// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef UI_ACCESSIBILITY_PLATFORM_BROWSER_ACCESSIBILITY_COM_WIN_H_
#define UI_ACCESSIBILITY_PLATFORM_BROWSER_ACCESSIBILITY_COM_WIN_H_
#include <oleacc.h>
#include <stddef.h>
#include <stdint.h>
#include <map>
#include <memory>
#include <string>
#include <vector>
#include "base/win/atl.h"
#include "ui/accessibility/platform/browser_accessibility.h"
#include "ui/accessibility/platform/browser_accessibility_win.h"
#include "base/component_export.h"
#include "third_party/iaccessible2/ia2_api_all.h"
#include "third_party/isimpledom/ISimpleDOMDocument.h"
#include "third_party/isimpledom/ISimpleDOMNode.h"
#include "third_party/isimpledom/ISimpleDOMText.h"
#include "ui/accessibility/ax_enums.mojom-forward.h"
#include "ui/accessibility/platform/ax_platform_node_delegate.h"
#include "ui/accessibility/platform/ax_platform_node_win.h"
// This nonstandard GUID is taken directly from the Mozilla sources
// (https://searchfox.org/mozilla-central/source/accessible/windows/msaa/ServiceProvider.cpp#110).
const GUID GUID_ISimpleDOM = {0x0c539790,
0x12e4,
0x11cf,
{0xb6, 0x61, 0x00, 0xaa, 0x00, 0x4c, 0xd6, 0xd8}};
namespace ui {
class BrowserAccessibilityWin;
////////////////////////////////////////////////////////////////////////////////
//
// BrowserAccessibilityComWin
//
// Class implementing the windows accessible interface used by screen readers
// and other assistive technology (AT). It typically is created and owned by
// a BrowserAccessibilityWin delegate. When this owner goes away, the
// BrowserAccessibilityComWin objects may continue to exists being held onto by
// MSCOM (due to reference counting). However, such objects are invalid and
// should gracefully fail by returning E_FAIL from all MSCOM methods.
//
////////////////////////////////////////////////////////////////////////////////
class __declspec(uuid("562072fe-3390-43b1-9e2c-dd4118f5ac79"))
BrowserAccessibilityComWin : public AXPlatformNodeWin,
public IAccessibleApplication,
public IAccessibleHyperlink,
public IAccessibleImage,
public ISimpleDOMDocument,
public ISimpleDOMNode,
public ISimpleDOMText {
public:
BEGIN_COM_MAP(BrowserAccessibilityComWin)
COM_INTERFACE_ENTRY(IAccessibleAction)
COM_INTERFACE_ENTRY(IAccessibleApplication)
COM_INTERFACE_ENTRY(IAccessibleHyperlink)
COM_INTERFACE_ENTRY(IAccessibleImage)
COM_INTERFACE_ENTRY(ISimpleDOMDocument)
COM_INTERFACE_ENTRY(ISimpleDOMNode)
COM_INTERFACE_ENTRY(ISimpleDOMText)
COM_INTERFACE_ENTRY_CHAIN(AXPlatformNodeWin)
END_COM_MAP()
// Mappings from roles and states to human readable strings. Initialize
// with |InitializeStringMaps|.
static std::map<int32_t, std::u16string> role_string_map;
static std::map<int32_t, std::u16string> state_string_map;
COMPONENT_EXPORT(AX_PLATFORM) BrowserAccessibilityComWin();
BrowserAccessibilityComWin(const BrowserAccessibilityComWin&) = delete;
BrowserAccessibilityComWin& operator=(const BrowserAccessibilityComWin&) =
delete;
COMPONENT_EXPORT(AX_PLATFORM) ~BrowserAccessibilityComWin() override;
// AXPlatformNodeWin methods.
COMPONENT_EXPORT(AX_PLATFORM) void OnReferenced() override;
COMPONENT_EXPORT(AX_PLATFORM) void OnDereferenced() override;
// Called after an atomic tree update completes. See
// BrowserAccessibilityManagerWin::OnAtomicUpdateFinished for more
// details on what these do.
COMPONENT_EXPORT(AX_PLATFORM) void UpdateStep1ComputeWinAttributes();
COMPONENT_EXPORT(AX_PLATFORM) void UpdateStep2ComputeHypertext();
COMPONENT_EXPORT(AX_PLATFORM) void UpdateStep3FireEvents();
//
// IAccessible2 methods.
//
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_attributes(BSTR* attributes) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
scrollTo(enum IA2ScrollType scroll_type) override;
//
// IAccessibleApplication methods.
//
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_appName(BSTR* app_name) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_appVersion(BSTR* app_version) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_toolkitName(BSTR* toolkit_name) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
get_toolkitVersion(BSTR* toolkit_version) override;
//
// IAccessibleImage methods.
//
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_description(BSTR* description) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
get_imagePosition(enum IA2CoordinateType coordinate_type,
LONG* x,
LONG* y) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_imageSize(LONG* height,
LONG* width) override;
//
// IAccessibleText methods.
//
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
get_characterExtents(LONG offset,
enum IA2CoordinateType coord_type,
LONG* out_x,
LONG* out_y,
LONG* out_width,
LONG* out_height) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_nSelections(LONG* n_selections) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_selection(LONG selection_index,
LONG* start_offset,
LONG* end_offset) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_text(LONG start_offset,
LONG end_offset,
BSTR* text) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_newText(IA2TextSegment* new_text) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_oldText(IA2TextSegment* old_text) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
scrollSubstringTo(LONG start_index,
LONG end_index,
enum IA2ScrollType scroll_type) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
scrollSubstringToPoint(LONG start_index,
LONG end_index,
enum IA2CoordinateType coordinate_type,
LONG x,
LONG y) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP setCaretOffset(LONG offset) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP setSelection(LONG selection_index,
LONG start_offset,
LONG end_offset) override;
// IAccessibleText methods not implemented.
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_attributes(LONG offset,
LONG* start_offset,
LONG* end_offset,
BSTR* text_attributes) override;
//
// IAccessibleHypertext methods.
//
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_nHyperlinks(LONG* hyperlink_count) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
// A hyperlink represents an embedded object character (leading to a subtree).
get_hyperlink(LONG index, IAccessibleHyperlink** hyperlink) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
get_hyperlinkIndex(LONG char_index, LONG* hyperlink_index) override;
// IAccessibleHyperlink methods.
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_anchor(LONG index,
VARIANT* anchor) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
get_anchorTarget(LONG index, VARIANT* anchor_target) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_startIndex(LONG* index) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_endIndex(LONG* index) override;
// This method is deprecated in the IA2 Spec and so we don't implement it.
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_valid(boolean* valid) override;
// IAccessibleAction mostly not implemented.
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP nActions(LONG* n_actions) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP doAction(LONG action_index) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_description(LONG action_index,
BSTR* description) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_keyBinding(LONG action_index,
LONG n_max_bindings,
BSTR** key_bindings,
LONG* n_bindings) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_name(LONG action_index,
BSTR* name) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
get_localizedName(LONG action_index, BSTR* localized_name) override;
//
// ISimpleDOMDocument methods.
//
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_URL(BSTR* url) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_title(BSTR* title) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_mimeType(BSTR* mime_type) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_docType(BSTR* doc_type) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
get_nameSpaceURIForID(SHORT name_space_id, BSTR* name_space_uri) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
put_alternateViewMediaTypes(BSTR* comma_separated_media_types) override;
//
// ISimpleDOMNode methods.
//
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_nodeInfo(BSTR* node_name,
SHORT* name_space_id,
BSTR* node_value,
unsigned int* num_children,
unsigned int* unique_id,
USHORT* node_type) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_attributes(USHORT max_attribs,
BSTR* attrib_names,
SHORT* name_space_id,
BSTR* attrib_values,
USHORT* num_attribs) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
get_attributesForNames(USHORT num_attribs,
BSTR* attrib_names,
SHORT* name_space_id,
BSTR* attrib_values) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
get_computedStyle(USHORT max_style_properties,
boolean use_alternate_view,
BSTR* style_properties,
BSTR* style_values,
USHORT* num_style_properties) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
get_computedStyleForProperties(USHORT num_style_properties,
boolean use_alternate_view,
BSTR* style_properties,
BSTR* style_values) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP scrollTo(boolean placeTopLeft) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_parentNode(ISimpleDOMNode** node) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_firstChild(ISimpleDOMNode** node) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_lastChild(ISimpleDOMNode** node) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
get_previousSibling(ISimpleDOMNode** node) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_nextSibling(ISimpleDOMNode** node) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_childAt(unsigned int child_index,
ISimpleDOMNode** node) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_innerHTML(BSTR* innerHTML) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
get_localInterface(void** local_interface) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_language(BSTR* language) override;
//
// ISimpleDOMText methods.
//
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_domText(BSTR* dom_text) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
get_clippedSubstringBounds(unsigned int start_index,
unsigned int end_index,
int* out_x,
int* out_y,
int* out_width,
int* out_height) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
get_unclippedSubstringBounds(unsigned int start_index,
unsigned int end_index,
int* out_x,
int* out_y,
int* out_width,
int* out_height) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP
scrollToSubstring(unsigned int start_index, unsigned int end_index) override;
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP get_fontFamily(BSTR* font_family) override;
//
// IServiceProvider methods.
//
COMPONENT_EXPORT(AX_PLATFORM) IFACEMETHODIMP QueryService(REFGUID guidService,
REFIID riid,
void** object) override;
//
// CComObjectRootEx methods.
//
// Called by BEGIN_COM_MAP() / END_COM_MAP().
static COMPONENT_EXPORT(AX_PLATFORM) STDMETHODIMP
InternalQueryInterface(void* this_ptr,
const _ATL_INTMAP_ENTRY* entries,
REFIID iid,
void** object);
// Computes and caches the IA2 text style attributes for the text and other
// embedded child objects.
COMPONENT_EXPORT(AX_PLATFORM) void ComputeStylesIfNeeded();
// Public accessors (these do not have COM accessible accessors)
const TextAttributeMap& offset_to_text_attributes() const {
return win_attributes_->offset_to_text_attributes;
}
private:
// Private accessors.
const std::vector<std::wstring>& ia2_attributes() const {
return win_attributes_->ia2_attributes;
}
std::wstring name() const { return win_attributes_->name; }
std::wstring description() const { return win_attributes_->description; }
std::wstring value() const { return win_attributes_->value; }
BrowserAccessibilityWin* GetOwner() const;
BrowserAccessibilityManager* Manager() const;
// Returns the IA2 text attributes for this object.
TextAttributeList ComputeTextAttributes() const;
// Add one to the reference count and return the same object. Always
// use this method when returning a BrowserAccessibilityComWin object as
// an output parameter to a COM interface, never use it otherwise.
BrowserAccessibilityComWin* NewReference();
// 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.
BrowserAccessibilityComWin* GetTargetFromChildID(const VARIANT& var_id);
// Retrieve the value of an attribute from the string attribute map and
// if found and nonempty, allocate a new BSTR (with SysAllocString)
// and return S_OK. If not found or empty, return S_FALSE.
HRESULT GetStringAttributeAsBstr(ax::mojom::StringAttribute attribute,
BSTR* value_bstr);
// Retrieves the name, allocates a new BSTR if non-empty and returns S_OK. If
// name is empty, returns S_FALSE.
HRESULT GetNameAsBstr(BSTR* value_bstr);
// Sets the selection given a start and end offset in IA2 Hypertext.
void SetIA2HypertextSelection(LONG start_offset, LONG end_offset);
// Searches forward from the given offset until the start of the next style
// is found, or searches backward from the given offset until the start of the
// current style is found.
LONG FindStartOfStyle(LONG start_offset, ax::mojom::MoveDirection direction);
// ID refers to the node ID in the current tree, not the globally unique ID.
// TODO(nektar): Could we use globally unique IDs everywhere?
// TODO(nektar): Rename this function to GetFromNodeID.
BrowserAccessibilityComWin* GetFromID(int32_t id) const;
// Fire a Windows-specific accessibility event notification on this node.
void FireNativeEvent(LONG win_event_type) const;
struct WinAttributes {
WinAttributes();
~WinAttributes();
// Ignored state
bool ignored;
// IAccessible role and state.
int32_t ia_role;
int32_t ia_state;
// IAccessible name, description, help, value.
std::wstring name;
std::wstring description;
std::wstring value;
// IAccessible2 role and state.
int32_t ia2_role;
int32_t ia2_state;
// IAccessible2 attributes.
std::vector<std::wstring> ia2_attributes;
// Maps each style span to its start offset in hypertext.
TextAttributeMap offset_to_text_attributes;
};
std::unique_ptr<WinAttributes> win_attributes_;
// Holds transient state needed only while processing a tree update.
struct UpdateState {
UpdateState(std::unique_ptr<WinAttributes> old_win_attributes,
AXLegacyHypertext old_hypertext);
UpdateState(const UpdateState&) = delete;
UpdateState& operator=(const UpdateState&) = delete;
~UpdateState();
std::unique_ptr<WinAttributes> old_win_attributes;
AXLegacyHypertext old_hypertext;
};
// Only valid during the scope of a IA2_EVENT_TEXT_REMOVED or
// IA2_EVENT_TEXT_INSERTED event.
std::unique_ptr<UpdateState> update_state_;
// The previous scroll position, so we can tell if this object scrolled.
int previous_scroll_x_;
int previous_scroll_y_;
// Give BrowserAccessibility::Create access to our constructor.
friend class BrowserAccessibility;
friend class BrowserAccessibilityWin;
};
COMPONENT_EXPORT(AX_PLATFORM) BrowserAccessibilityComWin* ToBrowserAccessibilityComWin(
BrowserAccessibility* obj);
} // namespace ui
#endif // UI_ACCESSIBILITY_PLATFORM_BROWSER_ACCESSIBILITY_COM_WIN_H_
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