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1 // Copyright (c) 2011 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 VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_WIN_H_ | |
6 #define VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_WIN_H_ | |
7 #pragma once | |
8 | |
9 #include <atlbase.h> | |
10 #include <atlcom.h> | |
11 | |
12 #include <oleacc.h> | |
13 | |
14 #include "base/memory/scoped_ptr.h" | |
15 #include "third_party/iaccessible2/ia2_api_all.h" | |
16 #include "ui/base/accessibility/accessible_view_state.h" | |
17 #include "views/controls/native/native_view_host.h" | |
18 #include "views/view.h" | |
19 | |
20 namespace ui { | |
21 enum TextBoundaryDirection; | |
22 enum TextBoundaryType; | |
23 } | |
24 | |
25 // Note: do not put NativeViewAccessibilityWin in the namespace "views"; | |
26 // Visual Studio 2005 does not allow an ATL::CComObject symbol in a namespace. | |
27 | |
28 //////////////////////////////////////////////////////////////////////////////// | |
29 // | |
30 // NativeViewAccessibilityWin | |
31 // | |
32 // Class implementing the MSAA IAccessible COM interface for a generic View, | |
33 // providing accessibility to be used by screen readers and other assistive | |
34 // technology (AT). | |
35 // | |
36 //////////////////////////////////////////////////////////////////////////////// | |
37 class __declspec(uuid("26f5641a-246d-457b-a96d-07f3fae6acf2")) | |
38 NativeViewAccessibilityWin | |
39 : public CComObjectRootEx<CComMultiThreadModel>, | |
40 public IDispatchImpl<IAccessible2, &IID_IAccessible2, | |
41 &LIBID_IAccessible2Lib>, | |
42 public IAccessibleText, | |
43 public IServiceProvider { | |
44 public: | |
45 BEGIN_COM_MAP(NativeViewAccessibilityWin) | |
46 COM_INTERFACE_ENTRY2(IDispatch, IAccessible2) | |
47 COM_INTERFACE_ENTRY2(IAccessible, IAccessible2) | |
48 COM_INTERFACE_ENTRY(IAccessible2) | |
49 COM_INTERFACE_ENTRY(IAccessibleText) | |
50 COM_INTERFACE_ENTRY(IServiceProvider) | |
51 END_COM_MAP() | |
52 | |
53 // Create method for view accessibility. | |
54 static scoped_refptr<NativeViewAccessibilityWin> Create(views::View* view); | |
55 | |
56 virtual ~NativeViewAccessibilityWin(); | |
57 | |
58 void set_view(views::View* view) { view_ = view; } | |
59 | |
60 // Supported IAccessible methods. | |
61 | |
62 // Retrieves the child element or child object at a given point on the screen. | |
63 STDMETHODIMP accHitTest(LONG x_left, LONG y_top, VARIANT* child); | |
64 | |
65 // Performs the object's default action. | |
66 STDMETHODIMP accDoDefaultAction(VARIANT var_id); | |
67 | |
68 // Retrieves the specified object's current screen location. | |
69 STDMETHODIMP accLocation(LONG* x_left, | |
70 LONG* y_top, | |
71 LONG* width, | |
72 LONG* height, | |
73 VARIANT var_id); | |
74 | |
75 // Traverses to another UI element and retrieves the object. | |
76 STDMETHODIMP accNavigate(LONG nav_dir, VARIANT start, VARIANT* end); | |
77 | |
78 // Retrieves an IDispatch interface pointer for the specified child. | |
79 STDMETHODIMP get_accChild(VARIANT var_child, IDispatch** disp_child); | |
80 | |
81 // Retrieves the number of accessible children. | |
82 STDMETHODIMP get_accChildCount(LONG* child_count); | |
83 | |
84 // Retrieves a string that describes the object's default action. | |
85 STDMETHODIMP get_accDefaultAction(VARIANT var_id, BSTR* default_action); | |
86 | |
87 // Retrieves the tooltip description. | |
88 STDMETHODIMP get_accDescription(VARIANT var_id, BSTR* desc); | |
89 | |
90 // Retrieves the object that has the keyboard focus. | |
91 STDMETHODIMP get_accFocus(VARIANT* focus_child); | |
92 | |
93 // Retrieves the specified object's shortcut. | |
94 STDMETHODIMP get_accKeyboardShortcut(VARIANT var_id, BSTR* access_key); | |
95 | |
96 // Retrieves the name of the specified object. | |
97 STDMETHODIMP get_accName(VARIANT var_id, BSTR* name); | |
98 | |
99 // Retrieves the IDispatch interface of the object's parent. | |
100 STDMETHODIMP get_accParent(IDispatch** disp_parent); | |
101 | |
102 // Retrieves information describing the role of the specified object. | |
103 STDMETHODIMP get_accRole(VARIANT var_id, VARIANT* role); | |
104 | |
105 // Retrieves the current state of the specified object. | |
106 STDMETHODIMP get_accState(VARIANT var_id, VARIANT* state); | |
107 | |
108 // Retrieves the current value associated with the specified object. | |
109 STDMETHODIMP get_accValue(VARIANT var_id, BSTR* value); | |
110 | |
111 // Non-supported IAccessible methods. | |
112 | |
113 // Selections not applicable to views. | |
114 STDMETHODIMP get_accSelection(VARIANT* selected); | |
115 STDMETHODIMP accSelect(LONG flags_sel, VARIANT var_id); | |
116 | |
117 // Help functions not supported. | |
118 STDMETHODIMP get_accHelp(VARIANT var_id, BSTR* help); | |
119 STDMETHODIMP get_accHelpTopic(BSTR* help_file, | |
120 VARIANT var_id, | |
121 LONG* topic_id); | |
122 | |
123 // Deprecated functions, not implemented here. | |
124 STDMETHODIMP put_accName(VARIANT var_id, BSTR put_name); | |
125 STDMETHODIMP put_accValue(VARIANT var_id, BSTR put_val); | |
126 | |
127 // | |
128 // IAccessible2 | |
129 // | |
130 | |
131 STDMETHODIMP role(LONG* role); | |
132 | |
133 STDMETHODIMP get_states(AccessibleStates* states); | |
134 | |
135 STDMETHODIMP get_uniqueID(LONG* unique_id); | |
136 | |
137 STDMETHODIMP get_windowHandle(HWND* window_handle); | |
138 | |
139 // | |
140 // IAccessible2 methods not implemented. | |
141 // | |
142 | |
143 STDMETHODIMP get_attributes(BSTR* attributes) { | |
144 return E_NOTIMPL; | |
145 } | |
146 STDMETHODIMP get_indexInParent(LONG* index_in_parent) { | |
147 return E_NOTIMPL; | |
148 } | |
149 STDMETHODIMP get_extendedRole(BSTR* extended_role) { | |
150 return E_NOTIMPL; | |
151 } | |
152 STDMETHODIMP get_nRelations(LONG* n_relations) { | |
153 return E_NOTIMPL; | |
154 } | |
155 STDMETHODIMP get_relation(LONG relation_index, | |
156 IAccessibleRelation** relation) { | |
157 return E_NOTIMPL; | |
158 } | |
159 STDMETHODIMP get_relations(LONG max_relations, | |
160 IAccessibleRelation** relations, | |
161 LONG* n_relations) { | |
162 return E_NOTIMPL; | |
163 } | |
164 STDMETHODIMP scrollTo(enum IA2ScrollType scroll_type) { | |
165 return E_NOTIMPL; | |
166 } | |
167 STDMETHODIMP scrollToPoint( | |
168 enum IA2CoordinateType coordinate_type, | |
169 LONG x, | |
170 LONG y) { | |
171 return E_NOTIMPL; | |
172 } | |
173 STDMETHODIMP get_groupPosition(LONG* group_level, | |
174 LONG* similar_items_in_group, | |
175 LONG* position_in_group) { | |
176 return E_NOTIMPL; | |
177 } | |
178 STDMETHODIMP get_localizedExtendedRole( | |
179 BSTR* localized_extended_role) { | |
180 return E_NOTIMPL; | |
181 } | |
182 STDMETHODIMP get_nExtendedStates(LONG* n_extended_states) { | |
183 return E_NOTIMPL; | |
184 } | |
185 STDMETHODIMP get_extendedStates(LONG max_extended_states, | |
186 BSTR** extended_states, | |
187 LONG* n_extended_states) { | |
188 return E_NOTIMPL; | |
189 } | |
190 STDMETHODIMP get_localizedExtendedStates( | |
191 LONG max_localized_extended_states, | |
192 BSTR** localized_extended_states, | |
193 LONG* n_localized_extended_states) { | |
194 return E_NOTIMPL; | |
195 } | |
196 STDMETHODIMP get_locale(IA2Locale* locale) { | |
197 return E_NOTIMPL; | |
198 } | |
199 | |
200 // | |
201 // IAccessibleText methods. | |
202 // | |
203 | |
204 STDMETHODIMP get_nCharacters(LONG* n_characters); | |
205 | |
206 STDMETHODIMP get_caretOffset(LONG* offset); | |
207 | |
208 STDMETHODIMP get_nSelections(LONG* n_selections); | |
209 | |
210 STDMETHODIMP get_selection(LONG selection_index, | |
211 LONG* start_offset, | |
212 LONG* end_offset); | |
213 | |
214 STDMETHODIMP get_text(LONG start_offset, LONG end_offset, BSTR* text); | |
215 | |
216 STDMETHODIMP get_textAtOffset(LONG offset, | |
217 enum IA2TextBoundaryType boundary_type, | |
218 LONG* start_offset, LONG* end_offset, | |
219 BSTR* text); | |
220 | |
221 STDMETHODIMP get_textBeforeOffset(LONG offset, | |
222 enum IA2TextBoundaryType boundary_type, | |
223 LONG* start_offset, LONG* end_offset, | |
224 BSTR* text); | |
225 | |
226 STDMETHODIMP get_textAfterOffset(LONG offset, | |
227 enum IA2TextBoundaryType boundary_type, | |
228 LONG* start_offset, LONG* end_offset, | |
229 BSTR* text); | |
230 | |
231 STDMETHODIMP get_offsetAtPoint(LONG x, LONG y, | |
232 enum IA2CoordinateType coord_type, | |
233 LONG* offset); | |
234 | |
235 // | |
236 // IAccessibleText methods not implemented. | |
237 // | |
238 | |
239 STDMETHODIMP get_newText(IA2TextSegment* new_text) { | |
240 return E_NOTIMPL; | |
241 } | |
242 STDMETHODIMP get_oldText(IA2TextSegment* old_text) { | |
243 return E_NOTIMPL; | |
244 } | |
245 STDMETHODIMP addSelection(LONG start_offset, LONG end_offset) { | |
246 return E_NOTIMPL; | |
247 } | |
248 STDMETHODIMP get_attributes(LONG offset, | |
249 LONG* start_offset, | |
250 LONG* end_offset, | |
251 BSTR* text_attributes) { | |
252 return E_NOTIMPL; | |
253 } | |
254 STDMETHODIMP get_characterExtents(LONG offset, | |
255 enum IA2CoordinateType coord_type, | |
256 LONG* x, LONG* y, | |
257 LONG* width, LONG* height) { | |
258 return E_NOTIMPL; | |
259 } | |
260 STDMETHODIMP removeSelection(LONG selection_index) { | |
261 return E_NOTIMPL; | |
262 } | |
263 STDMETHODIMP setCaretOffset(LONG offset) { | |
264 return E_NOTIMPL; | |
265 } | |
266 STDMETHODIMP setSelection(LONG selection_index, | |
267 LONG start_offset, | |
268 LONG end_offset) { | |
269 return E_NOTIMPL; | |
270 } | |
271 STDMETHODIMP scrollSubstringTo(LONG start_index, | |
272 LONG end_index, | |
273 enum IA2ScrollType scroll_type) { | |
274 return E_NOTIMPL; | |
275 } | |
276 STDMETHODIMP scrollSubstringToPoint(LONG start_index, | |
277 LONG end_index, | |
278 enum IA2CoordinateType coordinate_type, | |
279 LONG x, LONG y) { | |
280 return E_NOTIMPL; | |
281 } | |
282 | |
283 // | |
284 // IServiceProvider methods. | |
285 // | |
286 | |
287 STDMETHODIMP QueryService(REFGUID guidService, REFIID riid, void** object); | |
288 | |
289 // Returns a conversion from the event (as defined in accessibility_types.h) | |
290 // to an MSAA event. | |
291 static int32 MSAAEvent(ui::AccessibilityTypes::Event event); | |
292 | |
293 // Returns a conversion from the Role (as defined in accessibility_types.h) | |
294 // to an MSAA role. | |
295 static int32 MSAARole(ui::AccessibilityTypes::Role role); | |
296 | |
297 // Returns a conversion from the State (as defined in accessibility_types.h) | |
298 // to MSAA states set. | |
299 static int32 MSAAState(ui::AccessibilityTypes::State state); | |
300 | |
301 private: | |
302 NativeViewAccessibilityWin(); | |
303 | |
304 // Determines navigation direction for accNavigate, based on left, up and | |
305 // previous being mapped all to previous and right, down, next being mapped | |
306 // to next. Returns true if navigation direction is next, false otherwise. | |
307 bool IsNavDirNext(int nav_dir) const; | |
308 | |
309 // Determines if the navigation target is within the allowed bounds. Returns | |
310 // true if it is, false otherwise. | |
311 bool IsValidNav(int nav_dir, | |
312 int start_id, | |
313 int lower_bound, | |
314 int upper_bound) const; | |
315 | |
316 // Determines if the child id variant is valid. | |
317 bool IsValidId(const VARIANT& child) const; | |
318 | |
319 // Helper function which sets applicable states of view. | |
320 void SetState(VARIANT* msaa_state, views::View* view); | |
321 | |
322 // Return the text to use for IAccessibleText. | |
323 string16 TextForIAccessibleText(); | |
324 | |
325 // If offset is a member of IA2TextSpecialOffsets this function updates the | |
326 // value of offset and returns, otherwise offset remains unchanged. | |
327 void HandleSpecialTextOffset(const string16& text, LONG* offset); | |
328 | |
329 // Convert from a IA2TextBoundaryType to a ui::TextBoundaryType. | |
330 ui::TextBoundaryType IA2TextBoundaryToTextBoundary(IA2TextBoundaryType type); | |
331 | |
332 // Search forwards (direction == 1) or backwards (direction == -1) | |
333 // from the given offset until the given boundary is found, and | |
334 // return the offset of that boundary. | |
335 LONG FindBoundary(const string16& text, | |
336 IA2TextBoundaryType ia2_boundary, | |
337 LONG start_offset, | |
338 ui::TextBoundaryDirection direction); | |
339 | |
340 // Give CComObject access to the class constructor. | |
341 template <class Base> friend class CComObject; | |
342 | |
343 // Member View needed for view-specific calls. | |
344 views::View* view_; | |
345 | |
346 // A unique id for each object, needed for IAccessible2. | |
347 long unique_id_; | |
348 | |
349 // Next unique id to assign. | |
350 static long next_unique_id_; | |
351 | |
352 DISALLOW_COPY_AND_ASSIGN(NativeViewAccessibilityWin); | |
353 }; | |
354 | |
355 #endif // VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_WIN_H_ | |
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