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Diffstat (limited to 'ui/views/accessibility/native_view_accessibility_win.h')
| -rw-r--r-- | ui/views/accessibility/native_view_accessibility_win.h | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/ui/views/accessibility/native_view_accessibility_win.h b/ui/views/accessibility/native_view_accessibility_win.h new file mode 100644 index 0000000..854f023 --- /dev/null +++ b/ui/views/accessibility/native_view_accessibility_win.h @@ -0,0 +1,355 @@ +// Copyright (c) 2011 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#ifndef VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_WIN_H_ +#define VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_WIN_H_ +#pragma once + +#include <atlbase.h> +#include <atlcom.h> + +#include <oleacc.h> + +#include "base/memory/scoped_ptr.h" +#include "third_party/iaccessible2/ia2_api_all.h" +#include "ui/base/accessibility/accessible_view_state.h" +#include "views/controls/native/native_view_host.h" +#include "views/view.h" + +namespace ui { +enum TextBoundaryDirection; +enum TextBoundaryType; +} + +// Note: do not put NativeViewAccessibilityWin in the namespace "views"; +// Visual Studio 2005 does not allow an ATL::CComObject symbol in a namespace. + +//////////////////////////////////////////////////////////////////////////////// +// +// NativeViewAccessibilityWin +// +// Class implementing the MSAA IAccessible COM interface for a generic View, +// providing accessibility to be used by screen readers and other assistive +// technology (AT). +// +//////////////////////////////////////////////////////////////////////////////// +class __declspec(uuid("26f5641a-246d-457b-a96d-07f3fae6acf2")) +NativeViewAccessibilityWin + : public CComObjectRootEx<CComMultiThreadModel>, + public IDispatchImpl<IAccessible2, &IID_IAccessible2, + &LIBID_IAccessible2Lib>, + public IAccessibleText, + public IServiceProvider { + public: + BEGIN_COM_MAP(NativeViewAccessibilityWin) + COM_INTERFACE_ENTRY2(IDispatch, IAccessible2) + COM_INTERFACE_ENTRY2(IAccessible, IAccessible2) + COM_INTERFACE_ENTRY(IAccessible2) + COM_INTERFACE_ENTRY(IAccessibleText) + COM_INTERFACE_ENTRY(IServiceProvider) + END_COM_MAP() + + // Create method for view accessibility. + static scoped_refptr<NativeViewAccessibilityWin> Create(views::View* view); + + virtual ~NativeViewAccessibilityWin(); + + void set_view(views::View* view) { view_ = view; } + + // Supported IAccessible methods. + + // Retrieves the child element or child object at a given point on the screen. + STDMETHODIMP accHitTest(LONG x_left, LONG y_top, VARIANT* child); + + // Performs the object's default action. + STDMETHODIMP accDoDefaultAction(VARIANT var_id); + + // Retrieves the specified object's current screen location. + STDMETHODIMP accLocation(LONG* x_left, + LONG* y_top, + LONG* width, + LONG* height, + VARIANT var_id); + + // Traverses to another UI element and retrieves the object. + STDMETHODIMP accNavigate(LONG nav_dir, VARIANT start, VARIANT* end); + + // Retrieves an IDispatch interface pointer for the specified child. + STDMETHODIMP get_accChild(VARIANT var_child, IDispatch** disp_child); + + // Retrieves the number of accessible children. + STDMETHODIMP get_accChildCount(LONG* child_count); + + // Retrieves a string that describes the object's default action. + STDMETHODIMP get_accDefaultAction(VARIANT var_id, BSTR* default_action); + + // Retrieves the tooltip description. + STDMETHODIMP get_accDescription(VARIANT var_id, BSTR* desc); + + // Retrieves the object that has the keyboard focus. + STDMETHODIMP get_accFocus(VARIANT* focus_child); + + // Retrieves the specified object's shortcut. + STDMETHODIMP get_accKeyboardShortcut(VARIANT var_id, BSTR* access_key); + + // Retrieves the name of the specified object. + STDMETHODIMP get_accName(VARIANT var_id, BSTR* name); + + // Retrieves the IDispatch interface of the object's parent. + STDMETHODIMP get_accParent(IDispatch** disp_parent); + + // Retrieves information describing the role of the specified object. + STDMETHODIMP get_accRole(VARIANT var_id, VARIANT* role); + + // Retrieves the current state of the specified object. + STDMETHODIMP get_accState(VARIANT var_id, VARIANT* state); + + // Retrieves the current value associated with the specified object. + STDMETHODIMP get_accValue(VARIANT var_id, BSTR* value); + + // Non-supported IAccessible methods. + + // Selections not applicable to views. + STDMETHODIMP get_accSelection(VARIANT* selected); + STDMETHODIMP accSelect(LONG flags_sel, VARIANT var_id); + + // Help functions not supported. + STDMETHODIMP get_accHelp(VARIANT var_id, BSTR* help); + STDMETHODIMP get_accHelpTopic(BSTR* help_file, + VARIANT var_id, + LONG* topic_id); + + // Deprecated functions, not implemented here. + STDMETHODIMP put_accName(VARIANT var_id, BSTR put_name); + STDMETHODIMP put_accValue(VARIANT var_id, BSTR put_val); + + // + // IAccessible2 + // + + STDMETHODIMP role(LONG* role); + + STDMETHODIMP get_states(AccessibleStates* states); + + STDMETHODIMP get_uniqueID(LONG* unique_id); + + STDMETHODIMP get_windowHandle(HWND* window_handle); + + // + // IAccessible2 methods not implemented. + // + + STDMETHODIMP get_attributes(BSTR* attributes) { + return E_NOTIMPL; + } + STDMETHODIMP get_indexInParent(LONG* index_in_parent) { + return E_NOTIMPL; + } + STDMETHODIMP get_extendedRole(BSTR* extended_role) { + return E_NOTIMPL; + } + STDMETHODIMP get_nRelations(LONG* n_relations) { + return E_NOTIMPL; + } + STDMETHODIMP get_relation(LONG relation_index, + IAccessibleRelation** relation) { + return E_NOTIMPL; + } + STDMETHODIMP get_relations(LONG max_relations, + IAccessibleRelation** relations, + LONG* n_relations) { + return E_NOTIMPL; + } + STDMETHODIMP scrollTo(enum IA2ScrollType scroll_type) { + return E_NOTIMPL; + } + STDMETHODIMP scrollToPoint( + enum IA2CoordinateType coordinate_type, + LONG x, + LONG y) { + return E_NOTIMPL; + } + STDMETHODIMP get_groupPosition(LONG* group_level, + LONG* similar_items_in_group, + LONG* position_in_group) { + return E_NOTIMPL; + } + STDMETHODIMP get_localizedExtendedRole( + BSTR* localized_extended_role) { + return E_NOTIMPL; + } + STDMETHODIMP get_nExtendedStates(LONG* n_extended_states) { + return E_NOTIMPL; + } + STDMETHODIMP get_extendedStates(LONG max_extended_states, + BSTR** extended_states, + LONG* n_extended_states) { + return E_NOTIMPL; + } + STDMETHODIMP get_localizedExtendedStates( + LONG max_localized_extended_states, + BSTR** localized_extended_states, + LONG* n_localized_extended_states) { + return E_NOTIMPL; + } + STDMETHODIMP get_locale(IA2Locale* locale) { + return E_NOTIMPL; + } + + // + // IAccessibleText methods. + // + + STDMETHODIMP get_nCharacters(LONG* n_characters); + + STDMETHODIMP get_caretOffset(LONG* offset); + + STDMETHODIMP get_nSelections(LONG* n_selections); + + STDMETHODIMP get_selection(LONG selection_index, + LONG* start_offset, + LONG* end_offset); + + STDMETHODIMP get_text(LONG start_offset, LONG end_offset, BSTR* text); + + STDMETHODIMP get_textAtOffset(LONG offset, + enum IA2TextBoundaryType boundary_type, + LONG* start_offset, LONG* end_offset, + BSTR* text); + + STDMETHODIMP get_textBeforeOffset(LONG offset, + enum IA2TextBoundaryType boundary_type, + LONG* start_offset, LONG* end_offset, + BSTR* text); + + STDMETHODIMP get_textAfterOffset(LONG offset, + enum IA2TextBoundaryType boundary_type, + LONG* start_offset, LONG* end_offset, + BSTR* text); + + STDMETHODIMP get_offsetAtPoint(LONG x, LONG y, + enum IA2CoordinateType coord_type, + LONG* offset); + + // + // IAccessibleText methods not implemented. + // + + STDMETHODIMP get_newText(IA2TextSegment* new_text) { + return E_NOTIMPL; + } + STDMETHODIMP get_oldText(IA2TextSegment* old_text) { + return E_NOTIMPL; + } + STDMETHODIMP addSelection(LONG start_offset, LONG end_offset) { + return E_NOTIMPL; + } + STDMETHODIMP get_attributes(LONG offset, + LONG* start_offset, + LONG* end_offset, + BSTR* text_attributes) { + return E_NOTIMPL; + } + STDMETHODIMP get_characterExtents(LONG offset, + enum IA2CoordinateType coord_type, + LONG* x, LONG* y, + LONG* width, LONG* height) { + return E_NOTIMPL; + } + STDMETHODIMP removeSelection(LONG selection_index) { + return E_NOTIMPL; + } + STDMETHODIMP setCaretOffset(LONG offset) { + return E_NOTIMPL; + } + STDMETHODIMP setSelection(LONG selection_index, + LONG start_offset, + LONG end_offset) { + return E_NOTIMPL; + } + STDMETHODIMP scrollSubstringTo(LONG start_index, + LONG end_index, + enum IA2ScrollType scroll_type) { + return E_NOTIMPL; + } + STDMETHODIMP scrollSubstringToPoint(LONG start_index, + LONG end_index, + enum IA2CoordinateType coordinate_type, + LONG x, LONG y) { + return E_NOTIMPL; + } + + // + // IServiceProvider methods. + // + + STDMETHODIMP QueryService(REFGUID guidService, REFIID riid, void** object); + + // Returns a conversion from the event (as defined in accessibility_types.h) + // to an MSAA event. + static int32 MSAAEvent(ui::AccessibilityTypes::Event event); + + // Returns a conversion from the Role (as defined in accessibility_types.h) + // to an MSAA role. + static int32 MSAARole(ui::AccessibilityTypes::Role role); + + // Returns a conversion from the State (as defined in accessibility_types.h) + // to MSAA states set. + static int32 MSAAState(ui::AccessibilityTypes::State state); + + private: + NativeViewAccessibilityWin(); + + // Determines navigation direction for accNavigate, based on left, up and + // previous being mapped all to previous and right, down, next being mapped + // to next. Returns true if navigation direction is next, false otherwise. + bool IsNavDirNext(int nav_dir) const; + + // Determines if the navigation target is within the allowed bounds. Returns + // true if it is, false otherwise. + bool IsValidNav(int nav_dir, + int start_id, + int lower_bound, + int upper_bound) const; + + // Determines if the child id variant is valid. + bool IsValidId(const VARIANT& child) const; + + // Helper function which sets applicable states of view. + void SetState(VARIANT* msaa_state, views::View* view); + + // Return the text to use for IAccessibleText. + string16 TextForIAccessibleText(); + + // If offset is a member of IA2TextSpecialOffsets this function updates the + // value of offset and returns, otherwise offset remains unchanged. + void HandleSpecialTextOffset(const string16& text, LONG* offset); + + // Convert from a IA2TextBoundaryType to a ui::TextBoundaryType. + ui::TextBoundaryType IA2TextBoundaryToTextBoundary(IA2TextBoundaryType type); + + // Search forwards (direction == 1) or backwards (direction == -1) + // from the given offset until the given boundary is found, and + // return the offset of that boundary. + LONG FindBoundary(const string16& text, + IA2TextBoundaryType ia2_boundary, + LONG start_offset, + ui::TextBoundaryDirection direction); + + // Give CComObject access to the class constructor. + template <class Base> friend class CComObject; + + // Member View needed for view-specific calls. + views::View* view_; + + // A unique id for each object, needed for IAccessible2. + long unique_id_; + + // Next unique id to assign. + static long next_unique_id_; + + DISALLOW_COPY_AND_ASSIGN(NativeViewAccessibilityWin); +}; + +#endif // VIEWS_ACCESSIBILITY_NATIVE_VIEW_ACCESSIBILITY_WIN_H_ |