blob: 2845822fcce5a925c14e097f06ea5a8ec4a5a2ca [file] [log] [blame]
// Copyright 2015 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.
#include <atlbase.h>
#include <atlcom.h>
#include <limits.h>
#include <oleacc.h>
#include <stdint.h>
#include "base/containers/hash_tables.h"
#include "base/lazy_instance.h"
#include "base/win/scoped_comptr.h"
#include "base/win/scoped_variant.h"
#include "third_party/iaccessible2/ia2_api_all.h"
#include "ui/accessibility/ax_action_data.h"
#include "ui/accessibility/ax_node_data.h"
#include "ui/accessibility/ax_text_utils.h"
#include "ui/accessibility/platform/ax_platform_node_delegate.h"
#include "ui/accessibility/platform/ax_platform_node_win.h"
#include "ui/base/win/atl_module.h"
#include "ui/gfx/geometry/rect_conversions.h"
//
// Macros to use at the top of any AXPlatformNodeWin function that implements
// a COM interface. Because COM objects are reference counted and clients
// are completely untrusted, it's important to always first check that our
// object is still valid, and then check that all pointer arguments are
// not NULL.
//
#define COM_OBJECT_VALIDATE() \
if (!delegate_) \
return E_FAIL;
#define COM_OBJECT_VALIDATE_1_ARG(arg) \
if (!delegate_) \
return E_FAIL; \
if (!arg) \
return E_INVALIDARG;
#define COM_OBJECT_VALIDATE_2_ARGS(arg1, arg2) \
if (!delegate_) \
return E_FAIL; \
if (!arg1) \
return E_INVALIDARG; \
if (!arg2) \
return E_INVALIDARG;
#define COM_OBJECT_VALIDATE_3_ARGS(arg1, arg2, arg3) \
if (!delegate_) \
return E_FAIL; \
if (!arg1) \
return E_INVALIDARG; \
if (!arg2) \
return E_INVALIDARG; \
if (!arg3) \
return E_INVALIDARG;
#define COM_OBJECT_VALIDATE_4_ARGS(arg1, arg2, arg3, arg4) \
if (!delegate_) \
return E_FAIL; \
if (!arg1) \
return E_INVALIDARG; \
if (!arg2) \
return E_INVALIDARG; \
if (!arg3) \
return E_INVALIDARG; \
if (!arg4) \
return E_INVALIDARG;
#define COM_OBJECT_VALIDATE_VAR_ID_AND_GET_TARGET(var_id, target) \
if (!delegate_) \
return E_FAIL; \
target = GetTargetFromChildID(var_id); \
if (!target) \
return E_INVALIDARG; \
if (!target->delegate_) \
return E_INVALIDARG;
#define COM_OBJECT_VALIDATE_VAR_ID_1_ARG_AND_GET_TARGET(var_id, arg, target) \
if (!delegate_) \
return E_FAIL; \
if (!arg) \
return E_INVALIDARG; \
target = GetTargetFromChildID(var_id); \
if (!target) \
return E_INVALIDARG; \
if (!target->delegate_) \
return E_INVALIDARG;
#define COM_OBJECT_VALIDATE_VAR_ID_2_ARGS_AND_GET_TARGET(var_id, arg1, arg2, \
target) \
if (!delegate_) \
return E_FAIL; \
if (!arg1) \
return E_INVALIDARG; \
if (!arg2) \
return E_INVALIDARG; \
target = GetTargetFromChildID(var_id); \
if (!target) \
return E_INVALIDARG; \
if (!target->delegate_) \
return E_INVALIDARG;
#define COM_OBJECT_VALIDATE_VAR_ID_3_ARGS_AND_GET_TARGET(var_id, arg1, arg2, \
arg3, target) \
if (!delegate_) \
return E_FAIL; \
if (!arg1) \
return E_INVALIDARG; \
if (!arg2) \
return E_INVALIDARG; \
if (!arg3) \
return E_INVALIDARG; \
target = GetTargetFromChildID(var_id); \
if (!target) \
return E_INVALIDARG; \
if (!target->delegate_) \
return E_INVALIDARG;
#define COM_OBJECT_VALIDATE_VAR_ID_4_ARGS_AND_GET_TARGET(var_id, arg1, arg2, \
arg3, arg4, target) \
if (!delegate_) \
return E_FAIL; \
if (!arg1) \
return E_INVALIDARG; \
if (!arg2) \
return E_INVALIDARG; \
if (!arg3) \
return E_INVALIDARG; \
if (!arg4) \
return E_INVALIDARG; \
target = GetTargetFromChildID(var_id); \
if (!target) \
return E_INVALIDARG; \
if (!target->delegate_) \
return E_INVALIDARG;
namespace ui {
namespace {
typedef base::hash_set<AXPlatformNodeWin*> AXPlatformNodeWinSet;
// Set of all AXPlatformNodeWin objects that were the target of an
// alert event.
base::LazyInstance<AXPlatformNodeWinSet>::DestructorAtExit g_alert_targets =
LAZY_INSTANCE_INITIALIZER;
base::LazyInstance<base::ObserverList<IAccessible2UsageObserver>>::
DestructorAtExit g_iaccessible2_usage_observer_list =
LAZY_INSTANCE_INITIALIZER;
} // namespace
//
// IAccessible2UsageObserver
//
IAccessible2UsageObserver::IAccessible2UsageObserver() {
}
IAccessible2UsageObserver::~IAccessible2UsageObserver() {
}
// static
base::ObserverList<IAccessible2UsageObserver>&
GetIAccessible2UsageObserverList() {
return g_iaccessible2_usage_observer_list.Get();
}
//
// AXPlatformNode::Create
//
// static
AXPlatformNode* AXPlatformNode::Create(AXPlatformNodeDelegate* delegate) {
// Make sure ATL is initialized in this module.
ui::win::CreateATLModuleIfNeeded();
CComObject<AXPlatformNodeWin>* instance = nullptr;
HRESULT hr = CComObject<AXPlatformNodeWin>::CreateInstance(&instance);
DCHECK(SUCCEEDED(hr));
instance->Init(delegate);
instance->AddRef();
return instance;
}
// static
AXPlatformNode* AXPlatformNode::FromNativeViewAccessible(
gfx::NativeViewAccessible accessible) {
if (!accessible)
return nullptr;
base::win::ScopedComPtr<AXPlatformNodeWin> ax_platform_node;
accessible->QueryInterface(ax_platform_node.Receive());
return ax_platform_node.Get();
}
//
// AXPlatformNodeWin
//
AXPlatformNodeWin::AXPlatformNodeWin() {
}
AXPlatformNodeWin::~AXPlatformNodeWin() {
}
//
// AXPlatformNodeBase implementation.
//
void AXPlatformNodeWin::Dispose() {
Release();
}
void AXPlatformNodeWin::Destroy() {
RemoveAlertTarget();
AXPlatformNodeBase::Destroy();
}
//
// AXPlatformNode implementation.
//
gfx::NativeViewAccessible AXPlatformNodeWin::GetNativeViewAccessible() {
return this;
}
void AXPlatformNodeWin::NotifyAccessibilityEvent(ui::AXEvent event_type) {
HWND hwnd = delegate_->GetTargetForNativeAccessibilityEvent();
if (!hwnd)
return;
// Menu items fire selection events but Windows screen readers work reliably
// with focus events. Remap here.
if (event_type == ui::AX_EVENT_SELECTION &&
GetData().role == ui::AX_ROLE_MENU_ITEM)
event_type = ui::AX_EVENT_FOCUS;
int native_event = MSAAEvent(event_type);
if (native_event < EVENT_MIN)
return;
::NotifyWinEvent(native_event, hwnd, OBJID_CLIENT, -unique_id_);
// Keep track of objects that are a target of an alert event.
if (event_type == ui::AX_EVENT_ALERT)
AddAlertTarget();
}
int AXPlatformNodeWin::GetIndexInParent() {
base::win::ScopedComPtr<IDispatch> parent_dispatch;
base::win::ScopedComPtr<IAccessible> parent_accessible;
if (S_OK != get_accParent(parent_dispatch.Receive()))
return -1;
if (S_OK != parent_dispatch.QueryInterface(parent_accessible.Receive()))
return -1;
LONG child_count = 0;
if (S_OK != parent_accessible->get_accChildCount(&child_count))
return -1;
for (LONG index = 1; index <= child_count; ++index) {
base::win::ScopedVariant childid_index(index);
base::win::ScopedComPtr<IDispatch> child_dispatch;
base::win::ScopedComPtr<IAccessible> child_accessible;
if (S_OK == parent_accessible->get_accChild(childid_index,
child_dispatch.Receive()) &&
S_OK == child_dispatch.QueryInterface(child_accessible.Receive())) {
if (child_accessible.Get() == this)
return index - 1;
}
}
return -1;
}
//
// IAccessible implementation.
//
STDMETHODIMP AXPlatformNodeWin::accHitTest(
LONG x_left, LONG y_top, VARIANT* child) {
COM_OBJECT_VALIDATE_1_ARG(child);
gfx::NativeViewAccessible hit_child = delegate_->HitTestSync(x_left, y_top);
if (!hit_child) {
child->vt = VT_EMPTY;
return S_FALSE;
}
if (hit_child == this) {
// This object is the best match, so return CHILDID_SELF. It's tempting to
// simplify the logic and use VT_DISPATCH everywhere, but the Windows
// call AccessibleObjectFromPoint will keep calling accHitTest until some
// object returns CHILDID_SELF.
child->vt = VT_I4;
child->lVal = CHILDID_SELF;
return S_OK;
}
// Call accHitTest recursively on the result, which may be a recursive call
// to this function or it may be overridden, for example in the case of a
// WebView.
HRESULT result = hit_child->accHitTest(x_left, y_top, child);
// If the recursive call returned CHILDID_SELF, we have to convert that
// into a VT_DISPATCH for the return value to this call.
if (S_OK == result && child->vt == VT_I4 && child->lVal == CHILDID_SELF) {
child->vt = VT_DISPATCH;
child->pdispVal = hit_child;
// Always increment ref when returning a reference to a COM object.
child->pdispVal->AddRef();
}
return result;
}
HRESULT AXPlatformNodeWin::accDoDefaultAction(VARIANT var_id) {
AXPlatformNodeWin* target;
COM_OBJECT_VALIDATE_VAR_ID_AND_GET_TARGET(var_id, target);
AXActionData data;
data.action = ui::AX_ACTION_DO_DEFAULT;
if (target->delegate_->AccessibilityPerformAction(data))
return S_OK;
return E_FAIL;
}
STDMETHODIMP AXPlatformNodeWin::accLocation(
LONG* x_left, LONG* y_top, LONG* width, LONG* height, VARIANT var_id) {
AXPlatformNodeWin* target;
COM_OBJECT_VALIDATE_VAR_ID_4_ARGS_AND_GET_TARGET(var_id, x_left, y_top, width,
height, target);
gfx::Rect bounds = target->delegate_->GetScreenBoundsRect();
*x_left = bounds.x();
*y_top = bounds.y();
*width = bounds.width();
*height = bounds.height();
if (bounds.IsEmpty())
return S_FALSE;
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::accNavigate(
LONG nav_dir, VARIANT start, VARIANT* end) {
AXPlatformNodeWin* target;
COM_OBJECT_VALIDATE_VAR_ID_1_ARG_AND_GET_TARGET(start, end, target);
IAccessible* result = nullptr;
if ((nav_dir == NAVDIR_LASTCHILD || nav_dir == NAVDIR_FIRSTCHILD) &&
start.lVal != CHILDID_SELF) {
// MSAA states that navigating to first/last child can only be from self.
return E_INVALIDARG;
}
switch (nav_dir) {
case NAVDIR_DOWN:
case NAVDIR_UP:
case NAVDIR_LEFT:
case NAVDIR_RIGHT:
// These directions are not implemented, matching Mozilla and IE.
return E_NOTIMPL;
case NAVDIR_FIRSTCHILD:
if (delegate_->GetChildCount() > 0)
result = delegate_->ChildAtIndex(0);
break;
case NAVDIR_LASTCHILD:
if (delegate_->GetChildCount() > 0)
result = delegate_->ChildAtIndex(delegate_->GetChildCount() - 1);
break;
case NAVDIR_NEXT: {
AXPlatformNodeBase* next = GetNextSibling();
if (next)
result = next->GetNativeViewAccessible();
break;
}
case NAVDIR_PREVIOUS: {
AXPlatformNodeBase* previous = GetPreviousSibling();
if (previous)
result = previous->GetNativeViewAccessible();
break;
}
default:
return E_INVALIDARG;
}
if (!result) {
end->vt = VT_EMPTY;
return S_FALSE;
}
end->vt = VT_DISPATCH;
end->pdispVal = result;
// Always increment ref when returning a reference to a COM object.
end->pdispVal->AddRef();
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::get_accChild(VARIANT var_child,
IDispatch** disp_child) {
*disp_child = nullptr;
AXPlatformNodeWin* target;
COM_OBJECT_VALIDATE_VAR_ID_AND_GET_TARGET(var_child, target);
*disp_child = target;
(*disp_child)->AddRef();
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::get_accChildCount(LONG* child_count) {
COM_OBJECT_VALIDATE_1_ARG(child_count);
*child_count = delegate_->GetChildCount();
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::get_accDefaultAction(
VARIANT var_id, BSTR* def_action) {
AXPlatformNodeWin* target;
COM_OBJECT_VALIDATE_VAR_ID_1_ARG_AND_GET_TARGET(var_id, def_action, target);
int action;
if (!target->GetIntAttribute(AX_ATTR_ACTION, &action)) {
*def_action = nullptr;
return S_FALSE;
}
base::string16 action_verb =
ActionToString(static_cast<AXSupportedAction>(action));
if (action_verb.empty()) {
*def_action = nullptr;
return S_FALSE;
}
*def_action = SysAllocString(action_verb.c_str());
DCHECK(def_action);
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::get_accDescription(
VARIANT var_id, BSTR* desc) {
AXPlatformNodeWin* target;
COM_OBJECT_VALIDATE_VAR_ID_1_ARG_AND_GET_TARGET(var_id, desc, target);
return target->GetStringAttributeAsBstr(ui::AX_ATTR_DESCRIPTION, desc);
}
STDMETHODIMP AXPlatformNodeWin::get_accFocus(VARIANT* focus_child) {
COM_OBJECT_VALIDATE_1_ARG(focus_child);
gfx::NativeViewAccessible focus_accessible = delegate_->GetFocus();
if (focus_accessible == this) {
focus_child->vt = VT_I4;
focus_child->lVal = CHILDID_SELF;
} else if (focus_accessible) {
focus_child->vt = VT_DISPATCH;
focus_child->pdispVal = focus_accessible;
focus_child->pdispVal->AddRef();
return S_OK;
} else {
focus_child->vt = VT_EMPTY;
}
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::get_accKeyboardShortcut(
VARIANT var_id, BSTR* acc_key) {
AXPlatformNodeWin* target;
COM_OBJECT_VALIDATE_VAR_ID_1_ARG_AND_GET_TARGET(var_id, acc_key, target);
return target->GetStringAttributeAsBstr(ui::AX_ATTR_SHORTCUT, acc_key);
}
STDMETHODIMP AXPlatformNodeWin::get_accName(
VARIANT var_id, BSTR* name) {
AXPlatformNodeWin* target;
COM_OBJECT_VALIDATE_VAR_ID_1_ARG_AND_GET_TARGET(var_id, name, target);
HRESULT result = target->GetStringAttributeAsBstr(ui::AX_ATTR_NAME, name);
if (FAILED(result) && MSAARole() == ROLE_SYSTEM_DOCUMENT && GetParent()) {
// Hack: Some versions of JAWS crash if they get an empty name on
// a document that's the child of an iframe, so always return a
// nonempty string for this role. https://crbug.com/583057
base::string16 str = L" ";
*name = SysAllocString(str.c_str());
DCHECK(*name);
}
return result;
}
STDMETHODIMP AXPlatformNodeWin::get_accParent(
IDispatch** disp_parent) {
COM_OBJECT_VALIDATE_1_ARG(disp_parent);
*disp_parent = GetParent();
if (*disp_parent) {
(*disp_parent)->AddRef();
return S_OK;
}
return S_FALSE;
}
STDMETHODIMP AXPlatformNodeWin::get_accRole(
VARIANT var_id, VARIANT* role) {
AXPlatformNodeWin* target;
COM_OBJECT_VALIDATE_VAR_ID_1_ARG_AND_GET_TARGET(var_id, role, target);
role->vt = VT_I4;
role->lVal = target->MSAARole();
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::get_accState(
VARIANT var_id, VARIANT* state) {
AXPlatformNodeWin* target;
COM_OBJECT_VALIDATE_VAR_ID_1_ARG_AND_GET_TARGET(var_id, state, target);
state->vt = VT_I4;
state->lVal = target->MSAAState();
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::get_accHelp(
VARIANT var_id, BSTR* help) {
COM_OBJECT_VALIDATE_1_ARG(help);
return S_FALSE;
}
STDMETHODIMP AXPlatformNodeWin::get_accValue(VARIANT var_id, BSTR* value) {
AXPlatformNodeWin* target;
COM_OBJECT_VALIDATE_VAR_ID_1_ARG_AND_GET_TARGET(var_id, value, target);
return target->GetStringAttributeAsBstr(ui::AX_ATTR_VALUE, value);
}
STDMETHODIMP AXPlatformNodeWin::put_accValue(VARIANT var_id,
BSTR new_value) {
AXPlatformNodeWin* target;
COM_OBJECT_VALIDATE_VAR_ID_AND_GET_TARGET(var_id, target);
AXActionData data;
data.action = ui::AX_ACTION_SET_VALUE;
data.value = new_value;
if (target->delegate_->AccessibilityPerformAction(data))
return S_OK;
return E_FAIL;
}
// IAccessible functions not supported.
STDMETHODIMP AXPlatformNodeWin::get_accSelection(VARIANT* selected) {
COM_OBJECT_VALIDATE_1_ARG(selected);
if (selected)
selected->vt = VT_EMPTY;
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::accSelect(
LONG flagsSelect, VARIANT var_id) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::get_accHelpTopic(
BSTR* help_file, VARIANT var_id, LONG* topic_id) {
AXPlatformNodeWin* target;
COM_OBJECT_VALIDATE_VAR_ID_2_ARGS_AND_GET_TARGET(var_id, help_file, topic_id,
target);
if (help_file) {
*help_file = nullptr;
}
if (topic_id) {
*topic_id = static_cast<LONG>(-1);
}
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::put_accName(
VARIANT var_id, BSTR put_name) {
// Deprecated.
return E_NOTIMPL;
}
//
// IAccessible2 implementation.
//
STDMETHODIMP AXPlatformNodeWin::role(LONG* role) {
COM_OBJECT_VALIDATE_1_ARG(role);
*role = MSAARole();
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::get_states(AccessibleStates* states) {
COM_OBJECT_VALIDATE_1_ARG(states);
// There are only a couple of states we need to support
// in IAccessible2. If any more are added, we may want to
// add a helper function like MSAAState.
*states = IA2_STATE_OPAQUE;
if (GetData().state & (1 << ui::AX_STATE_EDITABLE))
*states |= IA2_STATE_EDITABLE;
if (GetData().state & (1 << ui::AX_STATE_VERTICAL))
*states |= IA2_STATE_VERTICAL;
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::get_uniqueID(LONG* unique_id) {
COM_OBJECT_VALIDATE_1_ARG(unique_id);
*unique_id = -unique_id_;
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::get_windowHandle(HWND* window_handle) {
COM_OBJECT_VALIDATE_1_ARG(window_handle);
*window_handle = delegate_->GetTargetForNativeAccessibilityEvent();
return *window_handle ? S_OK : S_FALSE;
}
STDMETHODIMP AXPlatformNodeWin::get_relationTargetsOfType(
BSTR type_bstr,
long max_targets,
IUnknown ***targets,
long *n_targets) {
COM_OBJECT_VALIDATE_2_ARGS(targets, n_targets);
*n_targets = 0;
*targets = nullptr;
// Only respond to requests for relations of type "alerts".
base::string16 type(type_bstr);
if (type != L"alerts")
return S_FALSE;
// Collect all of the objects that have had an alert fired on them that
// are a descendant of this object.
std::vector<AXPlatformNodeWin*> alert_targets;
for (auto iter = g_alert_targets.Get().begin();
iter != g_alert_targets.Get().end();
++iter) {
AXPlatformNodeWin* target = *iter;
if (IsDescendant(target))
alert_targets.push_back(target);
}
long count = static_cast<long>(alert_targets.size());
if (count == 0)
return S_FALSE;
// Don't return more targets than max_targets - but note that the caller
// is allowed to specify max_targets=0 to mean no limit.
if (max_targets > 0 && count > max_targets)
count = max_targets;
// Return the number of targets.
*n_targets = count;
// Allocate COM memory for the result array and populate it.
*targets = static_cast<IUnknown**>(
CoTaskMemAlloc(count * sizeof(IUnknown*)));
for (long i = 0; i < count; ++i) {
(*targets)[i] = static_cast<IAccessible*>(alert_targets[i]);
(*targets)[i]->AddRef();
}
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::get_attributes(BSTR* attributes) {
COM_OBJECT_VALIDATE_1_ARG(attributes);
base::string16 attributes_str;
// Text fields need to report the attribute "text-model:a1" to instruct
// screen readers to use IAccessible2 APIs to handle text editing in this
// object (as opposed to treating it like a native Windows text box).
// The text-model:a1 attribute is documented here:
// http://www.linuxfoundation.org/collaborate/workgroups/accessibility/ia2/ia2_implementation_guide
if (GetData().role == ui::AX_ROLE_TEXT_FIELD) {
attributes_str = L"text-model:a1;";
}
*attributes = SysAllocString(attributes_str.c_str());
DCHECK(*attributes);
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::get_indexInParent(LONG* index_in_parent) {
COM_OBJECT_VALIDATE_1_ARG(index_in_parent);
*index_in_parent = GetIndexInParent();
if (*index_in_parent < 0)
return E_FAIL;
return S_OK;
}
//
// IAccessible2 methods not implemented.
//
STDMETHODIMP AXPlatformNodeWin::get_attribute(BSTR name, VARIANT* attribute) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::get_extendedRole(BSTR* extended_role) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::get_nRelations(LONG* n_relations) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::get_relation(LONG relation_index,
IAccessibleRelation** relation) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::get_relations(LONG max_relations,
IAccessibleRelation** relations,
LONG* n_relations) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::scrollTo(enum IA2ScrollType scroll_type) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::scrollToPoint(
enum IA2CoordinateType coordinate_type,
LONG x,
LONG y) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::get_groupPosition(LONG* group_level,
LONG* similar_items_in_group,
LONG* position_in_group) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::get_localizedExtendedRole(
BSTR* localized_extended_role) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::get_nExtendedStates(LONG* n_extended_states) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::get_extendedStates(LONG max_extended_states,
BSTR** extended_states,
LONG* n_extended_states) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::get_localizedExtendedStates(
LONG max_localized_extended_states,
BSTR** localized_extended_states,
LONG* n_localized_extended_states) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::get_locale(IA2Locale* locale) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::get_accessibleWithCaret(IUnknown** accessible,
long* caret_offset) {
return E_NOTIMPL;
}
//
// IAccessibleText
//
STDMETHODIMP AXPlatformNodeWin::get_nCharacters(LONG* n_characters) {
COM_OBJECT_VALIDATE_1_ARG(n_characters);
base::string16 text = TextForIAccessibleText();
*n_characters = static_cast<LONG>(text.size());
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::get_caretOffset(LONG* offset) {
COM_OBJECT_VALIDATE_1_ARG(offset);
*offset = static_cast<LONG>(GetIntAttribute(ui::AX_ATTR_TEXT_SEL_END));
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::get_nSelections(LONG* n_selections) {
COM_OBJECT_VALIDATE_1_ARG(n_selections);
int sel_start = GetIntAttribute(ui::AX_ATTR_TEXT_SEL_START);
int sel_end = GetIntAttribute(ui::AX_ATTR_TEXT_SEL_END);
if (sel_start != sel_end)
*n_selections = 1;
else
*n_selections = 0;
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::get_selection(LONG selection_index,
LONG* start_offset,
LONG* end_offset) {
COM_OBJECT_VALIDATE_2_ARGS(start_offset, end_offset);
if (selection_index != 0)
return E_INVALIDARG;
*start_offset = static_cast<LONG>(
GetIntAttribute(ui::AX_ATTR_TEXT_SEL_START));
*end_offset = static_cast<LONG>(
GetIntAttribute(ui::AX_ATTR_TEXT_SEL_END));
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::get_text(LONG start_offset,
LONG end_offset,
BSTR* text) {
COM_OBJECT_VALIDATE_1_ARG(text);
int sel_end = GetIntAttribute(ui::AX_ATTR_TEXT_SEL_START);
base::string16 text_str = TextForIAccessibleText();
LONG len = static_cast<LONG>(text_str.size());
if (start_offset == IA2_TEXT_OFFSET_LENGTH) {
start_offset = len;
} else if (start_offset == IA2_TEXT_OFFSET_CARET) {
start_offset = static_cast<LONG>(sel_end);
}
if (end_offset == IA2_TEXT_OFFSET_LENGTH) {
end_offset = static_cast<LONG>(text_str.size());
} else if (end_offset == IA2_TEXT_OFFSET_CARET) {
end_offset = static_cast<LONG>(sel_end);
}
// The spec allows the arguments to be reversed.
if (start_offset > end_offset) {
LONG tmp = start_offset;
start_offset = end_offset;
end_offset = tmp;
}
// The spec does not allow the start or end offsets to be out or range;
// we must return an error if so.
if (start_offset < 0)
return E_INVALIDARG;
if (end_offset > len)
return E_INVALIDARG;
base::string16 substr =
text_str.substr(start_offset, end_offset - start_offset);
if (substr.empty())
return S_FALSE;
*text = SysAllocString(substr.c_str());
DCHECK(*text);
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::get_textAtOffset(
LONG offset,
enum IA2TextBoundaryType boundary_type,
LONG* start_offset, LONG* end_offset,
BSTR* text) {
COM_OBJECT_VALIDATE_3_ARGS(start_offset, end_offset, text);
// The IAccessible2 spec says we don't have to implement the "sentence"
// boundary type, we can just let the screen reader handle it.
if (boundary_type == IA2_TEXT_BOUNDARY_SENTENCE) {
*start_offset = 0;
*end_offset = 0;
*text = nullptr;
return S_FALSE;
}
const base::string16& text_str = TextForIAccessibleText();
*start_offset = FindBoundary(
text_str, boundary_type, offset, ui::BACKWARDS_DIRECTION);
*end_offset = FindBoundary(
text_str, boundary_type, offset, ui::FORWARDS_DIRECTION);
return get_text(*start_offset, *end_offset, text);
}
STDMETHODIMP AXPlatformNodeWin::get_textBeforeOffset(
LONG offset,
enum IA2TextBoundaryType boundary_type,
LONG* start_offset, LONG* end_offset,
BSTR* text) {
if (!start_offset || !end_offset || !text)
return E_INVALIDARG;
// The IAccessible2 spec says we don't have to implement the "sentence"
// boundary type, we can just let the screenreader handle it.
if (boundary_type == IA2_TEXT_BOUNDARY_SENTENCE) {
*start_offset = 0;
*end_offset = 0;
*text = nullptr;
return S_FALSE;
}
const base::string16& text_str = TextForIAccessibleText();
*start_offset = FindBoundary(
text_str, boundary_type, offset, ui::BACKWARDS_DIRECTION);
*end_offset = offset;
return get_text(*start_offset, *end_offset, text);
}
STDMETHODIMP AXPlatformNodeWin::get_textAfterOffset(
LONG offset,
enum IA2TextBoundaryType boundary_type,
LONG* start_offset, LONG* end_offset,
BSTR* text) {
if (!start_offset || !end_offset || !text)
return E_INVALIDARG;
// The IAccessible2 spec says we don't have to implement the "sentence"
// boundary type, we can just let the screenreader handle it.
if (boundary_type == IA2_TEXT_BOUNDARY_SENTENCE) {
*start_offset = 0;
*end_offset = 0;
*text = nullptr;
return S_FALSE;
}
const base::string16& text_str = TextForIAccessibleText();
*start_offset = offset;
*end_offset = FindBoundary(
text_str, boundary_type, offset, ui::FORWARDS_DIRECTION);
return get_text(*start_offset, *end_offset, text);
}
STDMETHODIMP AXPlatformNodeWin::get_offsetAtPoint(
LONG x, LONG y, enum IA2CoordinateType coord_type, LONG* offset) {
COM_OBJECT_VALIDATE_1_ARG(offset);
// We don't support this method, but we have to return something
// rather than E_NOTIMPL or screen readers will complain.
*offset = 0;
return S_OK;
}
STDMETHODIMP AXPlatformNodeWin::addSelection(LONG start_offset,
LONG end_offset) {
// We only support one selection.
return setSelection(0, start_offset, end_offset);
}
STDMETHODIMP AXPlatformNodeWin::removeSelection(LONG selection_index) {
if (selection_index != 0)
return E_INVALIDARG;
// Simply collapse the selection to the position of the caret if a caret is
// visible, otherwise set the selection to 0.
return setCaretOffset(GetIntAttribute(ui::AX_ATTR_TEXT_SEL_END));
}
STDMETHODIMP AXPlatformNodeWin::setCaretOffset(LONG offset) {
return setSelection(0, offset, offset);
}
STDMETHODIMP AXPlatformNodeWin::setSelection(LONG selection_index,
LONG start_offset,
LONG end_offset) {
if (selection_index != 0)
return E_INVALIDARG;
HandleSpecialTextOffset(&start_offset);
HandleSpecialTextOffset(&end_offset);
if (start_offset < 0 ||
start_offset > static_cast<LONG>(TextForIAccessibleText().length())) {
return E_INVALIDARG;
}
if (end_offset < 0 ||
end_offset > static_cast<LONG>(TextForIAccessibleText().length())) {
return E_INVALIDARG;
}
if (SetTextSelection(static_cast<int>(start_offset),
static_cast<int>(end_offset))) {
return S_OK;
}
return E_FAIL;
}
//
// IAccessibleText methods not implemented.
//
STDMETHODIMP AXPlatformNodeWin::get_newText(IA2TextSegment* new_text) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::get_oldText(IA2TextSegment* old_text) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::get_characterExtents(
LONG offset,
enum IA2CoordinateType coord_type,
LONG* x,
LONG* y,
LONG* width,
LONG* height) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::scrollSubstringTo(
LONG start_index,
LONG end_index,
enum IA2ScrollType scroll_type) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::scrollSubstringToPoint(
LONG start_index,
LONG end_index,
enum IA2CoordinateType coordinate_type,
LONG x,
LONG y) {
return E_NOTIMPL;
}
STDMETHODIMP AXPlatformNodeWin::get_attributes(LONG offset,
LONG* start_offset,
LONG* end_offset,
BSTR* text_attributes) {
return E_NOTIMPL;
}
//
// IServiceProvider implementation.
//
STDMETHODIMP AXPlatformNodeWin::QueryService(
REFGUID guidService, REFIID riid, void** object) {
COM_OBJECT_VALIDATE_1_ARG(object);
if (riid == IID_IAccessible2) {
for (IAccessible2UsageObserver& observer :
GetIAccessible2UsageObserverList()) {
observer.OnIAccessible2Used();
}
}
if (guidService == IID_IAccessible ||
guidService == IID_IAccessible2 ||
guidService == IID_IAccessible2_2 ||
guidService == IID_IAccessibleText) {
return QueryInterface(riid, object);
}
*object = nullptr;
return E_FAIL;
}
//
// Private member functions.
//
int AXPlatformNodeWin::MSAARole() {
switch (GetData().role) {
case ui::AX_ROLE_ALERT:
return ROLE_SYSTEM_ALERT;
case ui::AX_ROLE_APPLICATION:
return ROLE_SYSTEM_APPLICATION;
case ui::AX_ROLE_BUTTON_DROP_DOWN:
return ROLE_SYSTEM_BUTTONDROPDOWN;
case ui::AX_ROLE_POP_UP_BUTTON:
return ROLE_SYSTEM_BUTTONMENU;
case ui::AX_ROLE_CHECK_BOX:
return ROLE_SYSTEM_CHECKBUTTON;
case ui::AX_ROLE_COMBO_BOX:
return ROLE_SYSTEM_COMBOBOX;
case ui::AX_ROLE_DIALOG:
return ROLE_SYSTEM_DIALOG;
case ui::AX_ROLE_GROUP:
return ROLE_SYSTEM_GROUPING;
case ui::AX_ROLE_IMAGE:
return ROLE_SYSTEM_GRAPHIC;
case ui::AX_ROLE_LINK:
return ROLE_SYSTEM_LINK;
case ui::AX_ROLE_LOCATION_BAR:
return ROLE_SYSTEM_GROUPING;
case ui::AX_ROLE_MENU_BAR:
return ROLE_SYSTEM_MENUBAR;
case ui::AX_ROLE_MENU_ITEM:
return ROLE_SYSTEM_MENUITEM;
case ui::AX_ROLE_MENU_LIST_POPUP:
return ROLE_SYSTEM_MENUPOPUP;
case ui::AX_ROLE_TREE:
return ROLE_SYSTEM_OUTLINE;
case ui::AX_ROLE_TREE_ITEM:
return ROLE_SYSTEM_OUTLINEITEM;
case ui::AX_ROLE_TAB:
return ROLE_SYSTEM_PAGETAB;
case ui::AX_ROLE_TAB_LIST:
return ROLE_SYSTEM_PAGETABLIST;
case ui::AX_ROLE_PANE:
return ROLE_SYSTEM_PANE;
case ui::AX_ROLE_PROGRESS_INDICATOR:
return ROLE_SYSTEM_PROGRESSBAR;
case ui::AX_ROLE_BUTTON:
return ROLE_SYSTEM_PUSHBUTTON;
case ui::AX_ROLE_RADIO_BUTTON:
return ROLE_SYSTEM_RADIOBUTTON;
case ui::AX_ROLE_SCROLL_BAR:
return ROLE_SYSTEM_SCROLLBAR;
case ui::AX_ROLE_SPLITTER:
return ROLE_SYSTEM_SEPARATOR;
case ui::AX_ROLE_SLIDER:
return ROLE_SYSTEM_SLIDER;
case ui::AX_ROLE_STATIC_TEXT:
return ROLE_SYSTEM_STATICTEXT;
case ui::AX_ROLE_TEXT_FIELD:
return ROLE_SYSTEM_TEXT;
case ui::AX_ROLE_TITLE_BAR:
return ROLE_SYSTEM_TITLEBAR;
case ui::AX_ROLE_TOOLBAR:
return ROLE_SYSTEM_TOOLBAR;
case ui::AX_ROLE_WEB_VIEW:
return ROLE_SYSTEM_GROUPING;
case ui::AX_ROLE_WINDOW:
return ROLE_SYSTEM_WINDOW;
case ui::AX_ROLE_CLIENT:
default:
// This is the default role for MSAA.
return ROLE_SYSTEM_CLIENT;
}
}
int AXPlatformNodeWin::MSAAState() {
const AXNodeData& data = GetData();
const uint32_t state = data.state;
int msaa_state = 0;
if (state & (1 << ui::AX_STATE_COLLAPSED))
msaa_state |= STATE_SYSTEM_COLLAPSED;
if (state & (1 << ui::AX_STATE_DEFAULT))
msaa_state |= STATE_SYSTEM_DEFAULT;
if (state & (1 << ui::AX_STATE_EXPANDED))
msaa_state |= STATE_SYSTEM_EXPANDED;
if (state & (1 << ui::AX_STATE_FOCUSABLE))
msaa_state |= STATE_SYSTEM_FOCUSABLE;
if (state & (1 << ui::AX_STATE_HASPOPUP))
msaa_state |= STATE_SYSTEM_HASPOPUP;
if (state & (1 << ui::AX_STATE_HOVERED))
msaa_state |= STATE_SYSTEM_HOTTRACKED;
if (state & (1 << ui::AX_STATE_INVISIBLE))
msaa_state |= STATE_SYSTEM_INVISIBLE;
if (state & (1 << ui::AX_STATE_LINKED))
msaa_state |= STATE_SYSTEM_LINKED;
if (state & (1 << ui::AX_STATE_OFFSCREEN))
msaa_state |= STATE_SYSTEM_OFFSCREEN;
if (state & (1 << ui::AX_STATE_PRESSED))
msaa_state |= STATE_SYSTEM_PRESSED;
if (state & (1 << ui::AX_STATE_PROTECTED))
msaa_state |= STATE_SYSTEM_PROTECTED;
if (state & (1 << ui::AX_STATE_READ_ONLY))
msaa_state |= STATE_SYSTEM_READONLY;
if (state & (1 << ui::AX_STATE_SELECTABLE))
msaa_state |= STATE_SYSTEM_SELECTABLE;
if (state & (1 << ui::AX_STATE_SELECTED))
msaa_state |= STATE_SYSTEM_SELECTED;
if (state & (1 << ui::AX_STATE_DISABLED))
msaa_state |= STATE_SYSTEM_UNAVAILABLE;
// Checked state
const auto checked_state = static_cast<ui::AXCheckedState>(
GetIntAttribute(ui::AX_ATTR_CHECKED_STATE));
switch (checked_state) {
case ui::AX_CHECKED_STATE_TRUE:
msaa_state |= STATE_SYSTEM_CHECKED;
break;
case ui::AX_CHECKED_STATE_MIXED:
msaa_state |= STATE_SYSTEM_MIXED;
break;
default:
break;
}
gfx::NativeViewAccessible focus = delegate_->GetFocus();
if (focus == GetNativeViewAccessible())
msaa_state |= STATE_SYSTEM_FOCUSED;
// On Windows, the "focus" bit should be set on certain containers, like
// menu bars, when visible.
//
// TODO(dmazzoni): this should probably check if focus is actually inside
// the menu bar, but we don't currently track focus inside menu pop-ups,
// and Chrome only has one menu visible at a time so this works for now.
if (data.role == ui::AX_ROLE_MENU_BAR &&
!(state & (1 << ui::AX_STATE_INVISIBLE))) {
msaa_state |= STATE_SYSTEM_FOCUSED;
}
return msaa_state;
}
int AXPlatformNodeWin::MSAAEvent(ui::AXEvent event) {
switch (event) {
case ui::AX_EVENT_ALERT:
return EVENT_SYSTEM_ALERT;
case ui::AX_EVENT_FOCUS:
return EVENT_OBJECT_FOCUS;
case ui::AX_EVENT_MENU_START:
return EVENT_SYSTEM_MENUSTART;
case ui::AX_EVENT_MENU_END:
return EVENT_SYSTEM_MENUEND;
case ui::AX_EVENT_MENU_POPUP_START:
return EVENT_SYSTEM_MENUPOPUPSTART;
case ui::AX_EVENT_MENU_POPUP_END:
return EVENT_SYSTEM_MENUPOPUPEND;
case ui::AX_EVENT_SELECTION:
return EVENT_OBJECT_SELECTION;
case ui::AX_EVENT_SELECTION_ADD:
return EVENT_OBJECT_SELECTIONADD;
case ui::AX_EVENT_SELECTION_REMOVE:
return EVENT_OBJECT_SELECTIONREMOVE;
case ui::AX_EVENT_TEXT_CHANGED:
return EVENT_OBJECT_NAMECHANGE;
case ui::AX_EVENT_TEXT_SELECTION_CHANGED:
return IA2_EVENT_TEXT_CARET_MOVED;
case ui::AX_EVENT_VALUE_CHANGED:
return EVENT_OBJECT_VALUECHANGE;
default:
return -1;
}
}
HRESULT AXPlatformNodeWin::GetStringAttributeAsBstr(
ui::AXStringAttribute attribute,
BSTR* value_bstr) const {
base::string16 str;
if (!GetString16Attribute(attribute, &str))
return S_FALSE;
if (str.empty())
return S_FALSE;
*value_bstr = SysAllocString(str.c_str());
DCHECK(*value_bstr);
return S_OK;
}
void AXPlatformNodeWin::AddAlertTarget() {
g_alert_targets.Get().insert(this);
}
void AXPlatformNodeWin::RemoveAlertTarget() {
if (g_alert_targets.Get().find(this) != g_alert_targets.Get().end())
g_alert_targets.Get().erase(this);
}
base::string16 AXPlatformNodeWin::TextForIAccessibleText() {
if (GetData().role == ui::AX_ROLE_TEXT_FIELD)
return GetString16Attribute(ui::AX_ATTR_VALUE);
return GetString16Attribute(ui::AX_ATTR_NAME);
}
void AXPlatformNodeWin::HandleSpecialTextOffset(LONG* offset) {
if (*offset == IA2_TEXT_OFFSET_LENGTH) {
*offset = static_cast<LONG>(TextForIAccessibleText().length());
} else if (*offset == IA2_TEXT_OFFSET_CARET) {
get_caretOffset(offset);
}
}
ui::TextBoundaryType AXPlatformNodeWin::IA2TextBoundaryToTextBoundary(
IA2TextBoundaryType ia2_boundary) {
switch(ia2_boundary) {
case IA2_TEXT_BOUNDARY_CHAR: return ui::CHAR_BOUNDARY;
case IA2_TEXT_BOUNDARY_WORD: return ui::WORD_BOUNDARY;
case IA2_TEXT_BOUNDARY_LINE: return ui::LINE_BOUNDARY;
case IA2_TEXT_BOUNDARY_SENTENCE: return ui::SENTENCE_BOUNDARY;
case IA2_TEXT_BOUNDARY_PARAGRAPH: return ui::PARAGRAPH_BOUNDARY;
case IA2_TEXT_BOUNDARY_ALL: return ui::ALL_BOUNDARY;
default:
NOTREACHED();
return ui::CHAR_BOUNDARY;
}
}
LONG AXPlatformNodeWin::FindBoundary(
const base::string16& text,
IA2TextBoundaryType ia2_boundary,
LONG start_offset,
ui::TextBoundaryDirection direction) {
HandleSpecialTextOffset(&start_offset);
ui::TextBoundaryType boundary = IA2TextBoundaryToTextBoundary(ia2_boundary);
std::vector<int32_t> line_breaks;
return static_cast<LONG>(ui::FindAccessibleTextBoundary(
text, line_breaks, boundary, start_offset, direction,
AX_TEXT_AFFINITY_DOWNSTREAM));
}
AXPlatformNodeWin* AXPlatformNodeWin::GetTargetFromChildID(
const VARIANT& var_id) {
LONG child_id = V_I4(&var_id);
if (child_id == CHILDID_SELF) {
return this;
}
if (child_id >= 1 && child_id <= delegate_->GetChildCount()) {
// Positive child ids are a 1-based child index, used by clients
// that want to enumerate all immediate children.
AXPlatformNodeBase* base =
FromNativeViewAccessible(delegate_->ChildAtIndex(child_id - 1));
return static_cast<AXPlatformNodeWin*>(base);
}
if (child_id >= 0)
return nullptr;
// Negative child ids can be used to map to any descendant.
AXPlatformNode* node = GetFromUniqueId(-child_id);
if (!node)
return nullptr;
AXPlatformNodeBase* base =
FromNativeViewAccessible(node->GetNativeViewAccessible());
if (base && !IsDescendant(base))
base = nullptr;
return static_cast<AXPlatformNodeWin*>(base);
}
} // namespace ui