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// Copyright (c) 2017 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 CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_COM_WIN_H_
#define CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_COM_WIN_H_
#include <oleacc.h>
#include <stddef.h>
#include <stdint.h>
#include <vector>
#include "base/compiler_specific.h"
#include "base/gtest_prod_util.h"
#include "base/macros.h"
#include "base/win/atl.h"
#include "content/browser/accessibility/browser_accessibility.h"
#include "content/browser/accessibility/browser_accessibility_win.h"
#include "content/common/content_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/platform/ax_platform_node_delegate.h"
#include "ui/accessibility/platform/ax_platform_node_win.h"
// These nonstandard GUIDs are taken directly from the Mozilla sources
// (accessible/src/msaa/nsAccessNodeWrap.cpp); some documentation is here:
// http://developer.mozilla.org/en/Accessibility/AT-APIs/ImplementationFeatures/MSAA
const GUID GUID_ISimpleDOM = {0x0c539790,
0x12e4,
0x11cf,
{0xb6, 0x61, 0x00, 0xaa, 0x00, 0x4c, 0xd6, 0xd8}};
const GUID GUID_IAccessibleContentDocument = {
0xa5d8e1f3,
0x3571,
0x4d8f,
{0x95, 0x21, 0x07, 0xed, 0x28, 0xfb, 0x07, 0x2e}};
namespace ui {
enum TextBoundaryDirection;
enum TextBoundaryType;
}
namespace content {
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 |owner_|. 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 ui::AXPlatformNodeWin,
public IAccessibleApplication,
public IAccessibleHyperlink,
public IAccessibleHypertext,
public IAccessibleImage,
public IAccessibleValue,
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(IAccessibleHypertext)
COM_INTERFACE_ENTRY(IAccessibleImage)
COM_INTERFACE_ENTRY(IAccessibleValue)
COM_INTERFACE_ENTRY(ISimpleDOMDocument)
COM_INTERFACE_ENTRY(ISimpleDOMNode)
COM_INTERFACE_ENTRY(ISimpleDOMText)
COM_INTERFACE_ENTRY_CHAIN(ui::AXPlatformNodeWin)
END_COM_MAP()
// Mappings from roles and states to human readable strings. Initialize
// with |InitializeStringMaps|.
static std::map<int32_t, base::string16> role_string_map;
static std::map<int32_t, base::string16> state_string_map;
CONTENT_EXPORT BrowserAccessibilityComWin();
CONTENT_EXPORT ~BrowserAccessibilityComWin() override;
// Called after an atomic tree update completes. See
// BrowserAccessibilityManagerWin::OnAtomicUpdateFinished for more
// details on what these do.
CONTENT_EXPORT void UpdateStep1ComputeWinAttributes();
CONTENT_EXPORT void UpdateStep2ComputeHypertext();
CONTENT_EXPORT void UpdateStep3FireEvents(bool is_subtree_creation);
//
// IAccessible2 methods.
//
CONTENT_EXPORT IFACEMETHODIMP get_attributes(BSTR* attributes) override;
CONTENT_EXPORT IFACEMETHODIMP
scrollTo(enum IA2ScrollType scroll_type) override;
//
// IAccessibleApplication methods.
//
CONTENT_EXPORT IFACEMETHODIMP get_appName(BSTR* app_name) override;
CONTENT_EXPORT IFACEMETHODIMP get_appVersion(BSTR* app_version) override;
CONTENT_EXPORT IFACEMETHODIMP get_toolkitName(BSTR* toolkit_name) override;
CONTENT_EXPORT IFACEMETHODIMP
get_toolkitVersion(BSTR* toolkit_version) override;
//
// IAccessibleImage methods.
//
CONTENT_EXPORT IFACEMETHODIMP get_description(BSTR* description) override;
CONTENT_EXPORT IFACEMETHODIMP
get_imagePosition(enum IA2CoordinateType coordinate_type,
LONG* x,
LONG* y) override;
CONTENT_EXPORT IFACEMETHODIMP get_imageSize(LONG* height,
LONG* width) override;
//
// IAccessibleText methods.
//
CONTENT_EXPORT IFACEMETHODIMP get_nCharacters(LONG* n_characters) override;
CONTENT_EXPORT IFACEMETHODIMP get_caretOffset(LONG* offset) override;
CONTENT_EXPORT IFACEMETHODIMP
get_characterExtents(LONG offset,
enum IA2CoordinateType coord_type,
LONG* out_x,
LONG* out_y,
LONG* out_width,
LONG* out_height) override;
CONTENT_EXPORT IFACEMETHODIMP get_nSelections(LONG* n_selections) override;
CONTENT_EXPORT IFACEMETHODIMP get_selection(LONG selection_index,
LONG* start_offset,
LONG* end_offset) override;
CONTENT_EXPORT IFACEMETHODIMP get_text(LONG start_offset,
LONG end_offset,
BSTR* text) override;
CONTENT_EXPORT IFACEMETHODIMP
get_textAtOffset(LONG offset,
enum IA2TextBoundaryType boundary_type,
LONG* start_offset,
LONG* end_offset,
BSTR* text) override;
CONTENT_EXPORT IFACEMETHODIMP
get_textBeforeOffset(LONG offset,
enum IA2TextBoundaryType boundary_type,
LONG* start_offset,
LONG* end_offset,
BSTR* text) override;
CONTENT_EXPORT IFACEMETHODIMP
get_textAfterOffset(LONG offset,
enum IA2TextBoundaryType boundary_type,
LONG* start_offset,
LONG* end_offset,
BSTR* text) override;
CONTENT_EXPORT IFACEMETHODIMP get_newText(IA2TextSegment* new_text) override;
CONTENT_EXPORT IFACEMETHODIMP get_oldText(IA2TextSegment* old_text) override;
CONTENT_EXPORT IFACEMETHODIMP
get_offsetAtPoint(LONG x,
LONG y,
enum IA2CoordinateType coord_type,
LONG* offset) override;
CONTENT_EXPORT IFACEMETHODIMP
scrollSubstringTo(LONG start_index,
LONG end_index,
enum IA2ScrollType scroll_type) override;
CONTENT_EXPORT IFACEMETHODIMP
scrollSubstringToPoint(LONG start_index,
LONG end_index,
enum IA2CoordinateType coordinate_type,
LONG x,
LONG y) override;
CONTENT_EXPORT IFACEMETHODIMP addSelection(LONG start_offset,
LONG end_offset) override;
CONTENT_EXPORT IFACEMETHODIMP removeSelection(LONG selection_index) override;
CONTENT_EXPORT IFACEMETHODIMP setCaretOffset(LONG offset) override;
CONTENT_EXPORT IFACEMETHODIMP setSelection(LONG selection_index,
LONG start_offset,
LONG end_offset) override;
// IAccessibleText methods not implemented.
CONTENT_EXPORT IFACEMETHODIMP get_attributes(LONG offset,
LONG* start_offset,
LONG* end_offset,
BSTR* text_attributes) override;
//
// IAccessibleHypertext methods.
//
CONTENT_EXPORT IFACEMETHODIMP get_nHyperlinks(LONG* hyperlink_count) override;
CONTENT_EXPORT IFACEMETHODIMP
get_hyperlink(LONG index, IAccessibleHyperlink** hyperlink) override;
CONTENT_EXPORT IFACEMETHODIMP
get_hyperlinkIndex(LONG char_index, LONG* hyperlink_index) override;
// IAccessibleHyperlink methods.
CONTENT_EXPORT IFACEMETHODIMP get_anchor(LONG index,
VARIANT* anchor) override;
CONTENT_EXPORT IFACEMETHODIMP
get_anchorTarget(LONG index, VARIANT* anchor_target) override;
CONTENT_EXPORT IFACEMETHODIMP get_startIndex(LONG* index) override;
CONTENT_EXPORT IFACEMETHODIMP get_endIndex(LONG* index) override;
// This method is deprecated in the IA2 Spec and so we don't implement it.
CONTENT_EXPORT IFACEMETHODIMP get_valid(boolean* valid) override;
// IAccessibleAction mostly not implemented.
CONTENT_EXPORT IFACEMETHODIMP nActions(LONG* n_actions) override;
CONTENT_EXPORT IFACEMETHODIMP doAction(LONG action_index) override;
CONTENT_EXPORT IFACEMETHODIMP get_description(LONG action_index,
BSTR* description) override;
CONTENT_EXPORT IFACEMETHODIMP get_keyBinding(LONG action_index,
LONG n_max_bindings,
BSTR** key_bindings,
LONG* n_bindings) override;
CONTENT_EXPORT IFACEMETHODIMP get_name(LONG action_index,
BSTR* name) override;
CONTENT_EXPORT IFACEMETHODIMP
get_localizedName(LONG action_index, BSTR* localized_name) override;
//
// IAccessibleValue methods.
//
CONTENT_EXPORT IFACEMETHODIMP get_currentValue(VARIANT* value) override;
CONTENT_EXPORT IFACEMETHODIMP get_minimumValue(VARIANT* value) override;
CONTENT_EXPORT IFACEMETHODIMP get_maximumValue(VARIANT* value) override;
CONTENT_EXPORT IFACEMETHODIMP setCurrentValue(VARIANT new_value) override;
//
// ISimpleDOMDocument methods.
//
CONTENT_EXPORT IFACEMETHODIMP get_URL(BSTR* url) override;
CONTENT_EXPORT IFACEMETHODIMP get_title(BSTR* title) override;
CONTENT_EXPORT IFACEMETHODIMP get_mimeType(BSTR* mime_type) override;
CONTENT_EXPORT IFACEMETHODIMP get_docType(BSTR* doc_type) override;
CONTENT_EXPORT IFACEMETHODIMP
get_nameSpaceURIForID(short name_space_id, BSTR* name_space_uri) override;
CONTENT_EXPORT IFACEMETHODIMP
put_alternateViewMediaTypes(BSTR* comma_separated_media_types) override;
//
// ISimpleDOMNode methods.
//
CONTENT_EXPORT IFACEMETHODIMP
get_nodeInfo(BSTR* node_name,
short* name_space_id,
BSTR* node_value,
unsigned int* num_children,
unsigned int* unique_id,
unsigned short* node_type) override;
CONTENT_EXPORT IFACEMETHODIMP
get_attributes(unsigned short max_attribs,
BSTR* attrib_names,
short* name_space_id,
BSTR* attrib_values,
unsigned short* num_attribs) override;
CONTENT_EXPORT IFACEMETHODIMP
get_attributesForNames(unsigned short num_attribs,
BSTR* attrib_names,
short* name_space_id,
BSTR* attrib_values) override;
CONTENT_EXPORT IFACEMETHODIMP
get_computedStyle(unsigned short max_style_properties,
boolean use_alternate_view,
BSTR* style_properties,
BSTR* style_values,
unsigned short* num_style_properties) override;
CONTENT_EXPORT IFACEMETHODIMP
get_computedStyleForProperties(unsigned short num_style_properties,
boolean use_alternate_view,
BSTR* style_properties,
BSTR* style_values) override;
CONTENT_EXPORT IFACEMETHODIMP scrollTo(boolean placeTopLeft) override;
CONTENT_EXPORT IFACEMETHODIMP get_parentNode(ISimpleDOMNode** node) override;
CONTENT_EXPORT IFACEMETHODIMP get_firstChild(ISimpleDOMNode** node) override;
CONTENT_EXPORT IFACEMETHODIMP get_lastChild(ISimpleDOMNode** node) override;
CONTENT_EXPORT IFACEMETHODIMP
get_previousSibling(ISimpleDOMNode** node) override;
CONTENT_EXPORT IFACEMETHODIMP get_nextSibling(ISimpleDOMNode** node) override;
CONTENT_EXPORT IFACEMETHODIMP get_childAt(unsigned int child_index,
ISimpleDOMNode** node) override;
CONTENT_EXPORT IFACEMETHODIMP get_innerHTML(BSTR* innerHTML) override;
CONTENT_EXPORT IFACEMETHODIMP
get_localInterface(void** local_interface) override;
CONTENT_EXPORT IFACEMETHODIMP get_language(BSTR* language) override;
//
// ISimpleDOMText methods.
//
CONTENT_EXPORT IFACEMETHODIMP get_domText(BSTR* dom_text) override;
CONTENT_EXPORT IFACEMETHODIMP
get_clippedSubstringBounds(unsigned int start_index,
unsigned int end_index,
int* out_x,
int* out_y,
int* out_width,
int* out_height) override;
CONTENT_EXPORT IFACEMETHODIMP
get_unclippedSubstringBounds(unsigned int start_index,
unsigned int end_index,
int* out_x,
int* out_y,
int* out_width,
int* out_height) override;
CONTENT_EXPORT IFACEMETHODIMP
scrollToSubstring(unsigned int start_index, unsigned int end_index) override;
CONTENT_EXPORT IFACEMETHODIMP get_fontFamily(BSTR* font_family) override;
//
// IServiceProvider methods.
//
CONTENT_EXPORT IFACEMETHODIMP QueryService(REFGUID guidService,
REFIID riid,
void** object) override;
//
// CComObjectRootEx methods.
//
// Called by BEGIN_COM_MAP() / END_COM_MAP().
static CONTENT_EXPORT 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.
CONTENT_EXPORT void ComputeStylesIfNeeded();
// |offset| could either be a text character or a child index in case of
// non-text objects.
BrowserAccessibilityPosition::AXPositionInstance CreatePositionForSelectionAt(
int offset) const;
// Public accessors (these do not have COM accessible accessors)
const base::string16& role_name() const { return win_attributes_->role_name; }
const std::map<int, std::vector<base::string16>>& offset_to_text_attributes()
const {
return win_attributes_->offset_to_text_attributes;
}
private:
// Private accessors.
const std::vector<base::string16>& ia2_attributes() const {
return win_attributes_->ia2_attributes;
}
base::string16 name() const { return win_attributes_->name; }
base::string16 description() const { return win_attributes_->description; }
base::string16 value() const { return win_attributes_->value; }
// Setter and getter for the browser accessibility owner
BrowserAccessibilityWin* owner() const { return owner_; }
void SetOwner(BrowserAccessibilityWin* owner) { owner_ = owner; }
BrowserAccessibilityManager* Manager() const;
//
// AXPlatformNode overrides
//
void Destroy() override;
void Init(ui::AXPlatformNodeDelegate* delegate) override;
// Returns the IA2 text attributes for this object.
std::vector<base::string16> 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();
// Returns a list of IA2 attributes indicating the offsets in the text of a
// leaf object, such as a text field or static text, where spelling errors are
// present.
std::map<int, std::vector<base::string16>> GetSpellingAttributes();
// 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);
base::string16 GetInvalidValue() const;
// Merges the given spelling attributes, i.e. document marker information,
// into the given text attributes starting at the given character offset. This
// is required for two reasons: 1. Document markers that are present on text
// leaves need to be propagated to their parent object for compatibility with
// Firefox. 2. Spelling markers need to overwrite any aria-invalid="false" in
// the text attributes.
static void MergeSpellingIntoTextAttributes(
const std::map<int, std::vector<base::string16>>& spelling_attributes,
int start_offset,
std::map<int, std::vector<base::string16>>* text_attributes);
// Escapes characters in string attributes as required by the IA2 Spec.
// It's okay for input to be the same as output.
CONTENT_EXPORT static void SanitizeStringAttributeForIA2(
const base::string16& input,
base::string16* output);
FRIEND_TEST_ALL_PREFIXES(BrowserAccessibilityTest,
TestSanitizeStringAttributeForIA2);
// Sets the selection given a start and end offset in IA2 Hypertext.
void SetIA2HypertextSelection(LONG start_offset, LONG end_offset);
// 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(IA2TextBoundaryType ia2_boundary,
LONG start_offset,
ui::TextBoundaryDirection direction);
// 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, ui::TextBoundaryDirection 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;
// Returns true if this is a list box option with a parent of type list box,
// or a menu list option with a parent of type menu list popup.
bool IsListBoxOptionOrMenuListOption();
// Fire a Windows-specific accessibility event notification on this node.
void FireNativeEvent(LONG win_event_type) const;
struct WinAttributes {
WinAttributes();
~WinAttributes();
// IAccessible role and state.
int32_t ia_role;
int32_t ia_state;
base::string16 role_name;
// IAccessible name, description, help, value.
base::string16 name;
base::string16 description;
base::string16 value;
// IAccessible2 role and state.
int32_t ia2_role;
int32_t ia2_state;
// IAccessible2 attributes.
std::vector<base::string16> ia2_attributes;
// Maps each style span to its start offset in hypertext.
std::map<int, std::vector<base::string16>> offset_to_text_attributes;
};
BrowserAccessibilityWin* owner_;
std::unique_ptr<WinAttributes> win_attributes_;
// Only valid during the scope of a IA2_EVENT_TEXT_REMOVED or
// IA2_EVENT_TEXT_INSERTED event.
std::unique_ptr<WinAttributes> old_win_attributes_;
// 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;
DISALLOW_COPY_AND_ASSIGN(BrowserAccessibilityComWin);
};
CONTENT_EXPORT BrowserAccessibilityComWin* ToBrowserAccessibilityComWin(
BrowserAccessibility* obj);
} // namespace content
#endif // CONTENT_BROWSER_ACCESSIBILITY_BROWSER_ACCESSIBILITY_COM_WIN_H_