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 #ifndef UI_VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_WIN_H_ 6 #define UI_VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_WIN_H_ 7 8 #include <atlbase.h> 9 #include <atlcom.h> 10 #include <oleacc.h> 11 12 #include <UIAutomationCore.h> 13 14 #include <set> 15 #include <vector> 16 17 #include "third_party/iaccessible2/ia2_api_all.h" 18 #include "ui/accessibility/ax_view_state.h" 19 #include "ui/views/accessibility/native_view_accessibility.h" 20 #include "ui/views/controls/native/native_view_host.h" 21 #include "ui/views/view.h" 22 23 namespace ui { 24 enum TextBoundaryDirection; 25 enum TextBoundaryType; 26 } 27 28 namespace views { 29 30 //////////////////////////////////////////////////////////////////////////////// 31 // 32 // NativeViewAccessibilityWin 33 // 34 // Class implementing the MSAA IAccessible COM interface for a generic View, 35 // providing accessibility to be used by screen readers and other assistive 36 // technology (AT). 37 // 38 //////////////////////////////////////////////////////////////////////////////// 39 class __declspec(uuid("26f5641a-246d-457b-a96d-07f3fae6acf2")) 40 NativeViewAccessibilityWin 41 : public CComObjectRootEx<CComMultiThreadModel>, 42 public IDispatchImpl<IAccessible2_2, &IID_IAccessible2_2, 43 &LIBID_IAccessible2Lib>, 44 public IAccessibleText, 45 public IServiceProvider, 46 public IAccessibleEx, 47 public IRawElementProviderSimple, 48 public NativeViewAccessibility { 49 public: 50 BEGIN_COM_MAP(NativeViewAccessibilityWin) 51 COM_INTERFACE_ENTRY2(IDispatch, IAccessible2_2) 52 COM_INTERFACE_ENTRY(IAccessible) 53 COM_INTERFACE_ENTRY(IAccessible2) 54 COM_INTERFACE_ENTRY(IAccessible2_2) 55 COM_INTERFACE_ENTRY(IAccessibleEx) 56 COM_INTERFACE_ENTRY(IAccessibleText) 57 COM_INTERFACE_ENTRY(IRawElementProviderSimple) 58 COM_INTERFACE_ENTRY(IServiceProvider) 59 END_COM_MAP() 60 61 virtual ~NativeViewAccessibilityWin(); 62 63 // NativeViewAccessibility. 64 virtual void NotifyAccessibilityEvent( 65 ui::AXEvent event_type) OVERRIDE; 66 virtual gfx::NativeViewAccessible GetNativeObject() OVERRIDE; 67 virtual void Destroy() OVERRIDE; 68 69 // Supported IAccessible methods. 70 71 // Retrieves the child element or child object at a given point on the screen. 72 virtual STDMETHODIMP accHitTest(LONG x_left, LONG y_top, VARIANT* child); 73 74 // Performs the object's default action. 75 STDMETHODIMP accDoDefaultAction(VARIANT var_id); 76 77 // Retrieves the specified object's current screen location. 78 STDMETHODIMP accLocation(LONG* x_left, 79 LONG* y_top, 80 LONG* width, 81 LONG* height, 82 VARIANT var_id); 83 84 // Traverses to another UI element and retrieves the object. 85 STDMETHODIMP accNavigate(LONG nav_dir, VARIANT start, VARIANT* end); 86 87 // Retrieves an IDispatch interface pointer for the specified child. 88 virtual STDMETHODIMP get_accChild(VARIANT var_child, IDispatch** disp_child); 89 90 // Retrieves the number of accessible children. 91 virtual STDMETHODIMP get_accChildCount(LONG* child_count); 92 93 // Retrieves a string that describes the object's default action. 94 STDMETHODIMP get_accDefaultAction(VARIANT var_id, BSTR* default_action); 95 96 // Retrieves the tooltip description. 97 STDMETHODIMP get_accDescription(VARIANT var_id, BSTR* desc); 98 99 // Retrieves the object that has the keyboard focus. 100 STDMETHODIMP get_accFocus(VARIANT* focus_child); 101 102 // Retrieves the specified object's shortcut. 103 STDMETHODIMP get_accKeyboardShortcut(VARIANT var_id, BSTR* access_key); 104 105 // Retrieves the name of the specified object. 106 STDMETHODIMP get_accName(VARIANT var_id, BSTR* name); 107 108 // Retrieves the IDispatch interface of the object's parent. 109 STDMETHODIMP get_accParent(IDispatch** disp_parent); 110 111 // Retrieves information describing the role of the specified object. 112 STDMETHODIMP get_accRole(VARIANT var_id, VARIANT* role); 113 114 // Retrieves the current state of the specified object. 115 STDMETHODIMP get_accState(VARIANT var_id, VARIANT* state); 116 117 // Retrieve or set the string value associated with the specified object. 118 // Setting the value is not typically used by screen readers, but it's 119 // used frequently by automation software. 120 STDMETHODIMP get_accValue(VARIANT var_id, BSTR* value); 121 STDMETHODIMP put_accValue(VARIANT var_id, BSTR new_value); 122 123 // Selections not applicable to views. 124 STDMETHODIMP get_accSelection(VARIANT* selected); 125 STDMETHODIMP accSelect(LONG flags_sel, VARIANT var_id); 126 127 // Help functions not supported. 128 STDMETHODIMP get_accHelp(VARIANT var_id, BSTR* help); 129 STDMETHODIMP get_accHelpTopic(BSTR* help_file, 130 VARIANT var_id, 131 LONG* topic_id); 132 133 // Deprecated functions, not implemented here. 134 STDMETHODIMP put_accName(VARIANT var_id, BSTR put_name); 135 136 // 137 // IAccessible2 138 // 139 140 STDMETHODIMP role(LONG* role); 141 142 STDMETHODIMP get_states(AccessibleStates* states); 143 144 STDMETHODIMP get_uniqueID(LONG* unique_id); 145 146 STDMETHODIMP get_windowHandle(HWND* window_handle); 147 148 STDMETHODIMP get_relationTargetsOfType(BSTR type, 149 long max_targets, 150 IUnknown ***targets, 151 long *n_targets); 152 153 STDMETHODIMP get_attributes(BSTR* attributes); 154 155 // 156 // IAccessible2 methods not implemented. 157 // 158 159 STDMETHODIMP get_attribute(BSTR name, VARIANT* attribute) { 160 return E_NOTIMPL; 161 } 162 STDMETHODIMP get_indexInParent(LONG* index_in_parent) { 163 return E_NOTIMPL; 164 } 165 STDMETHODIMP get_extendedRole(BSTR* extended_role) { 166 return E_NOTIMPL; 167 } 168 STDMETHODIMP get_nRelations(LONG* n_relations) { 169 return E_NOTIMPL; 170 } 171 STDMETHODIMP get_relation(LONG relation_index, 172 IAccessibleRelation** relation) { 173 return E_NOTIMPL; 174 } 175 STDMETHODIMP get_relations(LONG max_relations, 176 IAccessibleRelation** relations, 177 LONG* n_relations) { 178 return E_NOTIMPL; 179 } 180 STDMETHODIMP scrollTo(enum IA2ScrollType scroll_type) { 181 return E_NOTIMPL; 182 } 183 STDMETHODIMP scrollToPoint( 184 enum IA2CoordinateType coordinate_type, 185 LONG x, 186 LONG y) { 187 return E_NOTIMPL; 188 } 189 STDMETHODIMP get_groupPosition(LONG* group_level, 190 LONG* similar_items_in_group, 191 LONG* position_in_group) { 192 return E_NOTIMPL; 193 } 194 STDMETHODIMP get_localizedExtendedRole( 195 BSTR* localized_extended_role) { 196 return E_NOTIMPL; 197 } 198 STDMETHODIMP get_nExtendedStates(LONG* n_extended_states) { 199 return E_NOTIMPL; 200 } 201 STDMETHODIMP get_extendedStates(LONG max_extended_states, 202 BSTR** extended_states, 203 LONG* n_extended_states) { 204 return E_NOTIMPL; 205 } 206 STDMETHODIMP get_localizedExtendedStates( 207 LONG max_localized_extended_states, 208 BSTR** localized_extended_states, 209 LONG* n_localized_extended_states) { 210 return E_NOTIMPL; 211 } 212 STDMETHODIMP get_locale(IA2Locale* locale) { 213 return E_NOTIMPL; 214 } 215 STDMETHODIMP get_accessibleWithCaret(IUnknown** accessible, 216 long* caret_offset) { 217 return E_NOTIMPL; 218 } 219 220 // 221 // IAccessibleText methods. 222 // 223 224 STDMETHODIMP get_nCharacters(LONG* n_characters); 225 226 STDMETHODIMP get_caretOffset(LONG* offset); 227 228 STDMETHODIMP get_nSelections(LONG* n_selections); 229 230 STDMETHODIMP get_selection(LONG selection_index, 231 LONG* start_offset, 232 LONG* end_offset); 233 234 STDMETHODIMP get_text(LONG start_offset, LONG end_offset, BSTR* text); 235 236 STDMETHODIMP get_textAtOffset(LONG offset, 237 enum IA2TextBoundaryType boundary_type, 238 LONG* start_offset, LONG* end_offset, 239 BSTR* text); 240 241 STDMETHODIMP get_textBeforeOffset(LONG offset, 242 enum IA2TextBoundaryType boundary_type, 243 LONG* start_offset, LONG* end_offset, 244 BSTR* text); 245 246 STDMETHODIMP get_textAfterOffset(LONG offset, 247 enum IA2TextBoundaryType boundary_type, 248 LONG* start_offset, LONG* end_offset, 249 BSTR* text); 250 251 STDMETHODIMP get_offsetAtPoint(LONG x, LONG y, 252 enum IA2CoordinateType coord_type, 253 LONG* offset); 254 255 // 256 // IAccessibleText methods not implemented. 257 // 258 259 STDMETHODIMP get_newText(IA2TextSegment* new_text) { 260 return E_NOTIMPL; 261 } 262 STDMETHODIMP get_oldText(IA2TextSegment* old_text) { 263 return E_NOTIMPL; 264 } 265 STDMETHODIMP addSelection(LONG start_offset, LONG end_offset) { 266 return E_NOTIMPL; 267 } 268 STDMETHODIMP get_attributes(LONG offset, 269 LONG* start_offset, 270 LONG* end_offset, 271 BSTR* text_attributes) { 272 return E_NOTIMPL; 273 } 274 STDMETHODIMP get_characterExtents(LONG offset, 275 enum IA2CoordinateType coord_type, 276 LONG* x, LONG* y, 277 LONG* width, LONG* height) { 278 return E_NOTIMPL; 279 } 280 STDMETHODIMP removeSelection(LONG selection_index) { 281 return E_NOTIMPL; 282 } 283 STDMETHODIMP setCaretOffset(LONG offset) { 284 return E_NOTIMPL; 285 } 286 STDMETHODIMP setSelection(LONG selection_index, 287 LONG start_offset, 288 LONG end_offset) { 289 return E_NOTIMPL; 290 } 291 STDMETHODIMP scrollSubstringTo(LONG start_index, 292 LONG end_index, 293 enum IA2ScrollType scroll_type) { 294 return E_NOTIMPL; 295 } 296 STDMETHODIMP scrollSubstringToPoint(LONG start_index, 297 LONG end_index, 298 enum IA2CoordinateType coordinate_type, 299 LONG x, LONG y) { 300 return E_NOTIMPL; 301 } 302 303 // 304 // IServiceProvider methods. 305 // 306 307 STDMETHODIMP QueryService(REFGUID guidService, REFIID riid, void** object); 308 309 // 310 // IAccessibleEx methods not implemented. 311 // 312 STDMETHODIMP GetObjectForChild(long child_id, IAccessibleEx** ret) { 313 return E_NOTIMPL; 314 } 315 316 STDMETHODIMP GetIAccessiblePair(IAccessible** acc, long* child_id) { 317 return E_NOTIMPL; 318 } 319 320 STDMETHODIMP GetRuntimeId(SAFEARRAY** runtime_id) { 321 return E_NOTIMPL; 322 } 323 324 STDMETHODIMP ConvertReturnedElement(IRawElementProviderSimple* element, 325 IAccessibleEx** acc) { 326 return E_NOTIMPL; 327 } 328 329 // 330 // IRawElementProviderSimple methods. 331 // 332 // The GetPatternProvider/GetPropertyValue methods need to be implemented for 333 // the on-screen keyboard to show up in Windows 8 metro. 334 STDMETHODIMP GetPatternProvider(PATTERNID id, IUnknown** provider); 335 STDMETHODIMP GetPropertyValue(PROPERTYID id, VARIANT* ret); 336 337 // 338 // IRawElementProviderSimple methods not implemented. 339 // 340 STDMETHODIMP get_ProviderOptions(enum ProviderOptions* ret) { 341 return E_NOTIMPL; 342 } 343 344 STDMETHODIMP get_HostRawElementProvider( 345 IRawElementProviderSimple** provider) { 346 return E_NOTIMPL; 347 } 348 349 // Static methods 350 351 // Returns a conversion from the event (as defined in ax_enums.idl) 352 // to an MSAA event. 353 static int32 MSAAEvent(ui::AXEvent event); 354 355 // Returns a conversion from the Role (as defined in ax_enums.idl) 356 // to an MSAA role. 357 static int32 MSAARole(ui::AXRole role); 358 359 // Returns a conversion from the State (as defined in ax_enums.idl) 360 // to MSAA states set. 361 static int32 MSAAState(const ui::AXViewState& state); 362 363 protected: 364 NativeViewAccessibilityWin(); 365 366 private: 367 // Determines navigation direction for accNavigate, based on left, up and 368 // previous being mapped all to previous and right, down, next being mapped 369 // to next. Returns true if navigation direction is next, false otherwise. 370 bool IsNavDirNext(int nav_dir) const; 371 372 // Determines if the navigation target is within the allowed bounds. Returns 373 // true if it is, false otherwise. 374 bool IsValidNav(int nav_dir, 375 int start_id, 376 int lower_bound, 377 int upper_bound) const; 378 379 // Determines if the child id variant is valid. 380 bool IsValidId(const VARIANT& child) const; 381 382 // Helper function which sets applicable states of view. 383 void SetState(VARIANT* msaa_state, View* view); 384 385 // Return the text to use for IAccessibleText. 386 base::string16 TextForIAccessibleText(); 387 388 // If offset is a member of IA2TextSpecialOffsets this function updates the 389 // value of offset and returns, otherwise offset remains unchanged. 390 void HandleSpecialTextOffset(const base::string16& text, LONG* offset); 391 392 // Convert from a IA2TextBoundaryType to a ui::TextBoundaryType. 393 ui::TextBoundaryType IA2TextBoundaryToTextBoundary(IA2TextBoundaryType type); 394 395 // Search forwards (direction == 1) or backwards (direction == -1) 396 // from the given offset until the given boundary is found, and 397 // return the offset of that boundary. 398 LONG FindBoundary(const base::string16& text, 399 IA2TextBoundaryType ia2_boundary, 400 LONG start_offset, 401 ui::TextBoundaryDirection direction); 402 403 // Populates the given vector with all widgets that are either a child 404 // or are owned by this view's widget, and who are not contained in a 405 // NativeViewHost. 406 void PopulateChildWidgetVector(std::vector<Widget*>* child_widgets); 407 408 // Adds this view to alert_target_view_storage_ids_. 409 void AddAlertTarget(); 410 411 // Removes this view from alert_target_view_storage_ids_. 412 void RemoveAlertTarget(); 413 414 // Give CComObject access to the class constructor. 415 template <class Base> friend class CComObject; 416 417 // A unique id for each object, needed for IAccessible2. 418 long unique_id_; 419 420 // Next unique id to assign. 421 static long next_unique_id_; 422 423 // Circular queue size. 424 static const int kMaxViewStorageIds = 20; 425 426 // Circular queue of view storage ids corresponding to child ids 427 // used to post notifications using NotifyWinEvent. 428 static int view_storage_ids_[kMaxViewStorageIds]; 429 430 // Next index into |view_storage_ids_| to use. 431 static int next_view_storage_id_index_; 432 433 // A vector of view storage ids of views that have been the target of 434 // an alert event, in order to provide an api to quickly identify all 435 // open alerts. 436 static std::vector<int> alert_target_view_storage_ids_; 437 438 DISALLOW_COPY_AND_ASSIGN(NativeViewAccessibilityWin); 439 }; 440 441 } // namespace views 442 443 #endif // UI_VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_WIN_H_ 444
