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Diffstat (limited to 'chrome/browser/browser_accessibility_win.h')
| -rw-r--r-- | chrome/browser/browser_accessibility_win.h | 399 |
1 files changed, 399 insertions, 0 deletions
diff --git a/chrome/browser/browser_accessibility_win.h b/chrome/browser/browser_accessibility_win.h new file mode 100644 index 0000000..08edb2b --- /dev/null +++ b/chrome/browser/browser_accessibility_win.h @@ -0,0 +1,399 @@ +// Copyright (c) 2010 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 CHROME_BROWSER_BROWSER_ACCESSIBILITY_WIN_H_ +#define CHROME_BROWSER_BROWSER_ACCESSIBILITY_WIN_H_ + +#include <atlbase.h> +#include <atlcom.h> +#include <oleacc.h> + +#include <vector> + +#include "base/scoped_comptr_win.h" +#include "chrome/browser/browser_accessibility_manager_win.h" +#include "ia2_api_all.h" // Generated +#include "webkit/glue/webaccessibility.h" + +using webkit_glue::WebAccessibility; + +//////////////////////////////////////////////////////////////////////////////// +// +// BrowserAccessibility +// +// Class implementing the MSAA IAccessible COM interface for the +// Browser-Renderer communication of MSAA information, providing accessibility +// to be used by screen readers and other assistive technology (AT). +// +//////////////////////////////////////////////////////////////////////////////// +class ATL_NO_VTABLE BrowserAccessibility + : public CComObjectRootEx<CComMultiThreadModel>, + public IDispatchImpl<IAccessible2, &IID_IAccessible2, + &LIBID_IAccessible2Lib>, + public IAccessibleImage, + public IAccessibleText, + public IServiceProvider { + public: + BEGIN_COM_MAP(BrowserAccessibility) + COM_INTERFACE_ENTRY2(IDispatch, IAccessible2) + COM_INTERFACE_ENTRY2(IAccessible, IAccessible2) + COM_INTERFACE_ENTRY(IAccessible2) + COM_INTERFACE_ENTRY(IAccessibleImage) + COM_INTERFACE_ENTRY(IAccessibleText) + COM_INTERFACE_ENTRY(IServiceProvider) + END_COM_MAP() + + BrowserAccessibility(); + + virtual ~BrowserAccessibility(); + + // Initialize this object and mark it as active. + void Initialize(BrowserAccessibilityManager* manager, + BrowserAccessibility* parent, + LONG child_id, + LONG index_in_parent, + const webkit_glue::WebAccessibility& src); + + // Add a child of this object. + void AddChild(BrowserAccessibility* child); + + // Mark this object as inactive, and remove references to all children. + // When no other clients hold any references to this object it will be + // deleted, and in the meantime, calls to any methods will return E_FAIL. + void InactivateTree(); + + // Return true if this object is equal to or a descendant of |ancestor|. + bool IsDescendantOf(BrowserAccessibility* ancestor); + + // Return the previous sibling of this object, or NULL if it's the first + // child of its parent. + BrowserAccessibility* GetPreviousSibling(); + + // Return the next sibling of this object, or NULL if it's the last child + // of its parent. + BrowserAccessibility* GetNextSibling(); + + // Accessors + LONG child_id() const { return child_id_; } + int32 renderer_id() const { return renderer_id_; } + + // Add one to the reference count and return the same object. Always + // use this method when returning a BrowserAccessibility object as + // an output parameter to a COM interface, never use it otherwise. + BrowserAccessibility* NewReference(); + + // + // IAccessible methods. + // + + // Performs the default action on a given object. + STDMETHODIMP accDoDefaultAction(VARIANT var_id); + + // Retrieves the child element or child object at a given point on the screen. + STDMETHODIMP accHitTest(LONG x_left, LONG y_top, VARIANT* child); + + // 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 object's 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 help information associated with the object. + STDMETHODIMP get_accHelp(VARIANT var_id, BSTR* help); + + // 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); + + // Returns the value associated with the object. + STDMETHODIMP get_accValue(VARIANT var_id, BSTR* value); + + // Make an object take focus or extend the selection. + STDMETHODIMP accSelect(LONG flags_sel, VARIANT var_id); + + STDMETHODIMP get_accHelpTopic(BSTR* help_file, + VARIANT var_id, + LONG* topic_id); + + STDMETHODIMP get_accSelection(VARIANT* selected); + + // Deprecated methods, not implemented. + STDMETHODIMP put_accName(VARIANT var_id, BSTR put_name) { + return E_NOTIMPL; + } + STDMETHODIMP put_accValue(VARIANT var_id, BSTR put_val) { + return E_NOTIMPL; + } + + // + // IAccessible2 methods. + // + + // Returns role from a longer list of possible roles. + STDMETHODIMP role(LONG* role); + + // Returns the state bitmask from a larger set of possible states. + STDMETHODIMP get_states(AccessibleStates* states); + + // Returns the attributes specific to this IAccessible2 object, + // such as a cell's formula. + STDMETHODIMP get_attributes(BSTR* attributes); + + // Get the unique ID of this object so that the client knows if it's + // been encountered previously. + STDMETHODIMP get_uniqueID(LONG* unique_id); + + // Get the window handle of the enclosing window. + STDMETHODIMP get_windowHandle(HWND* window_handle); + + // Get this object's index in its parent object. + STDMETHODIMP get_indexInParent(LONG* index_in_parent); + + // IAccessible2 methods not implemented. + 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; + } + + // + // IAccessibleImage methods. + // + + STDMETHODIMP get_description(BSTR* description); + + STDMETHODIMP get_imagePosition(enum IA2CoordinateType coordinate_type, + long* x, long* y); + + STDMETHODIMP get_imageSize(long* height, long* width); + + // + // IAccessibleText methods. + // + + STDMETHODIMP get_nCharacters(long* n_characters); + + STDMETHODIMP get_text(long start_offset, long end_offset, BSTR* text); + + STDMETHODIMP get_caretOffset(long* offset); + + // IAccessibleText methods not implemented. + 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 get_nSelections(long* n_selections) { + return E_NOTIMPL; + } + STDMETHODIMP get_offsetAtPoint(long x, long y, + enum IA2CoordinateType coord_type, + long* offset) { + return E_NOTIMPL; + } + STDMETHODIMP get_selection(long selection_index, + long* start_offset, + long* end_offset) { + return E_NOTIMPL; + } + STDMETHODIMP get_textBeforeOffset(long offset, + enum IA2TextBoundaryType boundary_type, + long* start_offset, long* end_offset, + BSTR* text) { + return E_NOTIMPL; + } + STDMETHODIMP get_textAfterOffset(long offset, + enum IA2TextBoundaryType boundary_type, + long* start_offset, long* end_offset, + BSTR* text) { + return E_NOTIMPL; + } + STDMETHODIMP get_textAtOffset(long offset, + enum IA2TextBoundaryType boundary_type, + long* start_offset, long* end_offset, + BSTR* text) { + 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; + } + STDMETHODIMP get_newText(IA2TextSegment* new_text) { + return E_NOTIMPL; + } + STDMETHODIMP get_oldText(IA2TextSegment* old_text) { + return E_NOTIMPL; + } + + // + // IServiceProvider methods. + // + + STDMETHODIMP QueryService(REFGUID guidService, REFIID riid, void** object); + + // + // CComObjectRootEx methods. + // + + HRESULT WINAPI InternalQueryInterface(void* this_ptr, + const _ATL_INTMAP_ENTRY* entries, + REFIID iid, + void** object); + + private: + // Many MSAA methods take a var_id parameter indicating that the operation + // should be performed on a particular child ID, rather than this object. + // This method tries to figure out the target object from |var_id| and + // returns a pointer to the target object if it exists, otherwise NULL. + // Does not return a new reference. + BrowserAccessibility* GetTargetFromChildID(const VARIANT& var_id); + + // Initialize the role and state metadata from the role enum and state + // bitmasks defined in webkit/glue/webaccessibility.h. + void InitRoleAndState(LONG web_accessibility_role, + LONG web_accessibility_state); + + // Return true if this attribute is in the attributes map. + bool HasAttribute(WebAccessibility::Attribute attribute); + + // Retrieve the string value of an attribute from the attribute map and + // returns true if found. + bool GetAttribute(WebAccessibility::Attribute attribute, string16* value); + + // The manager of this tree of accessibility objects; needed for + // global operations like focus tracking. + BrowserAccessibilityManager* manager_; + // The parent of this object, may be NULL if we're the root object. + BrowserAccessibility* parent_; + // The ID of this object; globally unique within the browser process. + LONG child_id_; + // The index of this within its parent object. + LONG index_in_parent_; + // The ID of this object in the renderer process. + int32 renderer_id_; + + // The children of this object. + std::vector<BrowserAccessibility*> children_; + + // Accessibility metadata from the renderer, used to respond to MSAA + // events. + string16 name_; + string16 value_; + std::map<int32, string16> attributes_; + + LONG role_; + LONG state_; + string16 role_name_; + LONG ia2_role_; + LONG ia2_state_; + WebKit::WebRect location_; + + // COM objects are reference-counted. When we're done with this object + // and it's removed from our accessibility tree, a client may still be + // holding onto a pointer to this object, so we mark it as inactive + // so that calls to any of this object's methods immediately return + // failure. + bool instance_active_; + + DISALLOW_COPY_AND_ASSIGN(BrowserAccessibility); +}; + +#endif // CHROME_BROWSER_BROWSER_ACCESSIBILITY_WIN_H_ |