessibleWebViewRegistry::AccessibleObjectFromChildId(
    154     View* web_view,
    155     long child_id) {
    156   IAccessible* web_view_accessible = web_view->GetNativeViewAccessible();
    157   if (web_view_accessible == NULL)
    158     return NULL;
    159 
    160   VARIANT var_child;
    161   var_child.vt = VT_I4;
    162   var_child.lVal = child_id;
    163   IAccessible* result = NULL;
    164   if (S_OK == web_view_accessible->get_accChild(
    165       var_child, reinterpret_cast<IDispatch**>(&result))) {
    166     return result;
    167   }
    168 
    169   return NULL;
    170 }
    171 
    172 void AccessibleWebViewRegistry::QueryIAccessible2Interface(View* web_view) {
    173   IAccessible* web_view_accessible = web_view->GetNativeViewAccessible();
    174   if (!web_view_accessible)
    175     return;
    176 
    177   base::win::ScopedComPtr<IServiceProvider> service_provider;
    178   if (S_OK != web_view_accessible->QueryInterface(service_provider.Receive()))
    179     return;
    180   base::win::ScopedComPtr<IAccessible2> iaccessible2;
    181   service_provider->QueryService(
    182       IID_IAccessible, IID_IAccessible2,
    183       reinterpret_cast<void**>(iaccessible2.Receive()));
    184 }
    185 
    186 }  // anonymous namespace
    187 
    188 // static
    189 long NativeViewAccessibilityWin::next_unique_id_ = 1;
    190 int NativeViewAccessibilityWin::view_storage_ids_[kMaxViewStorageIds] = {0};
    191 int NativeViewAccessibilityWin::next_view_storage_id_index_ = 0;
    192 std::vector<int> NativeViewAccessibilityWin::alert_target_view_storage_ids_;
    193 
    194 // static
    195 NativeViewAccessibility* NativeViewAccessibility::Create(View* view) {
    196   // Make sure ATL is initialized in this module.
    197   ui::win::CreateATLModuleIfNeeded();
    198 
    199   CComObject<NativeViewAccessibilityWin>* instance = NULL;
    200   HRESULT hr = CComObject<NativeViewAccessibilityWin>::CreateInstance(
    201       &instance);
    202   DCHECK(SUCCEEDED(hr));
    203   instance->set_view(view);
    204   instance->AddRef();
    205   return instance;
    206 }
    207 
    208 NativeViewAccessibilityWin::NativeViewAccessibilityWin()
    209     : unique_id_(next_unique_id_++) {
    210 }
    211 
    212 NativeViewAccessibilityWin::~NativeViewAccessibilityWin() {
    213   RemoveAlertTarget();
    214 }
    215 
    216 void NativeViewAccessibilityWin::NotifyAccessibilityEvent(
    217     ui::AXEvent event_type) {
    218   if (!view_)
    219     return;
    220 
    221   ViewStorage* view_storage = ViewStorage::GetInstance();
    222   HWND hwnd = HWNDForView(view_);
    223   int view_storage_id = view_storage_ids_[next_view_storage_id_index_];
    224   if (view_storage_id == 0) {
    225     view_storage_id = view_storage->CreateStorageID();
    226     view_storage_ids_[next_view_storage_id_index_] = view_storage_id;
    227   } else {
    228     view_storage->RemoveView(view_storage_id);
    229   }
    230   view_storage->StoreView(view_storage_id, view_);
    231 
    232   // Positive child ids are used for enumerating direct children,
    233   // negative child ids can be used as unique ids to refer to a specific
    234   // descendants.  Make index into view_storage_ids_ into a negative child id.
    235   int child_id =
    236       base::win::kFirstViewsAccessibilityId - next_view_storage_id_index_;
    237   ::NotifyWinEvent(MSAAEvent(event_type), hwnd, OBJID_CLIENT, child_id);
    238   next_view_storage_id_index_ =
    239       (next_view_storage_id_index_ + 1) % kMaxViewStorageIds;
    240 
    241   // Keep track of views that are a target of an alert event.
    242   if (event_type == ui::AX_EVENT_ALERT)
    243     AddAlertTarget();
    244 }
    245 
    246 gfx::NativeViewAccessible NativeViewAccessibilityWin::GetNativeObject() {
    247   return this;
    248 }
    249 
    250 void NativeViewAccessibilityWin::Destroy() {
    251   view_ = NULL;
    252   Release();
    253 }
    254 
    255 STDMETHODIMP NativeViewAccessibilityWin::accHitTest(
    256     LONG x_left, LONG y_top, VARIANT* child) {
    257   if (!child)
    258     return E_INVALIDARG;
    259 
    260   if (!view_ || !view_->GetWidget())
    261     return E_FAIL;
    262 
    263   // If this is a root view, our widget might have child widgets.
    264   // Search child widgets first, since they're on top in the z-order.
    265   if (view_->GetWidget()->GetRootView() == view_) {
    266     std::vector<Widget*> child_widgets;
    267     PopulateChildWidgetVector(&child_widgets);
    268     for (size_t i = 0; i < child_widgets.size(); ++i) {
    269       Widget* child_widget = child_widgets[i];
    270       IAccessible* child_accessible =
    271           child_widget->GetRootView()->GetNativeViewAccessible();
    272       HRESULT result = child_accessible->accHitTest(x_left, y_top, child);
    273       if (result == S_OK)
    274         return result;
    275     }
    276   }
    277 
    278   gfx::Point point(x_left, y_top);
    279   View::ConvertPointFromScreen(view_, &point);
    280 
    281   // If the point is not inside this view, return false.
    282   if (!view_->HitTestPoint(point)) {
    283     child->vt = VT_EMPTY;
    284     return S_FALSE;
    285   }
    286 
    287   // Check if the point is within any of the immediate children of this
    288   // view.
    289   View* hit_child_view = NULL;
    290   for (int i = view_->child_count() - 1; i >= 0; --i) {
    291     View* child_view = view_->child_at(i);
    292     if (!child_view->visible())
    293       continue;
    294 
    295     gfx::Point point_in_child_coords(point);
    296     view_->ConvertPointToTarget(view_, child_view, &point_in_child_coords);
    297     if (child_view->HitTestPoint(point_in_child_coords)) {
    298       hit_child_view = child_view;
    299       break;
    300     }
    301   }
    302 
    303   // If the point was within one of this view's immediate children,
    304   // call accHitTest recursively on that child's native view accessible -
    305   // which may be a recursive call to this function or it may be overridden,
    306   // for example in the case of a WebView.
    307   if (hit_child_view) {
    308     HRESULT result = hit_child_view->GetNativeViewAccessible()->accHitTest(
    309         x_left, y_top, child);
    310 
    311     // If the recursive call returned CHILDID_SELF, we have to convert that
    312     // into a VT_DISPATCH for the return value to this call.
    313     if (S_OK == result && child->vt == VT_I4 && child->lVal == CHILDID_SELF) {
    314       child->vt = VT_DISPATCH;
    315       child->pdispVal = hit_child_view->GetNativeViewAccessible();
    316       // Always increment ref when returning a reference to a COM object.
    317       child->pdispVal->AddRef();
    318     }
    319     return result;
    320   }
    321 
    322   // This object is the best match, so return CHILDID_SELF. It's tempting to
    323   // simplify the logic and use VT_DISPATCH everywhere, but the Windows
    324   // call AccessibleObjectFromPoint will keep calling accHitTest until some
    325   // object returns CHILDID_SELF.
    326   child->vt = VT_I4;
    327   child->lVal = CHILDID_SELF;
    328   return S_OK;
    329 }
    330 
    331 HRESULT NativeViewAccessibilityWin::accDoDefaultAction(VARIANT var_id) {
    332   if (!IsValidId(var_id))
    333     return E_INVALIDARG;
    334 
    335   // The object does not support the method. This value is returned for
    336   // controls that do not perform actions, such as edit fields.
    337   return DISP_E_MEMBERNOTFOUND;
    338 }
    339 
    340 STDMETHODIMP NativeViewAccessibilityWin::accLocation(
    341     LONG* x_left, LONG* y_top, LONG* width, LONG* height, VARIANT var_id) {
    342   if (!IsValidId(var_id) || !x_left || !y_top || !width || !height)
    343     return E_INVALIDARG;
    344 
    345   if (!view_)
    346     return E_FAIL;
    347 
    348   if (!view_->bounds().IsEmpty()) {
    349     *width  = view_->width();
    350     *height = view_->height();
    351     gfx::Point topleft(view_->bounds().origin());
    352     View::ConvertPointToScreen(
    353         view_->parent() ? view_->parent() : view_, &topleft);
    354     *x_left = topleft.x();
    355     *y_top  = topleft.y();
    356   } else {
    357     return E_FAIL;
    358   }
    359   return S_OK;
    360 }
    361 
    362 STDMETHODIMP NativeViewAccessibilityWin::accNavigate(
    363     LONG nav_dir, VARIANT start, VARIANT* end) {
    364   if (start.vt != VT_I4 || !end)
    365     return E_INVALIDARG;
    366 
    367   if (!view_)
    368     return E_FAIL;
    369 
    370   switch (nav_dir) {
    371     case NAVDIR_FIRSTCHILD:
    372     case NAVDIR_LASTCHILD: {
    373       if (start.lVal != CHILDID_SELF) {
    374         // Start of navigation must be on the View itself.
    375         return E_INVALIDARG;
    376       } else if (!view_->has_children()) {
    377         // No children found.
    378         return S_FALSE;
    379       }
    380 
    381       // Set child_id based on first or last child.
    382       int child_id = 0;
    383       if (nav_dir == NAVDIR_LASTCHILD)
    384         child_id = view_->child_count() - 1;
    385 
    386       View* child = view_->child_at(child_id);
    387       end->vt = VT_DISPATCH;
    388       end->pdispVal = child->GetNativeViewAccessible();
    389       end->pdispVal->AddRef();
    390       return S_OK;
    391     }
    392     case NAVDIR_LEFT:
    393     case NAVDIR_UP:
    394     case NAVDIR_PREVIOUS:
    395     case NAVDIR_RIGHT:
    396     case NAVDIR_DOWN:
    397     case NAVDIR_NEXT: {
    398       // Retrieve parent to access view index and perform bounds checking.
    399       View* parent = view_->parent();
    400       if (!parent) {
    401         return E_FAIL;
    402       }
    403 
    404       if (start.lVal == CHILDID_SELF) {
    405         int view_index = parent->GetIndexOf(view_);
    406         // Check navigation bounds, adjusting for View child indexing (MSAA
    407         // child indexing starts with 1, whereas View indexing starts with 0).
    408         if (!IsValidNav(nav_dir, view_index, -1,
    409                         parent->child_count() - 1)) {
    410           // Navigation attempted to go out-of-bounds.
    411           end->vt = VT_EMPTY;
    412           return S_FALSE;
    413         } else {
    414           if (IsNavDirNext(nav_dir)) {
    415             view_index += 1;
    416           } else {
    417             view_index -=1;
    418           }
    419         }
    420 
    421         View* child = parent->child_at(view_index);
    422         end->pdispVal = child->GetNativeViewAccessible();
    423         end->vt = VT_DISPATCH;
    424         end->pdispVal->AddRef();
    425         return S_OK;
    426       } else {
    427         // Check navigation bounds, adjusting for MSAA child indexing (MSAA
    428         // child indexing starts with 1, whereas View indexing starts with 0).
    429         if (!IsValidNav(nav_dir, start.lVal, 0, parent->child_count() + 1)) {
    430             // Navigation attempted to go out-of-bounds.
    431             end->vt = VT_EMPTY;
    432             return S_FALSE;
    433           } else {
    434             if (IsNavDirNext(nav_dir)) {
    435               start.lVal += 1;
    436             } else {
    437               start.lVal -= 1;
    438             }
    439         }
    440 
    441         HRESULT result = this->get_accChild(start, &end->pdispVal);
    442         if (result == S_FALSE) {
    443           // Child is a leaf.
    444           end->vt = VT_I4;
    445           end->lVal = start.lVal;
    446         } else if (result == E_INVALIDARG) {
    447           return E_INVALIDARG;
    448         } else {
    449           // Child is not a leaf.
    450           end->vt = VT_DISPATCH;
    451         }
    452       }
    453       break;
    454     }
    455     default:
    456       return E_INVALIDARG;
    457   }
    458   // Navigation performed correctly. Global return for this function, if no
    459   // error triggered an escape earlier.
    460   return S_OK;
    461 }
    462 
    463 STDMETHODIMP NativeViewAccessibilityWin::get_accChild(VARIANT var_child,
    464                                                       IDispatch** disp_child) {
    465   if (var_child.vt != VT_I4 || !disp_child)
    466     return E_INVALIDARG;
    467 
    468   if (!view_ || !view_->GetWidget())
    469     return E_FAIL;
    470 
    471   LONG child_id = V_I4(&var_child);
    472 
    473   if (child_id == CHILDID_SELF) {
    474     // Remain with the same dispatch.
    475     return S_OK;
    476   }
    477 
    478   // If this is a root view, our widget might have child widgets. Include
    479   std::vector<Widget*> child_widgets;
    480   if (view_->GetWidget()->GetRootView() == view_)
    481     PopulateChildWidgetVector(&child_widgets);
    482   int child_widget_count = static_cast<int>(child_widgets.size());
    483 
    484   View* child_view = NULL;
    485   if (child_id > 0) {
    486     // Positive child ids are a 1-based child index, used by clients
    487     // that want to enumerate all immediate children.
    488     int child_id_as_index = child_id - 1;
    489     if (child_id_as_index < view_->child_count()) {
    490       child_view = view_->child_at(child_id_as_index);
    491     } else if (child_id_as_index < view_->child_count() + child_widget_count) {
    492       Widget* child_widget =
    493           child_widgets[child_id_as_index - view_->child_count()];
    494       child_view = child_widget->GetRootView();
    495     }
    496   } else {
    497     // Negative child ids can be used to map to any descendant.
    498     // Check child widget first.
    499     for (int i = 0; i < child_widget_count; i++) {
    500       Widget* child_widget = child_widgets[i];
    501       IAccessible* child_accessible =
    502           child_widget->GetRootView()->GetNativeViewAccessible();
    503       HRESULT result = child_accessible->get_accChild(var_child, disp_child);
    504       if (result == S_OK)
    505         return result;
    506     }
    507 
    508     // We map child ids to a view storage id that can refer to a
    509     // specific view (if that view still exists).
    510     int view_storage_id_index =
    511         base::win::kFirstViewsAccessibilityId - child_id;
    512     if (view_storage_id_index >= 0 &&
    513         view_storage_id_index < kMaxViewStorageIds) {
    514       int view_storage_id = view_storage_ids_[view_storage_id_index];
    515       ViewStorage* view_storage = ViewStorage::GetInstance();
    516       child_view = view_storage->RetrieveView(view_storage_id);
    517     } else {
    518       *disp_child = AccessibleWebViewRegistry::GetInstance()->
    519           GetAccessibleFromWebView(view_, child_id);
    520       if (*disp_child)
    521         return S_OK;
    522     }
    523   }
    524 
    525   if (!child_view) {
    526     // No child found.
    527     *disp_child = NULL;
    528     return E_FAIL;
    529   }
    530 
    531   *disp_child = child_view->GetNativeViewAccessible();
    532   if (*disp_child) {
    533     (*disp_child)->AddRef();
    534     return S_OK;
    535   }
    536 
    537   return E_FAIL;
    538 }
    539 
    540 STDMETHODIMP NativeViewAccessibilityWin::get_accChildCount(LONG* child_count) {
    541   if (!child_count)
    542     return E_INVALIDARG;
    543 
    544   if (!view_ || !view_->GetWidget())
    545     return E_FAIL;
    546 
    547   *child_count = view_->child_count();
    548 
    549   // If this is a root view, our widget might have child widgets. Include
    550   // them, too.
    551   if (view_->GetWidget()->GetRootView() == view_) {
    552     std::vector<Widget*> child_widgets;
    553     PopulateChildWidgetVector(&child_widgets);
    554     *child_count += child_widgets.size();
    555   }
    556 
    557   return S_OK;
    558 }
    559 
    560 STDMETHODIMP NativeViewAccessibilityWin::get_accDefaultAction(
    561     VARIANT var_id, BSTR* def_action) {
    562   if (!IsValidId(var_id) || !def_action)
    563     return E_INVALIDARG;
    564 
    565   if (!view_)
    566     return E_FAIL;
    567 
    568   ui::AXViewState state;
    569   view_->GetAccessibleState(&state);
    570   base::string16 temp_action = state.default_action;
    571 
    572   if (!temp_action.empty()) {
    573     *def_action = SysAllocString(temp_action.c_str());
    574   } else {
    575     return S_FALSE;
    576   }
    577 
    578   return S_OK;
    579 }
    580 
    581 STDMETHODIMP NativeViewAccessibilityWin::get_accDescription(
    582     VARIANT var_id, BSTR* desc) {
    583   if (!IsValidId(var_id) || !desc)
    584     return E_INVALIDARG;
    585 
    586   if (!view_)
    587     return E_FAIL;
    588 
    589   base::string16 temp_desc;
    590 
    591   view_->GetTooltipText(gfx::Point(), &temp_desc);
    592   if (!temp_desc.empty()) {
    593     *desc = SysAllocString(temp_desc.c_str());
    594   } else {
    595     return S_FALSE;
    596   }
    597 
    598   return S_OK;
    599 }
    600 
    601 STDMETHODIMP NativeViewAccessibilityWin::get_accFocus(VARIANT* focus_child) {
    602   if (!focus_child)
    603     return E_INVALIDARG;
    604 
    605   if (!view_)
    606     return E_FAIL;
    607 
    608   FocusManager* focus_manager = view_->GetFocusManager();
    609   View* focus = focus_manager ? focus_manager->GetFocusedView() : NULL;
    610   if (focus == view_) {
    611     // This view has focus.
    612     focus_child->vt = VT_I4;
    613     focus_child->lVal = CHILDID_SELF;
    614   } else if (focus && view_->Contains(focus)) {
    615     // Return the child object that has the keyboard focus.
    616     focus_child->vt = VT_DISPATCH;
    617     focus_child->pdispVal = focus->GetNativeViewAccessible();
    618     focus_child->pdispVal->AddRef();
    619     return S_OK;
    620   } else {
    621     // Neither this object nor any of its children has the keyboard focus.
    622     focus_child->vt = VT_EMPTY;
    623   }
    624   return S_OK;
    625 }
    626 
    627 STDMETHODIMP NativeViewAccessibilityWin::get_accKeyboardShortcut(
    628     VARIANT var_id, BSTR* acc_key) {
    629   if (!IsValidId(var_id) || !acc_key)
    630     return E_INVALIDARG;
    631 
    632   if (!view_)
    633     return E_FAIL;
    634 
    635   ui::AXViewState state;
    636   view_->GetAccessibleState(&state);
    637   base::string16 temp_key = state.keyboard_shortcut;
    638 
    639   if (!temp_key.empty()) {
    640     *acc_key = SysAllocString(temp_key.c_str());
    641   } else {
    642     return S_FALSE;
    643   }
    644 
    645   return S_OK;
    646 }
    647 
    648 STDMETHODIMP NativeViewAccessibilityWin::get_accName(
    649     VARIANT var_id, BSTR* name) {
    650   if (!IsValidId(var_id) || !name)
    651     return E_INVALIDARG;
    652 
    653   if (!view_)
    654     return E_FAIL;
    655 
    656   // Retrieve the current view's name.
    657   ui::AXViewState state;
    658   view_->GetAccessibleState(&state);
    659   base::string16 temp_name = state.name;
    660   if (!temp_name.empty()) {
    661     // Return name retrieved.
    662     *name = SysAllocString(temp_name.c_str());
    663   } else {
    664     // If view has no name, return S_FALSE.
    665     return S_FALSE;
    666   }
    667 
    668   return S_OK;
    669 }
    670 
    671 STDMETHODIMP NativeViewAccessibilityWin::get_accParent(
    672     IDispatch** disp_parent) {
    673   if (!disp_parent)
    674     return E_INVALIDARG;
    675 
    676   if (!view_)
    677     return E_FAIL;
    678 
    679   *disp_parent = NULL;
    680   View* parent_view = view_->parent();
    681 
    682   if (!parent_view) {
    683     HWND hwnd = HWNDForView(view_);
    684     if (!hwnd)
    685       return S_FALSE;
    686 
    687     return ::AccessibleObjectFromWindow(
    688         hwnd, OBJID_WINDOW, IID_IAccessible,
    689         reinterpret_cast<void**>(disp_parent));
    690   }
    691 
    692   *disp_parent = parent_view->GetNativeViewAccessible();
    693   (*disp_parent)->AddRef();
    694   return S_OK;
    695 }
    696 
    697 STDMETHODIMP NativeViewAccessibilityWin::get_accRole(
    698     VARIANT var_id, VARIANT* role) {
    699   if (!IsValidId(var_id) || !role)
    700     return E_INVALIDARG;
    701 
    702   if (!view_)
    703     return E_FAIL;
    704 
    705   ui::AXViewState state;
    706   view_->GetAccessibleState(&state);
    707   role->vt = VT_I4;
    708   role->lVal = MSAARole(state.role);
    709   return S_OK;
    710 }
    711 
    712 STDMETHODIMP NativeViewAccessibilityWin::get_accState(
    713     VARIANT var_id, VARIANT* state) {
    714   // This returns MSAA states. See also the IAccessible2 interface
    715   // get_states().
    716 
    717   if (!IsValidId(var_id) || !state)
    718     return E_INVALIDARG;
    719 
    720   if (!view_)
    721     return E_FAIL;
    722 
    723   state->vt = VT_I4;
    724 
    725   // Retrieve all currently applicable states of the parent.
    726   SetState(state, view_);
    727 
    728   // Make sure that state is not empty, and has the proper type.
    729   if (state->vt == VT_EMPTY)
    730     return E_FAIL;
    731 
    732   return S_OK;
    733 }
    734 
    735 STDMETHODIMP NativeViewAccessibilityWin::get_accValue(VARIANT var_id,
    736                                                       BSTR* value) {
    737   if (!IsValidId(var_id) || !value)
    738     return E_INVALIDARG;
    739 
    740   if (!view_)
    741     return E_FAIL;
    742 
    743   // Retrieve the current view's value.
    744   ui::AXViewState state;
    745   view_->GetAccessibleState(&state);
    746   base::string16 temp_value = state.value;
    747 
    748   if (!temp_value.empty()) {
    749     // Return value retrieved.
    750     *value = SysAllocString(temp_value.c_str());
    751   } else {
    752     // If view has no value, fall back into the default implementation.
    753     *value = NULL;
    754     return E_NOTIMPL;
    755   }
    756 
    757   return S_OK;
    758 }
    759 
    760 STDMETHODIMP NativeViewAccessibilityWin::put_accValue(VARIANT var_id,
    761                                                       BSTR new_value) {
    762   if (!IsValidId(var_id) || !new_value)
    763     return E_INVALIDARG;
    764 
    765   if (!view_)
    766     return E_FAIL;
    767 
    768   // Return an error if the view can't set the value.
    769   ui::AXViewState state;
    770   view_->GetAccessibleState(&state);
    771   if (state.set_value_callback.is_null())
    772     return E_FAIL;
    773 
    774   state.set_value_callback.Run(new_value);
    775   return S_OK;
    776 }
    777 
    778 // IAccessible functions not supported.
    779 
    780 STDMETHODIMP NativeViewAccessibilityWin::get_accSelection(VARIANT* selected) {
    781   if (selected)
    782     selected->vt = VT_EMPTY;
    783   return E_NOTIMPL;
    784 }
    785 
    786 STDMETHODIMP NativeViewAccessibilityWin::accSelect(
    787     LONG flagsSelect, VARIANT var_id) {
    788   return E_NOTIMPL;
    789 }
    790 
    791 STDMETHODIMP NativeViewAccessibilityWin::get_accHelp(
    792     VARIANT var_id, BSTR* help) {
    793   base::string16 temp = base::UTF8ToUTF16(view_->GetClassName());
    794   *help = SysAllocString(temp.c_str());
    795   return S_OK;
    796 }
    797 
    798 STDMETHODIMP NativeViewAccessibilityWin::get_accHelpTopic(
    799     BSTR* help_file, VARIANT var_id, LONG* topic_id) {
    800   if (help_file) {
    801     *help_file = NULL;
    802   }
    803   if (topic_id) {
    804     *topic_id = static_cast<LONG>(-1);
    805   }
    806   return E_NOTIMPL;
    807 }
    808 
    809 STDMETHODIMP NativeViewAccessibilityWin::put_accName(
    810     VARIANT var_id, BSTR put_name) {
    811   // Deprecated.
    812   return E_NOTIMPL;
    813 }
    814 
    815 //
    816 // IAccessible2
    817 //
    818 
    819 STDMETHODIMP NativeViewAccessibilityWin::role(LONG* role) {
    820   if (!view_)
    821     return E_FAIL;
    822 
    823   if (!role)
    824     return E_INVALIDARG;
    825 
    826   ui::AXViewState state;
    827   view_->GetAccessibleState(&state);
    828   *role = MSAARole(state.role);
    829   return S_OK;
    830 }
    831 
    832 STDMETHODIMP NativeViewAccessibilityWin::get_states(AccessibleStates* states) {
    833   // This returns IAccessible2 states, which supplement MSAA states.
    834   // See also the MSAA interface get_accState.
    835 
    836   if (!view_)
    837     return E_FAIL;
    838 
    839   if (!states)
    840     return E_INVALIDARG;
    841 
    842   ui::AXViewState state;
    843   view_->GetAccessibleState(&state);
    844 
    845   // There are only a couple of states we need to support
    846   // in IAccessible2. If any more are added, we may want to
    847   // add a helper function like MSAAState.
    848   *states = IA2_STATE_OPAQUE;
    849   if (state.HasStateFlag(ui::AX_STATE_EDITABLE))
    850     *states |= IA2_STATE_EDITABLE;
    851 
    852   return S_OK;
    853 }
    854 
    855 STDMETHODIMP NativeViewAccessibilityWin::get_uniqueID(LONG* unique_id) {
    856   if (!view_)
    857     return E_FAIL;
    858 
    859   if (!unique_id)
    860     return E_INVALIDARG;
    861 
    862   *unique_id = unique_id_;
    863   return S_OK;
    864 }
    865 
    866 STDMETHODIMP NativeViewAccessibilityWin::get_windowHandle(HWND* window_handle) {
    867   if (!view_)
    868     return E_FAIL;
    869 
    870   if (!window_handle)
    871     return E_INVALIDARG;
    872 
    873   *window_handle = HWNDForView(view_);
    874   return *window_handle ? S_OK : S_FALSE;
    875 }
    876 
    877 STDMETHODIMP NativeViewAccessibilityWin::get_relationTargetsOfType(
    878     BSTR type_bstr,
    879     long max_targets,
    880     IUnknown ***targets,
    881     long *n_targets) {
    882   if (!view_)
    883     return E_FAIL;
    884 
    885   if (!targets || !n_targets)
    886     return E_INVALIDARG;
    887 
    888   *n_targets = 0;
    889   *targets = NULL;
    890 
    891   // Only respond to requests for relations of type "alerts" on the
    892   // root view.
    893   base::string16 type(type_bstr);
    894   if (type != L"alerts" || view_->parent())
    895     return S_FALSE;
    896 
    897   // Collect all of the alert views that are still valid.
    898   std::vector<View*> alert_views;
    899   ViewStorage* view_storage = ViewStorage::GetInstance();
    900   for (size_t i = 0; i < alert_target_view_storage_ids_.size(); ++i) {
    901     int view_storage_id = alert_target_view_storage_ids_[i];
    902     View* view = view_storage->RetrieveView(view_storage_id);
    903     if (!view || !view_->Contains(view))
    904       continue;
    905     alert_views.push_back(view);
    906   }
    907 
    908   long count = alert_views.size();
    909   if (count == 0)
    910     return S_FALSE;
    911 
    912   // Don't return more targets than max_targets - but note that the caller
    913   // is allowed to specify max_targets=0 to mean no limit.
    914   if (max_targets > 0 && count > max_targets)
    915     count = max_targets;
    916 
    917   // Return the number of targets.
    918   *n_targets = count;
    919 
    920   // Allocate COM memory for the result array and populate it.
    921   *targets = static_cast<IUnknown**>(
    922       CoTaskMemAlloc(count * sizeof(IUnknown*)));
    923   for (long i = 0; i < count; ++i) {
    924     (*targets)[i] = alert_views[i]->GetNativeViewAccessible();
    925     (*targets)[i]->AddRef();
    926   }
    927   return S_OK;
    928 }
    929 
    930 STDMETHODIMP NativeViewAccessibilityWin::get_attributes(BSTR* attributes) {
    931   if (!view_)
    932     return E_FAIL;
    933 
    934   if (!attributes)
    935     return E_INVALIDARG;
    936 
    937   base::string16 attributes_str;
    938 
    939   // Text fields need to report the attribute "text-model:a1" to instruct
    940   // screen readers to use IAccessible2 APIs to handle text editing in this
    941   // object (as opposed to treating it like a native Windows text box).
    942   // The text-model:a1 attribute is documented here:
    943   // http://www.linuxfoundation.org/collaborate/workgroups/accessibility/ia2/ia2_implementation_guide
    944   ui::AXViewState state;
    945   view_->GetAccessibleState(&state);
    946   if (state.role == ui::AX_ROLE_TEXT_FIELD) {
    947     attributes_str = L"text-model:a1;";
    948   }
    949 
    950   *attributes = SysAllocString(attributes_str.c_str());
    951   DCHECK(*attributes);
    952   return S_OK;
    953 }
    954 
    955 //
    956 // IAccessibleText
    957 //
    958 
    959 STDMETHODIMP NativeViewAccessibilityWin::get_nCharacters(LONG* n_characters) {
    960   if (!view_)
    961     return E_FAIL;
    962 
    963   if (!n_characters)
    964     return E_INVALIDARG;
    965 
    966   base::string16 text = TextForIAccessibleText();
    967   *n_characters = static_cast<LONG>(text.size());
    968   return S_OK;
    969 }
    970 
    971 STDMETHODIMP NativeViewAccessibilityWin::get_caretOffset(LONG* offset) {
    972   if (!view_)
    973     return E_FAIL;
    974 
    975   if (!offset)
    976     return E_INVALIDARG;
    977 
    978   ui::AXViewState state;
    979   view_->GetAccessibleState(&state);
    980   *offset = static_cast<LONG>(state.selection_end);
    981   return S_OK;
    982 }
    983 
    984 STDMETHODIMP NativeViewAccessibilityWin::get_nSelections(LONG* n_selections) {
    985   if (!view_)
    986     return E_FAIL;
    987 
    988   if (!n_selections)
    989     return E_INVALIDARG;
    990 
    991   ui::AXViewState state;
    992   view_->GetAccessibleState(&state);
    993   if (state.selection_start != state.selection_end)
    994     *n_selections = 1;
    995   else
    996     *n_selections = 0;
    997   return S_OK;
    998 }
    999 
   1000 STDMETHODIMP NativeViewAccessibilityWin::get_selection(LONG selection_index,
   1001                                                       LONG* start_offset,
   1002                                                       LONG* end_offset) {
   1003   if (!view_)
   1004     return E_FAIL;
   1005 
   1006   if (!start_offset || !end_offset || selection_index != 0)
   1007     return E_INVALIDARG;
   1008 
   1009   ui::AXViewState state;
   1010   view_->GetAccessibleState(&state);
   1011   *start_offset = static_cast<LONG>(state.selection_start);
   1012   *end_offset = static_cast<LONG>(state.selection_end);
   1013   return S_OK;
   1014 }
   1015 
   1016 STDMETHODIMP NativeViewAccessibilityWin::get_text(LONG start_offset,
   1017                                                   LONG end_offset,
   1018                                                   BSTR* text) {
   1019   if (!view_)
   1020     return E_FAIL;
   1021 
   1022   ui::AXViewState state;
   1023   view_->GetAccessibleState(&state);
   1024   base::string16 text_str = TextForIAccessibleText();
   1025   LONG len = static_cast<LONG>(text_str.size());
   1026 
   1027   if (start_offset == IA2_TEXT_OFFSET_LENGTH) {
   1028     start_offset = len;
   1029   } else if (start_offset == IA2_TEXT_OFFSET_CARET) {
   1030     start_offset = static_cast<LONG>(state.selection_end);
   1031   }
   1032   if (end_offset == IA2_TEXT_OFFSET_LENGTH) {
   1033     end_offset = static_cast<LONG>(text_str.size());
   1034   } else if (end_offset == IA2_TEXT_OFFSET_CARET) {
   1035     end_offset = static_cast<LONG>(state.selection_end);
   1036   }
   1037 
   1038   // The spec allows the arguments to be reversed.
   1039   if (start_offset > end_offset) {
   1040     LONG tmp = start_offset;
   1041     start_offset = end_offset;
   1042     end_offset = tmp;
   1043   }
   1044 
   1045   // The spec does not allow the start or end offsets to be out or range;
   1046   // we must return an error if so.
   1047   if (start_offset < 0)
   1048     return E_INVALIDARG;
   1049   if (end_offset > len)
   1050     return E_INVALIDARG;
   1051 
   1052   base::string16 substr =
   1053       text_str.substr(start_offset, end_offset - start_offset);
   1054   if (substr.empty())
   1055     return S_FALSE;
   1056 
   1057   *text = SysAllocString(substr.c_str());
   1058   DCHECK(*text);
   1059   return S_OK;
   1060 }
   1061 
   1062 STDMETHODIMP NativeViewAccessibilityWin::get_textAtOffset(
   1063     LONG offset,
   1064     enum IA2TextBoundaryType boundary_type,
   1065     LONG* start_offset, LONG* end_offset,
   1066     BSTR* text) {
   1067   if (!start_offset || !end_offset || !text)
   1068     return E_INVALIDARG;
   1069 
   1070   // The IAccessible2 spec says we don't have to implement the "sentence"
   1071   // boundary type, we can just let the screenreader handle it.
   1072   if (boundary_type == IA2_TEXT_BOUNDARY_SENTENCE) {
   1073     *start_offset = 0;
   1074     *end_offset = 0;
   1075     *text = NULL;
   1076     return S_FALSE;
   1077   }
   1078 
   1079   const base::string16& text_str = TextForIAccessibleText();
   1080 
   1081   *start_offset = FindBoundary(
   1082       text_str, boundary_type, offset, ui::BACKWARDS_DIRECTION);
   1083   *end_offset = FindBoundary(
   1084       text_str, boundary_type, offset, ui::FORWARDS_DIRECTION);
   1085   return get_text(*start_offset, *end_offset, text);
   1086 }
   1087 
   1088 STDMETHODIMP NativeViewAccessibilityWin::get_textBeforeOffset(
   1089     LONG offset,
   1090     enum IA2TextBoundaryType boundary_type,
   1091     LONG* start_offset, LONG* end_offset,
   1092     BSTR* text) {
   1093   if (!start_offset || !end_offset || !text)
   1094     return E_INVALIDARG;
   1095 
   1096   // The IAccessible2 spec says we don't have to implement the "sentence"
   1097   // boundary type, we can just let the screenreader handle it.
   1098   if (boundary_type == IA2_TEXT_BOUNDARY_SENTENCE) {
   1099     *start_offset = 0;
   1100     *end_offset = 0;
   1101     *text = NULL;
   1102     return S_FALSE;
   1103   }
   1104 
   1105   const base::string16& text_str = TextForIAccessibleText();
   1106 
   1107   *start_offset = FindBoundary(
   1108       text_str, boundary_type, offset, ui::BACKWARDS_DIRECTION);
   1109   *end_offset = offset;
   1110   return get_text(*start_offset, *end_offset, text);
   1111 }
   1112 
   1113 STDMETHODIMP NativeViewAccessibilityWin::get_textAfterOffset(
   1114     LONG offset,
   1115     enum IA2TextBoundaryType boundary_type,
   1116     LONG* start_offset, LONG* end_offset,
   1117     BSTR* text) {
   1118   if (!start_offset || !end_offset || !text)
   1119     return E_INVALIDARG;
   1120 
   1121   // The IAccessible2 spec says we don't have to implement the "sentence"
   1122   // boundary type, we can just let the screenreader handle it.
   1123   if (boundary_type == IA2_TEXT_BOUNDARY_SENTENCE) {
   1124     *start_offset = 0;
   1125     *end_offset = 0;
   1126     *text = NULL;
   1127     return S_FALSE;
   1128   }
   1129 
   1130   const base::string16& text_str = TextForIAccessibleText();
   1131 
   1132   *start_offset = offset;
   1133   *end_offset = FindBoundary(
   1134       text_str, boundary_type, offset, ui::FORWARDS_DIRECTION);
   1135   return get_text(*start_offset, *end_offset, text);
   1136 }
   1137 
   1138 STDMETHODIMP NativeViewAccessibilityWin::get_offsetAtPoint(
   1139     LONG x, LONG y, enum IA2CoordinateType coord_type, LONG* offset) {
   1140   if (!view_)
   1141     return E_FAIL;
   1142 
   1143   if (!offset)
   1144     return E_INVALIDARG;
   1145 
   1146   // We don't support this method, but we have to return something
   1147   // rather than E_NOTIMPL or screen readers will complain.
   1148   *offset = 0;
   1149   return S_OK;
   1150 }
   1151 
   1152 //
   1153 // IServiceProvider methods.
   1154 //
   1155 
   1156 STDMETHODIMP NativeViewAccessibilityWin::QueryService(
   1157     REFGUID guidService, REFIID riid, void** object) {
   1158   if (!view_)
   1159     return E_FAIL;
   1160 
   1161   if (riid == IID_IAccessible2 || riid == IID_IAccessible2_2)
   1162     AccessibleWebViewRegistry::GetInstance()->EnableIAccessible2Support();
   1163 
   1164   if (guidService == IID_IAccessible ||
   1165       guidService == IID_IAccessible2 ||
   1166       guidService == IID_IAccessible2_2 ||
   1167       guidService == IID_IAccessibleText)  {
   1168     return QueryInterface(riid, object);
   1169   }
   1170 
   1171   // We only support the IAccessibleEx interface on Windows 8 and above. This
   1172   // is needed for the On screen Keyboard to show up in metro mode, when the
   1173   // user taps an editable region in the window.
   1174   // All methods in the IAccessibleEx interface are unimplemented.
   1175   if (riid == IID_IAccessibleEx &&
   1176       base::win::GetVersion() >= base::win::VERSION_WIN8) {
   1177     return QueryInterface(riid, object);
   1178   }
   1179 
   1180   *object = NULL;
   1181   return E_FAIL;
   1182 }
   1183 
   1184 STDMETHODIMP NativeViewAccessibilityWin::GetPatternProvider(
   1185     PATTERNID id, IUnknown** provider) {
   1186   DVLOG(1) << "In Function: "
   1187            << __FUNCTION__
   1188            << " for pattern id: "
   1189            << id;
   1190   if (id == UIA_ValuePatternId || id == UIA_TextPatternId) {
   1191     ui::AXViewState state;
   1192     view_->GetAccessibleState(&state);
   1193     long role = MSAARole(state.role);
   1194 
   1195     if (role == ROLE_SYSTEM_TEXT) {
   1196       DVLOG(1) << "Returning UIA text provider";
   1197       base::win::UIATextProvider::CreateTextProvider(
   1198           state.value, true, provider);
   1199       return S_OK;
   1200     }
   1201   }
   1202   return E_NOTIMPL;
   1203 }
   1204 
   1205 STDMETHODIMP NativeViewAccessibilityWin::GetPropertyValue(PROPERTYID id,
   1206                                                           VARIANT* ret) {
   1207   DVLOG(1) << "In Function: "
   1208            << __FUNCTION__
   1209            << " for property id: "
   1210            << id;
   1211   if (id == UIA_ControlTypePropertyId) {
   1212     ui::AXViewState state;
   1213     view_->GetAccessibleState(&state);
   1214     long role = MSAARole(state.role);
   1215     if (role == ROLE_SYSTEM_TEXT) {
   1216       V_VT(ret) = VT_I4;
   1217       ret->lVal = UIA_EditControlTypeId;
   1218       DVLOG(1) << "Returning Edit control type";
   1219     } else {
   1220       DVLOG(1) << "Returning empty control type";
   1221       V_VT(ret) = VT_EMPTY;
   1222     }
   1223   } else {
   1224     V_VT(ret) = VT_EMPTY;
   1225   }
   1226   return S_OK;
   1227 }
   1228 
   1229 //
   1230 // Static methods.
   1231 //
   1232 
   1233 void NativeViewAccessibility::RegisterWebView(View* web_view) {
   1234   AccessibleWebViewRegistry::GetInstance()->RegisterWebView(web_view);
   1235 }
   1236 
   1237 void NativeViewAccessibility::UnregisterWebView(View* web_view) {
   1238   AccessibleWebViewRegistry::GetInstance()->UnregisterWebView(web_view);
   1239 }
   1240 
   1241 int32 NativeViewAccessibilityWin::MSAAEvent(ui::AXEvent event) {
   1242   switch (event) {
   1243     case ui::AX_EVENT_ALERT:
   1244       return EVENT_SYSTEM_ALERT;
   1245     case ui::AX_EVENT_FOCUS:
   1246       return EVENT_OBJECT_FOCUS;
   1247     case ui::AX_EVENT_MENU_START:
   1248       return EVENT_SYSTEM_MENUSTART;
   1249     case ui::AX_EVENT_MENU_END:
   1250       return EVENT_SYSTEM_MENUEND;
   1251     case ui::AX_EVENT_MENU_POPUP_START:
   1252       return EVENT_SYSTEM_MENUPOPUPSTART;
   1253     case ui::AX_EVENT_MENU_POPUP_END:
   1254       return EVENT_SYSTEM_MENUPOPUPEND;
   1255     case ui::AX_EVENT_SELECTION:
   1256       return EVENT_OBJECT_SELECTION;
   1257     case ui::AX_EVENT_SELECTION_ADD:
   1258       return EVENT_OBJECT_SELECTIONADD;
   1259     case ui::AX_EVENT_SELECTION_REMOVE:
   1260       return EVENT_OBJECT_SELECTIONREMOVE;
   1261     case ui::AX_EVENT_TEXT_CHANGED:
   1262       return EVENT_OBJECT_NAMECHANGE;
   1263     case ui::AX_EVENT_TEXT_SELECTION_CHANGED:
   1264       return IA2_EVENT_TEXT_CARET_MOVED;
   1265     case ui::AX_EVENT_VALUE_CHANGED:
   1266       return EVENT_OBJECT_VALUECHANGE;
   1267     default:
   1268       // Not supported or invalid event.
   1269       NOTREACHED();
   1270       return -1;
   1271   }
   1272 }
   1273 
   1274 int32 NativeViewAccessibilityWin::MSAARole(ui::AXRole role) {
   1275   switch (role) {
   1276     case ui::AX_ROLE_ALERT:
   1277       return ROLE_SYSTEM_ALERT;
   1278     case ui::AX_ROLE_APPLICATION:
   1279       return ROLE_SYSTEM_APPLICATION;
   1280     case ui::AX_ROLE_BUTTON_DROP_DOWN:
   1281       return ROLE_SYSTEM_BUTTONDROPDOWN;
   1282     case ui::AX_ROLE_POP_UP_BUTTON:
   1283       return ROLE_SYSTEM_BUTTONMENU;
   1284     case ui::AX_ROLE_CHECK_BOX:
   1285       return ROLE_SYSTEM_CHECKBUTTON;
   1286     case ui::AX_ROLE_COMBO_BOX:
   1287       return ROLE_SYSTEM_COMBOBOX;
   1288     case ui::AX_ROLE_DIALOG:
   1289       return ROLE_SYSTEM_DIALOG;
   1290     case ui::AX_ROLE_GROUP:
   1291       return ROLE_SYSTEM_GROUPING;
   1292     case ui::AX_ROLE_IMAGE:
   1293       return ROLE_SYSTEM_GRAPHIC;
   1294     case ui::AX_ROLE_LINK:
   1295       return ROLE_SYSTEM_LINK;
   1296     case ui::AX_ROLE_LOCATION_BAR:
   1297       return ROLE_SYSTEM_GROUPING;
   1298     case ui::AX_ROLE_MENU_BAR:
   1299       return ROLE_SYSTEM_MENUBAR;
   1300     case ui::AX_ROLE_MENU_ITEM:
   1301       return ROLE_SYSTEM_MENUITEM;
   1302     case ui::AX_ROLE_MENU_LIST_POPUP:
   1303       return ROLE_SYSTEM_MENUPOPUP;
   1304     case ui::AX_ROLE_TREE:
   1305       return ROLE_SYSTEM_OUTLINE;
   1306     case ui::AX_ROLE_TREE_ITEM:
   1307       return ROLE_SYSTEM_OUTLINEITEM;
   1308     case ui::AX_ROLE_TAB:
   1309       return ROLE_SYSTEM_PAGETAB;
   1310     case ui::AX_ROLE_TAB_LIST:
   1311       return ROLE_SYSTEM_PAGETABLIST;
   1312     case ui::AX_ROLE_PANE:
   1313       return ROLE_SYSTEM_PANE;
   1314     case ui::AX_ROLE_PROGRESS_INDICATOR:
   1315       return ROLE_SYSTEM_PROGRESSBAR;
   1316     case ui::AX_ROLE_BUTTON:
   1317       return ROLE_SYSTEM_PUSHBUTTON;
   1318     case ui::AX_ROLE_RADIO_BUTTON:
   1319       return ROLE_SYSTEM_RADIOBUTTON;
   1320     case ui::AX_ROLE_SCROLL_BAR:
   1321       return ROLE_SYSTEM_SCROLLBAR;
   1322     case ui::AX_ROLE_SPLITTER:
   1323       return ROLE_SYSTEM_SEPARATOR;
   1324     case ui::AX_ROLE_SLIDER:
   1325       return ROLE_SYSTEM_SLIDER;
   1326     case ui::AX_ROLE_STATIC_TEXT:
   1327       return ROLE_SYSTEM_STATICTEXT;
   1328     case ui::AX_ROLE_TEXT_FIELD:
   1329       return ROLE_SYSTEM_TEXT;
   1330     case ui::AX_ROLE_TITLE_BAR:
   1331       return ROLE_SYSTEM_TITLEBAR;
   1332     case ui::AX_ROLE_TOOLBAR:
   1333       return ROLE_SYSTEM_TOOLBAR;
   1334     case ui::AX_ROLE_WINDOW:
   1335       return ROLE_SYSTEM_WINDOW;
   1336     case ui::AX_ROLE_CLIENT:
   1337     default:
   1338       // This is the default role for MSAA.
   1339       return ROLE_SYSTEM_CLIENT;
   1340   }
   1341 }
   1342 
   1343 int32 NativeViewAccessibilityWin::MSAAState(const ui::AXViewState& state) {
   1344   // This maps MSAA states for get_accState(). See also the IAccessible2
   1345   // interface get_states().
   1346 
   1347   int32 msaa_state = 0;
   1348   if (state.HasStateFlag(ui::AX_STATE_CHECKED))
   1349     msaa_state |= STATE_SYSTEM_CHECKED;
   1350   if (state.HasStateFlag(ui::AX_STATE_COLLAPSED))
   1351     msaa_state |= STATE_SYSTEM_COLLAPSED;
   1352   if (state.HasStateFlag(ui::AX_STATE_DEFAULT))
   1353     msaa_state |= STATE_SYSTEM_DEFAULT;
   1354   if (state.HasStateFlag(ui::AX_STATE_EXPANDED))
   1355     msaa_state |= STATE_SYSTEM_EXPANDED;
   1356   if (state.HasStateFlag(ui::AX_STATE_HASPOPUP))
   1357     msaa_state |= STATE_SYSTEM_HASPOPUP;
   1358   if (state.HasStateFlag(ui::AX_STATE_HOVERED))
   1359     msaa_state |= STATE_SYSTEM_HOTTRACKED;
   1360   if (state.HasStateFlag(ui::AX_STATE_INVISIBLE))
   1361     msaa_state |= STATE_SYSTEM_INVISIBLE;
   1362   if (state.HasStateFlag(ui::AX_STATE_LINKED))
   1363     msaa_state |= STATE_SYSTEM_LINKED;
   1364   if (state.HasStateFlag(ui::AX_STATE_OFFSCREEN))
   1365     msaa_state |= STATE_SYSTEM_OFFSCREEN;
   1366   if (state.HasStateFlag(ui::AX_STATE_PRESSED))
   1367     msaa_state |= STATE_SYSTEM_PRESSED;
   1368   if (state.HasStateFlag(ui::AX_STATE_PROTECTED))
   1369     msaa_state |= STATE_SYSTEM_PROTECTED;
   1370   if (state.HasStateFlag(ui::AX_STATE_READ_ONLY))
   1371     msaa_state |= STATE_SYSTEM_READONLY;
   1372   if (state.HasStateFlag(ui::AX_STATE_SELECTABLE))
   1373     msaa_state |= STATE_SYSTEM_SELECTABLE;
   1374   if (state.HasStateFlag(ui::AX_STATE_SELECTED))
   1375     msaa_state |= STATE_SYSTEM_SELECTED;
   1376   if (state.HasStateFlag(ui::AX_STATE_FOCUSED))
   1377     msaa_state |= STATE_SYSTEM_FOCUSED;
   1378   if (state.HasStateFlag(ui::AX_STATE_DISABLED))
   1379     msaa_state |= STATE_SYSTEM_UNAVAILABLE;
   1380   return msaa_state;
   1381 }
   1382 
   1383 //
   1384 // Private methods.
   1385 //
   1386 
   1387 bool NativeViewAccessibilityWin::IsNavDirNext(int nav_dir) const {
   1388   return (nav_dir == NAVDIR_RIGHT ||
   1389           nav_dir == NAVDIR_DOWN ||
   1390           nav_dir == NAVDIR_NEXT);
   1391 }
   1392 
   1393 bool NativeViewAccessibilityWin::IsValidNav(
   1394     int nav_dir, int start_id, int lower_bound, int upper_bound) const {
   1395   if (IsNavDirNext(nav_dir)) {
   1396     if ((start_id + 1) > upper_bound) {
   1397       return false;
   1398     }
   1399   } else {
   1400     if ((start_id - 1) <= lower_bound) {
   1401       return false;
   1402     }
   1403   }
   1404   return true;
   1405 }
   1406 
   1407 bool NativeViewAccessibilityWin::IsValidId(const VARIANT& child) const {
   1408   // View accessibility returns an IAccessible for each view so we only support
   1409   // the CHILDID_SELF id.
   1410   return (VT_I4 == child.vt) && (CHILDID_SELF == child.lVal);
   1411 }
   1412 
   1413 void NativeViewAccessibilityWin::SetState(
   1414     VARIANT* msaa_state, View* view) {
   1415   // Ensure the output param is initialized to zero.
   1416   msaa_state->lVal = 0;
   1417 
   1418   // Default state; all views can have accessibility focus.
   1419   msaa_state->lVal |= STATE_SYSTEM_FOCUSABLE;
   1420 
   1421   if (!view)
   1422     return;
   1423 
   1424   if (!view->enabled())
   1425     msaa_state->lVal |= STATE_SYSTEM_UNAVAILABLE;
   1426   if (!view->visible())
   1427     msaa_state->lVal |= STATE_SYSTEM_INVISIBLE;
   1428   if (!strcmp(view->GetClassName(), CustomButton::kViewClassName)) {
   1429     CustomButton* button = static_cast<CustomButton*>(view);
   1430     if (button->IsHotTracked())
   1431       msaa_state->lVal |= STATE_SYSTEM_HOTTRACKED;
   1432   }
   1433   if (view->HasFocus())
   1434     msaa_state->lVal |= STATE_SYSTEM_FOCUSED;
   1435 
   1436   // Add on any view-specific states.
   1437   ui::AXViewState view_state;
   1438   view->GetAccessibleState(&view_state);
   1439   msaa_state->lVal |= MSAAState(view_state);
   1440 }
   1441 
   1442 base::string16 NativeViewAccessibilityWin::TextForIAccessibleText() {
   1443   ui::AXViewState state;
   1444   view_->GetAccessibleState(&state);
   1445   if (state.role == ui::AX_ROLE_TEXT_FIELD)
   1446     return state.value;
   1447   else
   1448     return state.name;
   1449 }
   1450 
   1451 void NativeViewAccessibilityWin::HandleSpecialTextOffset(
   1452     const base::string16& text, LONG* offset) {
   1453   if (*offset == IA2_TEXT_OFFSET_LENGTH) {
   1454     *offset = static_cast<LONG>(text.size());
   1455   } else if (*offset == IA2_TEXT_OFFSET_CARET) {
   1456     get_caretOffset(offset);
   1457   }
   1458 }
   1459 
   1460 ui::TextBoundaryType NativeViewAccessibilityWin::IA2TextBoundaryToTextBoundary(
   1461     IA2TextBoundaryType ia2_boundary) {
   1462   switch(ia2_boundary) {
   1463     case IA2_TEXT_BOUNDARY_CHAR: return ui::CHAR_BOUNDARY;
   1464     case IA2_TEXT_BOUNDARY_WORD: return ui::WORD_BOUNDARY;
   1465     case IA2_TEXT_BOUNDARY_LINE: return ui::LINE_BOUNDARY;
   1466     case IA2_TEXT_BOUNDARY_SENTENCE: return ui::SENTENCE_BOUNDARY;
   1467     case IA2_TEXT_BOUNDARY_PARAGRAPH: return ui::PARAGRAPH_BOUNDARY;
   1468     case IA2_TEXT_BOUNDARY_ALL: return ui::ALL_BOUNDARY;
   1469     default:
   1470       NOTREACHED();
   1471       return ui::CHAR_BOUNDARY;
   1472   }
   1473 }
   1474 
   1475 LONG NativeViewAccessibilityWin::FindBoundary(
   1476     const base::string16& text,
   1477     IA2TextBoundaryType ia2_boundary,
   1478     LONG start_offset,
   1479     ui::TextBoundaryDirection direction) {
   1480   HandleSpecialTextOffset(text, &start_offset);
   1481   ui::TextBoundaryType boundary = IA2TextBoundaryToTextBoundary(ia2_boundary);
   1482   std::vector<int32> line_breaks;
   1483   return ui::FindAccessibleTextBoundary(
   1484       text, line_breaks, boundary, start_offset, direction);
   1485 }
   1486 
   1487 void NativeViewAccessibilityWin::PopulateChildWidgetVector(
   1488     std::vector<Widget*>* result_child_widgets) {
   1489   const Widget* widget = view()->GetWidget();
   1490   if (!widget)
   1491     return;
   1492 
   1493   std::set<Widget*> child_widgets;
   1494   Widget::GetAllChildWidgets(widget->GetNativeView(), &child_widgets);
   1495   Widget::GetAllOwnedWidgets(widget->GetNativeView(), &child_widgets);
   1496   for (std::set<Widget*>::const_iterator iter = child_widgets.begin();
   1497            iter != child_widgets.end(); ++iter) {
   1498     Widget* child_widget = *iter;
   1499     if (child_widget == widget)
   1500       continue;
   1501 
   1502     if (!child_widget->IsVisible())
   1503       continue;
   1504 
   1505     if (widget->GetNativeWindowProperty(kWidgetNativeViewHostKey))
   1506       continue;
   1507 
   1508     result_child_widgets->push_back(child_widget);
   1509   }
   1510 }
   1511 
   1512 void NativeViewAccessibilityWin::AddAlertTarget() {
   1513   ViewStorage* view_storage = ViewStorage::GetInstance();
   1514   for (size_t i = 0; i < alert_target_view_storage_ids_.size(); ++i) {
   1515     int view_storage_id = alert_target_view_storage_ids_[i];
   1516     View* view = view_storage->RetrieveView(view_storage_id);
   1517     if (view == view_)
   1518       return;
   1519   }
   1520   int view_storage_id = view_storage->CreateStorageID();
   1521   view_storage->StoreView(view_storage_id, view_);
   1522   alert_target_view_storage_ids_.push_back(view_storage_id);
   1523 }
   1524 
   1525 void NativeViewAccessibilityWin::RemoveAlertTarget() {
   1526   ViewStorage* view_storage = ViewStorage::GetInstance();
   1527   size_t i = 0;
   1528   while (i < alert_target_view_storage_ids_.size()) {
   1529     int view_storage_id = alert_target_view_storage_ids_[i];
   1530     View* view = view_storage->RetrieveView(view_storage_id);
   1531     if (view == NULL || view == view_) {
   1532       alert_target_view_storage_ids_.erase(
   1533           alert_target_view_storage_ids_.begin() + i);
   1534     } else {
   1535       ++i;
   1536     }
   1537   }
   1538 }
   1539 
   1540 }  // namespace views
   1541