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::AXNodeData& src,
  20     BrowserAccessibilityDelegate* delegate,
  21     BrowserAccessibilityFactory* factory) {
  22   return new BrowserAccessibilityManagerWin(
  23       content::LegacyRenderWidgetHostHWND::Create(GetDesktopWindow()).get(),
  24       NULL, src, 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::AXNodeData& src,
  36     BrowserAccessibilityDelegate* delegate,
  37     BrowserAccessibilityFactory* factory)
  38     : BrowserAccessibilityManager(src, 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::AXNodeData 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   return empty_document;
  65 }
  66
  67 void BrowserAccessibilityManagerWin::MaybeCallNotifyWinEvent(DWORD event,
  68                                                              LONG child_id) {
  69   // Don't fire events if this view isn't hooked up to its parent.
  70   if (!parent_iaccessible())
  71     return;
  72
  73   // If on Win 7 and complete accessibility is enabled, use the fake child HWND
  74   // to use as the root of the accessibility tree. See comments above
  75   // LegacyRenderWidgetHostHWND for details.
  76   if (BrowserAccessibilityStateImpl::GetInstance()->IsAccessibleBrowser()) {
  77     DCHECK(accessible_hwnd_);
  78     parent_hwnd_ = accessible_hwnd_->hwnd();
  79     parent_iaccessible_ = accessible_hwnd_->window_accessible();
  80   }
  81   ::NotifyWinEvent(event, parent_hwnd(), OBJID_CLIENT, child_id);
  82 }
  83
  84 void BrowserAccessibilityManagerWin::AddNodeToMap(BrowserAccessibility* node) {
  85   BrowserAccessibilityManager::AddNodeToMap(node);
  86   LONG unique_id_win = node->ToBrowserAccessibilityWin()->unique_id_win();
  87   unique_id_to_renderer_id_map_[unique_id_win] = node->renderer_id();
  88 }
  89
  90 void BrowserAccessibilityManagerWin::RemoveNode(BrowserAccessibility* node) {
  91   unique_id_to_renderer_id_map_.erase(
  92       node->ToBrowserAccessibilityWin()->unique_id_win());
  93   BrowserAccessibilityManager::RemoveNode(node);
  94   if (node == tracked_scroll_object_) {
  95     tracked_scroll_object_->Release();
  96     tracked_scroll_object_ = NULL;
  97   }
  98 }
  99
 100 void BrowserAccessibilityManagerWin::NotifyAccessibilityEvent(
 101     ui::AXEvent event_type,
 102     BrowserAccessibility* node) {
 103   if (node->role() == ui::AX_ROLE_INLINE_TEXT_BOX)
 104     return;
 105
 106   LONG event_id = EVENT_MIN;
 107   switch (event_type) {
 108     case ui::AX_EVENT_ACTIVEDESCENDANTCHANGED:
 109       event_id = IA2_EVENT_ACTIVE_DESCENDANT_CHANGED;
 110       break;
 111     case ui::AX_EVENT_ALERT:
 112       event_id = EVENT_SYSTEM_ALERT;
 113       break;
 114     case ui::AX_EVENT_ARIA_ATTRIBUTE_CHANGED:
 115       event_id = IA2_EVENT_OBJECT_ATTRIBUTE_CHANGED;
 116       break;
 117     case ui::AX_EVENT_AUTOCORRECTION_OCCURED:
 118       event_id = IA2_EVENT_OBJECT_ATTRIBUTE_CHANGED;
 119       break;
 120     case ui::AX_EVENT_BLUR:
 121       // Equivalent to focus on the root.
 122       event_id = EVENT_OBJECT_FOCUS;
 123       node = GetRoot();
 124       break;
 125     case ui::AX_EVENT_CHECKED_STATE_CHANGED:
 126       event_id = EVENT_OBJECT_STATECHANGE;
 127       break;
 128     case ui::AX_EVENT_CHILDREN_CHANGED:
 129       event_id = EVENT_OBJECT_REORDER;
 130       break;
 131     case ui::AX_EVENT_FOCUS:
 132       event_id = EVENT_OBJECT_FOCUS;
 133       break;
 134     case ui::AX_EVENT_INVALID_STATUS_CHANGED:
 135       event_id = EVENT_OBJECT_STATECHANGE;
 136       break;
 137     case ui::AX_EVENT_LIVE_REGION_CHANGED:
 138       // TODO: try not firing a native notification at all, since
 139       // on Windows, each individual item in a live region that changes
 140       // already gets its own notification.
 141       event_id = EVENT_OBJECT_REORDER;
 142       break;
 143     case ui::AX_EVENT_LOAD_COMPLETE:
 144       event_id = IA2_EVENT_DOCUMENT_LOAD_COMPLETE;
 145       break;
 146     case ui::AX_EVENT_MENU_LIST_ITEM_SELECTED:
 147       event_id = EVENT_OBJECT_FOCUS;
 148       break;
 149     case ui::AX_EVENT_MENU_LIST_VALUE_CHANGED:
 150       event_id = EVENT_OBJECT_VALUECHANGE;
 151       break;
 152     case ui::AX_EVENT_HIDE:
 153       event_id = EVENT_OBJECT_HIDE;
 154       break;
 155     case ui::AX_EVENT_SHOW:
 156       event_id = EVENT_OBJECT_SHOW;
 157       break;
 158     case ui::AX_EVENT_SCROLL_POSITION_CHANGED:
 159       event_id = EVENT_SYSTEM_SCROLLINGEND;
 160       break;
 161     case ui::AX_EVENT_SCROLLED_TO_ANCHOR:
 162       event_id = EVENT_SYSTEM_SCROLLINGSTART;
 163       break;
 164     case ui::AX_EVENT_SELECTED_CHILDREN_CHANGED:
 165       event_id = EVENT_OBJECT_SELECTIONWITHIN;
 166       break;
 167     case ui::AX_EVENT_SELECTED_TEXT_CHANGED:
 168       event_id = IA2_EVENT_TEXT_CARET_MOVED;
 169       break;
 170     case ui::AX_EVENT_TEXT_CHANGED:
 171       event_id = EVENT_OBJECT_NAMECHANGE;
 172       break;
 173     case ui::AX_EVENT_TEXT_INSERTED:
 174       event_id = IA2_EVENT_TEXT_INSERTED;
 175       break;
 176     case ui::AX_EVENT_TEXT_REMOVED:
 177       event_id = IA2_EVENT_TEXT_REMOVED;
 178       break;
 179     case ui::AX_EVENT_VALUE_CHANGED:
 180       event_id = EVENT_OBJECT_VALUECHANGE;
 181       break;
 182     default:
 183       // Not all WebKit accessibility events result in a Windows
 184       // accessibility notification.
 185       break;
 186   }
 187
 188   if (event_id != EVENT_MIN) {
 189     // Pass the node's unique id in the |child_id| argument to NotifyWinEvent;
 190     // the AT client will then call get_accChild on the HWND's accessibility
 191     // object and pass it that same id, which we can use to retrieve the
 192     // IAccessible for this node.
 193     LONG child_id = node->ToBrowserAccessibilityWin()->unique_id_win();
 194     MaybeCallNotifyWinEvent(event_id, child_id);
 195   }
 196
 197   // If this is a layout complete notification (sent when a container scrolls)
 198   // and there is a descendant tracked object, send a notification on it.
 199   // TODO(dmazzoni): remove once http://crbug.com/113483 is fixed.
 200   if (event_type == ui::AX_EVENT_LAYOUT_COMPLETE &&
 201       tracked_scroll_object_ &&
 202       tracked_scroll_object_->IsDescendantOf(node)) {
 203     MaybeCallNotifyWinEvent(
 204         IA2_EVENT_VISIBLE_DATA_CHANGED,
 205         tracked_scroll_object_->ToBrowserAccessibilityWin()->unique_id_win());
 206     tracked_scroll_object_->Release();
 207     tracked_scroll_object_ = NULL;
 208   }
 209 }
 210
 211 void BrowserAccessibilityManagerWin::TrackScrollingObject(
 212     BrowserAccessibilityWin* node) {
 213   if (tracked_scroll_object_)
 214     tracked_scroll_object_->Release();
 215   tracked_scroll_object_ = node;
 216   tracked_scroll_object_->AddRef();
 217 }
 218
 219 BrowserAccessibilityWin* BrowserAccessibilityManagerWin::GetFromUniqueIdWin(
 220     LONG unique_id_win) {
 221   base::hash_map<LONG, int32>::iterator iter =
 222       unique_id_to_renderer_id_map_.find(unique_id_win);
 223   if (iter != unique_id_to_renderer_id_map_.end()) {
 224     BrowserAccessibility* result = GetFromRendererID(iter->second);
 225     if (result)
 226       return result->ToBrowserAccessibilityWin();
 227   }
 228   return NULL;
 229 }
 230
 231 void BrowserAccessibilityManagerWin::OnAccessibleHwndDeleted() {
 232   // If the AccessibleHWND is deleted, |parent_hwnd_| and
 233   // |parent_iaccessible_| are no longer valid either, since they were
 234   // derived from AccessibleHWND. We don't have to restore them to
 235   // previous values, though, because this should only happen
 236   // during the destruct sequence for this window.
 237   accessible_hwnd_ = NULL;
 238   parent_hwnd_ = NULL;
 239   parent_iaccessible_ = NULL;
 240 }
 241
 242 }  // namespace content