src/content/browser/accessibility/browser_accessibility_manager_win.cc

   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 "content/browser/accessibility/browser_accessibility_manager_win.h"
   6
   7 #include "base/command_line.h"
   8 #include "base/win/scoped_comptr.h"
   9 #include "base/win/windows_version.h"
  10 #include "content/browser/accessibility/browser_accessibility_state_impl.h"
  11 #include "content/browser/accessibility/browser_accessibility_win.h"
  12 #include "content/browser/renderer_host/legacy_render_widget_host_win.h"
  13 #include "content/common/accessibility_messages.h"
  14
  15 namespace content {
  16
  17 // static
  18 BrowserAccessibilityManager* BrowserAccessibilityManager::Create(
  19     const ui::AXTreeUpdate& initial_tree,
  20     BrowserAccessibilityDelegate* delegate,
  21     BrowserAccessibilityFactory* factory) {
  22   return new BrowserAccessibilityManagerWin(
  23       content::LegacyRenderWidgetHostHWND::Create(GetDesktopWindow()).get(),
  24       NULL, initial_tree, delegate, factory);
  25 }
  26
  27 BrowserAccessibilityManagerWin*
  28 BrowserAccessibilityManager::ToBrowserAccessibilityManagerWin() {
  29   return static_cast<BrowserAccessibilityManagerWin*>(this);
  30 }
  31
  32 BrowserAccessibilityManagerWin::BrowserAccessibilityManagerWin(
  33     LegacyRenderWidgetHostHWND* accessible_hwnd,
  34     IAccessible* parent_iaccessible,
  35     const ui::AXTreeUpdate& initial_tree,
  36     BrowserAccessibilityDelegate* delegate,
  37     BrowserAccessibilityFactory* factory)
  38     : BrowserAccessibilityManager(initial_tree, delegate, factory),
  39       parent_hwnd_(accessible_hwnd->GetParent()),
  40       parent_iaccessible_(parent_iaccessible),
  41       tracked_scroll_object_(NULL),
  42       accessible_hwnd_(accessible_hwnd) {
  43   accessible_hwnd_->set_browser_accessibility_manager(this);
  44 }
  45
  46 BrowserAccessibilityManagerWin::~BrowserAccessibilityManagerWin() {
  47   if (tracked_scroll_object_) {
  48     tracked_scroll_object_->Release();
  49     tracked_scroll_object_ = NULL;
  50   }
  51   if (accessible_hwnd_)
  52     accessible_hwnd_->OnManagerDeleted();
  53 }
  54
  55 // static
  56 ui::AXTreeUpdate BrowserAccessibilityManagerWin::GetEmptyDocument() {
  57   ui::AXNodeData empty_document;
  58   empty_document.id = 0;
  59   empty_document.role = ui::AX_ROLE_ROOT_WEB_AREA;
  60   empty_document.state =
  61       (1 << ui::AX_STATE_ENABLED) |
  62       (1 << ui::AX_STATE_READ_ONLY) |
  63       (1 << ui::AX_STATE_BUSY);
  64
  65   ui::AXTreeUpdate update;
  66   update.nodes.push_back(empty_document);
  67   return update;
  68 }
  69
  70 void BrowserAccessibilityManagerWin::MaybeCallNotifyWinEvent(DWORD event,
  71                                                              LONG child_id) {
  72   // Don't fire events if this view isn't hooked up to its parent.
  73   if (!parent_iaccessible())
  74     return;
  75
  76   // If on Win 7 and complete accessibility is enabled, use the fake child HWND
  77   // to use as the root of the accessibility tree. See comments above
  78   // LegacyRenderWidgetHostHWND for details.
  79   if (BrowserAccessibilityStateImpl::GetInstance()->IsAccessibleBrowser()) {
  80     DCHECK(accessible_hwnd_);
  81     parent_hwnd_ = accessible_hwnd_->hwnd();
  82     parent_iaccessible_ = accessible_hwnd_->window_accessible();
  83   }
  84   ::NotifyWinEvent(event, parent_hwnd(), OBJID_CLIENT, child_id);
  85 }
  86
  87
  88 void BrowserAccessibilityManagerWin::OnNodeCreated(ui::AXNode* node) {
  89   BrowserAccessibilityManager::OnNodeCreated(node);
  90   BrowserAccessibility* obj = GetFromAXNode(node);
  91   LONG unique_id_win = obj->ToBrowserAccessibilityWin()->unique_id_win();
  92   unique_id_to_ax_id_map_[unique_id_win] = obj->GetId();
  93 }
  94
  95 void BrowserAccessibilityManagerWin::OnNodeWillBeDeleted(ui::AXNode* node) {
  96   BrowserAccessibilityManager::OnNodeWillBeDeleted(node);
  97   BrowserAccessibility* obj = GetFromAXNode(node);
  98   if (!obj)
  99     return;
 100   unique_id_to_ax_id_map_.erase(
 101       obj->ToBrowserAccessibilityWin()->unique_id_win());
 102   if (obj == tracked_scroll_object_) {
 103     tracked_scroll_object_->Release();
 104     tracked_scroll_object_ = NULL;
 105   }
 106 }
 107
 108 void BrowserAccessibilityManagerWin::OnWindowFocused() {
 109   // Fire a focus event on the root first and then the focused node.
 110   if (focus_ != tree_->GetRoot())
 111     NotifyAccessibilityEvent(ui::AX_EVENT_FOCUS, GetRoot());
 112   BrowserAccessibilityManager::OnWindowFocused();
 113 }
 114
 115 void BrowserAccessibilityManagerWin::OnWindowBlurred() {
 116   // Fire a blur event on the focused node first and then the root.
 117   BrowserAccessibilityManager::OnWindowBlurred();
 118   if (focus_ != tree_->GetRoot())
 119     NotifyAccessibilityEvent(ui::AX_EVENT_BLUR, GetRoot());
 120 }
 121
 122 void BrowserAccessibilityManagerWin::NotifyAccessibilityEvent(
 123     ui::AXEvent event_type,
 124     BrowserAccessibility* node) {
 125   if (node->GetRole() == ui::AX_ROLE_INLINE_TEXT_BOX)
 126     return;
 127
 128   LONG event_id = EVENT_MIN;
 129   switch (event_type) {
 130     case ui::AX_EVENT_ACTIVEDESCENDANTCHANGED:
 131       event_id = IA2_EVENT_ACTIVE_DESCENDANT_CHANGED;
 132       break;
 133     case ui::AX_EVENT_ALERT:
 134       event_id = EVENT_SYSTEM_ALERT;
 135       break;
 136     case ui::AX_EVENT_ARIA_ATTRIBUTE_CHANGED:
 137       event_id = IA2_EVENT_OBJECT_ATTRIBUTE_CHANGED;
 138       break;
 139     case ui::AX_EVENT_AUTOCORRECTION_OCCURED:
 140       event_id = IA2_EVENT_OBJECT_ATTRIBUTE_CHANGED;
 141       break;
 142     case ui::AX_EVENT_BLUR:
 143       // Equivalent to focus on the root.
 144       event_id = EVENT_OBJECT_FOCUS;
 145       node = GetRoot();
 146       break;
 147     case ui::AX_EVENT_CHECKED_STATE_CHANGED:
 148       event_id = EVENT_OBJECT_STATECHANGE;
 149       break;
 150     case ui::AX_EVENT_CHILDREN_CHANGED:
 151       event_id = EVENT_OBJECT_REORDER;
 152       break;
 153     case ui::AX_EVENT_FOCUS:
 154       event_id = EVENT_OBJECT_FOCUS;
 155       break;
 156     case ui::AX_EVENT_INVALID_STATUS_CHANGED:
 157       event_id = EVENT_OBJECT_STATECHANGE;
 158       break;
 159     case ui::AX_EVENT_LIVE_REGION_CHANGED:
 160       if (node->GetBoolAttribute(ui::AX_ATTR_CONTAINER_LIVE_BUSY))
 161         return;
 162       event_id = EVENT_OBJECT_LIVEREGIONCHANGED;
 163       break;
 164     case ui::AX_EVENT_LOAD_COMPLETE:
 165       event_id = IA2_EVENT_DOCUMENT_LOAD_COMPLETE;
 166       break;
 167     case ui::AX_EVENT_MENU_LIST_ITEM_SELECTED:
 168       event_id = EVENT_OBJECT_FOCUS;
 169       break;
 170     case ui::AX_EVENT_MENU_LIST_VALUE_CHANGED:
 171       event_id = EVENT_OBJECT_VALUECHANGE;
 172       break;
 173     case ui::AX_EVENT_HIDE:
 174       event_id = EVENT_OBJECT_HIDE;
 175       break;
 176     case ui::AX_EVENT_SHOW:
 177       event_id = EVENT_OBJECT_SHOW;
 178       break;
 179     case ui::AX_EVENT_SCROLL_POSITION_CHANGED:
 180       event_id = EVENT_SYSTEM_SCROLLINGEND;
 181       break;
 182     case ui::AX_EVENT_SCROLLED_TO_ANCHOR:
 183       event_id = EVENT_SYSTEM_SCROLLINGSTART;
 184       break;
 185     case ui::AX_EVENT_SELECTED_CHILDREN_CHANGED:
 186       event_id = EVENT_OBJECT_SELECTIONWITHIN;
 187       break;
 188     case ui::AX_EVENT_SELECTED_TEXT_CHANGED:
 189       event_id = IA2_EVENT_TEXT_CARET_MOVED;
 190       break;
 191     case ui::AX_EVENT_TEXT_CHANGED:
 192       event_id = EVENT_OBJECT_NAMECHANGE;
 193       break;
 194     case ui::AX_EVENT_TEXT_INSERTED:
 195       event_id = IA2_EVENT_TEXT_INSERTED;
 196       break;
 197     case ui::AX_EVENT_TEXT_REMOVED:
 198       event_id = IA2_EVENT_TEXT_REMOVED;
 199       break;
 200     case ui::AX_EVENT_VALUE_CHANGED:
 201       event_id = EVENT_OBJECT_VALUECHANGE;
 202       break;
 203     default:
 204       // Not all WebKit accessibility events result in a Windows
 205       // accessibility notification.
 206       break;
 207   }
 208
 209   if (event_id != EVENT_MIN) {
 210     // Pass the node's unique id in the |child_id| argument to NotifyWinEvent;
 211     // the AT client will then call get_accChild on the HWND's accessibility
 212     // object and pass it that same id, which we can use to retrieve the
 213     // IAccessible for this node.
 214     LONG child_id = node->ToBrowserAccessibilityWin()->unique_id_win();
 215     MaybeCallNotifyWinEvent(event_id, child_id);
 216   }
 217
 218   // If this is a layout complete notification (sent when a container scrolls)
 219   // and there is a descendant tracked object, send a notification on it.
 220   // TODO(dmazzoni): remove once http://crbug.com/113483 is fixed.
 221   if (event_type == ui::AX_EVENT_LAYOUT_COMPLETE &&
 222       tracked_scroll_object_ &&
 223       tracked_scroll_object_->IsDescendantOf(node)) {
 224     MaybeCallNotifyWinEvent(
 225         IA2_EVENT_VISIBLE_DATA_CHANGED,
 226         tracked_scroll_object_->ToBrowserAccessibilityWin()->unique_id_win());
 227     tracked_scroll_object_->Release();
 228     tracked_scroll_object_ = NULL;
 229   }
 230 }
 231
 232 void BrowserAccessibilityManagerWin::OnRootChanged(ui::AXNode* new_root) {
 233   if (delegate_ && delegate_->AccessibilityViewHasFocus())
 234     NotifyAccessibilityEvent(ui::AX_EVENT_FOCUS, GetRoot());
 235 }
 236
 237 void BrowserAccessibilityManagerWin::TrackScrollingObject(
 238     BrowserAccessibilityWin* node) {
 239   if (tracked_scroll_object_)
 240     tracked_scroll_object_->Release();
 241   tracked_scroll_object_ = node;
 242   tracked_scroll_object_->AddRef();
 243 }
 244
 245 BrowserAccessibilityWin* BrowserAccessibilityManagerWin::GetFromUniqueIdWin(
 246     LONG unique_id_win) {
 247   base::hash_map<LONG, int32>::iterator iter =
 248       unique_id_to_ax_id_map_.find(unique_id_win);
 249   if (iter != unique_id_to_ax_id_map_.end()) {
 250     BrowserAccessibility* result = GetFromID(iter->second);
 251     if (result)
 252       return result->ToBrowserAccessibilityWin();
 253   }
 254   return NULL;
 255 }
 256
 257 void BrowserAccessibilityManagerWin::OnAccessibleHwndDeleted() {
 258   // If the AccessibleHWND is deleted, |parent_hwnd_| and
 259   // |parent_iaccessible_| are no longer valid either, since they were
 260   // derived from AccessibleHWND. We don't have to restore them to
 261   // previous values, though, because this should only happen
 262   // during the destruct sequence for this window.
 263   accessible_hwnd_ = NULL;
 264   parent_hwnd_ = NULL;
 265   parent_iaccessible_ = NULL;
 266 }
 267
 268 }  // namespace content