src/chrome/browser/ui/views/accessibility/accessibility_event_router_views.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 "chrome/browser/ui/views/accessibility/accessibility_event_router_views.h"
   6
   7 #include "base/basictypes.h"
   8 #include "base/callback.h"
   9 #include "base/memory/singleton.h"
  10 #include "base/message_loop/message_loop.h"
  11 #include "base/strings/utf_string_conversions.h"
  12 #include "chrome/browser/accessibility/accessibility_extension_api.h"
  13 #include "chrome/browser/browser_process.h"
  14 #include "chrome/browser/chrome_notification_types.h"
  15 #include "chrome/browser/profiles/profile.h"
  16 #include "chrome/browser/profiles/profile_manager.h"
  17 #include "content/public/browser/notification_service.h"
  18 #include "ui/base/accessibility/accessible_view_state.h"
  19 #include "ui/views/controls/menu/menu_item_view.h"
  20 #include "ui/views/controls/menu/submenu_view.h"
  21 #include "ui/views/focus/view_storage.h"
  22 #include "ui/views/view.h"
  23 #include "ui/views/widget/widget.h"
  24
  25 using views::FocusManager;
  26
  27 AccessibilityEventRouterViews::AccessibilityEventRouterViews()
  28     : most_recent_profile_(NULL) {
  29   // Register for notification when profile is destroyed to ensure that all
  30   // observers are detatched at that time.
  31   registrar_.Add(this, chrome::NOTIFICATION_PROFILE_DESTROYED,
  32                  content::NotificationService::AllSources());
  33 }
  34
  35 AccessibilityEventRouterViews::~AccessibilityEventRouterViews() {
  36 }
  37
  38 // static
  39 AccessibilityEventRouterViews* AccessibilityEventRouterViews::GetInstance() {
  40   return Singleton<AccessibilityEventRouterViews>::get();
  41 }
  42
  43 void AccessibilityEventRouterViews::HandleAccessibilityEvent(
  44     views::View* view, ui::AccessibilityTypes::Event event_type) {
  45   if (!ExtensionAccessibilityEventRouter::GetInstance()->
  46       IsAccessibilityEnabled()) {
  47     return;
  48   }
  49
  50   if (event_type == ui::AccessibilityTypes::EVENT_TEXT_CHANGED ||
  51       event_type == ui::AccessibilityTypes::EVENT_SELECTION_CHANGED) {
  52     // These two events should only be sent for views that have focus. This
  53     // enforces the invariant that we fire events triggered by user action and
  54     // not by programmatic logic. For example, the location bar can be updated
  55     // by javascript while the user focus is within some other part of the
  56     // user interface. In contrast, the other supported events here do not
  57     // depend on focus. For example, a menu within a menubar can open or close
  58     // while focus is within the location bar or anywhere else as a result of
  59     // user action. Note that the below logic can at some point be removed if
  60     // we pass more information along to the listener such as focused state.
  61     if (!view->GetFocusManager() ||
  62         view->GetFocusManager()->GetFocusedView() != view)
  63       return;
  64   }
  65
  66   // Don't dispatch the accessibility event until the next time through the
  67   // event loop, to handle cases where the view's state changes after
  68   // the call to post the event. It's safe to use base::Unretained(this)
  69   // because AccessibilityEventRouterViews is a singleton.
  70   views::ViewStorage* view_storage = views::ViewStorage::GetInstance();
  71   int view_storage_id = view_storage->CreateStorageID();
  72   view_storage->StoreView(view_storage_id, view);
  73   base::MessageLoop::current()->PostTask(
  74       FROM_HERE,
  75       base::Bind(
  76           &AccessibilityEventRouterViews::DispatchEventOnViewStorageId,
  77           view_storage_id,
  78           event_type));
  79 }
  80
  81 void AccessibilityEventRouterViews::HandleMenuItemFocused(
  82     const string16& menu_name,
  83     const string16& menu_item_name,
  84     int item_index,
  85     int item_count,
  86     bool has_submenu) {
  87   if (!ExtensionAccessibilityEventRouter::GetInstance()->
  88       IsAccessibilityEnabled()) {
  89     return;
  90   }
  91
  92   if (!most_recent_profile_)
  93     return;
  94
  95   AccessibilityMenuItemInfo info(most_recent_profile_,
  96                                  UTF16ToUTF8(menu_item_name),
  97                                  UTF16ToUTF8(menu_name),
  98                                  has_submenu,
  99                                  item_index,
 100                                  item_count);
 101   SendControlAccessibilityNotification(
 102       ui::AccessibilityTypes::EVENT_FOCUS, &info);
 103 }
 104
 105 void AccessibilityEventRouterViews::Observe(
 106     int type,
 107     const content::NotificationSource& source,
 108     const content::NotificationDetails& details) {
 109   DCHECK_EQ(type, chrome::NOTIFICATION_PROFILE_DESTROYED);
 110   Profile* profile = content::Source<Profile>(source).ptr();
 111   if (profile == most_recent_profile_)
 112     most_recent_profile_ = NULL;
 113 }
 114
 115 //
 116 // Private methods
 117 //
 118
 119 void AccessibilityEventRouterViews::DispatchEventOnViewStorageId(
 120     int view_storage_id,
 121     ui::AccessibilityTypes::Event type) {
 122   views::ViewStorage* view_storage = views::ViewStorage::GetInstance();
 123   views::View* view = view_storage->RetrieveView(view_storage_id);
 124   view_storage->RemoveView(view_storage_id);
 125   if (!view)
 126     return;
 127
 128   AccessibilityEventRouterViews* instance =
 129       AccessibilityEventRouterViews::GetInstance();
 130   instance->DispatchAccessibilityEvent(view, type);
 131 }
 132
 133 void AccessibilityEventRouterViews::DispatchAccessibilityEvent(
 134     views::View* view, ui::AccessibilityTypes::Event type) {
 135   // Get the profile associated with this view. If it's not found, use
 136   // the most recent profile where accessibility events were sent, or
 137   // the default profile.
 138   Profile* profile = NULL;
 139   views::Widget* widget = view->GetWidget();
 140   if (widget) {
 141     profile = reinterpret_cast<Profile*>(
 142         widget->GetNativeWindowProperty(Profile::kProfileKey));
 143   }
 144   if (!profile)
 145     profile = most_recent_profile_;
 146   if (!profile) {
 147     if (g_browser_process->profile_manager())
 148       profile = g_browser_process->profile_manager()->GetLastUsedProfile();
 149   }
 150   if (!profile) {
 151     LOG(WARNING) << "Accessibility notification but no profile";
 152     return;
 153   }
 154
 155   most_recent_profile_ = profile;
 156
 157   if (type == ui::AccessibilityTypes::EVENT_MENUSTART ||
 158       type == ui::AccessibilityTypes::EVENT_MENUPOPUPSTART ||
 159       type == ui::AccessibilityTypes::EVENT_MENUEND ||
 160       type == ui::AccessibilityTypes::EVENT_MENUPOPUPEND) {
 161     SendMenuNotification(view, type, profile);
 162     return;
 163   }
 164
 165   ui::AccessibleViewState state;
 166   view->GetAccessibleState(&state);
 167
 168   switch (state.role) {
 169   case ui::AccessibilityTypes::ROLE_ALERT:
 170   case ui::AccessibilityTypes::ROLE_WINDOW:
 171     SendWindowNotification(view, type, profile);
 172     break;
 173   case ui::AccessibilityTypes::ROLE_BUTTONMENU:
 174   case ui::AccessibilityTypes::ROLE_MENUBAR:
 175   case ui::AccessibilityTypes::ROLE_MENUPOPUP:
 176     SendMenuNotification(view, type, profile);
 177     break;
 178   case ui::AccessibilityTypes::ROLE_BUTTONDROPDOWN:
 179   case ui::AccessibilityTypes::ROLE_PUSHBUTTON:
 180     SendButtonNotification(view, type, profile);
 181     break;
 182   case ui::AccessibilityTypes::ROLE_CHECKBUTTON:
 183     SendCheckboxNotification(view, type, profile);
 184     break;
 185   case ui::AccessibilityTypes::ROLE_COMBOBOX:
 186     SendComboboxNotification(view, type, profile);
 187     break;
 188   case ui::AccessibilityTypes::ROLE_LINK:
 189     SendLinkNotification(view, type, profile);
 190     break;
 191   case ui::AccessibilityTypes::ROLE_LOCATION_BAR:
 192   case ui::AccessibilityTypes::ROLE_TEXT:
 193     SendTextfieldNotification(view, type, profile);
 194     break;
 195   case ui::AccessibilityTypes::ROLE_MENUITEM:
 196     SendMenuItemNotification(view, type, profile);
 197     break;
 198   case ui::AccessibilityTypes::ROLE_RADIOBUTTON:
 199     // Not used anymore?
 200   case ui::AccessibilityTypes::ROLE_SLIDER:
 201     SendSliderNotification(view, type, profile);
 202     break;
 203   default:
 204     // If this is encountered, please file a bug with the role that wasn't
 205     // caught so we can add accessibility extension API support.
 206     NOTREACHED();
 207   }
 208 }
 209
 210 // static
 211 void AccessibilityEventRouterViews::SendButtonNotification(
 212     views::View* view,
 213     ui::AccessibilityTypes::Event event,
 214     Profile* profile) {
 215   AccessibilityButtonInfo info(
 216       profile, GetViewName(view), GetViewContext(view));
 217   SendControlAccessibilityNotification(event, &info);
 218 }
 219
 220 // static
 221 void AccessibilityEventRouterViews::SendLinkNotification(
 222     views::View* view,
 223     ui::AccessibilityTypes::Event event,
 224     Profile* profile) {
 225   AccessibilityLinkInfo info(profile, GetViewName(view), GetViewContext(view));
 226   SendControlAccessibilityNotification(event, &info);
 227 }
 228
 229 // static
 230 void AccessibilityEventRouterViews::SendMenuNotification(
 231     views::View* view,
 232     ui::AccessibilityTypes::Event event,
 233     Profile* profile) {
 234   AccessibilityMenuInfo info(profile, GetViewName(view));
 235   SendMenuAccessibilityNotification(event, &info);
 236 }
 237
 238 // static
 239 void AccessibilityEventRouterViews::SendMenuItemNotification(
 240     views::View* view,
 241     ui::AccessibilityTypes::Event event,
 242     Profile* profile) {
 243   std::string name = GetViewName(view);
 244   std::string context = GetViewContext(view);
 245
 246   bool has_submenu = false;
 247   int index = -1;
 248   int count = -1;
 249
 250   if (!strcmp(view->GetClassName(), views::MenuItemView::kViewClassName))
 251     has_submenu = static_cast<views::MenuItemView*>(view)->HasSubmenu();
 252
 253   views::View* parent_menu = view->parent();
 254   while (parent_menu != NULL && strcmp(parent_menu->GetClassName(),
 255                                        views::SubmenuView::kViewClassName)) {
 256     parent_menu = parent_menu->parent();
 257   }
 258   if (parent_menu) {
 259     count = 0;
 260     RecursiveGetMenuItemIndexAndCount(parent_menu, view, &index, &count);
 261   }
 262
 263   AccessibilityMenuItemInfo info(
 264       profile, name, context, has_submenu, index, count);
 265   SendControlAccessibilityNotification(event, &info);
 266 }
 267
 268 // static
 269 void AccessibilityEventRouterViews::SendTextfieldNotification(
 270     views::View* view,
 271     ui::AccessibilityTypes::Event event,
 272     Profile* profile) {
 273   ui::AccessibleViewState state;
 274   view->GetAccessibleState(&state);
 275   std::string name = UTF16ToUTF8(state.name);
 276   std::string context = GetViewContext(view);
 277   bool password =
 278       (state.state & ui::AccessibilityTypes::STATE_PROTECTED) != 0;
 279   AccessibilityTextBoxInfo info(profile, name, context, password);
 280   std::string value = UTF16ToUTF8(state.value);
 281   info.SetValue(value, state.selection_start, state.selection_end);
 282   SendControlAccessibilityNotification(event, &info);
 283 }
 284
 285 // static
 286 void AccessibilityEventRouterViews::SendComboboxNotification(
 287     views::View* view,
 288     ui::AccessibilityTypes::Event event,
 289     Profile* profile) {
 290   ui::AccessibleViewState state;
 291   view->GetAccessibleState(&state);
 292   std::string name = UTF16ToUTF8(state.name);
 293   std::string value = UTF16ToUTF8(state.value);
 294   std::string context = GetViewContext(view);
 295   AccessibilityComboBoxInfo info(
 296       profile, name, context, value, state.index, state.count);
 297   SendControlAccessibilityNotification(event, &info);
 298 }
 299
 300 // static
 301 void AccessibilityEventRouterViews::SendCheckboxNotification(
 302     views::View* view,
 303     ui::AccessibilityTypes::Event event,
 304     Profile* profile) {
 305   ui::AccessibleViewState state;
 306   view->GetAccessibleState(&state);
 307   std::string name = UTF16ToUTF8(state.name);
 308   std::string context = GetViewContext(view);
 309   AccessibilityCheckboxInfo info(
 310       profile,
 311       name,
 312       context,
 313       state.state == ui::AccessibilityTypes::STATE_CHECKED);
 314   SendControlAccessibilityNotification(event, &info);
 315 }
 316
 317 // static
 318 void AccessibilityEventRouterViews::SendWindowNotification(
 319     views::View* view,
 320     ui::AccessibilityTypes::Event event,
 321     Profile* profile) {
 322   ui::AccessibleViewState state;
 323   view->GetAccessibleState(&state);
 324   std::string window_text;
 325
 326   // If it's an alert, try to get the text from the contents of the
 327   // static text, not the window title.
 328   if (state.role == ui::AccessibilityTypes::ROLE_ALERT)
 329     window_text = RecursiveGetStaticText(view);
 330
 331   // Otherwise get it from the window's accessible name.
 332   if (window_text.empty())
 333     window_text = UTF16ToUTF8(state.name);
 334
 335   AccessibilityWindowInfo info(profile, window_text);
 336   SendWindowAccessibilityNotification(event, &info);
 337 }
 338
 339 // static
 340 void AccessibilityEventRouterViews::SendSliderNotification(
 341     views::View* view,
 342     ui::AccessibilityTypes::Event event,
 343     Profile* profile) {
 344   ui::AccessibleViewState state;
 345   view->GetAccessibleState(&state);
 346
 347   std::string name = UTF16ToUTF8(state.name);
 348   std::string value = UTF16ToUTF8(state.value);
 349   std::string context = GetViewContext(view);
 350   AccessibilitySliderInfo info(
 351       profile,
 352       name,
 353       context,
 354       value);
 355   SendControlAccessibilityNotification(event, &info);
 356 }
 357
 358 // static
 359 std::string AccessibilityEventRouterViews::GetViewName(views::View* view) {
 360   ui::AccessibleViewState state;
 361   view->GetAccessibleState(&state);
 362   return UTF16ToUTF8(state.name);
 363 }
 364
 365 // static
 366 std::string AccessibilityEventRouterViews::GetViewContext(views::View* view) {
 367   for (views::View* parent = view->parent();
 368        parent;
 369        parent = parent->parent()) {
 370     ui::AccessibleViewState state;
 371     parent->GetAccessibleState(&state);
 372
 373     // Two cases are handled right now. More could be added in the future
 374     // depending on how the UI evolves.
 375
 376     // A control in a toolbar should use the toolbar's accessible name
 377     // as the context.
 378     if (state.role == ui::AccessibilityTypes::ROLE_TOOLBAR &&
 379         !state.name.empty()) {
 380       return UTF16ToUTF8(state.name);
 381     }
 382
 383     // A control inside of an alert or dialog (including an infobar)
 384     // should grab the first static text descendant as the context;
 385     // that's the prompt.
 386     if (state.role == ui::AccessibilityTypes::ROLE_ALERT ||
 387         state.role == ui::AccessibilityTypes::ROLE_DIALOG) {
 388       views::View* static_text_child = FindDescendantWithAccessibleRole(
 389           parent, ui::AccessibilityTypes::ROLE_STATICTEXT);
 390       if (static_text_child) {
 391         ui::AccessibleViewState state;
 392         static_text_child->GetAccessibleState(&state);
 393         if (!state.name.empty())
 394           return UTF16ToUTF8(state.name);
 395       }
 396       return std::string();
 397     }
 398   }
 399
 400   return std::string();
 401 }
 402
 403 // static
 404 views::View* AccessibilityEventRouterViews::FindDescendantWithAccessibleRole(
 405     views::View* view, ui::AccessibilityTypes::Role role) {
 406   ui::AccessibleViewState state;
 407   view->GetAccessibleState(&state);
 408   if (state.role == role)
 409     return view;
 410
 411   for (int i = 0; i < view->child_count(); i++) {
 412     views::View* child = view->child_at(i);
 413     views::View* result = FindDescendantWithAccessibleRole(child, role);
 414     if (result)
 415       return result;
 416   }
 417
 418   return NULL;
 419 }
 420
 421 // static
 422 void AccessibilityEventRouterViews::RecursiveGetMenuItemIndexAndCount(
 423     views::View* menu,
 424     views::View* item,
 425     int* index,
 426     int* count) {
 427   for (int i = 0; i < menu->child_count(); ++i) {
 428     views::View* child = menu->child_at(i);
 429     int previous_count = *count;
 430     RecursiveGetMenuItemIndexAndCount(child, item, index, count);
 431     ui::AccessibleViewState state;
 432     child->GetAccessibleState(&state);
 433     if (state.role == ui::AccessibilityTypes::ROLE_MENUITEM &&
 434         *count == previous_count) {
 435       if (item == child)
 436         *index = *count;
 437       (*count)++;
 438     } else if (state.role == ui::AccessibilityTypes::ROLE_PUSHBUTTON) {
 439       if (item == child)
 440         *index = *count;
 441       (*count)++;
 442     }
 443   }
 444 }
 445
 446 // static
 447 std::string AccessibilityEventRouterViews::RecursiveGetStaticText(
 448     views::View* view) {
 449   ui::AccessibleViewState state;
 450   view->GetAccessibleState(&state);
 451   if (state.role == ui::AccessibilityTypes::ROLE_STATICTEXT)
 452     return UTF16ToUTF8(state.name);
 453
 454   for (int i = 0; i < view->child_count(); ++i) {
 455     views::View* child = view->child_at(i);
 456     std::string result = RecursiveGetStaticText(child);
 457     if (!result.empty())
 458       return result;
 459   }
 460   return std::string();
 461 }