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/*
* Copyright (C) 2012, Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "third_party/blink/renderer/modules/accessibility/ax_node_object.h"
#include <math.h>
#include <algorithm>
#include <memory>
#include <queue>
#include "base/auto_reset.h"
#include "base/numerics/safe_conversions.h"
#include "third_party/abseil-cpp/absl/types/optional.h"
#include "third_party/blink/public/common/features.h"
#include "third_party/blink/public/common/input/web_keyboard_event.h"
#include "third_party/blink/public/mojom/frame/user_activation_notification_type.mojom-blink.h"
#include "third_party/blink/public/strings/grit/blink_strings.h"
#include "third_party/blink/renderer/bindings/core/v8/v8_image_bitmap_options.h"
#include "third_party/blink/renderer/core/aom/accessible_node.h"
#include "third_party/blink/renderer/core/css/css_resolution_units.h"
#include "third_party/blink/renderer/core/css/properties/longhands.h"
#include "third_party/blink/renderer/core/display_lock/display_lock_utilities.h"
#include "third_party/blink/renderer/core/dom/flat_tree_traversal.h"
#include "third_party/blink/renderer/core/dom/layout_tree_builder_traversal.h"
#include "third_party/blink/renderer/core/dom/node_computed_style.h"
#include "third_party/blink/renderer/core/dom/node_traversal.h"
#include "third_party/blink/renderer/core/dom/qualified_name.h"
#include "third_party/blink/renderer/core/dom/shadow_root.h"
#include "third_party/blink/renderer/core/dom/text.h"
#include "third_party/blink/renderer/core/editing/editing_utilities.h"
#include "third_party/blink/renderer/core/editing/markers/custom_highlight_marker.h"
#include "third_party/blink/renderer/core/editing/markers/document_marker_controller.h"
#include "third_party/blink/renderer/core/editing/position.h"
#include "third_party/blink/renderer/core/events/event_util.h"
#include "third_party/blink/renderer/core/events/keyboard_event.h"
#include "third_party/blink/renderer/core/frame/local_dom_window.h"
#include "third_party/blink/renderer/core/frame/local_frame.h"
#include "third_party/blink/renderer/core/frame/local_frame_view.h"
#include "third_party/blink/renderer/core/frame/settings.h"
#include "third_party/blink/renderer/core/highlight/highlight.h"
#include "third_party/blink/renderer/core/html/canvas/html_canvas_element.h"
#include "third_party/blink/renderer/core/html/canvas/image_data.h"
#include "third_party/blink/renderer/core/html/custom/element_internals.h"
#include "third_party/blink/renderer/core/html/fenced_frame/html_fenced_frame_element.h"
#include "third_party/blink/renderer/core/html/forms/html_button_element.h"
#include "third_party/blink/renderer/core/html/forms/html_field_set_element.h"
#include "third_party/blink/renderer/core/html/forms/html_form_control_element.h"
#include "third_party/blink/renderer/core/html/forms/html_input_element.h"
#include "third_party/blink/renderer/core/html/forms/html_label_element.h"
#include "third_party/blink/renderer/core/html/forms/html_legend_element.h"
#include "third_party/blink/renderer/core/html/forms/html_opt_group_element.h"
#include "third_party/blink/renderer/core/html/forms/html_option_element.h"
#include "third_party/blink/renderer/core/html/forms/html_select_element.h"
#include "third_party/blink/renderer/core/html/forms/html_select_menu_element.h"
#include "third_party/blink/renderer/core/html/forms/html_text_area_element.h"
#include "third_party/blink/renderer/core/html/forms/labels_node_list.h"
#include "third_party/blink/renderer/core/html/forms/radio_input_type.h"
#include "third_party/blink/renderer/core/html/forms/text_control_element.h"
#include "third_party/blink/renderer/core/html/html_anchor_element.h"
#include "third_party/blink/renderer/core/html/html_div_element.h"
#include "third_party/blink/renderer/core/html/html_dlist_element.h"
#include "third_party/blink/renderer/core/html/html_element.h"
#include "third_party/blink/renderer/core/html/html_frame_element_base.h"
#include "third_party/blink/renderer/core/html/html_image_element.h"
#include "third_party/blink/renderer/core/html/html_map_element.h"
#include "third_party/blink/renderer/core/html/html_meter_element.h"
#include "third_party/blink/renderer/core/html/html_plugin_element.h"
#include "third_party/blink/renderer/core/html/html_slot_element.h"
#include "third_party/blink/renderer/core/html/html_table_caption_element.h"
#include "third_party/blink/renderer/core/html/html_table_cell_element.h"
#include "third_party/blink/renderer/core/html/html_table_element.h"
#include "third_party/blink/renderer/core/html/html_table_row_element.h"
#include "third_party/blink/renderer/core/html/html_table_section_element.h"
#include "third_party/blink/renderer/core/html/media/html_media_element.h"
#include "third_party/blink/renderer/core/html/media/html_video_element.h"
#include "third_party/blink/renderer/core/html/parser/html_parser_idioms.h"
#include "third_party/blink/renderer/core/html/portal/html_portal_element.h"
#include "third_party/blink/renderer/core/html/shadow/shadow_element_names.h"
#include "third_party/blink/renderer/core/imagebitmap/image_bitmap.h"
#include "third_party/blink/renderer/core/input_type_names.h"
#include "third_party/blink/renderer/core/layout/layout_block_flow.h"
#include "third_party/blink/renderer/core/layout/layout_box_model_object.h"
#include "third_party/blink/renderer/core/layout/layout_file_upload_control.h"
#include "third_party/blink/renderer/core/layout/layout_inline.h"
#include "third_party/blink/renderer/core/layout/layout_object.h"
#include "third_party/blink/renderer/core/layout/layout_table.h"
#include "third_party/blink/renderer/core/layout/layout_view.h"
#include "third_party/blink/renderer/core/layout/ng/inline/ng_inline_node.h"
#include "third_party/blink/renderer/core/layout/ng/inline/ng_offset_mapping.h"
#include "third_party/blink/renderer/core/loader/progress_tracker.h"
#include "third_party/blink/renderer/core/mathml/mathml_element.h"
#include "third_party/blink/renderer/core/mathml_names.h"
#include "third_party/blink/renderer/core/navigation_api/navigation_api.h"
#include "third_party/blink/renderer/core/page/focus_controller.h"
#include "third_party/blink/renderer/core/page/page.h"
#include "third_party/blink/renderer/core/style/computed_style_constants.h"
#include "third_party/blink/renderer/core/svg/svg_desc_element.h"
#include "third_party/blink/renderer/core/svg/svg_element.h"
#include "third_party/blink/renderer/core/svg/svg_symbol_element.h"
#include "third_party/blink/renderer/core/svg/svg_text_element.h"
#include "third_party/blink/renderer/core/svg/svg_title_element.h"
#include "third_party/blink/renderer/core/xlink_names.h"
#include "third_party/blink/renderer/modules/accessibility/ax_image_map_link.h"
#include "third_party/blink/renderer/modules/accessibility/ax_inline_text_box.h"
#include "third_party/blink/renderer/modules/accessibility/ax_layout_object.h"
#include "third_party/blink/renderer/modules/accessibility/ax_menu_list_option.h"
#include "third_party/blink/renderer/modules/accessibility/ax_menu_list_popup.h"
#include "third_party/blink/renderer/modules/accessibility/ax_object_cache_impl.h"
#include "third_party/blink/renderer/modules/accessibility/ax_position.h"
#include "third_party/blink/renderer/modules/accessibility/ax_range.h"
#include "third_party/blink/renderer/modules/accessibility/ax_relation_cache.h"
#include "third_party/blink/renderer/platform/graphics/image_data_buffer.h"
#include "third_party/blink/renderer/platform/keyboard_codes.h"
#include "third_party/blink/renderer/platform/runtime_enabled_features.h"
#include "third_party/blink/renderer/platform/text/platform_locale.h"
#include "third_party/blink/renderer/platform/text/text_direction.h"
#include "third_party/blink/renderer/platform/weborigin/kurl.h"
#include "third_party/blink/renderer/platform/wtf/text/string_builder.h"
#include "ui/accessibility/ax_common.h"
#include "ui/accessibility/ax_role_properties.h"
#include "ui/events/keycodes/dom/dom_code.h"
#include "ui/events/keycodes/dom/keycode_converter.h"
#include "ui/gfx/geometry/transform.h"
namespace {
// It is not easily possible to find out if an element is the target of an
// in-page link.
// As a workaround, we consider the following to be potential targets:
// - <a name>
// - <foo id> -- an element with an id that is not SVG, a <label> or <optgroup>.
// <label> does not make much sense as an in-page link target.
// Exposing <optgroup> is redundant, as the group is already exposed via a
// child in its shadow DOM, which contains the accessible name.
// #document -- this is always a potential link target via <a name="#">.
// This is a compromise that does not include too many elements, and
// has minimal impact on tests.
bool IsPotentialInPageLinkTarget(blink::Node& node) {
auto* element = blink::DynamicTo<blink::Element>(&node);
if (!element) {
// The document itself is a potential link target, e.g. via <a name="#">.
return blink::IsA<blink::Document>(node);
}
// We exclude elements that are in the shadow DOM. They cannot be linked by a
// document fragment from the main page:as they have their own id namespace.
if (element->ContainingShadowRoot())
return false;
// SVG elements are unlikely link targets, and we want to avoid creating
// a lot of noise in the AX tree or breaking tests unnecessarily.
if (element->IsSVGElement())
return false;
// <a name>
if (auto* anchor = blink::DynamicTo<blink::HTMLAnchorElement>(element)) {
if (anchor->HasName())
return true;
}
// <foo id> not in an <optgroup> or <label>.
if (element->HasID() && !blink::IsA<blink::HTMLLabelElement>(element) &&
!blink::IsA<blink::HTMLOptGroupElement>(element)) {
return true;
}
return false;
}
bool IsNeutralWithinTable(blink::AXObject* obj) {
if (!obj)
return false;
ax::mojom::blink::Role role = obj->RoleValue();
return role == ax::mojom::blink::Role::kGroup ||
role == ax::mojom::blink::Role::kGenericContainer ||
role == ax::mojom::blink::Role::kRowGroup;
}
// Within a table, provide the accessible, semantic parent of |node|,
// by traversing the DOM tree, ignoring elements that are neutral in a table.
// Return the AXObject for the ancestor.
blink::AXObject* GetDOMTableAXAncestor(blink::Node* node,
blink::AXObjectCacheImpl& cache) {
// Used by code to determine roles of elements inside of an HTML table,
// Use DOM to get parent since parent_ is not initialized yet when role is
// being computed, and because HTML table structure should not take into
// account aria-owns.
if (!node)
return nullptr;
while (true) {
node = blink::LayoutTreeBuilderTraversal::Parent(*node);
if (!node)
return nullptr;
blink::AXObject* ax_object = cache.GetOrCreate(node);
if (ax_object && !IsNeutralWithinTable(ax_object))
return ax_object;
}
}
enum class AXAction {
kActionIncrement = 0,
kActionDecrement,
};
blink::KeyboardEvent* CreateKeyboardEvent(
blink::LocalDOMWindow* local_dom_window,
blink::WebInputEvent::Type type,
AXAction action,
blink::AccessibilityOrientation orientation,
ax::mojom::blink::WritingDirection text_direction) {
blink::WebKeyboardEvent key(type,
blink::WebInputEvent::Modifiers::kNoModifiers,
base::TimeTicks::Now());
if (action == AXAction::kActionIncrement) {
if (orientation == blink::kAccessibilityOrientationVertical) {
key.dom_key = ui::DomKey::ARROW_UP;
key.dom_code = static_cast<int>(ui::DomCode::ARROW_UP);
key.native_key_code = key.windows_key_code = blink::VKEY_UP;
} else if (text_direction == ax::mojom::blink::WritingDirection::kRtl) {
key.dom_key = ui::DomKey::ARROW_LEFT;
key.dom_code = static_cast<int>(ui::DomCode::ARROW_LEFT);
key.native_key_code = key.windows_key_code = blink::VKEY_LEFT;
} else { // horizontal and left to right
key.dom_key = ui::DomKey::ARROW_RIGHT;
key.dom_code = static_cast<int>(ui::DomCode::ARROW_RIGHT);
key.native_key_code = key.windows_key_code = blink::VKEY_RIGHT;
}
} else if (action == AXAction::kActionDecrement) {
if (orientation == blink::kAccessibilityOrientationVertical) {
key.dom_key = ui::DomKey::ARROW_DOWN;
key.dom_code = static_cast<int>(ui::DomCode::ARROW_DOWN);
key.native_key_code = key.windows_key_code = blink::VKEY_DOWN;
} else if (text_direction == ax::mojom::blink::WritingDirection::kRtl) {
key.dom_key = ui::DomKey::ARROW_RIGHT;
key.dom_code = static_cast<int>(ui::DomCode::ARROW_RIGHT);
key.native_key_code = key.windows_key_code = blink::VKEY_RIGHT;
} else { // horizontal and left to right
key.dom_key = ui::DomKey::ARROW_LEFT;
key.dom_code = static_cast<int>(ui::DomCode::ARROW_LEFT);
key.native_key_code = key.windows_key_code = blink::VKEY_LEFT;
}
}
return blink::KeyboardEvent::Create(key, local_dom_window, true);
}
unsigned TextStyleFlag(ax::mojom::blink::TextStyle text_style_enum) {
return static_cast<unsigned>(1 << static_cast<int>(text_style_enum));
}
ax::mojom::blink::TextDecorationStyle
TextDecorationStyleToAXTextDecorationStyle(
const blink::ETextDecorationStyle text_decoration_style) {
switch (text_decoration_style) {
case blink::ETextDecorationStyle::kDashed:
return ax::mojom::blink::TextDecorationStyle::kDashed;
case blink::ETextDecorationStyle::kSolid:
return ax::mojom::blink::TextDecorationStyle::kSolid;
case blink::ETextDecorationStyle::kDotted:
return ax::mojom::blink::TextDecorationStyle::kDotted;
case blink::ETextDecorationStyle::kDouble:
return ax::mojom::blink::TextDecorationStyle::kDouble;
case blink::ETextDecorationStyle::kWavy:
return ax::mojom::blink::TextDecorationStyle::kWavy;
}
NOTREACHED();
return ax::mojom::blink::TextDecorationStyle::kNone;
}
String GetTitle(blink::Element* element) {
if (!element)
return String();
if (blink::SVGElement* svg_element =
blink::DynamicTo<blink::SVGElement>(element)) {
// Don't use title() in SVG, as it calls innerText() which updates layout.
// Unfortunately, this must duplicate some logic from SVGElement::title().
if (svg_element->InUseShadowTree()) {
String title = GetTitle(svg_element->OwnerShadowHost());
if (!title.empty())
return title;
}
// If we aren't an instance in a <use> or the <use> title was not found,
// then find the first <title> child of this element. If a title child was
// found, return the text contents.
if (auto* title_element =
blink::Traversal<blink::SVGTitleElement>::FirstChild(*element)) {
return title_element->GetInnerTextWithoutUpdate();
}
return String();
}
return element->title();
}
} // namespace
namespace blink {
using html_names::kAltAttr;
using html_names::kTitleAttr;
using html_names::kTypeAttr;
using html_names::kValueAttr;
// In ARIA 1.1, default value of aria-level was changed to 2.
const int kDefaultHeadingLevel = 2;
AXNodeObject::AXNodeObject(Node* node, AXObjectCacheImpl& ax_object_cache)
: AXObject(ax_object_cache),
native_role_(ax::mojom::blink::Role::kUnknown),
aria_role_(ax::mojom::blink::Role::kUnknown),
node_(node) {}
AXNodeObject::~AXNodeObject() {
DCHECK(!node_);
}
void AXNodeObject::AlterSliderOrSpinButtonValue(bool increase) {
if (!GetNode())
return;
if (!IsSlider() && !IsSpinButton())
return;
float value;
if (!ValueForRange(&value))
return;
if (!RuntimeEnabledFeatures::
SynthesizedKeyboardEventsForAccessibilityActionsEnabled()) {
// If synthesized keyboard events are disabled, we need to set the value
// directly here.
// If no step was provided on the element, use a default value.
float step;
if (!StepValueForRange(&step)) {
if (IsNativeSlider() || IsNativeSpinButton()) {
step = StepRange().Step().ToString().ToFloat();
} else {
return;
}
}
value += increase ? step : -step;
if (native_role_ == ax::mojom::blink::Role::kSlider ||
native_role_ == ax::mojom::blink::Role::kSpinButton) {
OnNativeSetValueAction(String::Number(value));
// Dispatching an event could result in changes to the document, like
// this AXObject becoming detached.
if (IsDetached())
return;
AXObjectCache().HandleValueChanged(GetNode());
return;
}
}
// If we have synthesized keyboard events enabled, we generate a keydown
// event:
// * For a native slider, the dispatch of the event will reach
// RangeInputType::HandleKeydownEvent(), where the value will be set and the
// AXObjectCache notified. The corresponding keydown/up JS events will be
// fired so the website doesn't know it was produced by an AT action.
// * For an ARIA slider, the corresponding keydown/up JS events will be
// fired. It is expected that the handlers for those events manage the
// update of the slider value.
AXAction action =
increase ? AXAction::kActionIncrement : AXAction::kActionDecrement;
LocalDOMWindow* local_dom_window = GetDocument()->domWindow();
AccessibilityOrientation orientation = Orientation();
ax::mojom::blink::WritingDirection text_direction = GetTextDirection();
// A kKeyDown event is kRawKeyDown + kChar events. We cannot synthesize it
// because the KeyboardEvent constructor will prevent it, to force us to
// decide if we must produce both events. In our case, we don't have to
// produce a kChar event because we are synthesizing arrow key presses, and
// only keys that output characters are expected to produce kChar events.
KeyboardEvent* keydown =
CreateKeyboardEvent(local_dom_window, WebInputEvent::Type::kRawKeyDown,
action, orientation, text_direction);
GetNode()->DispatchEvent(*keydown);
// The keydown handler may have caused the node to be removed.
if (!GetNode())
return;
KeyboardEvent* keyup =
CreateKeyboardEvent(local_dom_window, WebInputEvent::Type::kKeyUp, action,
orientation, text_direction);
// Add a 100ms delay between keydown and keyup to make events look less
// evidently synthesized.
GetDocument()
->GetTaskRunner(TaskType::kUserInteraction)
->PostDelayedTask(
FROM_HERE,
WTF::BindOnce(
[](Node* node, KeyboardEvent* evt) { node->DispatchEvent(*evt); },
WrapWeakPersistent(GetNode()), WrapPersistent(keyup)),
base::Milliseconds(100));
}
AXObject* AXNodeObject::ActiveDescendant() {
Element* element = GetElement();
if (!element)
return nullptr;
Element* descendant =
GetAOMPropertyOrARIAAttribute(AOMRelationProperty::kActiveDescendant);
if (!descendant)
return nullptr;
AXObject* ax_descendant = AXObjectCache().GetOrCreate(descendant);
return ax_descendant && ax_descendant->IsVisible() ? ax_descendant : nullptr;
}
AXObjectInclusion AXNodeObject::ShouldIncludeBasedOnSemantics(
IgnoredReasons* ignored_reasons) const {
DCHECK(GetDocument());
if (IsPresentational()) {
if (ignored_reasons)
ignored_reasons->push_back(IgnoredReason(kAXPresentational));
return kIgnoreObject;
}
// Objects inside a portal should be ignored. Portals don't directly expose
// their contents as the contents are not focusable (portals do not currently
// support input events). Portals do use their contents to compute a default
// accessible name.
if (GetDocument()->GetPage() && GetDocument()->GetPage()->InsidePortal())
return kIgnoreObject;
Node* node = GetNode();
if (!node) {
// Nodeless pseudo element images are included, even if they don't have CSS
// alt text. This can allow auto alt to be applied to them.
if (IsImage())
return kIncludeObject;
return kDefaultBehavior;
}
// Avoid double speech. The ruby text describes pronunciation of the ruby
// base, and generally produces redundant screen reader output. Expose it only
// as a description on the <ruby> element so that screen reader users can
// toggle it on/off as with other descriptions/annotations.
if (RoleValue() == ax::mojom::blink::Role::kRubyAnnotation ||
(RoleValue() == ax::mojom::blink::Role::kStaticText && ParentObject() &&
ParentObject()->RoleValue() ==
ax::mojom::blink::Role::kRubyAnnotation)) {
return kIgnoreObject;
}
Element* element = GetElement();
if (!element)
return kDefaultBehavior;
if (IsA<SVGElement>(node)) {
// The symbol element is used to define graphical templates which can be
// instantiated by a use element but which are not rendered directly. We
// don't want to include these template objects, or their subtrees, where
// they appear in the DOM. Any associated semantic information (e.g. the
// title child of a symbol) may participate in the text alternative
// computation where it is instantiated by the use element.
// https://svgwg.org/svg2-draft/struct.html#SymbolElement
if (Traversal<SVGSymbolElement>::FirstAncestorOrSelf(*node))
return kIgnoreObject;
// The SVG-AAM states that user agents MUST provide an accessible object
// for rendered SVG elements that have at least one direct child title or
// desc element that is not empty after trimming whitespace. But it also
// says, "User agents MAY include elements with these child elements without
// checking for valid text content." So just check for their existence in
// order to be performant. https://w3c.github.io/svg-aam/#include_elements
if (ElementTraversal::FirstChild(
*To<ContainerNode>(node), [](auto& element) {
return element.HasTagName(svg_names::kTitleTag) ||
element.HasTagName(svg_names::kDescTag);
})) {
return kIncludeObject;
}
// If we return kDefaultBehavior here, the logic related to inclusion of
// clickable objects, links, controls, etc. will not be reached. We handle
// SVG elements early to ensure properties in a <symbol> subtree do not
// result in inclusion.
}
if (IsTableLikeRole() || IsTableRowLikeRole() || IsTableCellLikeRole())
return kIncludeObject;
// All focusable elements except the <body> are included.
if (!IsA<HTMLBodyElement>(node) && CanSetFocusAttribute())
return kIncludeObject;
if (IsLink())
return kIncludeObject;
// A click handler might be placed on an otherwise ignored non-empty block
// element, e.g. a div. We shouldn't ignore such elements because if an AT
// sees the |ax::mojom::blink::DefaultActionVerb::kClickAncestor|, it will
// look for the clickable ancestor and it expects to find one.
if (IsClickable())
return kIncludeObject;
if (IsHeading())
return kIncludeObject;
// Header and footer tags may also be exposed as landmark roles but not
// always.
if (node->HasTagName(html_names::kHeaderTag) ||
node->HasTagName(html_names::kFooterTag))
return kIncludeObject;
// All controls are accessible.
if (IsControl())
return kIncludeObject;
// Anything with an explicit ARIA role should be included.
if (AriaRoleAttribute() != ax::mojom::blink::Role::kUnknown)
return kIncludeObject;
// Anything with CSS alt should be included.
// Descendants are pruned: IsRelevantPseudoElementDescendant() returns false.
// Note: this is duplicated from AXLayoutObject because CSS alt text may apply
// to both Elements and pseudo-elements.
absl::optional<String> alt_text = GetCSSAltText(GetNode());
if (alt_text && !alt_text->empty())
return kIncludeObject;
// Don't ignored legends, because JAWS uses them to determine redundant text.
if (IsA<HTMLLegendElement>(node))
return kIncludeObject;
// Anything that is an editable root should not be ignored. However, one
// cannot just call `AXObject::IsEditable()` since that will include the
// contents of an editable region too. Only the editable root should always be
// exposed.
if (IsEditableRoot())
return kIncludeObject;
static const HashSet<ax::mojom::blink::Role> always_included_computed_roles =
{
ax::mojom::blink::Role::kAbbr,
ax::mojom::blink::Role::kApplication,
ax::mojom::blink::Role::kArticle,
ax::mojom::blink::Role::kBanner,
ax::mojom::blink::Role::kBlockquote,
ax::mojom::blink::Role::kComplementary,
ax::mojom::blink::Role::kContentDeletion,
ax::mojom::blink::Role::kContentInfo,
ax::mojom::blink::Role::kContentInsertion,
ax::mojom::blink::Role::kDescriptionList,
ax::mojom::blink::Role::kDescriptionListDetail,
ax::mojom::blink::Role::kDescriptionListTerm,
ax::mojom::blink::Role::kDetails,
ax::mojom::blink::Role::kDialog,
ax::mojom::blink::Role::kDocAcknowledgments,
ax::mojom::blink::Role::kDocAfterword,
ax::mojom::blink::Role::kDocAppendix,
ax::mojom::blink::Role::kDocBibliography,
ax::mojom::blink::Role::kDocChapter,
ax::mojom::blink::Role::kDocConclusion,
ax::mojom::blink::Role::kDocCredits,
ax::mojom::blink::Role::kDocEndnotes,
ax::mojom::blink::Role::kDocEpilogue,
ax::mojom::blink::Role::kDocErrata,
ax::mojom::blink::Role::kDocForeword,
ax::mojom::blink::Role::kDocGlossary,
ax::mojom::blink::Role::kDocIntroduction,
ax::mojom::blink::Role::kDocPart,
ax::mojom::blink::Role::kDocPreface,
ax::mojom::blink::Role::kDocPrologue,
ax::mojom::blink::Role::kDocToc,
ax::mojom::blink::Role::kFigcaption,
ax::mojom::blink::Role::kFigure,
ax::mojom::blink::Role::kFooter,
ax::mojom::blink::Role::kForm,
ax::mojom::blink::Role::kHeader,
ax::mojom::blink::Role::kList,
ax::mojom::blink::Role::kListItem,
ax::mojom::blink::Role::kMain,
ax::mojom::blink::Role::kMark,
ax::mojom::blink::Role::kMath,
ax::mojom::blink::Role::kMathMLMath,
// Don't ignore MathML nodes by default, since MathML relies on child
// positions to determine semantics (e.g. numerator is the first
// child of a fraction).
ax::mojom::blink::Role::kMathMLFraction,
ax::mojom::blink::Role::kMathMLIdentifier,
ax::mojom::blink::Role::kMathMLMultiscripts,
ax::mojom::blink::Role::kMathMLNoneScript,
ax::mojom::blink::Role::kMathMLNumber,
ax::mojom::blink::Role::kMathMLOperator,
ax::mojom::blink::Role::kMathMLOver,
ax::mojom::blink::Role::kMathMLPrescriptDelimiter,
ax::mojom::blink::Role::kMathMLRoot,
ax::mojom::blink::Role::kMathMLRow,
ax::mojom::blink::Role::kMathMLSquareRoot,
ax::mojom::blink::Role::kMathMLStringLiteral,
ax::mojom::blink::Role::kMathMLSub,
ax::mojom::blink::Role::kMathMLSubSup,
ax::mojom::blink::Role::kMathMLSup,
ax::mojom::blink::Role::kMathMLTable,
ax::mojom::blink::Role::kMathMLTableCell,
ax::mojom::blink::Role::kMathMLTableRow,
ax::mojom::blink::Role::kMathMLText,
ax::mojom::blink::Role::kMathMLUnder,
ax::mojom::blink::Role::kMathMLUnderOver,
ax::mojom::blink::Role::kMeter,
ax::mojom::blink::Role::kNavigation,
ax::mojom::blink::Role::kPluginObject,
ax::mojom::blink::Role::kProgressIndicator,
ax::mojom::blink::Role::kRegion,
ax::mojom::blink::Role::kRuby,
ax::mojom::blink::Role::kSearch,
ax::mojom::blink::Role::kSection,
ax::mojom::blink::Role::kSplitter,
ax::mojom::blink::Role::kSubscript,
ax::mojom::blink::Role::kSuperscript,
ax::mojom::blink::Role::kTime,
};
if (always_included_computed_roles.find(RoleValue()) !=
always_included_computed_roles.end())
return kIncludeObject;
// Using the title or accessibility description (so we
// check if there's some kind of accessible name for the element)
// to decide an element's visibility is not as definitive as
// previous checks, so this should remain as one of the last.
if (HasAriaAttribute() || !GetAttribute(kTitleAttr).empty())
return kIncludeObject;
if (IsImage() && !IsA<SVGElement>(node)) {
String alt = GetAttribute(kAltAttr);
// A null alt attribute means the attribute is not present. We assume this
// is a mistake, and expose the image so that it can be repaired.
// In contrast, alt="" is treated as intentional markup to ignore the image.
if (!alt.empty() || alt.IsNull())
return kIncludeObject;
if (ignored_reasons)
ignored_reasons->push_back(IgnoredReason(kAXEmptyAlt));
return kIgnoreObject;
}
// Process potential in-page link targets
if (IsPotentialInPageLinkTarget(*element))
return kIncludeObject;
// <span> tags are inline tags and not meant to convey information if they
// have no other ARIA information on them. If we don't ignore them, they may
// emit signals expected to come from their parent.
if (IsA<HTMLSpanElement>(node)) {
if (ignored_reasons)
ignored_reasons->push_back(IgnoredReason(kAXUninteresting));
return kIgnoreObject;
}
// Ignore labels that are already used to name a control.
// See IsRedundantLabel() for more commentary.
if (HTMLLabelElement* label = DynamicTo<HTMLLabelElement>(node)) {
if (IsRedundantLabel(label)) {
if (ignored_reasons) {
ignored_reasons->push_back(
IgnoredReason(kAXLabelFor, AXObjectCache().Get(label->control())));
}
return kIgnoreObject;
}
return kIncludeObject;
}
return kDefaultBehavior;
}
// static
absl::optional<String> AXNodeObject::GetCSSAltText(const Node* node) {
// CSS alt text rules allow text to be assigned to ::before/::after content.
// For example, the following CSS assigns "bullet" text to bullet.png:
// .something::before {
// content: url(bullet.png) / "bullet";
// }
if (!node || !node->GetComputedStyle() ||
node->GetComputedStyle()->ContentBehavesAsNormal()) {
return absl::nullopt;
}
const ComputedStyle* style = node->GetComputedStyle();
if (node->IsPseudoElement()) {
for (const ContentData* content_data = style->GetContentData();
content_data; content_data = content_data->Next()) {
if (content_data->IsAltText())
return To<AltTextContentData>(content_data)->GetText();
}
return absl::nullopt;
}
// If the content property is used on a non-pseudo element, match the
// behaviour of LayoutObject::CreateObject and only honour the style if
// there is exactly one piece of content, which is an image.
const ContentData* content_data = style->GetContentData();
if (content_data && content_data->IsImage() && content_data->Next() &&
content_data->Next()->IsAltText()) {
return To<AltTextContentData>(content_data->Next())->GetText();
}
return absl::nullopt;
}
bool AXNodeObject::ComputeAccessibilityIsIgnored(
IgnoredReasons* ignored_reasons) const {
#if DCHECK_IS_ON()
// Double-check that an AXObject is never accessed before
// it's been initialized.
DCHECK(initialized_);
#endif
// If we don't have a node, then ignore the node object.
// TODO(vmpstr/aleventhal): Investigate how this can happen.
if (!GetNode()) {
NOTREACHED();
return true;
}
// All nodes must have an unignored parent within their tree under
// the root node of the web area, so force that node to always be unignored.
if (IsA<Document>(GetNode())) {
return false;
}
DCHECK_NE(role_, ax::mojom::blink::Role::kUnknown);
// Use AXLayoutObject::ComputeAccessibilityIsIgnored().
DCHECK(!GetLayoutObject());
if (DisplayLockUtilities::IsDisplayLockedPreventingPaint(GetNode())) {
if (IsAriaHidden() ||
DisplayLockUtilities::ShouldIgnoreNodeDueToDisplayLock(
*GetNode(), DisplayLockActivationReason::kAccessibility)) {
if (ignored_reasons)
ignored_reasons->push_back(IgnoredReason(kAXNotRendered));
return true;
}
return ShouldIncludeBasedOnSemantics(ignored_reasons) == kIgnoreObject;
}
auto* element = DynamicTo<Element>(GetNode());
if (!element)
element = GetNode()->parentElement();
if (!element)
return true;
if (element->IsInCanvasSubtree())
return ShouldIncludeBasedOnSemantics(ignored_reasons) == kIgnoreObject;
if (AOMPropertyOrARIAAttributeIsFalse(AOMBooleanProperty::kHidden))
return false;
if (element->HasDisplayContentsStyle()) {
if (ShouldIncludeBasedOnSemantics(ignored_reasons) == kIncludeObject)
return false;
}
if (ignored_reasons)
ignored_reasons->push_back(IgnoredReason(kAXNotRendered));
return true;
}
// There should only be one banner/contentInfo per page. If header/footer are
// being used within an article, aside, nave, section, blockquote, details,
// fieldset, figure, td, or main, then it should not be exposed as whole
// page's banner/contentInfo.
static HashSet<QualifiedName>& GetLandmarkRolesNotAllowed() {
DEFINE_STATIC_LOCAL(HashSet<QualifiedName>, landmark_roles_not_allowed, ());
if (landmark_roles_not_allowed.empty()) {
landmark_roles_not_allowed.insert(html_names::kArticleTag);
landmark_roles_not_allowed.insert(html_names::kAsideTag);
landmark_roles_not_allowed.insert(html_names::kNavTag);
landmark_roles_not_allowed.insert(html_names::kSectionTag);
landmark_roles_not_allowed.insert(html_names::kBlockquoteTag);
landmark_roles_not_allowed.insert(html_names::kDetailsTag);
landmark_roles_not_allowed.insert(html_names::kFieldsetTag);
landmark_roles_not_allowed.insert(html_names::kFigureTag);
landmark_roles_not_allowed.insert(html_names::kTdTag);
landmark_roles_not_allowed.insert(html_names::kMainTag);
}
return landmark_roles_not_allowed;
}
bool AXNodeObject::IsDescendantOfElementType(
HashSet<QualifiedName>& tag_names) const {
if (!GetNode())
return false;
for (Element* parent = GetNode()->parentElement(); parent;
parent = parent->parentElement()) {
if (tag_names.Contains(parent->TagQName()))
return true;
}
return false;
}
static bool IsNonEmptyNonHeaderCell(const Node* cell) {
return cell && cell->hasChildren() && cell->HasTagName(html_names::kTdTag);
}
static bool IsHeaderCell(const Node* cell) {
return cell && cell->HasTagName(html_names::kThTag);
}
static ax::mojom::blink::Role DecideRoleFromSiblings(Element* cell) {
// If this header is only cell in its row, it is a column header.
// It is also a column header if it has a header on either side of it.
// If instead it has a non-empty td element next to it, it is a row header.
const Node* next_cell = LayoutTreeBuilderTraversal::NextSibling(*cell);
const Node* previous_cell =
LayoutTreeBuilderTraversal::PreviousSibling(*cell);
if (!next_cell && !previous_cell)
return ax::mojom::blink::Role::kColumnHeader;
if (IsHeaderCell(next_cell) && IsHeaderCell(previous_cell))
return ax::mojom::blink::Role::kColumnHeader;
if (IsNonEmptyNonHeaderCell(next_cell) ||
IsNonEmptyNonHeaderCell(previous_cell))
return ax::mojom::blink::Role::kRowHeader;
const auto* row = DynamicTo<HTMLTableRowElement>(cell->parentNode());
if (!row)
return ax::mojom::blink::Role::kColumnHeader;
// If this row's first or last cell is a non-empty td, this is a row header.
// Do the same check for the second and second-to-last cells because tables
// often have an empty cell at the intersection of the row and column headers.
const Element* first_cell = ElementTraversal::FirstChild(*row);
DCHECK(first_cell);
const Element* last_cell = ElementTraversal::LastChild(*row);
DCHECK(last_cell);
if (IsNonEmptyNonHeaderCell(first_cell) || IsNonEmptyNonHeaderCell(last_cell))
return ax::mojom::blink::Role::kRowHeader;
if (IsNonEmptyNonHeaderCell(ElementTraversal::NextSibling(*first_cell)) ||
IsNonEmptyNonHeaderCell(ElementTraversal::PreviousSibling(*last_cell)))
return ax::mojom::blink::Role::kRowHeader;
// We have no evidence that this is not a column header.
return ax::mojom::blink::Role::kColumnHeader;
}
ax::mojom::blink::Role AXNodeObject::DetermineTableSectionRole() const {
if (!GetElement())
return ax::mojom::blink::Role::kGenericContainer;
AXObject* parent = GetDOMTableAXAncestor(GetNode(), AXObjectCache());
if (!parent || !parent->IsTableLikeRole())
return ax::mojom::blink::Role::kGenericContainer;
if (parent->RoleValue() == ax::mojom::blink::Role::kLayoutTable)
return ax::mojom::blink::Role::kGenericContainer;
return ax::mojom::blink::Role::kRowGroup;
}
ax::mojom::blink::Role AXNodeObject::DetermineTableRowRole() const {
AXObject* parent = GetDOMTableAXAncestor(GetNode(), AXObjectCache());
if (!parent || !parent->IsTableLikeRole())
return ax::mojom::blink::Role::kGenericContainer;
if (parent->RoleValue() == ax::mojom::blink::Role::kLayoutTable)
return ax::mojom::blink::Role::kLayoutTableRow;
return ax::mojom::blink::Role::kRow;
}
ax::mojom::blink::Role AXNodeObject::DetermineTableCellRole() const {
AXObject* parent = GetDOMTableAXAncestor(GetNode(), AXObjectCache());
if (!parent || !parent->IsTableRowLikeRole())
return ax::mojom::blink::Role::kGenericContainer;
// Ensure table container.
AXObject* grandparent =
GetDOMTableAXAncestor(parent->GetNode(), AXObjectCache());
if (!grandparent || !grandparent->IsTableLikeRole())
return ax::mojom::blink::Role::kGenericContainer;
if (parent->RoleValue() == ax::mojom::blink::Role::kLayoutTableRow)
return ax::mojom::blink::Role::kLayoutTableCell;
if (!GetElement() || !GetNode()->HasTagName(html_names::kThTag))
return ax::mojom::blink::Role::kCell;
const AtomicString& scope = GetAttribute(html_names::kScopeAttr);
if (EqualIgnoringASCIICase(scope, "row") ||
EqualIgnoringASCIICase(scope, "rowgroup"))
return ax::mojom::blink::Role::kRowHeader;
if (EqualIgnoringASCIICase(scope, "col") ||
EqualIgnoringASCIICase(scope, "colgroup"))
return ax::mojom::blink::Role::kColumnHeader;
return DecideRoleFromSiblings(GetElement());
}
ax::mojom::blink::Role AXNodeObject::RoleFromLayoutObjectOrNode() const {
return ax::mojom::blink::Role::kGenericContainer;
}
// Does not check ARIA role, but does check some ARIA properties, specifically
// @aria-haspopup/aria-pressed via ButtonType().
// TODO(accessibility) Ensure that if the native role needs to change, that the
// object is destroyed and a new one is created. Examples are changes to
// IsClickable(), DataList(), aria-pressed, the parent's tag, @role.
ax::mojom::blink::Role AXNodeObject::NativeRoleIgnoringAria() const {
if (!GetNode()) {
// Can be null in the case of pseudo content.
return RoleFromLayoutObjectOrNode();
}
if (GetNode()->IsPseudoElement() && GetCSSAltText(GetNode())) {
const ComputedStyle* style = GetNode()->GetComputedStyle();
ContentData* content_data = style->GetContentData();
// We just check the first item of the content list to determine the
// appropriate role, should only ever be image or text.
// TODO(accessibility) Is it possible to use CSS alt text on an HTML tag
// with strong semantics? If so, why are we overriding the role here?
// We only need to ensure the accessible name gets the CSS alt text.
// Note: by doing this, we are often hiding child pseudo element content
// because IsRelevantPseudoElementDescendant() returns false when an
// ancestor has CSS alt text.
if (content_data->IsImage())
return ax::mojom::blink::Role::kImage;
return ax::mojom::blink::Role::kStaticText;
}
if (GetNode()->IsTextNode())
return ax::mojom::blink::Role::kStaticText;
const HTMLSelectMenuElement* owner_select_menu =
HTMLSelectMenuElement::OwnerSelectMenu(GetNode());
if (owner_select_menu) {
HTMLSelectMenuElement::PartType part_type =
owner_select_menu->AssignedPartType(GetNode());
if (part_type == HTMLSelectMenuElement::PartType::kButton) {
return ax::mojom::blink::Role::kComboBoxMenuButton;
} else if (part_type == HTMLSelectMenuElement::PartType::kListBox) {
return ax::mojom::blink::Role::kListBox;
} else if (part_type == HTMLSelectMenuElement::PartType::kOption) {
return ax::mojom::blink::Role::kListBoxOption;
}
}
if (IsA<HTMLImageElement>(GetNode()))
return ax::mojom::blink::Role::kImage;
// <a> or <svg:a>.
if (IsA<HTMLAnchorElement>(GetNode()) || IsA<SVGAElement>(GetNode())) {
// Assume that an anchor element is a Role::kLink if it has an href or a
// click event listener.
if (GetNode()->IsLink() || IsClickable())
return ax::mojom::blink::Role::kLink;
// According to the SVG-AAM, a non-link 'a' element should be exposed like
// a 'g' if it does not descend from a 'text' element and like a 'tspan'
// if it does. This is consistent with the SVG spec which states that an
// 'a' within 'text' acts as an inline element, whereas it otherwise acts
// as a container element.
if (IsA<SVGAElement>(GetNode()) &&
!Traversal<SVGTextElement>::FirstAncestor(*GetNode())) {
return ax::mojom::blink::Role::kGroup;
}
return ax::mojom::blink::Role::kGenericContainer;
}
if (IsA<HTMLPortalElement>(*GetNode()))
return ax::mojom::blink::Role::kPortal;
if (IsA<HTMLButtonElement>(*GetNode()))
return ButtonRoleType();
if (IsA<HTMLDetailsElement>(*GetNode()))
return ax::mojom::blink::Role::kDetails;
if (IsA<HTMLSummaryElement>(*GetNode())) {
ContainerNode* parent = LayoutTreeBuilderTraversal::Parent(*GetNode());
if (ToHTMLSlotElementIfSupportsAssignmentOrNull(parent))
parent = LayoutTreeBuilderTraversal::Parent(*parent);
if (parent && IsA<HTMLDetailsElement>(parent))
return ax::mojom::blink::Role::kDisclosureTriangle;
return ax::mojom::blink::Role::kGenericContainer;
}
// Chrome exposes both table markup and table CSS as a table, letting
// the screen reader determine what to do for CSS tables.
if (IsA<HTMLTableElement>(*GetNode())) {
if (IsDataTable())
return ax::mojom::blink::Role::kTable;
else
return ax::mojom::blink::Role::kLayoutTable;
}
if (IsA<HTMLTableRowElement>(*GetNode()))
return DetermineTableRowRole();
if (IsA<HTMLTableCellElement>(*GetNode()))
return DetermineTableCellRole();
if (IsA<HTMLTableSectionElement>(*GetNode()))
return DetermineTableSectionRole();
if (const auto* input = DynamicTo<HTMLInputElement>(*GetNode())) {
const AtomicString& type = input->type();
if (input->DataList() && type != input_type_names::kColor)
return ax::mojom::blink::Role::kTextFieldWithComboBox;
if (type == input_type_names::kButton)
return ButtonRoleType();
if (type == input_type_names::kCheckbox)
return ax::mojom::blink::Role::kCheckBox;
if (type == input_type_names::kDate)
return ax::mojom::blink::Role::kDate;
if (type == input_type_names::kDatetime ||
type == input_type_names::kDatetimeLocal ||
type == input_type_names::kMonth || type == input_type_names::kWeek) {
return ax::mojom::blink::Role::kDateTime;
}
if (type == input_type_names::kFile)
return ax::mojom::blink::Role::kButton;
if (type == input_type_names::kRadio)
return ax::mojom::blink::Role::kRadioButton;
if (type == input_type_names::kNumber)
return ax::mojom::blink::Role::kSpinButton;
if (input->IsTextButton())
return ButtonRoleType();
if (type == input_type_names::kRange)
return ax::mojom::blink::Role::kSlider;
if (type == input_type_names::kSearch)
return ax::mojom::blink::Role::kSearchBox;
if (type == input_type_names::kColor)
return ax::mojom::blink::Role::kColorWell;
if (type == input_type_names::kTime)
return ax::mojom::blink::Role::kInputTime;
if (type == input_type_names::kButton || type == input_type_names::kImage ||
type == input_type_names::kReset || type == input_type_names::kSubmit) {
return ax::mojom::blink::Role::kButton;
}
return ax::mojom::blink::Role::kTextField;
}
if (auto* select_element = DynamicTo<HTMLSelectElement>(*GetNode())) {
if (select_element->IsMultiple())
return ax::mojom::blink::Role::kListBox;
else
return ax::mojom::blink::Role::kComboBoxSelect;
}
if (auto* option = DynamicTo<HTMLOptionElement>(*GetNode())) {
HTMLSelectElement* select_element = option->OwnerSelectElement();
if (!select_element || select_element->IsMultiple())
return ax::mojom::blink::Role::kListBoxOption;
else
return ax::mojom::blink::Role::kMenuListOption;
}
if (IsA<HTMLTextAreaElement>(*GetNode()))
return ax::mojom::blink::Role::kTextField;
if (HeadingLevel())
return ax::mojom::blink::Role::kHeading;
if (IsA<HTMLDivElement>(*GetNode()))
return RoleFromLayoutObjectOrNode();
if (IsA<HTMLMenuElement>(*GetNode()) || IsA<HTMLUListElement>(*GetNode()) ||
IsA<HTMLOListElement>(*GetNode())) {
// <menu> is a deprecated feature of HTML 5, but is included for semantic
// compatibility with HTML3, and may contain list items. Exposing it as an
// unordered list works better than the current HTML-AAM recommendaton of
// exposing as a role=menu, because if it's just used semantically, it won't
// be interactive. If used as a widget, the author must provide role=menu.
return ax::mojom::blink::Role::kList;
}
if (IsA<HTMLMeterElement>(*GetNode()))
return ax::mojom::blink::Role::kMeter;
if (IsA<HTMLProgressElement>(*GetNode()))
return ax::mojom::blink::Role::kProgressIndicator;
if (IsA<HTMLOutputElement>(*GetNode()))
return ax::mojom::blink::Role::kStatus;
if (IsA<HTMLParagraphElement>(*GetNode()))
return ax::mojom::blink::Role::kParagraph;
if (IsA<HTMLLabelElement>(*GetNode()))
return ax::mojom::blink::Role::kLabelText;
if (IsA<HTMLLegendElement>(*GetNode()))
return ax::mojom::blink::Role::kLegend;
if (IsA<HTMLRubyElement>(*GetNode()))
return ax::mojom::blink::Role::kRuby;
if (IsA<HTMLDListElement>(*GetNode()))
return ax::mojom::blink::Role::kDescriptionList;
if (IsA<HTMLAudioElement>(*GetNode()))
return ax::mojom::blink::Role::kAudio;
if (IsA<HTMLVideoElement>(*GetNode()))
return ax::mojom::blink::Role::kVideo;
if (GetNode()->HasTagName(html_names::kDdTag))
return ax::mojom::blink::Role::kDescriptionListDetail;
if (GetNode()->HasTagName(html_names::kDtTag))
return ax::mojom::blink::Role::kDescriptionListTerm;
// Mapping of MathML elements. See https://w3c.github.io/mathml-aam/
if (auto* element = DynamicTo<MathMLElement>(GetNode())) {
if (element->HasTagName(mathml_names::kMathTag)) {
return RuntimeEnabledFeatures::MathMLCoreEnabled()
? ax::mojom::blink::Role::kMathMLMath
: ax::mojom::blink::Role::kMath;
}
if (element->HasTagName(mathml_names::kMfracTag))
return ax::mojom::blink::Role::kMathMLFraction;
if (element->HasTagName(mathml_names::kMiTag))
return ax::mojom::blink::Role::kMathMLIdentifier;
if (element->HasTagName(mathml_names::kMmultiscriptsTag))
return ax::mojom::blink::Role::kMathMLMultiscripts;
if (element->HasTagName(mathml_names::kMnTag))
return ax::mojom::blink::Role::kMathMLNumber;
if (element->HasTagName(mathml_names::kMoTag))
return ax::mojom::blink::Role::kMathMLOperator;
if (element->HasTagName(mathml_names::kMoverTag))
return ax::mojom::blink::Role::kMathMLOver;
if (element->HasTagName(mathml_names::kMunderTag))
return ax::mojom::blink::Role::kMathMLUnder;
if (element->HasTagName(mathml_names::kMunderoverTag))
return ax::mojom::blink::Role::kMathMLUnderOver;
if (element->HasTagName(mathml_names::kMrootTag))
return ax::mojom::blink::Role::kMathMLRoot;
if (element->HasTagName(mathml_names::kMrowTag) ||
element->HasTagName(mathml_names::kAnnotationXmlTag) ||
element->HasTagName(mathml_names::kMactionTag) ||
element->HasTagName(mathml_names::kMerrorTag) ||
element->HasTagName(mathml_names::kMpaddedTag) ||
element->HasTagName(mathml_names::kMphantomTag) ||
element->HasTagName(mathml_names::kMstyleTag) ||
element->HasTagName(mathml_names::kSemanticsTag)) {
return ax::mojom::blink::Role::kMathMLRow;
}
if (element->HasTagName(mathml_names::kMprescriptsTag))
return ax::mojom::blink::Role::kMathMLPrescriptDelimiter;
if (element->HasTagName(mathml_names::kNoneTag))
return ax::mojom::blink::Role::kMathMLNoneScript;
if (element->HasTagName(mathml_names::kMsqrtTag))
return ax::mojom::blink::Role::kMathMLSquareRoot;
if (element->HasTagName(mathml_names::kMsTag))
return ax::mojom::blink::Role::kMathMLStringLiteral;
if (element->HasTagName(mathml_names::kMsubTag))
return ax::mojom::blink::Role::kMathMLSub;
if (element->HasTagName(mathml_names::kMsubsupTag))
return ax::mojom::blink::Role::kMathMLSubSup;
if (element->HasTagName(mathml_names::kMsupTag))
return ax::mojom::blink::Role::kMathMLSup;
if (element->HasTagName(mathml_names::kMtableTag))
return ax::mojom::blink::Role::kMathMLTable;
if (element->HasTagName(mathml_names::kMtdTag))
return ax::mojom::blink::Role::kMathMLTableCell;
if (element->HasTagName(mathml_names::kMtrTag))
return ax::mojom::blink::Role::kMathMLTableRow;
if (element->HasTagName(mathml_names::kMtextTag) ||
element->HasTagName(mathml_names::kAnnotationTag)) {
return ax::mojom::blink::Role::kMathMLText;
}
}
if (GetNode()->HasTagName(html_names::kRpTag) ||
GetNode()->HasTagName(html_names::kRtTag)) {
return ax::mojom::blink::Role::kRubyAnnotation;
}
if (IsA<HTMLFormElement>(*GetNode())) {
// Only treat <form> as role="form" when it has an accessible name, which
// can only occur when the name is assigned by the author via aria-label,
// aria-labelledby, or title. Otherwise, treat as a <section>.
return IsNameFromAuthorAttribute() ? ax::mojom::blink::Role::kForm
: ax::mojom::blink::Role::kSection;
}
if (GetNode()->HasTagName(html_names::kAbbrTag))
return ax::mojom::blink::Role::kAbbr;
if (GetNode()->HasTagName(html_names::kArticleTag))
return ax::mojom::blink::Role::kArticle;
if (GetNode()->HasTagName(html_names::kCodeTag))
return ax::mojom::blink::Role::kCode;
if (GetNode()->HasTagName(html_names::kEmTag))
return ax::mojom::blink::Role::kEmphasis;
if (GetNode()->HasTagName(html_names::kStrongTag))
return ax::mojom::blink::Role::kStrong;
if (GetNode()->HasTagName(html_names::kDelTag) ||
GetNode()->HasTagName(html_names::kSTag)) {
return ax::mojom::blink::Role::kContentDeletion;
}
if (GetNode()->HasTagName(html_names::kInsTag))
return ax::mojom::blink::Role::kContentInsertion;
if (GetNode()->HasTagName(html_names::kSubTag))
return ax::mojom::blink::Role::kSubscript;
if (GetNode()->HasTagName(html_names::kSupTag))
return ax::mojom::blink::Role::kSuperscript;
if (GetNode()->HasTagName(html_names::kMainTag))
return ax::mojom::blink::Role::kMain;
if (GetNode()->HasTagName(html_names::kMarkTag))
return ax::mojom::blink::Role::kMark;
if (GetNode()->HasTagName(html_names::kNavTag))
return ax::mojom::blink::Role::kNavigation;
if (GetNode()->HasTagName(html_names::kAsideTag))
return ax::mojom::blink::Role::kComplementary;
if (GetNode()->HasTagName(html_names::kPreTag))
return ax::mojom::blink::Role::kPre;
if (GetNode()->HasTagName(html_names::kSectionTag)) {
// Treat a named <section> as role="region".
return IsNameFromAuthorAttribute() ? ax::mojom::blink::Role::kRegion
: ax::mojom::blink::Role::kSection;
}
if (GetNode()->HasTagName(html_names::kAddressTag))
return ax::mojom::blink::Role::kGroup;
if (IsA<HTMLDialogElement>(*GetNode()))
return ax::mojom::blink::Role::kDialog;
// The HTML element.
if (IsA<HTMLHtmlElement>(GetNode()))
return RoleFromLayoutObjectOrNode();
// Treat <iframe>, <frame> and <fencedframe> the same.
if (IsFrame(GetNode()))
return ax::mojom::blink::Role::kIframe;
// There should only be one banner/contentInfo per page. If header/footer are
// being used within an article or section then it should not be exposed as
// whole page's banner/contentInfo but as a generic container role.
if (GetNode()->HasTagName(html_names::kHeaderTag)) {
if (IsDescendantOfElementType(GetLandmarkRolesNotAllowed()))
return ax::mojom::blink::Role::kHeaderAsNonLandmark;
return ax::mojom::blink::Role::kHeader;
}
if (GetNode()->HasTagName(html_names::kFooterTag)) {
if (IsDescendantOfElementType(GetLandmarkRolesNotAllowed()))
return ax::mojom::blink::Role::kFooterAsNonLandmark;
return ax::mojom::blink::Role::kFooter;
}
if (GetNode()->HasTagName(html_names::kBlockquoteTag))
return ax::mojom::blink::Role::kBlockquote;
if (IsA<HTMLTableCaptionElement>(GetNode()))
return ax::mojom::blink::Role::kCaption;
if (GetNode()->HasTagName(html_names::kFigcaptionTag))
return ax::mojom::blink::Role::kFigcaption;
if (GetNode()->HasTagName(html_names::kFigureTag))
return ax::mojom::blink::Role::kFigure;
if (IsA<HTMLTimeElement>(GetNode()))
return ax::mojom::blink::Role::kTime;
if (IsA<HTMLPlugInElement>(GetNode())) {
if (IsA<HTMLEmbedElement>(GetNode()))
return ax::mojom::blink::Role::kEmbeddedObject;
return ax::mojom::blink::Role::kPluginObject;
}
if (IsA<HTMLHRElement>(*GetNode()))
return ax::mojom::blink::Role::kSplitter;
if (IsFieldset())
return ax::mojom::blink::Role::kGroup;
return RoleFromLayoutObjectOrNode();
}
ax::mojom::blink::Role AXNodeObject::DetermineAccessibilityRole() {
#if DCHECK_IS_ON()
base::AutoReset<bool> reentrancy_protector(&is_computing_role_, true);
#endif
if (IsDetached()) {
NOTREACHED();
return ax::mojom::blink::Role::kUnknown;
}
native_role_ = NativeRoleIgnoringAria();
aria_role_ = DetermineAriaRoleAttribute();
return aria_role_ == ax::mojom::blink::Role::kUnknown ? native_role_
: aria_role_;
}
void AXNodeObject::AccessibilityChildrenFromAOMProperty(
AOMRelationListProperty property,
AXObject::AXObjectVector& children) const {
HeapVector<Member<Element>> elements;
if (!HasAOMPropertyOrARIAAttribute(property, elements))
return;
AXObjectCacheImpl& cache = AXObjectCache();
for (const auto& element : elements) {
if (AXObject* child = cache.GetOrCreate(element)) {
// Only aria-labelledby and aria-describedby can target hidden elements.
if (!child)
continue;
if (child->AccessibilityIsIgnored() &&
property != AOMRelationListProperty::kLabeledBy &&
property != AOMRelationListProperty::kDescribedBy) {
continue;
}
children.push_back(child);
}
}
}
static Element* SiblingWithAriaRole(String role, Node* node) {
Node* parent = LayoutTreeBuilderTraversal::Parent(*node);
if (!parent)
return nullptr;
for (Node* sibling = LayoutTreeBuilderTraversal::FirstChild(*parent); sibling;
sibling = LayoutTreeBuilderTraversal::NextSibling(*sibling)) {
auto* element = DynamicTo<Element>(sibling);
if (!element)
continue;
const AtomicString& sibling_aria_role =
AccessibleNode::GetPropertyOrARIAAttribute(element,
AOMStringProperty::kRole);
if (EqualIgnoringASCIICase(sibling_aria_role, role))
return element;
}
return nullptr;
}
Element* AXNodeObject::MenuItemElementForMenu() const {
if (AriaRoleAttribute() != ax::mojom::blink::Role::kMenu)
return nullptr;
return SiblingWithAriaRole("menuitem", GetNode());
}
void AXNodeObject::Init(AXObject* parent) {
#if DCHECK_IS_ON()
DCHECK(!initialized_);
initialized_ = true;
#endif
AXObject::Init(parent);
DCHECK(role_ == native_role_ || role_ == aria_role_)
<< "Role must be either the cached native role or cached aria role: "
<< "\n* Final role: " << role_ << "\n* Native role: " << native_role_
<< "\n* Aria role: " << aria_role_ << "\n* Node: " << GetNode();
DCHECK(node_ || (GetLayoutObject() &&
AXObjectCacheImpl::IsRelevantPseudoElementDescendant(
*GetLayoutObject())))
<< "Nodeless AXNodeObject can only exist inside a pseudo element: "
<< GetLayoutObject();
}
void AXNodeObject::Detach() {
#if defined(AX_FAIL_FAST_BUILD)
SANITIZER_CHECK(!is_adding_children_)
<< "Cannot detach |this| during AddChildren(): " << GetNode();
#endif
AXObject::Detach();
node_ = nullptr;
}
bool AXNodeObject::IsAXNodeObject() const {
return true;
}
bool AXNodeObject::IsControl() const {
Node* node = GetNode();
if (!node)
return false;
auto* element = DynamicTo<Element>(node);
return ((element && element->IsFormControlElement()) ||
AXObject::IsARIAControl(AriaRoleAttribute()));
}
bool AXNodeObject::IsAutofillAvailable() const {
// Autofill state is stored in AXObjectCache.
WebAXAutofillState state = AXObjectCache().GetAutofillState(AXObjectID());
return state == WebAXAutofillState::kAutofillAvailable;
}
bool AXNodeObject::IsDefault() const {
if (IsDetached())
return false;
// Checks for any kind of disabled, including aria-disabled.
if (Restriction() == kRestrictionDisabled ||
RoleValue() != ax::mojom::blink::Role::kButton) {
return false;
}
// Will only match :default pseudo class if it's the first default button in
// a form.
return GetElement()->MatchesDefaultPseudoClass();
}
bool AXNodeObject::IsFieldset() const {
return IsA<HTMLFieldSetElement>(GetNode());
}
bool AXNodeObject::IsHovered() const {
if (Node* node = GetNode())
return node->IsHovered();
return false;
}
bool AXNodeObject::IsImageButton() const {
return IsNativeImage() && IsButton();
}
bool AXNodeObject::IsInputImage() const {
auto* html_input_element = DynamicTo<HTMLInputElement>(GetNode());
if (html_input_element && RoleValue() == ax::mojom::blink::Role::kButton)
return html_input_element->type() == input_type_names::kImage;
return false;
}
bool AXNodeObject::IsLineBreakingObject() const {
// According to Blink Editing, objects without an associated DOM node such as
// pseudo-elements and list bullets, are never considered as paragraph
// boundaries.
if (IsDetached() || !GetNode())
return false;
// Presentational objects should not contribute any of their semantic meaning
// to the accessibility tree, including to its text representation.
if (IsPresentational())
return false;
// `IsEnclosingBlock` includes all elements with display block, inline block,
// table related, flex, grid, list item, flow-root, webkit-box, and display
// contents. This is the same function used by Blink > Editing for determining
// paragraph boundaries, i.e. line breaking objects.
if (IsEnclosingBlock(GetNode()))
return true;
// Not all <br> elements have an associated layout object. They might be
// "visibility: hidden" or within a display locked region. We need to check
// their DOM node first.
if (IsA<HTMLBRElement>(GetNode()))
return true;
const LayoutObject* layout_object = GetLayoutObject();
if (!layout_object)
return AXObject::IsLineBreakingObject();
if (layout_object->IsBR())
return true;
// LayoutText objects could include a paragraph break in their text. This can
// only occur if line breaks are preserved and a newline character is present
// in their collapsed text. Text collapsing removes all whitespace found in
// the HTML file, but a special style rule could be used to preserve line
// breaks.
//
// The best example is the <pre> element:
// <pre>Line 1
// Line 2</pre>
if (const LayoutText* layout_text = DynamicTo<LayoutText>(layout_object)) {
const ComputedStyle& style = layout_object->StyleRef();
if (layout_text->HasNonCollapsedText() && style.PreserveNewline() &&
layout_text->PlainText().find('\n') != WTF::kNotFound) {
return true;
}
}
// Rely on the ARIA role to figure out if this object is line breaking.
return AXObject::IsLineBreakingObject();
}
bool AXNodeObject::IsLoaded() const {
if (!GetDocument())
return false;
if (!GetDocument()->IsLoadCompleted())
return false;
// Check for a navigation API single-page app navigation in progress.
if (auto* window = GetDocument()->domWindow()) {
if (window->navigation()->HasNonDroppedOngoingNavigation())
return false;
}
return true;
}
bool AXNodeObject::IsMultiSelectable() const {
switch (RoleValue()) {
case ax::mojom::blink::Role::kGrid:
case ax::mojom::blink::Role::kTreeGrid:
case ax::mojom::blink::Role::kTree:
case ax::mojom::blink::Role::kListBox:
case ax::mojom::blink::Role::kTabList: {
bool multiselectable = false;
if (HasAOMPropertyOrARIAAttribute(AOMBooleanProperty::kMultiselectable,
multiselectable)) {
return multiselectable;
}
break;
}
default:
break;
}
auto* html_select_element = DynamicTo<HTMLSelectElement>(GetNode());
return html_select_element && html_select_element->IsMultiple();
}
bool AXNodeObject::IsNativeImage() const {
Node* node = GetNode();
if (!node)
return false;
if (IsA<HTMLImageElement>(*node) || IsA<HTMLPlugInElement>(*node))
return true;
if (const auto* input = DynamicTo<HTMLInputElement>(*node))
return input->type() == input_type_names::kImage;
return false;
}
bool AXNodeObject::IsOffScreen() const {
if (IsDetached())
return false;
DCHECK(GetNode());
// Differs fromAXLayoutObject::IsOffScreen() in that there is no bounding box.
// However, we know that if it is display-locked that is an indicator that it
// is currently offscreen, and will likely be onscreen once scrolled to.
return DisplayLockUtilities::IsDisplayLockedPreventingPaint(GetNode());
}
bool AXNodeObject::IsProgressIndicator() const {
return RoleValue() == ax::mojom::blink::Role::kProgressIndicator;
}
bool AXNodeObject::IsSlider() const {
return RoleValue() == ax::mojom::blink::Role::kSlider;
}
bool AXNodeObject::IsSpinButton() const {
return RoleValue() == ax::mojom::blink::Role::kSpinButton;
}
bool AXNodeObject::IsNativeSlider() const {
if (const auto* input = DynamicTo<HTMLInputElement>(GetNode()))
return input->type() == input_type_names::kRange;
return false;
}
bool AXNodeObject::IsNativeSpinButton() const {
if (const auto* input = DynamicTo<HTMLInputElement>(GetNode()))
return input->type() == input_type_names::kNumber;
return false;
}
bool AXNodeObject::IsChildTreeOwner() const {
return ui::IsChildTreeOwner(native_role_);
}
bool AXNodeObject::IsClickable() const {
// Determine whether the element is clickable either because there is a
// mouse button handler or because it has a native element where click
// performs an action. Disabled nodes are never considered clickable.
// Note: we can't call |node->WillRespondToMouseClickEvents()| because that
// triggers a style recalc and can delete this.
// Treat mouse button listeners on the |window|, |document| as if they're on
// the |documentElement|.
if (GetNode() == GetDocument()->documentElement()) {
return GetNode()->HasAnyEventListeners(
event_util::MouseButtonEventTypes()) ||
GetDocument()->HasAnyEventListeners(
event_util::MouseButtonEventTypes()) ||
GetDocument()->domWindow()->HasAnyEventListeners(
event_util::MouseButtonEventTypes());
}
// Look for mouse listeners only on element nodes, e.g. skip text nodes.
const Element* element = GetElement();
if (!element)
return false;
if (IsDisabled())
return false;
if (element->HasAnyEventListeners(event_util::MouseButtonEventTypes()))
return true;
if (HasContentEditableAttributeSet())
return true;
// Certain user-agent shadow DOM elements are expected to be clickable but
// they do not have event listeners attached or a clickable native role. We
// whitelist them here.
if (element->ShadowPseudoId() ==
shadow_element_names::kPseudoCalendarPickerIndicator) {
return true;
}
// Only use native roles. For ARIA elements, require a click listener.
return ui::IsClickable(native_role_);
}
bool AXNodeObject::IsFocused() const {
if (!GetDocument())
return false;
// A web area is represented by the Document node in the DOM tree, which isn't
// focusable. Check instead if the frame's selection controller is focused.
if (IsWebArea() &&
GetDocument()->GetFrame()->Selection().FrameIsFocusedAndActive()) {
return true;
}
Element* focused_element = GetDocument()->FocusedElement();
return focused_element && focused_element == GetElement();
}
// aria-grabbed is deprecated in WAI-ARIA 1.1.
AccessibilityGrabbedState AXNodeObject::IsGrabbed() const {
if (!SupportsARIADragging())
return kGrabbedStateUndefined;
const AtomicString& grabbed = GetAttribute(html_names::kAriaGrabbedAttr);
return EqualIgnoringASCIICase(grabbed, "true") ? kGrabbedStateTrue
: kGrabbedStateFalse;
}
AccessibilitySelectedState AXNodeObject::IsSelected() const {
if (!GetNode() || !GetLayoutObject() || !IsSubWidget())
return kSelectedStateUndefined;
// The aria-selected attribute overrides automatic behaviors.
bool is_selected;
if (HasAOMPropertyOrARIAAttribute(AOMBooleanProperty::kSelected, is_selected))
return is_selected ? kSelectedStateTrue : kSelectedStateFalse;
// The selection should only follow the focus when the aria-selected attribute
// is marked as required or implied for this element in the ARIA specs.
// If this object can't follow the focus, then we can't say that it's selected
// nor that it's not.
if (!ui::IsSelectRequiredOrImplicit(RoleValue()))
return kSelectedStateUndefined;
// Selection follows focus, but ONLY in single selection containers, and only
// if aria-selected was not present to override.
return IsSelectedFromFocus() ? kSelectedStateTrue : kSelectedStateFalse;
}
bool AXNodeObject::IsSelectedFromFocusSupported() const {
// The selection should only follow the focus when the aria-selected attribute
// is marked as required or implied for this element in the ARIA specs.
// If this object can't follow the focus, then we can't say that it's selected
// nor that it's not.
// TODO(crbug.com/1143483): Consider allowing more roles.
if (!ui::IsSelectRequiredOrImplicit(RoleValue()))
return false;
// https://www.w3.org/TR/wai-aria-1.1/#aria-selected
// Any explicit assignment of aria-selected takes precedence over the implicit
// selection based on focus.
bool is_selected;
if (HasAOMPropertyOrARIAAttribute(AOMBooleanProperty::kSelected, is_selected))
return false;
// Selection follows focus only when in a single selection container.
const AXObject* container = ContainerWidget();
if (!container || container->IsMultiSelectable())
return false;
// TODO(crbug.com/1143451): https://www.w3.org/TR/wai-aria-1.1/#aria-selected
// If any DOM element in the widget is explicitly marked as selected, the user
// agent MUST NOT convey implicit selection for the widget.
return true;
}
// In single selection containers, selection follows focus unless aria_selected
// is set to false. This is only valid for a subset of elements.
bool AXNodeObject::IsSelectedFromFocus() const {
if (!IsSelectedFromFocusSupported())
return false;
// A tab item can also be selected if it is associated to a focused tabpanel
// via the aria-labelledby attribute.
if (IsTabItem() && IsTabItemSelected())
return true;
// If this object is not accessibility focused, then it is not selected from
// focus.
AXObject* focused_object = AXObjectCache().FocusedObject();
if (focused_object != this &&
(!focused_object || focused_object->ActiveDescendant() != this))
return false;
return true;
}
bool AXNodeObject::IsTabItemSelected() const {
if (!IsTabItem() || !GetLayoutObject())
return false;
Node* node = GetNode();
if (!node || !node->IsElementNode())
return false;
// The ARIA spec says a tab item can also be selected if it is aria-labeled by
// a tabpanel that has keyboard focus inside of it, or if a tabpanel in its
// aria-controls list has KB focus inside of it.
AXObject* focused_element = AXObjectCache().FocusedObject();
if (!focused_element)
return false;
HeapVector<Member<Element>> elements;
if (!HasAOMPropertyOrARIAAttribute(AOMRelationListProperty::kControls,
elements))
return false;
for (const auto& element : elements) {
AXObject* tab_panel = AXObjectCache().GetOrCreate(element);
// A tab item should only control tab panels.
if (!tab_panel ||
tab_panel->RoleValue() != ax::mojom::blink::Role::kTabPanel) {
continue;
}
AXObject* check_focus_element = focused_element;
// Check if the focused element is a descendant of the element controlled by
// the tab item.
while (check_focus_element) {
if (tab_panel == check_focus_element)
return true;
check_focus_element = check_focus_element->ParentObject();
}
}
return false;
}
AXRestriction AXNodeObject::Restriction() const {
Element* elem = GetElement();
if (!elem)
return kRestrictionNone;
// An <optgroup> is not exposed directly in the AX tree.
if (IsA<HTMLOptGroupElement>(elem))
return kRestrictionNone;
// According to ARIA, all elements of the base markup can be disabled.
// According to CORE-AAM, any focusable descendant of aria-disabled
// ancestor is also disabled.
if (IsDisabled())
return kRestrictionDisabled;
// Check aria-readonly if supported by current role.
bool is_read_only;
if (SupportsARIAReadOnly() &&
HasAOMPropertyOrARIAAttribute(AOMBooleanProperty::kReadOnly,
is_read_only)) {
// ARIA overrides other readonly state markup.
return is_read_only ? kRestrictionReadOnly : kRestrictionNone;
}
// Only editable fields can be marked @readonly (unlike @aria-readonly).
auto* text_area_element = DynamicTo<HTMLTextAreaElement>(*elem);
if (text_area_element && text_area_element->IsReadOnly())
return kRestrictionReadOnly;
if (const auto* input = DynamicTo<HTMLInputElement>(*elem)) {
if (input->IsTextField() && input->IsReadOnly())
return kRestrictionReadOnly;
}
// If a grid cell does not have it's own ARIA input restriction,
// fall back on parent grid's readonly state.
// See ARIA specification regarding grid/treegrid and readonly.
if (IsTableCellLikeRole()) {
AXObject* row = ParentObjectUnignored();
if (row && row->IsTableRowLikeRole()) {
AXObject* table = row->ParentObjectUnignored();
if (table && table->IsTableLikeRole() &&
(table->RoleValue() == ax::mojom::blink::Role::kGrid ||
table->RoleValue() == ax::mojom::blink::Role::kTreeGrid)) {
if (table->Restriction() == kRestrictionReadOnly)
return kRestrictionReadOnly;
}
}
}
// This is a node that is not readonly and not disabled.
return kRestrictionNone;
}
AccessibilityExpanded AXNodeObject::IsExpanded() const {
if (!SupportsARIAExpanded())
return kExpandedUndefined;
auto* element = GetElement();
if (!element)
return kExpandedUndefined;
if (HTMLSelectMenuElement* select_menu =
HTMLSelectMenuElement::OwnerSelectMenu(element)) {
if (select_menu->ButtonPart() == element) {
return select_menu->open() ? kExpandedExpanded : kExpandedCollapsed;
}
}
if (RoleValue() == ax::mojom::blink::Role::kComboBoxSelect &&
IsA<HTMLSelectElement>(*element)) {
return To<HTMLSelectElement>(element)->PopupIsVisible()
? kExpandedExpanded
: kExpandedCollapsed;
}
// For form controls that act as triggering elements for popovers of type
// kAuto, then set aria-expanded=false when the popover is hidden, and
// aria-expanded=true when it is showing.
if (auto* form_control = DynamicTo<HTMLFormControlElement>(element)) {
if (auto popover = form_control->popoverTargetElement().popover;
popover && popover->PopoverType() == PopoverValueType::kAuto) {
return popover->popoverOpen() ? kExpandedExpanded : kExpandedCollapsed;
}
}
if (IsA<HTMLSummaryElement>(*element)) {
if (element->parentNode() &&
IsA<HTMLDetailsElement>(element->parentNode())) {
return To<Element>(element->parentNode())
->FastHasAttribute(html_names::kOpenAttr)
? kExpandedExpanded
: kExpandedCollapsed;
}
}
bool expanded = false;
if (HasAOMPropertyOrARIAAttribute(AOMBooleanProperty::kExpanded, expanded)) {
return expanded ? kExpandedExpanded : kExpandedCollapsed;
}
return kExpandedUndefined;
}
bool AXNodeObject::IsRequired() const {
auto* form_control = DynamicTo<HTMLFormControlElement>(GetNode());
if (form_control && form_control->IsRequired())
return true;
if (AOMPropertyOrARIAAttributeIsTrue(AOMBooleanProperty::kRequired))
return true;
return false;
}
bool AXNodeObject::CanvasHasFallbackContent() const {
if (IsDetached())
return false;
Node* node = GetNode();
return IsA<HTMLCanvasElement>(node) && node->hasChildren();
}
int AXNodeObject::HeadingLevel() const {
// headings can be in block flow and non-block flow
Node* node = GetNode();
if (!node)
return 0;
if (RoleValue() == ax::mojom::blink::Role::kHeading) {
uint32_t level;
if (HasAOMPropertyOrARIAAttribute(AOMUIntProperty::kLevel, level)) {
if (level >= 1 && level <= 9)
return level;
}
}
auto* element = DynamicTo<HTMLElement>(node);
if (!element)
return 0;
if (element->HasTagName(html_names::kH1Tag))
return 1;
if (element->HasTagName(html_names::kH2Tag))
return 2;
if (element->HasTagName(html_names::kH3Tag))
return 3;
if (element->HasTagName(html_names::kH4Tag))
return 4;
if (element->HasTagName(html_names::kH5Tag))
return 5;
if (element->HasTagName(html_names::kH6Tag))
return 6;
if (RoleValue() == ax::mojom::blink::Role::kHeading)
return kDefaultHeadingLevel;
return 0;
}
unsigned AXNodeObject::HierarchicalLevel() const {
Element* element = GetElement();
if (!element)
return 0;
uint32_t level;
if (HasAOMPropertyOrARIAAttribute(AOMUIntProperty::kLevel, level)) {
if (level >= 1)
return level;
}
// Helper lambda for calculating hierarchical levels by counting ancestor
// nodes that match a target role.
auto accumulateLevel = [&](int initial_level,
ax::mojom::blink::Role target_role) {
int level = initial_level;
for (AXObject* parent = ParentObject(); parent;
parent = parent->ParentObject()) {
if (parent->RoleValue() == target_role)
level++;
}
return level;
};
switch (RoleValue()) {
case ax::mojom::blink::Role::kComment:
// Comment: level is based on counting comment ancestors until the root.
return accumulateLevel(1, ax::mojom::blink::Role::kComment);
case ax::mojom::blink::Role::kListItem:
level = accumulateLevel(0, ax::mojom::blink::Role::kList);
// When level count is 0 due to this list item not having an ancestor of
// Role::kList, not nested in list groups, this list item has a level
// of 1.
return level == 0 ? 1 : level;
case ax::mojom::blink::Role::kTabList:
return accumulateLevel(1, ax::mojom::blink::Role::kTabList);
case ax::mojom::blink::Role::kTreeItem: {
// Hierarchy leveling starts at 1, to match the aria-level spec.
// We measure tree hierarchy by the number of groups that the item is
// within.
level = 1;
for (AXObject* parent = ParentObject(); parent;
parent = parent->ParentObject()) {
ax::mojom::blink::Role parent_role = parent->RoleValue();
if (parent_role == ax::mojom::blink::Role::kGroup)
level++;
else if (parent_role == ax::mojom::blink::Role::kTree)
break;
}
return level;
}
default:
return 0;
}
}
String AXNodeObject::AutoComplete() const {
// Check cache for auto complete state.
if (AXObjectCache().GetAutofillState(AXObjectID()) ==
WebAXAutofillState::kAutocompleteAvailable)
return "list";
if (IsAtomicTextField() || IsARIATextField()) {
const AtomicString& aria_auto_complete =
GetAOMPropertyOrARIAAttribute(AOMStringProperty::kAutocomplete)
.LowerASCII();
// Illegal values must be passed through, according to CORE-AAM.
if (!aria_auto_complete.IsNull())
return aria_auto_complete == "none" ? String() : aria_auto_complete;
}
if (auto* input = DynamicTo<HTMLInputElement>(GetNode())) {
if (input->DataList())
return "list";
}
return String();
}
// TODO(nektar): Consider removing this method in favor of
// AXInlineTextBox::GetDocumentMarkers, or add document markers to the tree data
// instead of nodes objects.
void AXNodeObject::SerializeMarkerAttributes(ui::AXNodeData* node_data) const {
if (!GetNode() || !GetDocument() || !GetDocument()->View())
return;
auto* text_node = DynamicTo<Text>(GetNode());
if (!text_node)
return;
std::vector<int32_t> marker_types;
std::vector<int32_t> highlight_types;
std::vector<int32_t> marker_starts;
std::vector<int32_t> marker_ends;
// First use ARIA markers for spelling/grammar if available.
absl::optional<DocumentMarker::MarkerType> aria_marker_type =
GetAriaSpellingOrGrammarMarker();
if (aria_marker_type) {
AXRange range = AXRange::RangeOfContents(*this);
marker_types.push_back(ToAXMarkerType(aria_marker_type.value()));
marker_starts.push_back(range.Start().TextOffset());
marker_ends.push_back(range.End().TextOffset());
}
DocumentMarkerController& marker_controller = GetDocument()->Markers();
const DocumentMarker::MarkerTypes markers_used_by_accessibility(
DocumentMarker::kSpelling | DocumentMarker::kGrammar |
DocumentMarker::kTextMatch | DocumentMarker::kActiveSuggestion |
DocumentMarker::kSuggestion | DocumentMarker::kTextFragment |
DocumentMarker::kCustomHighlight);
const DocumentMarkerVector markers =
marker_controller.MarkersFor(*text_node, markers_used_by_accessibility);
for (const DocumentMarker* marker : markers) {
if (aria_marker_type == marker->GetType())
continue;
const Position start_position(*GetNode(), marker->StartOffset());
const Position end_position(*GetNode(), marker->EndOffset());
if (!start_position.IsValidFor(*GetDocument()) ||
!end_position.IsValidFor(*GetDocument())) {
continue;
}
int32_t highlight_type =
static_cast<int32_t>(ax::mojom::blink::HighlightType::kNone);
if (marker->GetType() == DocumentMarker::kCustomHighlight) {
const auto& highlight_marker = To<CustomHighlightMarker>(*marker);
highlight_type =
ToAXHighlightType(highlight_marker.GetHighlight()->type());
}
marker_types.push_back(ToAXMarkerType(marker->GetType()));
highlight_types.push_back(static_cast<int32_t>(highlight_type));
auto start_pos =
AXPosition::FromPosition(start_position, TextAffinity::kDownstream,
AXPositionAdjustmentBehavior::kMoveLeft);
auto end_pos =
AXPosition::FromPosition(end_position, TextAffinity::kDownstream,
AXPositionAdjustmentBehavior::kMoveRight);
marker_starts.push_back(start_pos.TextOffset());
marker_ends.push_back(end_pos.TextOffset());
}
if (marker_types.empty())
return;
node_data->AddIntListAttribute(
ax::mojom::blink::IntListAttribute::kMarkerTypes, marker_types);
node_data->AddIntListAttribute(
ax::mojom::blink::IntListAttribute::kHighlightTypes, highlight_types);
node_data->AddIntListAttribute(
ax::mojom::blink::IntListAttribute::kMarkerStarts, marker_starts);
node_data->AddIntListAttribute(
ax::mojom::blink::IntListAttribute::kMarkerEnds, marker_ends);
}
AXObject* AXNodeObject::InPageLinkTarget() const {
if (!IsLink() || !GetDocument())
return AXObject::InPageLinkTarget();
const Element* anchor = AnchorElement();
if (!anchor)
return AXObject::InPageLinkTarget();
KURL link_url = anchor->HrefURL();
if (!link_url.IsValid())
return AXObject::InPageLinkTarget();
KURL document_url = GetDocument()->Url();
if (!document_url.IsValid() ||
!EqualIgnoringFragmentIdentifier(document_url, link_url)) {
return AXObject::InPageLinkTarget();
}
String fragment = link_url.FragmentIdentifier();
TreeScope& tree_scope = anchor->GetTreeScope();
Node* target = tree_scope.FindAnchor(fragment);
AXObject* ax_target = AXObjectCache().GetOrCreate(target);
if (!ax_target || !IsPotentialInPageLinkTarget(*ax_target->GetNode()))
return AXObject::InPageLinkTarget();
#if DCHECK_IS_ON()
// Link targets always have an element, unless it is the document itself,
// e.g. via <a href="#">.
DCHECK(ax_target->IsWebArea() || ax_target->GetElement())
<< "The link target is expected to be a document or an element: "
<< ax_target->ToString(true, true) << "\n* URL fragment = " << fragment;
#endif
// Usually won't be ignored, but could be e.g. if aria-hidden.
if (ax_target->AccessibilityIsIgnored())
return nullptr;
return ax_target;
}
AccessibilityOrientation AXNodeObject::Orientation() const {
const AtomicString& aria_orientation =
GetAOMPropertyOrARIAAttribute(AOMStringProperty::kOrientation);
AccessibilityOrientation orientation = kAccessibilityOrientationUndefined;
if (EqualIgnoringASCIICase(aria_orientation, "horizontal"))
orientation = kAccessibilityOrientationHorizontal;
else if (EqualIgnoringASCIICase(aria_orientation, "vertical"))
orientation = kAccessibilityOrientationVertical;
switch (RoleValue()) {
case ax::mojom::blink::Role::kListBox:
case ax::mojom::blink::Role::kMenu:
case ax::mojom::blink::Role::kScrollBar:
case ax::mojom::blink::Role::kTree:
if (orientation == kAccessibilityOrientationUndefined)
orientation = kAccessibilityOrientationVertical;
return orientation;
case ax::mojom::blink::Role::kMenuBar:
case ax::mojom::blink::Role::kSlider:
case ax::mojom::blink::Role::kSplitter:
case ax::mojom::blink::Role::kTabList:
case ax::mojom::blink::Role::kToolbar:
if (orientation == kAccessibilityOrientationUndefined)
orientation = kAccessibilityOrientationHorizontal;
return orientation;
case ax::mojom::blink::Role::kComboBoxGrouping:
case ax::mojom::blink::Role::kComboBoxMenuButton:
case ax::mojom::blink::Role::kRadioGroup:
case ax::mojom::blink::Role::kTreeGrid:
return orientation;
default:
return AXObject::Orientation();
}
}
// According to the standard, the figcaption should only be the first or
// last child: https://html.spec.whatwg.org/#the-figcaption-element
AXObject* AXNodeObject::GetChildFigcaption() const {
AXObject* child = FirstChildIncludingIgnored();
if (!child)
return nullptr;
if (child->RoleValue() == ax::mojom::blink::Role::kFigcaption)
return child;
child = LastChildIncludingIgnored();
if (child->RoleValue() == ax::mojom::blink::Role::kFigcaption)
return child;
return nullptr;
}
AXObject::AXObjectVector AXNodeObject::RadioButtonsInGroup() const {
AXObjectVector radio_buttons;
if (!node_ || RoleValue() != ax::mojom::blink::Role::kRadioButton)
return radio_buttons;
if (auto* node_radio_button = DynamicTo<HTMLInputElement>(node_.Get())) {
HeapVector<Member<HTMLInputElement>> html_radio_buttons =
FindAllRadioButtonsWithSameName(node_radio_button);
for (HTMLInputElement* radio_button : html_radio_buttons) {
AXObject* ax_radio_button = AXObjectCache().GetOrCreate(radio_button);
if (ax_radio_button)
radio_buttons.push_back(ax_radio_button);
}
return radio_buttons;
}
// If the immediate parent is a radio group, return all its children that are
// radio buttons.
AXObject* parent = ParentObjectUnignored();
if (parent && parent->RoleValue() == ax::mojom::blink::Role::kRadioGroup) {
for (AXObject* child : parent->UnignoredChildren()) {
DCHECK(child);
if (child->RoleValue() == ax::mojom::blink::Role::kRadioButton &&
child->AccessibilityIsIncludedInTree()) {
radio_buttons.push_back(child);
}
}
}
return radio_buttons;
}
// static
HeapVector<Member<HTMLInputElement>>
AXNodeObject::FindAllRadioButtonsWithSameName(HTMLInputElement* radio_button) {
HeapVector<Member<HTMLInputElement>> all_radio_buttons;
if (!radio_button || radio_button->type() != input_type_names::kRadio)
return all_radio_buttons;
constexpr bool kTraverseForward = true;
constexpr bool kTraverseBackward = false;
HTMLInputElement* first_radio_button = radio_button;
do {
radio_button = RadioInputType::NextRadioButtonInGroup(first_radio_button,
kTraverseBackward);
if (radio_button)
first_radio_button = radio_button;
} while (radio_button);
HTMLInputElement* next_radio_button = first_radio_button;
do {
all_radio_buttons.push_back(next_radio_button);
next_radio_button = RadioInputType::NextRadioButtonInGroup(
next_radio_button, kTraverseForward);
} while (next_radio_button);
return all_radio_buttons;
}
ax::mojom::blink::WritingDirection AXNodeObject::GetTextDirection() const {
if (!GetLayoutObject())
return AXObject::GetTextDirection();
const ComputedStyle* style = GetLayoutObject()->Style();
if (!style)
return AXObject::GetTextDirection();
if (style->IsHorizontalWritingMode()) {
switch (style->Direction()) {
case TextDirection::kLtr:
return ax::mojom::blink::WritingDirection::kLtr;
case TextDirection::kRtl:
return ax::mojom::blink::WritingDirection::kRtl;
}
} else {
switch (style->Direction()) {
case TextDirection::kLtr:
return ax::mojom::blink::WritingDirection::kTtb;
case TextDirection::kRtl:
return ax::mojom::blink::WritingDirection::kBtt;
}
}
return AXNodeObject::GetTextDirection();
}
ax::mojom::blink::TextPosition AXNodeObject::GetTextPositionFromRole() const {
// Check for role="subscript" or role="superscript" on the element, or if
// static text, on the containing element.
AXObject* obj = nullptr;
if (RoleValue() == ax::mojom::blink::Role::kStaticText)
obj = ParentObject();
else
obj = const_cast<AXNodeObject*>(this);
if (obj->RoleValue() == ax::mojom::blink::Role::kSubscript)
return ax::mojom::blink::TextPosition::kSubscript;
if (obj->RoleValue() == ax::mojom::blink::Role::kSuperscript)
return ax::mojom::blink::TextPosition::kSuperscript;
if (!GetLayoutObject() || !GetLayoutObject()->IsInline())
return ax::mojom::blink::TextPosition::kNone;
// We could have an inline element which descends from a subscript or
// superscript.
if (auto* parent = obj->ParentObjectUnignored())
return static_cast<AXNodeObject*>(parent)->GetTextPositionFromRole();
return ax::mojom::blink::TextPosition::kNone;
}
ax::mojom::blink::TextPosition AXNodeObject::GetTextPosition() const {
if (GetNode()) {
const auto& text_position = GetTextPositionFromRole();
if (text_position != ax::mojom::blink::TextPosition::kNone)
return text_position;
}
if (!GetLayoutObject())
return AXObject::GetTextPosition();
const ComputedStyle* style = GetLayoutObject()->Style();
if (!style)
return AXObject::GetTextPosition();
switch (style->VerticalAlign()) {
case EVerticalAlign::kBaseline:
case EVerticalAlign::kMiddle:
case EVerticalAlign::kTextTop:
case EVerticalAlign::kTextBottom:
case EVerticalAlign::kTop:
case EVerticalAlign::kBottom:
case EVerticalAlign::kBaselineMiddle:
case EVerticalAlign::kLength:
return AXObject::GetTextPosition();
case EVerticalAlign::kSub:
return ax::mojom::blink::TextPosition::kSubscript;
case EVerticalAlign::kSuper:
return ax::mojom::blink::TextPosition::kSuperscript;
}
}
void AXNodeObject::GetTextStyleAndTextDecorationStyle(
int32_t* text_style,
ax::mojom::blink::TextDecorationStyle* text_overline_style,
ax::mojom::blink::TextDecorationStyle* text_strikethrough_style,
ax::mojom::blink::TextDecorationStyle* text_underline_style) const {
if (!GetLayoutObject()) {
AXObject::GetTextStyleAndTextDecorationStyle(
text_style, text_overline_style, text_strikethrough_style,
text_underline_style);
return;
}
const ComputedStyle* style = GetLayoutObject()->Style();
if (!style) {
AXObject::GetTextStyleAndTextDecorationStyle(
text_style, text_overline_style, text_strikethrough_style,
text_underline_style);
return;
}
*text_style = 0;
*text_overline_style = ax::mojom::blink::TextDecorationStyle::kNone;
*text_strikethrough_style = ax::mojom::blink::TextDecorationStyle::kNone;
*text_underline_style = ax::mojom::blink::TextDecorationStyle::kNone;
if (style->GetFontWeight() == BoldWeightValue())
*text_style |= TextStyleFlag(ax::mojom::blink::TextStyle::kBold);
if (style->GetFontDescription().Style() == ItalicSlopeValue())
*text_style |= TextStyleFlag(ax::mojom::blink::TextStyle::kItalic);
for (const auto& decoration : style->AppliedTextDecorations()) {
if (EnumHasFlags(decoration.Lines(), TextDecorationLine::kOverline)) {
*text_style |= TextStyleFlag(ax::mojom::blink::TextStyle::kOverline);
*text_overline_style =
TextDecorationStyleToAXTextDecorationStyle(decoration.Style());
}
if (EnumHasFlags(decoration.Lines(), TextDecorationLine::kLineThrough)) {
*text_style |= TextStyleFlag(ax::mojom::blink::TextStyle::kLineThrough);
*text_strikethrough_style =
TextDecorationStyleToAXTextDecorationStyle(decoration.Style());
}
if (EnumHasFlags(decoration.Lines(), TextDecorationLine::kUnderline)) {
*text_style |= TextStyleFlag(ax::mojom::blink::TextStyle::kUnderline);
*text_underline_style =
TextDecorationStyleToAXTextDecorationStyle(decoration.Style());
}
}
}
ax::mojom::blink::TextAlign AXNodeObject::GetTextAlign() const {
// Object attributes are not applied to text objects.
if (IsTextObject() || !GetLayoutObject())
return ax::mojom::blink::TextAlign::kNone;
const ComputedStyle* style = GetLayoutObject()->Style();
if (!style)
return ax::mojom::blink::TextAlign::kNone;
switch (style->GetTextAlign()) {
case ETextAlign::kLeft:
case ETextAlign::kWebkitLeft:
case ETextAlign::kStart:
return ax::mojom::blink::TextAlign::kLeft;
case ETextAlign::kRight:
case ETextAlign::kWebkitRight:
case ETextAlign::kEnd:
return ax::mojom::blink::TextAlign::kRight;
case ETextAlign::kCenter:
case ETextAlign::kWebkitCenter:
return ax::mojom::blink::TextAlign::kCenter;
case ETextAlign::kJustify:
return ax::mojom::blink::TextAlign::kJustify;
}
}
float AXNodeObject::GetTextIndent() const {
// Text-indent applies to lines or blocks, but not text.
if (IsTextObject() || !GetLayoutObject())
return 0.0f;
const ComputedStyle* style = GetLayoutObject()->Style();
if (!style)
return 0.0f;
const blink::LayoutBlock* layout_block =
GetLayoutObject()->InclusiveContainingBlock();
if (!layout_block)
return 0.0f;
float text_indent = layout_block->TextIndentOffset().ToFloat();
return text_indent / kCssPixelsPerMillimeter;
}
String AXNodeObject::ImageDataUrl(const gfx::Size& max_size) const {
Node* node = GetNode();
if (!node)
return String();
ImageBitmapOptions* options = ImageBitmapOptions::Create();
ImageBitmap* image_bitmap = nullptr;
if (auto* image = DynamicTo<HTMLImageElement>(node)) {
image_bitmap =
MakeGarbageCollected<ImageBitmap>(image, absl::nullopt, options);
} else if (auto* canvas = DynamicTo<HTMLCanvasElement>(node)) {
image_bitmap =
MakeGarbageCollected<ImageBitmap>(canvas, absl::nullopt, options);
} else if (auto* video = DynamicTo<HTMLVideoElement>(node)) {
image_bitmap =
MakeGarbageCollected<ImageBitmap>(video, absl::nullopt, options);
}
if (!image_bitmap)
return String();
scoped_refptr<StaticBitmapImage> bitmap_image = image_bitmap->BitmapImage();
if (!bitmap_image)
return String();
sk_sp<SkImage> image =
bitmap_image->PaintImageForCurrentFrame().GetSwSkImage();
if (!image || image->width() <= 0 || image->height() <= 0)
return String();
// Determine the width and height of the output image, using a proportional
// scale factor such that it's no larger than |maxSize|, if |maxSize| is not
// empty. It only resizes the image to be smaller (if necessary), not
// larger.
float x_scale =
max_size.width() ? max_size.width() * 1.0 / image->width() : 1.0;
float y_scale =
max_size.height() ? max_size.height() * 1.0 / image->height() : 1.0;
float scale = std::min(x_scale, y_scale);
if (scale >= 1.0)
scale = 1.0;
int width = std::round(image->width() * scale);
int height = std::round(image->height() * scale);
// Draw the image into a bitmap in native format.
SkBitmap bitmap;
SkPixmap unscaled_pixmap;
if (scale == 1.0 && image->peekPixels(&unscaled_pixmap)) {
bitmap.installPixels(unscaled_pixmap);
} else {
bitmap.allocPixels(
SkImageInfo::MakeN32(width, height, kPremul_SkAlphaType));
SkCanvas canvas(bitmap, SkSurfaceProps{});
canvas.clear(SK_ColorTRANSPARENT);
canvas.drawImageRect(image, SkRect::MakeIWH(width, height),
SkSamplingOptions());
}
// Copy the bits into a buffer in RGBA_8888 unpremultiplied format
// for encoding.
SkImageInfo info = SkImageInfo::Make(width, height, kRGBA_8888_SkColorType,
kUnpremul_SkAlphaType);
size_t row_bytes = info.minRowBytes();
Vector<char> pixel_storage(
base::checked_cast<wtf_size_t>(info.computeByteSize(row_bytes)));
SkPixmap pixmap(info, pixel_storage.data(), row_bytes);
if (!SkImage::MakeFromBitmap(bitmap)->readPixels(pixmap, 0, 0))
return String();
// Encode as a PNG and return as a data url.
std::unique_ptr<ImageDataBuffer> buffer = ImageDataBuffer::Create(pixmap);
if (!buffer)
return String();
return buffer->ToDataURL(kMimeTypePng, 1.0);
}
const AtomicString& AXNodeObject::AccessKey() const {
auto* element = DynamicTo<Element>(GetNode());
if (!element)
return g_null_atom;
return element->FastGetAttribute(html_names::kAccesskeyAttr);
}
RGBA32 AXNodeObject::ColorValue() const {
auto* input = DynamicTo<HTMLInputElement>(GetNode());
if (!input || !IsColorWell())
return AXObject::ColorValue();
const AtomicString& type = input->getAttribute(kTypeAttr);
if (!EqualIgnoringASCIICase(type, "color"))
return AXObject::ColorValue();
// HTMLInputElement::Value always returns a string parseable by Color.
Color color;
bool success = color.SetFromString(input->Value());
DCHECK(success);
return color.Rgb();
}
RGBA32 AXNodeObject::BackgroundColor() const {
LayoutObject* layout_object = GetLayoutObject();
if (!layout_object)
return Color::kTransparent.Rgb();
if (IsA<Document>(GetNode())) {
LocalFrameView* view = DocumentFrameView();
if (view)
return view->BaseBackgroundColor().Rgb();
else
return Color::kWhite.Rgb();
}
const ComputedStyle* style = layout_object->Style();
if (!style || !style->HasBackground())
return Color::kTransparent.Rgb();
return style->VisitedDependentColor(GetCSSPropertyBackgroundColor()).Rgb();
}
RGBA32 AXNodeObject::GetColor() const {
if (!GetLayoutObject() || IsColorWell())
return AXObject::GetColor();
const ComputedStyle* style = GetLayoutObject()->Style();
if (!style)
return AXObject::GetColor();
Color color = style->VisitedDependentColor(GetCSSPropertyColor());
return color.Rgb();
}
const AtomicString& AXNodeObject::ComputedFontFamily() const {
if (!GetLayoutObject())
return AXObject::ComputedFontFamily();
const ComputedStyle* style = GetLayoutObject()->Style();
if (!style)
return AXObject::ComputedFontFamily();
const FontDescription& font_description = style->GetFontDescription();
return font_description.FirstFamily().FamilyName();
}
String AXNodeObject::FontFamilyForSerialization() const {
if (!GetLayoutObject())
return AXObject::FontFamilyForSerialization();
const ComputedStyle* style = GetLayoutObject()->Style();
if (!style)
return AXObject::FontFamilyForSerialization();
const SimpleFontData* primary_font = style->GetFont().PrimaryFont();
if (!primary_font)
return AXObject::FontFamilyForSerialization();
// Note that repeatedly querying this can be expensive - only use this when
// serializing. For other comparisons consider using `ComputedFontFamily`.
return primary_font->PlatformData().FontFamilyName();
}
// Blink font size is provided in pixels.
// Platform APIs may convert to another unit (IA2 converts to points).
float AXNodeObject::FontSize() const {
if (!GetLayoutObject())
return AXObject::FontSize();
const ComputedStyle* style = GetLayoutObject()->Style();
if (!style)
return AXObject::FontSize();
// Font size should not be affected by scale transform or page zoom, because
// users of authoring tools may want to check that their text is formatted
// with the font size they expected.
// E.g. use SpecifiedFontSize() instead of ComputedFontSize(), and do not
// multiply by style->Scale()->Transform()->Y();
return style->SpecifiedFontSize();
}
float AXNodeObject::FontWeight() const {
if (!GetLayoutObject())
return AXObject::FontWeight();
const ComputedStyle* style = GetLayoutObject()->Style();
if (!style)
return AXObject::FontWeight();
return style->GetFontWeight();
}
ax::mojom::blink::AriaCurrentState AXNodeObject::GetAriaCurrentState() const {
const AtomicString& attribute_value =
GetAOMPropertyOrARIAAttribute(AOMStringProperty::kCurrent);
if (attribute_value.IsNull())
return ax::mojom::blink::AriaCurrentState::kNone;
if (attribute_value.empty() ||
EqualIgnoringASCIICase(attribute_value, "false"))
return ax::mojom::blink::AriaCurrentState::kFalse;
if (EqualIgnoringASCIICase(attribute_value, "true"))
return ax::mojom::blink::AriaCurrentState::kTrue;
if (EqualIgnoringASCIICase(attribute_value, "page"))
return ax::mojom::blink::AriaCurrentState::kPage;
if (EqualIgnoringASCIICase(attribute_value, "step"))
return ax::mojom::blink::AriaCurrentState::kStep;
if (EqualIgnoringASCIICase(attribute_value, "location"))
return ax::mojom::blink::AriaCurrentState::kLocation;
if (EqualIgnoringASCIICase(attribute_value, "date"))
return ax::mojom::blink::AriaCurrentState::kDate;
if (EqualIgnoringASCIICase(attribute_value, "time"))
return ax::mojom::blink::AriaCurrentState::kTime;
// An unknown value should return true.
if (!attribute_value.empty())
return ax::mojom::blink::AriaCurrentState::kTrue;
return AXObject::GetAriaCurrentState();
}
ax::mojom::blink::InvalidState AXNodeObject::GetInvalidState() const {
// First check aria-invalid.
const AtomicString& attribute_value =
GetAOMPropertyOrARIAAttribute(AOMStringProperty::kInvalid);
// aria-invalid="false".
if (EqualIgnoringASCIICase(attribute_value, "false"))
return ax::mojom::blink::InvalidState::kFalse;
// In most cases, aria-invalid="spelling"| "grammar" are used on inline text
// elements, and are exposed via Markers() as if they are native errors.
// Therefore, they are exposed as InvalidState:kNone here in order to avoid
// exposing the state twice, and to prevent superfluous "invalid"
// announcements in some screen readers.
// On text fields, they are simply exposed as if aria-invalid="true".
if (EqualIgnoringASCIICase(attribute_value, "spelling") ||
EqualIgnoringASCIICase(attribute_value, "grammar")) {
return RoleValue() == ax::mojom::blink::Role::kTextField
? ax::mojom::blink::InvalidState::kTrue
: ax::mojom::blink::InvalidState::kNone;
}
// Any other non-empty value is considered true.
if (!attribute_value.empty()) {
return ax::mojom::blink::InvalidState::kTrue;
}
// Next check for native the invalid state.
if (GetElement()) {
ListedElement* form_control = ListedElement::From(*GetElement());
if (form_control) {
return IsValidFormControl(form_control)
? ax::mojom::blink::InvalidState::kFalse
: ax::mojom::blink::InvalidState::kTrue;
}
}
return AXObject::GetInvalidState();
}
bool AXNodeObject::IsValidFormControl(ListedElement* form_control) const {
// If the control is marked with a custom error, the form control is invalid.
if (form_control->CustomError())
return false;
// If the form control checks for validity, and has passed the checks,
// then consider it valid.
if (form_control->IsNotCandidateOrValid())
return true;
// The control is invalid, as far as CSS is concerned.
// However, we ignore a failed check inside of an empty required text field,
// in order to avoid redundant verbalizations (screen reader already says
// required).
if (IsAtomicTextField() && IsRequired() && GetValueForControl().length() == 0)
return true;
return false;
}
int AXNodeObject::PosInSet() const {
if (RoleValue() == ax::mojom::blink::Role::kComboBoxSelect && GetNode() &&
!AXObjectCache().UseAXMenuList()) {
if (auto* select_element = DynamicTo<HTMLSelectElement>(*GetNode()))
return 1 + select_element->selectedIndex();
}
if (SupportsARIASetSizeAndPosInSet()) {
uint32_t pos_in_set;
if (HasAOMPropertyOrARIAAttribute(AOMUIntProperty::kPosInSet, pos_in_set))
return pos_in_set;
}
return 0;
}
int AXNodeObject::SetSize() const {
if (RoleValue() == ax::mojom::blink::Role::kComboBoxSelect && GetNode() &&
!AXObjectCache().UseAXMenuList()) {
if (auto* select_element = DynamicTo<HTMLSelectElement>(*GetNode()))
return static_cast<int>(select_element->length());
}
if (SupportsARIASetSizeAndPosInSet()) {
int32_t set_size;
if (HasAOMPropertyOrARIAAttribute(AOMIntProperty::kSetSize, set_size))
return set_size;
}
return 0;
}
bool AXNodeObject::ValueForRange(float* out_value) const {
float value_now;
if (HasAOMPropertyOrARIAAttribute(AOMFloatProperty::kValueNow, value_now)) {
*out_value = value_now;
return true;
}
if (IsNativeSlider() || IsNativeSpinButton()) {
*out_value = To<HTMLInputElement>(*GetNode()).valueAsNumber();
return std::isfinite(*out_value);
}
if (auto* meter = DynamicTo<HTMLMeterElement>(GetNode())) {
*out_value = meter->value();
return true;
}
// In ARIA 1.1, default values for aria-valuenow were changed as below.
// - scrollbar, slider : half way between aria-valuemin and aria-valuemax
// - separator : 50
// - spinbutton : 0
switch (AriaRoleAttribute()) {
case ax::mojom::blink::Role::kScrollBar:
case ax::mojom::blink::Role::kSlider: {
float min_value, max_value;
if (MinValueForRange(&min_value) && MaxValueForRange(&max_value)) {
*out_value = (min_value + max_value) / 2.0f;
return true;
}
[[fallthrough]];
}
case ax::mojom::blink::Role::kSplitter: {
*out_value = 50.0f;
return true;
}
case ax::mojom::blink::Role::kSpinButton: {
*out_value = 0.0f;
return true;
}
default:
break;
}
return false;
}
bool AXNodeObject::MaxValueForRange(float* out_value) const {
float value_max;
if (HasAOMPropertyOrARIAAttribute(AOMFloatProperty::kValueMax, value_max)) {
*out_value = value_max;
return true;
}
if (IsNativeSlider() || IsNativeSpinButton()) {
*out_value = static_cast<float>(To<HTMLInputElement>(*GetNode()).Maximum());
return std::isfinite(*out_value);
}
if (auto* meter = DynamicTo<HTMLMeterElement>(GetNode())) {
*out_value = meter->max();
return true;
}
// In ARIA 1.1, default value of scrollbar, separator and slider
// for aria-valuemax were changed to 100. This change was made for
// progressbar in ARIA 1.2.
switch (AriaRoleAttribute()) {
case ax::mojom::blink::Role::kProgressIndicator:
case ax::mojom::blink::Role::kScrollBar:
case ax::mojom::blink::Role::kSplitter:
case ax::mojom::blink::Role::kSlider: {
*out_value = 100.0f;
return true;
}
default:
break;
}
return false;
}
bool AXNodeObject::MinValueForRange(float* out_value) const {
float value_min;
if (HasAOMPropertyOrARIAAttribute(AOMFloatProperty::kValueMin, value_min)) {
*out_value = value_min;
return true;
}
if (IsNativeSlider() || IsNativeSpinButton()) {
*out_value = static_cast<float>(To<HTMLInputElement>(*GetNode()).Minimum());
return std::isfinite(*out_value);
}
if (auto* meter = DynamicTo<HTMLMeterElement>(GetNode())) {
*out_value = meter->min();
return true;
}
// In ARIA 1.1, default value of scrollbar, separator and slider
// for aria-valuemin were changed to 0. This change was made for
// progressbar in ARIA 1.2.
switch (AriaRoleAttribute()) {
case ax::mojom::blink::Role::kProgressIndicator:
case ax::mojom::blink::Role::kScrollBar:
case ax::mojom::blink::Role::kSplitter:
case ax::mojom::blink::Role::kSlider: {
*out_value = 0.0f;
return true;
}
default:
break;
}
return false;
}
bool AXNodeObject::StepValueForRange(float* out_value) const {
if (IsNativeSlider() || IsNativeSpinButton()) {
// AT may want to know whether a step value was explicitly provided or not,
// so return false if there was not one set.
if (!To<HTMLInputElement>(*GetNode())
.FastGetAttribute(html_names::kStepAttr)) {
*out_value = 0.0f;
return false;
}
auto step =
To<HTMLInputElement>(*GetNode()).CreateStepRange(kRejectAny).Step();
*out_value = step.ToString().ToFloat();
return std::isfinite(*out_value);
}
switch (AriaRoleAttribute()) {
case ax::mojom::blink::Role::kScrollBar:
case ax::mojom::blink::Role::kSplitter:
case ax::mojom::blink::Role::kSlider: {
*out_value = 0.0f;
return true;
}
default:
break;
}
return false;
}
KURL AXNodeObject::Url() const {
if (IsLink()) // <area>, <link>, <html:a> or <svg:a>
return GetElement()->HrefURL();
if (IsWebArea()) {
DCHECK(GetDocument());
return GetDocument()->Url();
}
auto* html_image_element = DynamicTo<HTMLImageElement>(GetNode());
if (IsImage() && html_image_element) {
// Using ImageSourceURL handles both src and srcset.
String source_url = html_image_element->ImageSourceURL();
String stripped_image_source_url =
StripLeadingAndTrailingHTMLSpaces(source_url);
if (!stripped_image_source_url.empty())
return GetDocument()->CompleteURL(stripped_image_source_url);
}
if (IsInputImage())
return To<HTMLInputElement>(GetNode())->Src();
return KURL();
}
AXObject* AXNodeObject::ChooserPopup() const {
// When color & date chooser popups are visible, they can be found in the tree
// as a group child of the <input> control itself.
switch (native_role_) {
case ax::mojom::blink::Role::kColorWell:
case ax::mojom::blink::Role::kComboBoxSelect:
case ax::mojom::blink::Role::kDate:
case ax::mojom::blink::Role::kDateTime:
case ax::mojom::blink::Role::kInputTime:
case ax::mojom::blink::Role::kTextFieldWithComboBox: {
for (const auto& child : ChildrenIncludingIgnored()) {
if (IsA<Document>(child->GetNode())) {
return child;
}
}
return nullptr;
}
default:
#if DCHECK_IS_ON()
for (const auto& child : ChildrenIncludingIgnored()) {
DCHECK(!IsA<Document>(child->GetNode()))
<< "Chooser popup exists for " << native_role_;
}
#endif
return nullptr;
}
}
String AXNodeObject::GetValueForControl() const {
// TODO(crbug.com/1165853): Remove this method completely and compute value on
// the browser side.
Node* node = GetNode();
if (!node)
return String();
if (const auto* select_element = DynamicTo<HTMLSelectElement>(*node)) {
if (!select_element->UsesMenuList())
return String();
// In most cases, we want to return what's actually displayed inside the
// <select> element on screen, unless there is an ARIA label overriding it.
int selected_index = select_element->SelectedListIndex();
const HeapVector<Member<HTMLElement>>& list_items =
select_element->GetListItems();
if (selected_index >= 0 &&
static_cast<wtf_size_t>(selected_index) < list_items.size()) {
const AtomicString& overridden_description =
list_items[selected_index]->FastGetAttribute(
html_names::kAriaLabelAttr);
if (!overridden_description.IsNull())
return overridden_description;
}
// We don't retrieve the element's value attribute on purpose. The value
// attribute might be sanitized and might be different from what is actually
// displayed inside the <select> element on screen.
return select_element->InnerElement().GetInnerTextWithoutUpdate();
}
if (IsAtomicTextField()) {
// This is an "<input type=text>" or a "<textarea>": We should not simply
// return the "value" attribute because it might be sanitized in some input
// control types, e.g. email fields. If we do that, then "selectionStart"
// and "selectionEnd" indices will not match with the text in the sanitized
// value.
String inner_text = ToTextControl(*node).InnerEditorValue();
if (!IsPasswordFieldAndShouldHideValue())
return inner_text;
if (!GetLayoutObject())
return inner_text;
const ComputedStyle* style = GetLayoutObject()->Style();
if (!style)
return inner_text;
unsigned int unmasked_text_length = inner_text.length();
if (!unmasked_text_length)
return String();
UChar mask_character = 0;
switch (style->TextSecurity()) {
case ETextSecurity::kNone:
break; // Fall through to the non-password branch.
case ETextSecurity::kDisc:
mask_character = kBulletCharacter;
break;
case ETextSecurity::kCircle:
mask_character = kWhiteBulletCharacter;
break;
case ETextSecurity::kSquare:
mask_character = kBlackSquareCharacter;
break;
}
if (!mask_character)
return inner_text;
StringBuilder masked_text;
masked_text.ReserveCapacity(unmasked_text_length);
for (unsigned int i = 0; i < unmasked_text_length; ++i)
masked_text.Append(mask_character);
return masked_text.ToString();
}
if (IsRangeValueSupported()) {
String aria_value_text =
GetAOMPropertyOrARIAAttribute(AOMStringProperty::kValueText)
.GetString();
return aria_value_text;
}
if (GetLayoutObject() && GetLayoutObject()->IsFileUploadControl())
return To<LayoutFileUploadControl>(GetLayoutObject())->FileTextValue();
// Handle other HTML input elements that aren't text controls, like date and
// time controls, by returning their value converted to text, with the
// exception of checkboxes and radio buttons (which would return "on"), and
// buttons which will return their name.
// https://html.spec.whatwg.org/C/#dom-input-value
if (const auto* input = DynamicTo<HTMLInputElement>(node)) {
if (input->type() == input_type_names::kFile)
return input->FileStatusText();
if (input->type() != input_type_names::kButton &&
input->type() != input_type_names::kCheckbox &&
input->type() != input_type_names::kImage &&
input->type() != input_type_names::kRadio &&
input->type() != input_type_names::kReset &&
input->type() != input_type_names::kSubmit) {
return input->Value();
}
}
if (RoleValue() == ax::mojom::blink::Role::kComboBoxMenuButton) {
// An HTML <selectmenu> gets its value from the selected option.
if (auto* select_menu = HTMLSelectMenuElement::OwnerSelectMenu(node)) {
DCHECK(RuntimeEnabledFeatures::HTMLSelectMenuElementEnabled());
if (HTMLOptionElement* selected = select_menu->selectedOption()) {
// TODO(accessibility) Because these <option> elements can contain
// anything, we need to create an AXObject for the selected option, and
// use ax_selected_option->ComputedName(). However, for now, the
// AXObject is not created because AXObject::IsRelevantSlotElement()
// returns false for the invisible slot parent. Also, strangely,
// selected->innerText()/GetInnerTextWithoutUpdate() are returning "".
// See the following content_browsertest:
// All/DumpAccessibilityTreeTest.AccessibilitySelectMenu/blink.
// TODO(crbug.com/1401767): DCHECK fails with synchronous serialization.
DCHECK(selected->firstChild())
<< "There is a selected option but it has no DOM children.";
return selected->textContent();
}
return String();
}
// An ARIA combobox can get value from inner contents.
AXObjectSet visited;
return TextFromDescendants(visited, nullptr, false);
}
return String();
}
String AXNodeObject::SlowGetValueForControlIncludingContentEditable() const {
if (IsNonAtomicTextField()) {
Element* element = GetElement();
return element ? element->GetInnerTextWithoutUpdate() : String();
}
return GetValueForControl();
}
ax::mojom::blink::Role AXNodeObject::AriaRoleAttribute() const {
return aria_role_;
}
void AXNodeObject::AriaDescribedbyElements(AXObjectVector& describedby) const {
AccessibilityChildrenFromAOMProperty(AOMRelationListProperty::kDescribedBy,
describedby);
}
void AXNodeObject::AriaOwnsElements(AXObjectVector& owns) const {
AccessibilityChildrenFromAOMProperty(AOMRelationListProperty::kOwns, owns);
}
// TODO(accessibility): Aria-dropeffect and aria-grabbed are deprecated in
// aria 1.1 Also those properties are expected to be replaced by a new feature
// in a future version of WAI-ARIA. After that we will re-implement them
// following new spec.
bool AXNodeObject::SupportsARIADragging() const {
const AtomicString& grabbed = GetAttribute(html_names::kAriaGrabbedAttr);
return EqualIgnoringASCIICase(grabbed, "true") ||
EqualIgnoringASCIICase(grabbed, "false");
}
ax::mojom::blink::Dropeffect AXNodeObject::ParseDropeffect(
String& dropeffect) const {
if (EqualIgnoringASCIICase(dropeffect, "copy"))
return ax::mojom::blink::Dropeffect::kCopy;
if (EqualIgnoringASCIICase(dropeffect, "execute"))
return ax::mojom::blink::Dropeffect::kExecute;
if (EqualIgnoringASCIICase(dropeffect, "link"))
return ax::mojom::blink::Dropeffect::kLink;
if (EqualIgnoringASCIICase(dropeffect, "move"))
return ax::mojom::blink::Dropeffect::kMove;
if (EqualIgnoringASCIICase(dropeffect, "popup"))
return ax::mojom::blink::Dropeffect::kPopup;
return ax::mojom::blink::Dropeffect::kNone;
}
void AXNodeObject::Dropeffects(
Vector<ax::mojom::blink::Dropeffect>& dropeffects) const {
if (!HasAttribute(html_names::kAriaDropeffectAttr))
return;
Vector<String> str_dropeffects;
TokenVectorFromAttribute(GetElement(), str_dropeffects,
html_names::kAriaDropeffectAttr);
if (str_dropeffects.empty()) {
dropeffects.push_back(ax::mojom::blink::Dropeffect::kNone);
return;
}
for (auto&& str : str_dropeffects) {
dropeffects.push_back(ParseDropeffect(str));
}
}
ax::mojom::blink::HasPopup AXNodeObject::HasPopup() const {
const AtomicString& has_popup =
GetAOMPropertyOrARIAAttribute(AOMStringProperty::kHasPopUp);
if (!has_popup.IsNull()) {
if (EqualIgnoringASCIICase(has_popup, "false"))
return ax::mojom::blink::HasPopup::kFalse;
if (EqualIgnoringASCIICase(has_popup, "listbox"))
return ax::mojom::blink::HasPopup::kListbox;
if (EqualIgnoringASCIICase(has_popup, "tree"))
return ax::mojom::blink::HasPopup::kTree;
if (EqualIgnoringASCIICase(has_popup, "grid"))
return ax::mojom::blink::HasPopup::kGrid;
if (EqualIgnoringASCIICase(has_popup, "dialog"))
return ax::mojom::blink::HasPopup::kDialog;
// To provide backward compatibility with ARIA 1.0 content,
// user agents MUST treat an aria-haspopup value of true
// as equivalent to a value of menu.
if (EqualIgnoringASCIICase(has_popup, "true") ||
EqualIgnoringASCIICase(has_popup, "menu"))
return ax::mojom::blink::HasPopup::kMenu;
}
// ARIA 1.1 default value of haspopup for combobox is "listbox".
if (RoleValue() == ax::mojom::blink::Role::kComboBoxMenuButton ||
RoleValue() == ax::mojom::blink::Role::kTextFieldWithComboBox) {
return ax::mojom::blink::HasPopup::kListbox;
}
if (AXObjectCache().GetAutofillState(AXObjectID()) !=
WebAXAutofillState::kNoSuggestions) {
return ax::mojom::blink::HasPopup::kMenu;
}
return AXObject::HasPopup();
}
bool AXNodeObject::IsEditableRoot() const {
const Node* node = GetNode();
if (IsDetached() || !node)
return false;
#if DCHECK_IS_ON() // Required in order to get Lifecycle().ToString()
DCHECK(GetDocument());
DCHECK_GE(GetDocument()->Lifecycle().GetState(),
DocumentLifecycle::kStyleClean)
<< "Unclean document style at lifecycle state "
<< GetDocument()->Lifecycle().ToString();
#endif // DCHECK_IS_ON()
// Catches the case where the 'contenteditable' attribute is set on an atomic
// text field (which shouldn't have any effect).
if (IsAtomicTextField())
return false;
// The DOM inside native text fields is an implementation detail that should
// not be exposed to platform accessibility APIs.
if (EnclosingTextControl(node))
return false;
if (IsRootEditableElement(*node))
return true;
// Catches the case where a contenteditable is inside another contenteditable.
// This is especially important when the two nested contenteditables have
// different attributes, e.g. "true" vs. "plaintext-only".
if (HasContentEditableAttributeSet())
return true;
return false;
}
bool AXNodeObject::HasContentEditableAttributeSet() const {
if (IsDetached() || !GetNode())
return false;
const auto* html_element = DynamicTo<HTMLElement>(GetNode());
if (!html_element)
return false;
ContentEditableType normalized_value =
html_element->contentEditableNormalized();
return normalized_value == ContentEditableType::kContentEditable ||
normalized_value == ContentEditableType::kPlaintextOnly;
}
// Returns the nearest block-level LayoutBlockFlow ancestor
static LayoutBlockFlow* NonInlineBlockFlow(LayoutObject* object) {
LayoutObject* current = object;
while (current) {
auto* block_flow = DynamicTo<LayoutBlockFlow>(current);
if (block_flow && !block_flow->IsAtomicInlineLevel())
return block_flow;
current = current->Parent();
}
NOTREACHED();
return nullptr;
}
// Returns true if |r1| and |r2| are both non-null, both inline, and are
// contained within the same non-inline LayoutBlockFlow.
static bool IsInSameNonInlineBlockFlow(LayoutObject* r1, LayoutObject* r2) {
if (!r1 || !r2)
return false;
if (!r1->IsInline() || !r2->IsInline())
return false;
LayoutBlockFlow* b1 = NonInlineBlockFlow(r1);
LayoutBlockFlow* b2 = NonInlineBlockFlow(r2);
return b1 && b2 && b1 == b2;
}
//
// Modify or take an action on an object.
//
bool AXNodeObject::OnNativeSetValueAction(const String& string) {
if (!GetNode() || !GetNode()->IsElementNode())
return false;
const LayoutObject* layout_object = GetLayoutObject();
if (!layout_object || !layout_object->IsBoxModelObject())
return false;
auto* html_input_element = DynamicTo<HTMLInputElement>(*GetNode());
if (html_input_element && layout_object->IsTextFieldIncludingNG()) {
html_input_element->SetValue(
string, TextFieldEventBehavior::kDispatchInputAndChangeEvent);
return true;
}
if (auto* text_area_element = DynamicTo<HTMLTextAreaElement>(*GetNode())) {
DCHECK(layout_object->IsTextAreaIncludingNG());
text_area_element->SetValue(
string, TextFieldEventBehavior::kDispatchInputAndChangeEvent);
return true;
}
if (HasContentEditableAttributeSet()) {
To<HTMLElement>(GetNode())->setInnerText(string);
return true;
}
return false;
}
//
// New AX name calculation.
//
String AXNodeObject::GetName(ax::mojom::blink::NameFrom& name_from,
AXObjectVector* name_objects) const {
String name = AXObject::GetName(name_from, name_objects);
if (RoleValue() == ax::mojom::blink::Role::kSpinButton &&
DatetimeAncestor()) {
// Fields inside a datetime control need to merge the field name with
// the name of the <input> element.
name_objects->clear();
String input_name = DatetimeAncestor()->GetName(name_from, name_objects);
if (!input_name.empty())
return name + " " + input_name;
}
return name;
}
String AXNodeObject::TextAlternative(
bool recursive,
const AXObject* aria_label_or_description_root,
AXObjectSet& visited,
ax::mojom::blink::NameFrom& name_from,
AXRelatedObjectVector* related_objects,
NameSources* name_sources) const {
// If nameSources is non-null, relatedObjects is used in filling it in, so it
// must be non-null as well.
DCHECK(!name_sources || related_objects);
bool found_text_alternative = false;
if (!GetNode() && !GetLayoutObject())
return String();
// Exclude offscreen objects inside a portal.
// NOTE: If an object is found to be offscreen, this also omits its children,
// which may not be offscreen in some cases.
Page* page = GetNode() ? GetNode()->GetDocument().GetPage() : nullptr;
if (page && page->InsidePortal()) {
LayoutRect bounds = GetBoundsInFrameCoordinates();
gfx::Size document_size =
GetNode()->GetDocument().GetLayoutView()->GetLayoutSize();
bool is_visible =
bounds.Intersects(LayoutRect(gfx::Point(), document_size));
if (!is_visible)
return String();
}
// Step 2E from: http://www.w3.org/TR/accname-aam-1.1 -- value from control.
// This must occur before 2C, because 2C is not applied if 2E will be:
// 2C: "If traversal of the current node is due to recursion and the current
// node is an embedded control as defined in step 2E, ignore aria-label and
// skip to rule 2E".
// Note that 2E only applies the label is for "another widget", therefore, the
// value cannot be used to label the original control, even if aria-labelledby
// points to itself. The easiest way to check this is by testing whether this
// node has already been visited.
if (recursive && !visited.Contains(this)) {
String value_for_name = GetValueContributionToName(visited);
if (!value_for_name.IsNull())
return value_for_name;
}
// Step 2C from: http://www.w3.org/TR/accname-aam-1.1 -- aria-label.
String text_alternative = AriaTextAlternative(
recursive, aria_label_or_description_root, visited, name_from,
related_objects, name_sources, &found_text_alternative);
if (found_text_alternative && !name_sources)
return text_alternative;
// Step 2D from: http://www.w3.org/TR/accname-aam-1.1 -- native markup.
text_alternative =
NativeTextAlternative(visited, name_from, related_objects, name_sources,
&found_text_alternative);
const bool has_text_alternative =
!text_alternative.empty() ||
name_from == ax::mojom::blink::NameFrom::kAttributeExplicitlyEmpty;
if (has_text_alternative && !name_sources)
return text_alternative;
// Step 2F / 2G from: http://www.w3.org/TR/accname-aam-1.1 -- from content.
if (aria_label_or_description_root || SupportsNameFromContents(recursive)) {
Node* node = GetNode();
if (!IsA<HTMLSelectElement>(node)) { // Avoid option descendant text
name_from = ax::mojom::blink::NameFrom::kContents;
if (name_sources) {
name_sources->push_back(NameSource(found_text_alternative));
name_sources->back().type = name_from;
}
if (auto* text_node = DynamicTo<Text>(node)) {
text_alternative = text_node->data();
} else if (IsA<HTMLBRElement>(node)) {
text_alternative = String("\n");
} else {
text_alternative =
TextFromDescendants(visited, aria_label_or_description_root, false);
}
if (!text_alternative.empty()) {
if (name_sources) {
found_text_alternative = true;
name_sources->back().text = text_alternative;
} else {
return text_alternative;
}
}
}
}
// Step 2I from: http://www.w3.org/TR/accname-aam-1.1
name_from = ax::mojom::blink::NameFrom::kTitle;
const AtomicString& title = GetAttribute(kTitleAttr);
String titleText = text_alternative = TextAlternativeFromTitleAttribute(
title, name_from, name_sources, &found_text_alternative);
if (!title.empty()) {
if (name_sources) {
text_alternative = titleText;
} else {
return titleText;
}
}
name_from = ax::mojom::blink::NameFrom::kNone;
if (name_sources && found_text_alternative) {
for (NameSource& name_source : *name_sources) {
if (!name_source.text.IsNull() && !name_source.superseded) {
name_from = name_source.type;
if (!name_source.related_objects.empty())
*related_objects = name_source.related_objects;
return name_source.text;
}
}
}
return String();
}
static bool ShouldInsertSpaceBetweenObjectsIfNeeded(
AXObject* previous,
AXObject* next,
ax::mojom::blink::NameFrom last_used_name_from,
ax::mojom::blink::NameFrom name_from) {
// If we're going between two layoutObjects that are in separate
// LayoutBoxes, add whitespace if it wasn't there already. Intuitively if
// you have <span>Hello</span><span>World</span>, those are part of the same
// LayoutBox so we should return "HelloWorld", but given
// <div>Hello</div><div>World</div> the strings are in separate boxes so we
// should return "Hello World".
if (!IsInSameNonInlineBlockFlow(next->GetLayoutObject(),
previous->GetLayoutObject()))
return true;
// Even if it is in the same inline block flow, if we are using a text
// alternative such as an ARIA label or HTML title, we should separate
// the strings. Doing so is consistent with what is stated in the AccName
// spec and with what is done in other user agents.
switch (last_used_name_from) {
case ax::mojom::blink::NameFrom::kNone:
case ax::mojom::blink::NameFrom::kAttributeExplicitlyEmpty:
case ax::mojom::blink::NameFrom::kContents:
break;
case ax::mojom::blink::NameFrom::kAttribute:
case ax::mojom::blink::NameFrom::kCaption:
case ax::mojom::blink::NameFrom::kPlaceholder:
case ax::mojom::blink::NameFrom::kRelatedElement:
case ax::mojom::blink::NameFrom::kTitle:
case ax::mojom::blink::NameFrom::kValue:
return true;
}
switch (name_from) {
case ax::mojom::blink::NameFrom::kNone:
case ax::mojom::blink::NameFrom::kAttributeExplicitlyEmpty:
case ax::mojom::blink::NameFrom::kContents:
break;
case ax::mojom::blink::NameFrom::kAttribute:
case ax::mojom::blink::NameFrom::kCaption:
case ax::mojom::blink::NameFrom::kPlaceholder:
case ax::mojom::blink::NameFrom::kRelatedElement:
case ax::mojom::blink::NameFrom::kTitle:
case ax::mojom::blink::NameFrom::kValue:
return true;
}
// According to the AccName spec, we need to separate controls from text nodes
// using a space.
if (previous->IsControl() || next->IsControl())
return true;
if (!RuntimeEnabledFeatures::LayoutNGBlockInInlineEnabled())
return false;
// When |previous| and |next| are in same inline formatting context, we
// may have block-in-inline between |previous| and |next|.
// For <div>abc<p aria-hidden=true>...</p>def</div>, we have following
// layout tree:
// LayoutBlockFlow {DIV}, children are inline
// LayoutText "abc" <= previous
// LayoutBlockFlow (anonymous) block-in-inline wrapper
// LayoutBlockFlow {P}
// ...
// LayoutText "def" <= next
// When block-in-inline disabled, layout tree is:
// LayoutBlockFlow {DIV}, children are block
// LayoutBlockFlow (anonymous)
// LayoutText "abc" <= previous
// LayoutBlockFlow (anonymous) block-in-inline wrapper
// LayoutBlockFlow {P}
// ...
// LayoutBlockFlow (anonymous)
// LayoutText "def" <= next
// See accessibility/name-calc-aria-hidden.html
const auto* next_layout_object = next->GetLayoutObject();
for (auto* layout_object = previous->GetLayoutObject();
layout_object && layout_object != next_layout_object;
layout_object = layout_object->NextInPreOrder()) {
if (layout_object->IsBlockInInline())
return true;
}
return false;
}
String AXNodeObject::TextFromDescendants(
AXObjectSet& visited,
const AXObject* aria_label_or_description_root,
bool recursive) const {
if (!CanHaveChildren())
return recursive ? String() : GetElement()->GetInnerTextWithoutUpdate();
StringBuilder accumulated_text;
AXObject* previous = nullptr;
ax::mojom::blink::NameFrom last_used_name_from =
ax::mojom::blink::NameFrom::kNone;
// Ensure that if this node needs to invalidate its children (e.g. due to
// included in tree status change), that we do it now, rather than while
// traversing the children.
UpdateCachedAttributeValuesIfNeeded();
const AXObjectVector& children = ChildrenIncludingIgnored();
#if defined(AX_FAIL_FAST_BUILD)
base::AutoReset<bool> auto_reset(&is_computing_text_from_descendants_, true);
#endif
for (AXObject* child : children) {
constexpr size_t kMaxDescendantsForTextAlternativeComputation = 100;
if (visited.size() > kMaxDescendantsForTextAlternativeComputation)
break;
if (child->IsHiddenForTextAlternativeCalculation(
aria_label_or_description_root)) {
continue;
}
ax::mojom::blink::NameFrom child_name_from =
ax::mojom::blink::NameFrom::kNone;
String result;
if (child->IsPresentational()) {
result = child->TextFromDescendants(visited,
aria_label_or_description_root, true);
} else {
result = RecursiveTextAlternative(*child, aria_label_or_description_root,
visited, child_name_from);
}
if (!result.empty() && previous && accumulated_text.length() &&
!IsHTMLSpace(accumulated_text[accumulated_text.length() - 1]) &&
!IsHTMLSpace(result[0])) {
if (ShouldInsertSpaceBetweenObjectsIfNeeded(
previous, child, last_used_name_from, child_name_from)) {
accumulated_text.Append(' ');
}
}
accumulated_text.Append(result);
// We keep track of all non-hidden children, even those whose content is
// not included, because all rendered children impact whether or not a
// space should be inserted between objects. Example: A label which has
// a single, nameless input surrounded by CSS-generated content should
// have a space separating the before and after content.
previous = child;
// We only keep track of the source of children whose content is included.
// Example: Three spans, the first with an aria-label, the second with no
// content, and the third whose name comes from content. There should be a
// space between the first and third because of the aria-label in the first.
if (!result.empty())
last_used_name_from = child_name_from;
}
return accumulated_text.ToString();
}
// static
bool AXNodeObject::IsNameFromLabelElement(HTMLElement* control) {
// This duplicates some logic from TextAlternative()/NativeTextAlternative(),
// but is necessary because IsNameFromLabelElement() needs to be called from
// ComputeAccessibilityIsIgnored(), which isn't allowed to call
// AXObjectCache().GetOrCreate() in random places in the tree.
if (!control)
return false;
// aria-label and aria-labelledby take precedence over <label>.
if (IsNameFromAriaAttribute(control))
return false;
// <label> will be used. It contains the control or points via <label for>.
// Based on https://www.w3.org/TR/html-aam-1.0
// 5.1/5.5 Text inputs, Other labelable Elements
auto* labels = control->labels();
return labels && labels->length();
}
// static
bool AXNodeObject::IsRedundantLabel(HTMLLabelElement* label) {
// Determine if label is redundant:
// - Labelling a checkbox or radio.
// - Text was already used to name the checkbox/radio.
// - No interesting content in the label (focusable or semantically useful)
// TODO(accessibility) Consider moving this logic to the browser side.
// TODO(accessibility) Consider this for more controls, such as textboxes.
// There isn't a clear history why this is only done for checkboxes, and not
// other controls such as textboxes. It may be because the checkbox/radio
// itself is small, so this makes a nicely sized combined click target. Most
// ATs do not already have features to combine labels and controls, e.g.
// removing redundant announcements caused by having text and named controls
// as separate objects.
HTMLInputElement* input = DynamicTo<HTMLInputElement>(label->control());
if (!input)
return false;
if (!input->GetLayoutObject() ||
input->GetLayoutObject()->Style()->Visibility() != EVisibility::kVisible)
return false;
if (!input->IsCheckable())
return false;
if (!IsNameFromLabelElement(input))
return false;
DCHECK_NE(input->labels()->length(), 0U);
// Look for any first child element that is not the input control itself.
// This could be important semantically.
Element* first_child = ElementTraversal::FirstChild(*label);
if (!first_child)
return true; // No element children.
if (first_child != input)
return false; // Has an element child that is not the input control.
// The first child was the input control.
// If there's another child, then it won't be the input control.
return ElementTraversal::NextSibling(*first_child) == nullptr;
}
void AXNodeObject::GetRelativeBounds(AXObject** out_container,
gfx::RectF& out_bounds_in_container,
gfx::Transform& out_container_transform,
bool* clips_children) const {
if (GetLayoutObject()) {
AXObject::GetRelativeBounds(out_container, out_bounds_in_container,
out_container_transform, clips_children);
return;
}
#if DCHECK_IS_ON()
DCHECK(!getting_bounds_) << "GetRelativeBounds reentrant: " << ToString(true);
base::AutoReset<bool> reentrancy_protector(&getting_bounds_, true);
#endif
*out_container = nullptr;
out_bounds_in_container = gfx::RectF();
out_container_transform.MakeIdentity();
// First check if it has explicit bounds, for example if this element is tied
// to a canvas path. When explicit coordinates are provided, the ID of the
// explicit container element that the coordinates are relative to must be
// provided too.
if (!explicit_element_rect_.IsEmpty()) {
*out_container = AXObjectCache().ObjectFromAXID(explicit_container_id_);
if (*out_container) {
out_bounds_in_container = gfx::RectF(explicit_element_rect_);
return;
}
}
Element* element = GetElement();
// If it's in a canvas but doesn't have an explicit rect, or has display:
// contents set, get the bounding rect of its children.
if ((GetNode()->parentElement() &&
GetNode()->parentElement()->IsInCanvasSubtree()) ||
(element && element->HasDisplayContentsStyle())) {
Vector<gfx::RectF> rects;
for (Node& child : NodeTraversal::ChildrenOf(*GetNode())) {
if (child.IsHTMLElement()) {
if (AXObject* obj = AXObjectCache().Get(&child)) {
AXObject* container;
gfx::RectF bounds;
obj->GetRelativeBounds(&container, bounds, out_container_transform,
clips_children);
if (container) {
*out_container = container;
rects.push_back(bounds);
}
}
}
}
if (*out_container) {
for (auto& rect : rects)
out_bounds_in_container.Union(rect);
return;
}
}
// If this object doesn't have an explicit element rect or computable from its
// children, for now, let's return the position of the ancestor that does have
// a position, and make it the width of that parent, and about the height of a
// line of text, so that it's clear the object is a child of the parent.
for (AXObject* position_provider = ParentObject(); position_provider;
position_provider = position_provider->ParentObject()) {
if (IsA<AXLayoutObject>(position_provider)) {
position_provider->GetRelativeBounds(
out_container, out_bounds_in_container, out_container_transform,
clips_children);
if (*out_container) {
out_bounds_in_container.set_size(
gfx::SizeF(out_bounds_in_container.width(),
std::min(10.0f, out_bounds_in_container.height())));
}
break;
}
}
}
bool AXNodeObject::HasValidHTMLTableStructureAndLayout() const {
// Is it a visible <table> with a table-like role and layout?
if (!IsTableLikeRole() || !GetLayoutObject() ||
!GetLayoutObject()->IsTable() || !IsA<HTMLTableElement>(GetNode()))
return false;
// Check for any invalid children, as far as W3C table validity is concerned.
// * If no invalid children exist, this will be considered a valid table,
// and AddTableChildren() can be used to add the children in rendered order.
// * If any invalid children exist, this table will be considered invalid.
// In that case the children will still be added via AddNodeChildren(),
// so that no content is lost.
// See comments in AddTableChildren() for more information about valid tables.
auto* table = To<HTMLTableElement>(GetNode());
auto* thead = table->tHead();
auto* tfoot = table->tFoot();
for (Element* child = ElementTraversal::FirstChild(*GetElement()); child;
child = ElementTraversal::NextSibling(*child)) {
if (child == thead || child == tfoot) {
// Only 1 thead and 1 tfoot are allowed.
continue;
}
if (IsA<HTMLTableSectionElement>(child) &&
child->HasTagName(html_names::kTbodyTag)) {
// Multiple <tbody>s are valid, but only 1 thead or tfoot.
continue;
}
if (!child->GetLayoutObject() &&
child->HasTagName(html_names::kColgroupTag)) {
continue;
}
if (IsA<HTMLTableCaptionElement>(child) && child == table->caption()) {
continue; // Only one caption is valid.
}
return false;
}
return true;
}
void AXNodeObject::AddTableChildren() {
// Add the caption (if any) and table sections in the visible order.
//
// Implementation notes:
//
// * In a valid table, there is always at least one section child DOM node.
// For example, if the HTML of the web page includes <tr>s as direct
// children of a <table>, Blink will insert a <tbody> as a child of the
// table, and parent of the <tr> elements.
//
// * Rendered order can differ from DOM order:
// The valid DOM order of <table> children is specified here:
// https://html.spec.whatwg.org/multipage/tables.html#the-table-element,
// "... optionally a caption element, followed by zero or more
// colgroup elements, followed optionally by a thead element, followed by
// either zero or more tbody elements or one or more tr elements, followed
// optionally by a tfoot element"
// However, even if the DOM children occur in an incorrect order, Blink
// automatically renders them as if they were in the correct order.
// The following code ensures that the children are added to the AX tree in
// the same order as Blink renders them.
DCHECK(HasValidHTMLTableStructureAndLayout());
auto* html_table_element = To<HTMLTableElement>(GetNode());
AddNodeChild(html_table_element->caption());
AddNodeChild(html_table_element->tHead());
for (Node* node : *html_table_element->tBodies())
AddNodeChild(node);
AddNodeChild(html_table_element->tFoot());
}
int AXNodeObject::TextOffsetInFormattingContext(int offset) const {
DCHECK_GE(offset, 0);
if (IsDetached())
return 0;
// When a node has the first-letter CSS style applied to it, it is split into
// two parts (two branches) in the layout tree. The "first-letter part"
// contains its first letter and any surrounding Punctuation. The "remaining
// part" contains the rest of the text.
//
// We need to ensure that we retrieve the correct layout object: either the
// one for the "first-letter part" or the one for the "remaining part",
// depending of the value of |offset|.
const LayoutObject* layout_obj =
GetNode() ? AssociatedLayoutObjectOf(*GetNode(), offset)
: GetLayoutObject();
if (!layout_obj)
return AXObject::TextOffsetInFormattingContext(offset);
// We support calculating the text offset from the start of the formatting
// contexts of the following layout objects, provided that they are at
// inline-level, (display=inline) or "display=inline-block":
//
// (Note that in the following examples, the paragraph is the formatting
// context.
//
// Layout replaced, e.g. <p><img></p>.
// Layout inline with a layout text child, e.g. <p><a href="#">link</a></p>.
// Layout block flow, e.g. <p><b style="display: inline-block;"></b></p>.
// Layout text, e.g. <p>Hello</p>.
// Layout br (subclass of layout text), e.g. <p><br></p>.
if (layout_obj->IsLayoutInline()) {
// The NGOffsetMapping class doesn't map layout inline objects to their text
// mappings because such an operation could be ambiguous. An inline object
// may have another inline object inside it. For example,
// <span><span>Inner</span outer</span>. We need to recursively retrieve the
// first layout text or layout replaced child so that any potential
// ambiguity would be removed.
const AXObject* first_child = FirstChildIncludingIgnored();
return first_child ? first_child->TextOffsetInFormattingContext(offset)
: offset;
}
// TODO(crbug.com/567964): LayoutObject::IsAtomicInlineLevel() also includes
// block-level replaced elements. We need to explicitly exclude them via
// LayoutObject::IsInline().
const bool is_atomic_inline_level =
layout_obj->IsInline() && layout_obj->IsAtomicInlineLevel();
if (!is_atomic_inline_level && !layout_obj->IsText()) {
// Not in a formatting context in which text offsets are meaningful.
return AXObject::TextOffsetInFormattingContext(offset);
}
// TODO(crbug.com/1149171): NGInlineOffsetMappingBuilder does not properly
// compute offset mappings for empty LayoutText objects. Other text objects
// (such as some list markers) are not affected.
if (const LayoutText* layout_text = DynamicTo<LayoutText>(layout_obj)) {
if (layout_text->GetText().empty())
return AXObject::TextOffsetInFormattingContext(offset);
}
LayoutBlockFlow* formatting_context =
NGOffsetMapping::GetInlineFormattingContextOf(*layout_obj);
if (!formatting_context || formatting_context == layout_obj)
return AXObject::TextOffsetInFormattingContext(offset);
// If "formatting_context" is not a Layout NG object, the offset mappings will
// be computed on demand and cached.
const NGOffsetMapping* inline_offset_mapping =
NGInlineNode::GetOffsetMapping(formatting_context);
if (!inline_offset_mapping)
return AXObject::TextOffsetInFormattingContext(offset);
const base::span<const NGOffsetMappingUnit> mapping_units =
inline_offset_mapping->GetMappingUnitsForLayoutObject(*layout_obj);
if (mapping_units.empty())
return AXObject::TextOffsetInFormattingContext(offset);
return static_cast<int>(mapping_units.front().TextContentStart()) + offset;
}
//
// Inline text boxes.
//
void AXNodeObject::LoadInlineTextBoxes() {
std::queue<AXID> work_queue;
work_queue.push(AXObjectID());
while (!work_queue.empty()) {
AXObject* work_obj = AXObjectCache().ObjectFromAXID(work_queue.front());
work_queue.pop();
if (!work_obj || !work_obj->AccessibilityIsIncludedInTree())
continue;
if (ui::CanHaveInlineTextBoxChildren(work_obj->RoleValue())) {
if (work_obj->CachedChildrenIncludingIgnored().empty()) {
// We only need to add inline textbox children if they aren't present.
// Although some platforms (e.g. Android), load inline text boxes
// on subtrees that may later be stale, once they are stale, the old
// inline text boxes are cleared because SetNeedsToUpdateChildren()
// calls ClearChildren().
work_obj->ForceAddInlineTextBoxChildren();
}
} else {
for (const auto& child : work_obj->ChildrenIncludingIgnored())
work_queue.push(child->AXObjectID());
}
}
}
void AXNodeObject::ForceAddInlineTextBoxChildren() {
AddInlineTextBoxChildren(true /*force*/);
children_dirty_ = false; // Avoid adding these children twice.
}
void AXNodeObject::AddInlineTextBoxChildren(bool force) {
Document* document = GetDocument();
if (!document) {
NOTREACHED();
return;
}
Settings* settings = document->GetSettings();
if (!force &&
(!settings || !settings->GetInlineTextBoxAccessibilityEnabled())) {
return;
}
if (!GetLayoutObject() || !GetLayoutObject()->IsText())
return;
if (GetLayoutObject()->NeedsLayout()) {
// If a LayoutText or a LayoutBR needs layout, its inline text boxes are
// either nonexistent or invalid, so defer until the layout happens and the
// layoutObject calls AXObjectCacheImpl::inlineTextBoxesUpdated.
return;
}
if (LastKnownIsIgnoredValue()) {
// Inline textboxes are included if and only if the parent is unignored.
// If the parent is ignored but included in tree, the inline textbox is
// still withheld.
return;
}
auto* layout_text = To<LayoutText>(GetLayoutObject());
for (scoped_refptr<AbstractInlineTextBox> box =
layout_text->FirstAbstractInlineTextBox();
box.get(); box = box->NextInlineTextBox()) {
AXObject* ax_box = AXObjectCache().GetOrCreate(box.get(), this);
if (!ax_box)
continue;
children_.push_back(ax_box);
}
}
void AXNodeObject::AddValidationMessageChild() {
DCHECK(IsWebArea()) << "Validation message must be child of root";
// First child requirement enables easy checking to see if a children changed
// event is needed in AXObjectCacheImpl::ValidationMessageObjectIfInvalid().
DCHECK_EQ(children_.size(), 0U)
<< "Validation message must be the first child";
AddChildAndCheckIncluded(AXObjectCache().ValidationMessageObjectIfInvalid(
/* suppress children changed, already processing that */ false));
}
void AXNodeObject::AddImageMapChildren() {
HTMLMapElement* map = GetMapForImage(GetNode());
if (!map)
return;
HTMLImageElement* curr_image_element = DynamicTo<HTMLImageElement>(GetNode());
DCHECK(curr_image_element);
DCHECK(curr_image_element->IsLink());
String usemap = curr_image_element->FastGetAttribute(html_names::kUsemapAttr);
DCHECK(!usemap.empty());
// Even though several images can point to the same map via usemap, only
// use one reported via HTMLImageMapElement::ImageElement(), which is always
// the first image in the DOM that matches the #usemap, even if there are
// changes to the DOM. Only allow map children for the primary image.
// This avoids two problems:
// 1. Focusing the same area but in a different image scrolls the page to
// the first image that uses that map. Safari does the same thing, and
// Firefox does something similar (but seems to prefer the last image).
// 2. When an object has multiple parents, serialization errors occur.
// While allowed in the spec, using multiple images with the same map is not
// handled well in browsers (problem #1), and serializer support for multiple
// parents of the same area children is messy.
// Get the primary image, which is the first image using this map.
HTMLImageElement* primary_image_element = map->ImageElement();
// Is this the primary image for this map?
if (primary_image_element != curr_image_element) {
// No, the current image (for |this|) is not the primary image.
// Therefore, do not add area children to it.
AXObject* ax_primary_image =
AXObjectCache().GetOrCreate(primary_image_element);
if (ax_primary_image &&
ax_primary_image->ChildCountIncludingIgnored() == 0 &&
NodeTraversal::FirstChild(*map)) {
// The primary image still needs to add the area children, and there's at
// least one to add.
AXObjectCache().ChildrenChanged(primary_image_element);
}
return;
}
// Yes, this is the primary image.
// If the children were part of a different parent, notify that parent that
// its children have changed.
if (AXObject* ax_previous_parent = AXObjectCache().GetAXImageForMap(*map)) {
if (ax_previous_parent != this) {
DCHECK(ax_previous_parent->GetNode());
AXObjectCache().ChildrenChangedWithCleanLayout(
ax_previous_parent->GetNode(), ax_previous_parent);
ax_previous_parent->ClearChildren();
}
}
// Add the children to |this|.
Node* child = LayoutTreeBuilderTraversal::FirstChild(*map);
while (child) {
AddChildAndCheckIncluded(AXObjectCache().GetOrCreate(child, this));
child = LayoutTreeBuilderTraversal::NextSibling(*child);
}
}
void AXNodeObject::AddPopupChildren() {
auto* html_select_element = DynamicTo<HTMLSelectElement>(GetNode());
if (html_select_element) {
if (!AXObjectCache().UseAXMenuList() && html_select_element->UsesMenuList())
AddChildAndCheckIncluded(html_select_element->PopupRootAXObject());
return;
}
auto* html_input_element = DynamicTo<HTMLInputElement>(GetNode());
if (html_input_element) {
AddChildAndCheckIncluded(html_input_element->PopupRootAXObject());
}
}
void AXNodeObject::AddPseudoElementChildrenFromLayoutTree() {
// Children are added this way only for pseudo-element subtrees.
// See AXObject::ShouldUseLayoutObjectTraversalForChildren().
if (!GetLayoutObject()) {
DCHECK(GetNode());
DCHECK(GetNode()->IsPseudoElement());
return; // Can't add children for hidden or display-locked pseudo elements.
}
LayoutObject* child = GetLayoutObject()->SlowFirstChild();
while (child) {
// All added pseudo element descendants are included in the tree.
if (AXObject* ax_child = AXObjectCache().GetOrCreate(child, this)) {
DCHECK(AXObjectCacheImpl::IsRelevantPseudoElementDescendant(*child));
AddChildAndCheckIncluded(ax_child);
}
child = child->NextSibling();
}
}
void AXNodeObject::AddNodeChildren() {
if (!node_)
return;
// Ignore DOM children of frame/iframe: they do not act as fallbacks and
// are never part of layout.
if (IsA<HTMLFrameElementBase>(GetNode()))
return;
for (Node* child = LayoutTreeBuilderTraversal::FirstChild(*node_); child;
child = LayoutTreeBuilderTraversal::NextSibling(*child)) {
AddNodeChild(child);
}
}
void AXNodeObject::AddAccessibleNodeChildren() {
Element* element = GetElement();
if (!element)
return;
AccessibleNode* accessible_node = element->ExistingAccessibleNode();
if (!accessible_node)
return;
for (const auto& child : accessible_node->GetChildren()) {
AddChildAndCheckIncluded(AXObjectCache().GetOrCreate(child, this));
}
}
void AXNodeObject::AddOwnedChildren() {
AXObjectVector owned_children;
AXObjectCache().ValidatedAriaOwnedChildren(this, owned_children);
DCHECK(owned_children.size() == 0 || AXRelationCache::IsValidOwner(this))
<< "This object is not allowed to use aria-owns, but it is.\n"
<< ToString(true, true);
// Always include owned children.
for (const auto& owned_child : owned_children) {
DCHECK(AXRelationCache::IsValidOwnedChild(owned_child))
<< "This object is not allowed to be owned, but it is.\n"
<< owned_child->ToString(true, true);
AddChildAndCheckIncluded(owned_child, true);
}
}
void AXNodeObject::AddChildrenImpl() {
#define CHECK_ATTACHED() \
if (IsDetached()) { \
NOTREACHED() << "Detached adding children: " << ToString(true, true); \
return; \
}
DCHECK(children_dirty_);
if (!CanHaveChildren()) {
NOTREACHED()
<< "Should not reach AddChildren() if CanHaveChildren() is false.\n"
<< ToString(true, true);
return;
}
if (ui::CanHaveInlineTextBoxChildren(RoleValue())) {
AddInlineTextBoxChildren();
CHECK_ATTACHED();
return;
}
if (IsA<HTMLImageElement>(GetNode())) {
AddImageMapChildren();
CHECK_ATTACHED();
return;
}
// If validation message exists, always make it the first child of the root,
// to enable easy checking of whether it's a known child of the root.
if (IsWebArea())
AddValidationMessageChild();
CHECK_ATTACHED();
if (HasValidHTMLTableStructureAndLayout())
AddTableChildren();
else if (ShouldUseLayoutObjectTraversalForChildren())
AddPseudoElementChildrenFromLayoutTree();
else
AddNodeChildren();
CHECK_ATTACHED();
AddPopupChildren();
CHECK_ATTACHED();
AddAccessibleNodeChildren();
CHECK_ATTACHED();
AddOwnedChildren();
CHECK_ATTACHED();
}
void AXNodeObject::AddChildren() {
#if DCHECK_IS_ON()
DCHECK(!IsDetached());
// If the need to add more children in addition to existing children arises,
// childrenChanged should have been called, which leads to children_dirty_
// being true, then UpdateChildrenIfNecessary() clears the children before
// calling AddChildren().
DCHECK(children_.empty())
<< "\nParent still has " << children_.size() << " children before adding:"
<< "\nParent is " << ToString(true, true) << "\nFirst child is "
<< children_[0]->ToString(true, true);
#endif
#if defined(AX_FAIL_FAST_BUILD)
SANITIZER_CHECK(!is_computing_text_from_descendants_)
<< "Should not attempt to simultaneously compute text from descendants "
"and add children on: "
<< ToString(true, true);
SANITIZER_CHECK(!is_adding_children_)
<< " Reentering method on " << GetNode();
base::AutoReset<bool> reentrancy_protector(&is_adding_children_, true);
#endif
AddChildrenImpl();
children_dirty_ = false;
#if DCHECK_IS_ON()
// All added children must be attached.
for (const auto& child : children_) {
DCHECK(!child->IsDetached()) << "A brand new child was detached.\n"
<< child->ToString(true, true)
<< "\n ... of parent " << ToString(true, true);
}
#endif
}
// Add non-owned children that are backed with a DOM node.
void AXNodeObject::AddNodeChild(Node* node) {
if (!node)
return;
AXObject* ax_child = AXObjectCache().Get(node);
// Should not have another parent unless owned.
if (AXObjectCache().IsAriaOwned(ax_child))
return; // Do not add owned children to their natural parent.
#if DCHECK_IS_ON()
AXObject* ax_cached_parent =
ax_child ? ax_child->CachedParentObject() : nullptr;
size_t num_children_before_add = children_.size();
#endif
if (!ax_child) {
ax_child = AXObjectCache().GetOrCreate(node, this);
if (!ax_child)
return;
}
AddChild(ax_child);
#if DCHECK_IS_ON()
bool did_add_child = children_.size() == num_children_before_add + 1 &&
children_[0] == ax_child;
if (did_add_child) {
DCHECK(!ax_cached_parent || ax_cached_parent->AXObjectID() == AXObjectID())
<< "Newly added child shouldn't have a different preexisting parent:"
<< "\nChild = " << ax_child->ToString(true, true)
<< "\nNew parent = " << ToString(true, true)
<< "\nPreexisting parent = " << ax_cached_parent->ToString(true, true);
}
#endif
}
#if DCHECK_IS_ON()
void AXNodeObject::CheckValidChild(AXObject* child) {
DCHECK(!child->IsDetached()) << "Cannot add a detached child.\n"
<< child->ToString(true, true);
Node* child_node = child->GetNode();
// <area> children should only be added via AddImageMapChildren(), as the
// descendants of an <image usemap> -- never alone or as children of a <map>.
if (IsA<HTMLAreaElement>(child_node)) {
AXObject* ancestor = this;
while (ancestor && !IsA<HTMLImageElement>(ancestor->GetNode()))
ancestor = ancestor->CachedParentObject();
DCHECK(ancestor && IsA<HTMLImageElement>(ancestor->GetNode()))
<< "Area elements can only be added by image parents: "
<< child->ToString(true, true) << " had a parent of "
<< ToString(true, true);
}
// An option or popup for a <select size=1> must only be added via an
// overridden AddChildren() on AXMenuList/AXMenuListPopup.
// These AXObjects must be added in an overridden AddChildren() method, and
// that will only occur if AXObjectCacheImpl::UseAXMenuList() returns true.
DCHECK(!IsA<AXMenuListOption>(child))
<< "Adding menulist option child in wrong place: "
<< "\nChild: " << child->ToString(true, true)
<< "\nParent: " << child->ParentObject()->ToString(true, true)
<< "\nUseAXMenuList()=" << AXObjectCacheImpl::UseAXMenuList();
// An popup for a <select size=1> must only be added via an overridden
// AddChildren() on AXMenuList.
DCHECK(!IsA<AXMenuListPopup>(child))
<< "Adding menulist popup in wrong place: "
<< "\nChild: " << child->ToString(true, true)
<< "\nParent: " << child->ParentObject()->ToString(true, true)
<< "\nUseAXMenuList()=" << AXObjectCacheImpl::UseAXMenuList()
<< "\nShouldCreateAXMenuListOptionFor()="
<< AXObjectCacheImpl::ShouldCreateAXMenuListOptionFor(child_node);
DCHECK(!IsA<HTMLFrameElementBase>(GetNode()) ||
IsA<Document>(child->GetNode()))
<< "Cannot have a non-document child of a frame or iframe."
<< "\nChild: " << child->ToString(true, true)
<< "\nParent: " << child->ParentObject()->ToString(true, true);
}
#endif
void AXNodeObject::AddChild(AXObject* child, bool is_from_aria_owns) {
if (!child)
return;
#if DCHECK_IS_ON()
CheckValidChild(child);
#endif
unsigned int index = children_.size();
InsertChild(child, index, is_from_aria_owns);
}
void AXNodeObject::AddChildAndCheckIncluded(AXObject* child,
bool is_from_aria_owns) {
if (!child)
return;
DCHECK(child->LastKnownIsIncludedInTreeValue());
AddChild(child, is_from_aria_owns);
}
void AXNodeObject::InsertChild(AXObject* child,
unsigned index,
bool is_from_aria_owns) {
if (!child)
return;
DCHECK(CanHaveChildren());
DCHECK(!child->IsDetached())
<< "Cannot add a detached child: " << child->ToString(true, true);
// Enforce expected aria-owns status:
// - Don't add a non-aria-owned child when called from AddOwnedChildren().
// - Don't add an aria-owned child to its natural parent, because it will
// already be the child of the element with aria-owns.
DCHECK_EQ(AXObjectCache().IsAriaOwned(child), is_from_aria_owns);
// Set the parent:
// - For a new object it will have already been set.
// - For a reused, older object, it may need to be changed to a new parent.
child->SetParent(this);
#if DCHECK_IS_ON()
child->EnsureCorrectParentComputation();
#endif
// Update cached values preemptively, but don't allow children changed to be
// called if ignored change, we are already recomputing children and don't
// want to recurse.
child->UpdateCachedAttributeValuesIfNeeded(false);
if (!child->LastKnownIsIncludedInTreeValue()) {
DCHECK(!is_from_aria_owns)
<< "Owned elements must be in tree: " << child->ToString(true, true)
<< "\nRecompute included in tree: "
<< child->ComputeAccessibilityIsIgnoredButIncludedInTree();
// Get the ignored child's children and add to children of ancestor
// included in tree. This will recurse if necessary, skipping levels of
// unignored descendants as it goes.
const auto& children = child->ChildrenIncludingIgnored();
wtf_size_t length = children.size();
int new_index = index;
for (wtf_size_t i = 0; i < length; ++i) {
if (children[i]->IsDetached()) {
// TODO(accessibility) Restore to CHECK().
#if defined(AX_FAIL_FAST_BUILD)
SANITIZER_NOTREACHED()
<< "Cannot add a detached child: "
<< "\n* Child: " << children[i]->ToString(true, true)
<< "\n* Parent: " << child->ToString(true, true)
<< "\n* Grandparent: " << ToString(true, true);
#endif
continue;
}
// If the child was owned, it will be added elsewhere as a direct
// child of the object owning it.
if (!AXObjectCache().IsAriaOwned(children[i]))
children_.insert(new_index++, children[i]);
}
} else {
children_.insert(index, child);
}
}
bool AXNodeObject::CanHaveChildren() const {
DCHECK(!IsDetached());
// Notes:
// * Native text fields expose any children they might have, complying
// with browser-side expectations that editable controls have children
// containing the actual text content.
// * ARIA roles with childrenPresentational:true in the ARIA spec expose
// their contents to the browser side, allowing platforms to decide whether
// to make them a leaf, ensuring that focusable content cannot be hidden,
// and improving stability in Blink.
bool result = !GetElement() || AXObject::CanHaveChildren(*GetElement());
switch (native_role_) {
case ax::mojom::blink::Role::kCheckBox:
case ax::mojom::blink::Role::kListBoxOption:
case ax::mojom::blink::Role::kMenuListOption:
case ax::mojom::blink::Role::kMenuItem:
case ax::mojom::blink::Role::kMenuItemCheckBox:
case ax::mojom::blink::Role::kMenuItemRadio:
case ax::mojom::blink::Role::kProgressIndicator:
case ax::mojom::blink::Role::kRadioButton:
case ax::mojom::blink::Role::kScrollBar:
case ax::mojom::blink::Role::kSlider:
case ax::mojom::blink::Role::kSplitter:
case ax::mojom::blink::Role::kSwitch:
case ax::mojom::blink::Role::kTab:
DCHECK(!result) << "Expected to disallow children for " << GetElement();
break;
case ax::mojom::blink::Role::kComboBoxSelect:
case ax::mojom::blink::Role::kPopUpButton:
case ax::mojom::blink::Role::kStaticText:
// Note: these can have AXInlineTextBox children, but when adding them, we
// also check AXObjectCache().InlineTextBoxAccessibilityEnabled().
DCHECK(result) << "Expected to allow children for " << GetElement()
<< " on role " << native_role_;
break;
default:
break;
}
return result;
}
//
// Properties of the object's owning document or page.
//
double AXNodeObject::EstimatedLoadingProgress() const {
if (!GetDocument())
return 0;
if (IsLoaded())
return 1.0;
if (LocalFrame* frame = GetDocument()->GetFrame())
return frame->Loader().Progress().EstimatedProgress();
return 0;
}
//
// DOM and Render tree access.
//
Element* AXNodeObject::ActionElement() const {
const AXObject* current = this;
if (blink::IsA<blink::Document>(current->GetNode()))
return nullptr; // Do not expose action element for document.
// In general, we look an action element up only for AXObjects that have a
// backing Element. We make an exception for text nodes and pseudo elements
// because we also want these to expose a default action when any of their
// ancestors is clickable. We have found Windows ATs relying on this behavior
// (see https://crbug.com/1382034).
DCHECK(current->GetElement() || current->IsTextObject() ||
current->ShouldUseLayoutObjectTraversalForChildren());
while (current) {
// Handles clicks or is a textfield and is not a disabled form control.
if (current->IsClickable()) {
Element* click_element = current->GetElement();
DCHECK(click_element) << "Only elements are clickable";
// Only return if the click element is a DOM ancestor as well, because
// the click handler won't propagate down via aria-owns.
if (!GetNode() || click_element->contains(GetNode()))
return click_element;
return nullptr;
}
current = current->ParentObject();
}
return nullptr;
}
Element* AXNodeObject::AnchorElement() const {
// Search up the DOM tree for an anchor. This can be anything that has the
// linked state, such as an HTMLAnchorElement or role=link/doc-backlink.
const AXObject* current = this;
while (current) {
if (current->IsLink()) {
DCHECK(current->GetElement())
<< "An AXObject* that is a link should always have an element.";
return current->GetElement();
}
current = current->ParentObject();
}
return nullptr;
}
Document* AXNodeObject::GetDocument() const {
if (!GetNode())
return nullptr;
return &GetNode()->GetDocument();
}
Node* AXNodeObject::GetNode() const {
if (IsDetached()) {
DCHECK(!node_);
return nullptr;
}
DCHECK(!GetLayoutObject() || GetLayoutObject()->GetNode() == node_)
<< "If there is an associated layout object, its node should match the "
"associated node of this accessibility object.\n"
<< ToString(true, true);
return node_;
}
// TODO(chrishall): consider merging this with AXObject::Language in followup.
AtomicString AXNodeObject::Language() const {
if (!GetNode())
return AXObject::Language();
// If it's the root, get the computed language for the document element,
// because the root LayoutObject doesn't have the right value.
if (IsWebArea()) {
Element* document_element = GetDocument()->documentElement();
if (!document_element)
return g_empty_atom;
// Ensure we return only the first language tag. ComputeInheritedLanguage
// consults ContentLanguage which can be set from 2 different sources.
// DocumentLoader::DidInstallNewDocument from HTTP headers which truncates
// until the first comma.
// HttpEquiv::Process from <meta> tag which does not truncate.
// TODO(chrishall): Consider moving this comma handling to setter side.
AtomicString lang = document_element->ComputeInheritedLanguage();
Vector<String> languages;
String(lang).Split(',', languages);
if (!languages.empty())
return AtomicString(languages[0].StripWhiteSpace());
}
return AXObject::Language();
}
bool AXNodeObject::HasAttribute(const QualifiedName& attribute) const {
Element* element = GetElement();
if (!element)
return false;
if (element->FastHasAttribute(attribute))
return true;
return HasInternalsAttribute(*element, attribute);
}
const AtomicString& AXNodeObject::GetAttribute(
const QualifiedName& attribute) const {
Element* element = GetElement();
if (!element)
return g_null_atom;
const AtomicString& value = element->FastGetAttribute(attribute);
if (!value.IsNull())
return value;
return GetInternalsAttribute(*element, attribute);
}
bool AXNodeObject::HasInternalsAttribute(Element& element,
const QualifiedName& attribute) const {
if (!element.DidAttachInternals())
return false;
return element.EnsureElementInternals().HasAttribute(attribute);
}
const AtomicString& AXNodeObject::GetInternalsAttribute(
Element& element,
const QualifiedName& attribute) const {
if (!element.DidAttachInternals())
return g_null_atom;
return element.EnsureElementInternals().FastGetAttribute(attribute);
}
bool AXNodeObject::OnNativeFocusAction() {
// Checking if node is focusable in a native focus action requires that we
// have updated style and layout tree, since the focus check relies on the
// existence of layout objects to determine the result. However, these layout
// objects may have been deferred by display-locking.
Document* document = GetDocument();
Node* node = GetNode();
if (!document || !node)
return false;
document->UpdateStyleAndLayoutTreeForNode(node);
if (!CanSetFocusAttribute())
return false;
if (IsWebArea()) {
// If another Frame has focused content (e.g. nested iframe), then we
// need to clear focus for the other Document Frame.
// Here we set the focused element via the FocusController so that the
// other Frame loses focus, and the target Document Element gains focus.
// This fixes a scenario with Narrator Item Navigation when the user
// navigates from the outer UI to the document when the last focused
// element was within a nested iframe before leaving the document frame.
Page* page = document->GetPage();
// Elements inside a portal should not be focusable.
if (page && !page->InsidePortal()) {
page->GetFocusController().SetFocusedElement(document->documentElement(),
document->GetFrame());
} else {
document->ClearFocusedElement();
}
return true;
}
Element* element = GetElement();
if (!element) {
document->ClearFocusedElement();
return true;
}
// If this node is already the currently focused node, then calling
// focus() won't do anything. That is a problem when focus is removed
// from the webpage to chrome, and then returns. In these cases, we need
// to do what keyboard and mouse focus do, which is reset focus first.
if (document->FocusedElement() == element) {
document->ClearFocusedElement();
// Calling ClearFocusedElement could result in changes to the document,
// like this AXObject becoming detached.
if (IsDetached())
return false;
}
if (base::FeatureList::IsEnabled(blink::features::kSimulateClickOnAXFocus)) {
// If the object is not natively focusable but can be focused using an ARIA
// active descendant, perform a native click instead. This will enable Web
// apps that set accessibility focus using an active descendant to capture
// and act on the click event. Otherwise, there is no other way to inform
// the app that an AT has requested the focus to be changed, except if the
// app is using AOM. To be extra safe, exclude objects that are clickable
// themselves. This won't prevent anyone from having a click handler on the
// object's container.
//
// This code is in the process of being removed. See the comment above
// |kSimulateClickOnAXFocus| in `blink/common/features.cc`.
if (!IsClickable()) {
return OnNativeClickAction();
}
}
element->Focus();
// Calling NotifyUserActivation here allows the browser to activate features
// that need user activation, such as showing an autofill suggestion.
LocalFrame::NotifyUserActivation(
document->GetFrame(),
mojom::blink::UserActivationNotificationType::kInteraction);
return true;
}
bool AXNodeObject::OnNativeIncrementAction() {
LocalFrame* frame = GetDocument() ? GetDocument()->GetFrame() : nullptr;
LocalFrame::NotifyUserActivation(
frame, mojom::blink::UserActivationNotificationType::kInteraction);
AlterSliderOrSpinButtonValue(true);
return true;
}
bool AXNodeObject::OnNativeDecrementAction() {
LocalFrame* frame = GetDocument() ? GetDocument()->GetFrame() : nullptr;
LocalFrame::NotifyUserActivation(
frame, mojom::blink::UserActivationNotificationType::kInteraction);
AlterSliderOrSpinButtonValue(false);
return true;
}
bool AXNodeObject::OnNativeSetSequentialFocusNavigationStartingPointAction() {
if (!GetNode())
return false;
Document* document = GetDocument();
document->ClearFocusedElement();
document->SetSequentialFocusNavigationStartingPoint(GetNode());
return true;
}
void AXNodeObject::ChildrenChangedWithCleanLayout() {
DCHECK(!IsDetached()) << "Don't call on detached node: "
<< ToString(true, true);
DCHECK(GetNode() || GetLayoutObject());
// When children changed on a <map> that means we need to forward the
// children changed to the <img> that parents the <area> elements.
// TODO(accessibility) Consider treating <img usemap> as aria-owns so that
// we get implementation "for free" vai relation cache, etc.
if (HTMLMapElement* map_element = DynamicTo<HTMLMapElement>(GetNode())) {
HTMLImageElement* image_element = map_element->ImageElement();
if (image_element) {
AXObject* ax_image = AXObjectCache().Get(image_element);
if (ax_image) {
ax_image->ChildrenChangedWithCleanLayout();
return;
}
}
}
// Always invalidate |children_| even if it was invalidated before, because
// now layout is clean.
SetNeedsToUpdateChildren();
// The caller, AXObjectCacheImpl::ChildrenChangedWithCleanLayout(), is only
// Between the time that AXObjectCacheImpl::ChildrenChanged() determines
// which included parent to use and now, it's possible that the parent will
// no longer be ignored. This is rare, but is covered by this test:
// external/wpt/accessibility/crashtests/delayed-ignored-change.html/
//
// If this object is no longer included in the tree, then our parent needs to
// recompute its included-in-the-tree children vector. (And if our parent
// isn't included in the tree either, it will recursively update its parent
// and so on.)
//
// The first ancestor that's included in the tree will
// be the one that actually fires the ChildrenChanged
// event notification.
if (!LastKnownIsIncludedInTreeValue()) {
if (AXObject* ax_parent = CachedParentObject()) {
ax_parent->ChildrenChangedWithCleanLayout();
return;
}
}
// TODO(accessibility) Move this up.
if (!CanHaveChildren())
return;
DCHECK(!IsDetached()) << "None of the above should be able to detach |this|: "
<< ToString(true, true);
AXObjectCache().MarkAXObjectDirtyWithCleanLayout(this);
}
void AXNodeObject::SelectedOptions(AXObjectVector& options) const {
if (auto* select = DynamicTo<HTMLSelectElement>(GetNode())) {
for (auto* const option : *select->selectedOptions()) {
AXObject* ax_option = AXObjectCache().GetOrCreate(option);
if (ax_option)
options.push_back(ax_option);
}
return;
}
const AXObjectVector& children = ChildrenIncludingIgnored();
if (RoleValue() == ax::mojom::blink::Role::kComboBoxGrouping ||
RoleValue() == ax::mojom::blink::Role::kComboBoxMenuButton) {
for (const auto& obj : children) {
if (obj->RoleValue() == ax::mojom::blink::Role::kListBox) {
obj->SelectedOptions(options);
return;
}
}
}
for (const auto& obj : children) {
if (obj->IsSelected() == kSelectedStateTrue)
options.push_back(obj);
}
}
//
// Notifications that this object may have changed.
//
void AXNodeObject::HandleAriaExpandedChanged() {
// Find if a parent of this object should handle aria-expanded changes.
AXObject* container_parent = ParentObject();
while (container_parent) {
bool found_parent = false;
switch (container_parent->RoleValue()) {
case ax::mojom::blink::Role::kLayoutTable:
case ax::mojom::blink::Role::kTree:
case ax::mojom::blink::Role::kTreeGrid:
case ax::mojom::blink::Role::kGrid:
case ax::mojom::blink::Role::kTable:
found_parent = true;
break;
default:
break;
}
if (found_parent)
break;
container_parent = container_parent->ParentObject();
}
// Post that the row count changed.
if (container_parent) {
AXObjectCache().PostNotification(container_parent,
ax::mojom::blink::Event::kRowCountChanged);
}
// Post that the specific row either collapsed or expanded.
AccessibilityExpanded expanded = IsExpanded();
if (!expanded)
return;
if (RoleValue() == ax::mojom::blink::Role::kRow ||
RoleValue() == ax::mojom::blink::Role::kTreeItem) {
ax::mojom::blink::Event notification =
ax::mojom::blink::Event::kRowExpanded;
if (expanded == kExpandedCollapsed)
notification = ax::mojom::blink::Event::kRowCollapsed;
AXObjectCache().PostNotification(this, notification);
} else {
AXObjectCache().PostNotification(this,
ax::mojom::blink::Event::kExpandedChanged);
}
}
void AXNodeObject::HandleActiveDescendantChanged() {
if (!GetLayoutObject() || !GetNode() || !GetDocument())
return;
Node* focused_node = GetDocument()->FocusedElement();
if (focused_node == GetNode()) {
AXObject* active_descendant = ActiveDescendant();
if (active_descendant && active_descendant->IsSelectedFromFocus()) {
// In single selection containers, selection follows focus, so a selection
// changed event must be fired. This ensures the AT is notified that the
// selected state has changed, so that it does not read "unselected" as
// the user navigates through the items.
AXObjectCache().HandleAriaSelectedChangedWithCleanLayout(
active_descendant->GetNode());
}
// Mark this node dirty. AXEventGenerator will automatically infer
// that the active descendant changed.
AXObjectCache().MarkAXObjectDirtyWithCleanLayout(this);
}
}
AXObject* AXNodeObject::ErrorMessage() const {
if (GetInvalidState() == ax::mojom::blink::InvalidState::kFalse)
return nullptr;
// Check for aria-errormessage.
Element* existing_error_message =
GetAOMPropertyOrARIAAttribute(AOMRelationProperty::kErrorMessage);
if (existing_error_message)
return AXObjectCache().GetOrCreate(existing_error_message);
// Check for visible validationMessage. This can only be visible for a focused
// control. Corollary: if there is a visible validationMessage alert box, then
// it is related to the current focus.
if (this != AXObjectCache().FocusedObject())
return nullptr;
return AXObjectCache().ValidationMessageObjectIfInvalid(true);
}
String AXNodeObject::TextAlternativeFromTitleAttribute(
const AtomicString& title,
ax::mojom::blink::NameFrom& name_from,
NameSources* name_sources,
bool* found_text_alternative) const {
String text_alternative;
if (name_sources) {
name_sources->push_back(NameSource(*found_text_alternative, kTitleAttr));
name_sources->back().type = name_from;
}
name_from = ax::mojom::blink::NameFrom::kTitle;
if (!title.IsNull()) {
text_alternative = title;
if (name_sources) {
NameSource& source = name_sources->back();
source.attribute_value = title;
source.attribute_value = title;
source.text = text_alternative;
*found_text_alternative = true;
}
}
return text_alternative;
}
// Based on
// http://rawgit.com/w3c/aria/master/html-aam/html-aam.html#accessible-name-and-description-calculation
String AXNodeObject::NativeTextAlternative(
AXObjectSet& visited,
ax::mojom::blink::NameFrom& name_from,
AXRelatedObjectVector* related_objects,
NameSources* name_sources,
bool* found_text_alternative) const {
if (!GetNode())
return String();
// If nameSources is non-null, relatedObjects is used in filling it in, so it
// must be non-null as well.
if (name_sources)
DCHECK(related_objects);
String text_alternative;
AXRelatedObjectVector local_related_objects;
// 5.1/5.5 Text inputs, Other labelable Elements
// If you change this logic, update AXNodeObject::nameFromLabelElement, too.
auto* html_element = DynamicTo<HTMLElement>(GetNode());
if (html_element && html_element->IsLabelable()) {
name_from = ax::mojom::blink::NameFrom::kRelatedElement;
if (name_sources) {
name_sources->push_back(NameSource(*found_text_alternative));
name_sources->back().type = name_from;
name_sources->back().native_source = kAXTextFromNativeHTMLLabel;
}
LabelsNodeList* labels = nullptr;
if (AXObjectCache().MayHaveHTMLLabel(*html_element))
labels = html_element->labels();
if (labels && labels->length() > 0) {
HeapVector<Member<Element>> label_elements;
for (unsigned label_index = 0; label_index < labels->length();
++label_index) {
Element* label = labels->item(label_index);
if (name_sources) {
if (!label->FastGetAttribute(html_names::kForAttr).empty() &&
label->FastGetAttribute(html_names::kForAttr) ==
html_element->GetIdAttribute()) {
name_sources->back().native_source = kAXTextFromNativeHTMLLabelFor;
} else {
name_sources->back().native_source =
kAXTextFromNativeHTMLLabelWrapped;
}
}
label_elements.push_back(label);
}
text_alternative =
TextFromElements(false, visited, label_elements, related_objects);
if (!text_alternative.IsNull()) {
*found_text_alternative = true;
if (name_sources) {
NameSource& source = name_sources->back();
source.related_objects = *related_objects;
source.text = text_alternative;
} else {
return text_alternative.StripWhiteSpace();
}
} else if (name_sources) {
name_sources->back().invalid = true;
}
}
}
// 5.2 input type="button", input type="submit" and input type="reset"
const auto* input_element = DynamicTo<HTMLInputElement>(GetNode());
if (input_element && input_element->IsTextButton()) {
// value attribute.
name_from = ax::mojom::blink::NameFrom::kValue;
if (name_sources) {
name_sources->push_back(NameSource(*found_text_alternative, kValueAttr));
name_sources->back().type = name_from;
}
String value = input_element->Value();
if (!value.IsNull()) {
text_alternative = value;
if (name_sources) {
NameSource& source = name_sources->back();
source.text = text_alternative;
*found_text_alternative = true;
} else {
return text_alternative;
}
}
// Get default value if object is not laid out.
// If object is laid out, it will have a layout object for the label.
if (!GetLayoutObject()) {
String default_label = input_element->ValueOrDefaultLabel();
if (value.IsNull() && !default_label.IsNull()) {
// default label
name_from = ax::mojom::blink::NameFrom::kContents;
if (name_sources) {
name_sources->push_back(NameSource(*found_text_alternative));
name_sources->back().type = name_from;
}
text_alternative = default_label;
if (name_sources) {
NameSource& source = name_sources->back();
source.text = text_alternative;
*found_text_alternative = true;
} else {
return text_alternative;
}
}
}
return text_alternative;
}
// 5.3 input type="image"
if (input_element &&
input_element->getAttribute(kTypeAttr) == input_type_names::kImage) {
// alt attr
const AtomicString& alt = input_element->getAttribute(kAltAttr);
const bool is_empty = alt.empty() && !alt.IsNull();
name_from = is_empty ? ax::mojom::blink::NameFrom::kAttributeExplicitlyEmpty
: ax::mojom::blink::NameFrom::kAttribute;
if (name_sources) {
name_sources->push_back(NameSource(*found_text_alternative, kAltAttr));
name_sources->back().type = name_from;
}
if (!alt.IsNull()) {
text_alternative = alt;
if (name_sources) {
NameSource& source = name_sources->back();
source.attribute_value = alt;
source.text = text_alternative;
*found_text_alternative = true;
} else {
return text_alternative;
}
}
// value attribute.
if (name_sources) {
name_sources->push_back(NameSource(*found_text_alternative, kValueAttr));
name_sources->back().type = name_from;
}
name_from = ax::mojom::blink::NameFrom::kAttribute;
String value = input_element->Value();
if (!value.IsNull()) {
text_alternative = value;
if (name_sources) {
NameSource& source = name_sources->back();
source.text = text_alternative;
*found_text_alternative = true;
} else {
return text_alternative;
}
}
// title attr
const AtomicString& title = input_element->getAttribute(kTitleAttr);
String titleText = text_alternative = TextAlternativeFromTitleAttribute(
title, name_from, name_sources, found_text_alternative);
if (!titleText.IsNull()) {
if (name_sources) {
text_alternative = titleText;
} else {
return titleText;
}
}
// localised default value ("Submit")
name_from = ax::mojom::blink::NameFrom::kValue;
text_alternative =
input_element->GetLocale().QueryString(IDS_FORM_SUBMIT_LABEL);
if (name_sources) {
name_sources->push_back(NameSource(*found_text_alternative, kTypeAttr));
NameSource& source = name_sources->back();
source.attribute_value = input_element->getAttribute(kTypeAttr);
source.type = name_from;
source.text = text_alternative;
*found_text_alternative = true;
} else {
return text_alternative;
}
return text_alternative;
}
// 5.1 Text inputs - step 3 (placeholder attribute)
if (html_element && html_element->IsTextControl()) {
// title attr
name_from = ax::mojom::blink::NameFrom::kAttribute;
const AtomicString& title = html_element->getAttribute(kTitleAttr);
String titleText = text_alternative = TextAlternativeFromTitleAttribute(
title, name_from, name_sources, found_text_alternative);
if (!titleText.IsNull()) {
if (name_sources) {
text_alternative = titleText;
} else {
return titleText;
}
}
name_from = ax::mojom::blink::NameFrom::kPlaceholder;
if (name_sources) {
name_sources->push_back(
NameSource(*found_text_alternative, html_names::kPlaceholderAttr));
NameSource& source = name_sources->back();
source.type = name_from;
}
const String placeholder = PlaceholderFromNativeAttribute();
if (!placeholder.empty()) {
text_alternative = placeholder;
if (name_sources) {
NameSource& source = name_sources->back();
source.text = text_alternative;
source.attribute_value =
html_element->FastGetAttribute(html_names::kPlaceholderAttr);
*found_text_alternative = true;
} else {
return text_alternative;
}
}
}
// Input type=file. Not part of the spec, but Blink implements it
// as a single control that has both a button ("Choose file...") and
// some text showing the filename, and we need to concatenate both into
// the name of the button.
if (input_element && input_element->type() == input_type_names::kFile) {
name_from = ax::mojom::blink::NameFrom::kValue;
String displayed_file_path = GetValueForControl();
String upload_button_text = input_element->UploadButton()->Value();
if (!displayed_file_path.empty()) {
text_alternative = displayed_file_path + ", " + upload_button_text;
} else {
text_alternative = upload_button_text;
}
*found_text_alternative = true;
if (name_sources) {
name_sources->push_back(NameSource(true, kValueAttr));
name_sources->back().type = name_from;
name_sources->back().text = text_alternative;
} else {
return text_alternative;
}
}
// Also check for aria-placeholder.
if (IsTextField()) {
name_from = ax::mojom::blink::NameFrom::kPlaceholder;
if (name_sources) {
name_sources->push_back(NameSource(*found_text_alternative,
html_names::kAriaPlaceholderAttr));
NameSource& source = name_sources->back();
source.type = name_from;
}
const AtomicString& aria_placeholder =
GetAOMPropertyOrARIAAttribute(AOMStringProperty::kPlaceholder);
if (!aria_placeholder.empty()) {
text_alternative = aria_placeholder;
if (name_sources) {
NameSource& source = name_sources->back();
source.text = text_alternative;
source.attribute_value = aria_placeholder;
*found_text_alternative = true;
} else {
return text_alternative;
}
}
return text_alternative;
}
// 5.8 img or area Element
if (IsA<HTMLImageElement>(GetNode()) || IsA<HTMLAreaElement>(GetNode()) ||
(GetLayoutObject() && GetLayoutObject()->IsSVGImage())) {
// alt
const AtomicString& alt = GetAttribute(kAltAttr);
const bool is_empty = alt.empty() && !alt.IsNull();
name_from = is_empty ? ax::mojom::blink::NameFrom::kAttributeExplicitlyEmpty
: ax::mojom::blink::NameFrom::kAttribute;
if (name_sources) {
name_sources->push_back(NameSource(*found_text_alternative, kAltAttr));
name_sources->back().type = name_from;
}
if (!alt.IsNull()) {
text_alternative = alt;
if (name_sources) {
NameSource& source = name_sources->back();
source.attribute_value = alt;
source.text = text_alternative;
*found_text_alternative = true;
} else {
return text_alternative;
}
}
return text_alternative;
}
// 5.9 table Element
if (auto* table_element = DynamicTo<HTMLTableElement>(GetNode())) {
// caption
name_from = ax::mojom::blink::NameFrom::kCaption;
if (name_sources) {
name_sources->push_back(NameSource(*found_text_alternative));
name_sources->back().type = name_from;
name_sources->back().native_source = kAXTextFromNativeHTMLTableCaption;
}
HTMLTableCaptionElement* caption = table_element->caption();
if (caption) {
AXObject* caption_ax_object = AXObjectCache().GetOrCreate(caption);
if (caption_ax_object) {
text_alternative =
RecursiveTextAlternative(*caption_ax_object, nullptr, visited);
if (related_objects) {
local_related_objects.push_back(
MakeGarbageCollected<NameSourceRelatedObject>(caption_ax_object,
text_alternative));
*related_objects = local_related_objects;
local_related_objects.clear();
}
if (name_sources) {
NameSource& source = name_sources->back();
source.related_objects = *related_objects;
source.text = text_alternative;
*found_text_alternative = true;
} else {
return text_alternative;
}
}
}
// summary
name_from = ax::mojom::blink::NameFrom::kAttribute;
if (name_sources) {
name_sources->push_back(
NameSource(*found_text_alternative, html_names::kSummaryAttr));
name_sources->back().type = name_from;
}
const AtomicString& summary = GetAttribute(html_names::kSummaryAttr);
if (!summary.IsNull()) {
text_alternative = summary;
if (name_sources) {
NameSource& source = name_sources->back();
source.attribute_value = summary;
source.text = text_alternative;
*found_text_alternative = true;
} else {
return text_alternative;
}
}
return text_alternative;
}
// Per SVG AAM 1.0's modifications to 2D of this algorithm.
if (GetNode()->IsSVGElement()) {
name_from = ax::mojom::blink::NameFrom::kRelatedElement;
if (name_sources) {
name_sources->push_back(NameSource(*found_text_alternative));
name_sources->back().type = name_from;
name_sources->back().native_source = kAXTextFromNativeTitleElement;
}
auto* container_node = To<ContainerNode>(GetNode());
Element* title = ElementTraversal::FirstChild(
*container_node, HasTagName(svg_names::kTitleTag));
if (title) {
// TODO(accessibility): In most cases <desc> and <title> can participate
// in the recursive text alternative calculation. However when the <desc>
// or <title> is the child of a <use>, |AXObjectCache::GetOrCreate| will
// fail when |AXObject::ComputeNonARIAParent| returns null because the
// <use> element's subtree isn't visited by LayoutTreeBuilderTraversal. In
// addition, while aria-label and other text alternative sources are are
// technically valid on SVG <desc> and <title>, it is not clear if user
// agents must expose their values. Therefore until we hear otherwise,
// just use the inner text. See https://github.com/w3c/svgwg/issues/867
text_alternative = title->GetInnerTextWithoutUpdate();
if (!text_alternative.empty()) {
if (name_sources) {
NameSource& source = name_sources->back();
source.text = text_alternative;
source.related_objects = *related_objects;
*found_text_alternative = true;
} else {
return text_alternative;
}
}
}
// The SVG-AAM says that the xlink:title participates as a name source
// for links.
if (IsA<SVGAElement>(GetNode())) {
name_from = ax::mojom::blink::NameFrom::kAttribute;
if (name_sources) {
name_sources->push_back(
NameSource(*found_text_alternative, xlink_names::kTitleAttr));
name_sources->back().type = name_from;
}
const AtomicString& title_attr =
DynamicTo<Element>(GetNode())->FastGetAttribute(
xlink_names::kTitleAttr);
if (!title_attr.empty()) {
text_alternative = title_attr;
if (name_sources) {
NameSource& source = name_sources->back();
source.text = text_alternative;
source.attribute_value = title_attr;
*found_text_alternative = true;
} else {
return text_alternative;
}
}
}
}
// Fieldset / legend.
if (auto* html_field_set_element =
DynamicTo<HTMLFieldSetElement>(GetNode())) {
name_from = ax::mojom::blink::NameFrom::kRelatedElement;
if (name_sources) {
name_sources->push_back(NameSource(*found_text_alternative));
name_sources->back().type = name_from;
name_sources->back().native_source = kAXTextFromNativeHTMLLegend;
}
HTMLElement* legend = html_field_set_element->Legend();
if (legend) {
AXObject* legend_ax_object = AXObjectCache().GetOrCreate(legend);
// Avoid an infinite loop
if (legend_ax_object && !visited.Contains(legend_ax_object)) {
text_alternative =
RecursiveTextAlternative(*legend_ax_object, nullptr, visited);
if (related_objects) {
local_related_objects.push_back(
MakeGarbageCollected<NameSourceRelatedObject>(legend_ax_object,
text_alternative));
*related_objects = local_related_objects;
local_related_objects.clear();
}
if (name_sources) {
NameSource& source = name_sources->back();
source.related_objects = *related_objects;
source.text = text_alternative;
*found_text_alternative = true;
} else {
return text_alternative;
}
}
}
}
// Document.
if (Document* document = DynamicTo<Document>(GetNode())) {
if (document) {
name_from = ax::mojom::blink::NameFrom::kAttribute;
if (name_sources) {
name_sources->push_back(
NameSource(found_text_alternative, html_names::kAriaLabelAttr));
name_sources->back().type = name_from;
}
if (Element* document_element = document->documentElement()) {
const AtomicString& aria_label =
AccessibleNode::GetPropertyOrARIAAttribute(
document_element, AOMStringProperty::kLabel);
if (!aria_label.empty()) {
text_alternative = aria_label;
if (name_sources) {
NameSource& source = name_sources->back();
source.text = text_alternative;
source.attribute_value = aria_label;
*found_text_alternative = true;
} else {
return text_alternative;
}
}
}
text_alternative = document->title();
bool is_empty_title_element =
text_alternative.empty() && document->TitleElement();
if (is_empty_title_element)
name_from = ax::mojom::blink::NameFrom::kAttributeExplicitlyEmpty;
else
name_from = ax::mojom::blink::NameFrom::kRelatedElement;
if (name_sources) {
name_sources->push_back(NameSource(*found_text_alternative));
NameSource& source = name_sources->back();
source.type = name_from;
source.native_source = kAXTextFromNativeTitleElement;
source.text = text_alternative;
*found_text_alternative = true;
} else {
return text_alternative;
}
}
}
return text_alternative;
}
String AXNodeObject::Description(
ax::mojom::blink::NameFrom name_from,
ax::mojom::blink::DescriptionFrom& description_from,
AXObjectVector* description_objects) const {
AXRelatedObjectVector related_objects;
String result =
Description(name_from, description_from, nullptr, &related_objects);
if (description_objects) {
description_objects->clear();
for (NameSourceRelatedObject* related_object : related_objects)
description_objects->push_back(related_object->object);
}
result = result.SimplifyWhiteSpace(IsHTMLSpace<UChar>);
if (RoleValue() == ax::mojom::blink::Role::kSpinButton &&
DatetimeAncestor()) {
// Fields inside a datetime control need to merge the field description
// with the description of the <input> element.
const AXObject* datetime_ancestor = DatetimeAncestor();
ax::mojom::blink::NameFrom datetime_ancestor_name_from;
datetime_ancestor->GetName(datetime_ancestor_name_from, nullptr);
if (description_objects)
description_objects->clear();
String ancestor_description = DatetimeAncestor()->Description(
datetime_ancestor_name_from, description_from, description_objects);
if (!result.empty() && !ancestor_description.empty())
return result + " " + ancestor_description;
if (!ancestor_description.empty())
return ancestor_description;
}
return result;
}
// Based on
// http://rawgit.com/w3c/aria/master/html-aam/html-aam.html#accessible-name-and-description-calculation
String AXNodeObject::Description(
ax::mojom::blink::NameFrom name_from,
ax::mojom::blink::DescriptionFrom& description_from,
DescriptionSources* description_sources,
AXRelatedObjectVector* related_objects) const {
// If descriptionSources is non-null, relatedObjects is used in filling it in,
// so it must be non-null as well.
// Important: create a DescriptionSource for every *potential* description
// source, even if it ends up not being present.
// When adding a new description_from type:
// * Also add it to AXValueNativeSourceType here:
// blink/public/devtools_protocol/browser_protocol.pdl
// * Update InspectorTypeBuilderHelper to map the new enum to
// the browser_protocol enum in NativeSourceType():
// blink/renderer/modules/accessibility/inspector_type_builder_helper.cc
// * Update devtools_frontend to add a new string for the new type of
// description. See AXNativeSourceTypes at:
// devtools-frontend/src/front_end/accessibility/AccessibilityStrings.js
if (description_sources)
DCHECK(related_objects);
if (!GetNode())
return String();
String description;
bool found_description = false;
description_from = ax::mojom::blink::DescriptionFrom::kRelatedElement;
if (description_sources) {
description_sources->push_back(
DescriptionSource(found_description, html_names::kAriaDescribedbyAttr));
description_sources->back().type = description_from;
}
// aria-describedby overrides any other accessible description, from:
// http://rawgit.com/w3c/aria/master/html-aam/html-aam.html
Element* element = GetElement();
if (!element)
return String();
Vector<String> ids;
HeapVector<Member<Element>> elements_from_attribute;
if (ElementsFromAttribute(element, elements_from_attribute,
html_names::kAriaDescribedbyAttr, ids)) {
// TODO(meredithl): Determine description sources when |aria_describedby| is
// the empty string, in order to make devtools work with attr-associated
// elements.
if (description_sources) {
description_sources->back().attribute_value =
GetAttribute(html_names::kAriaDescribedbyAttr);
}
AXObjectSet visited;
description = TextFromElements(true, visited, elements_from_attribute,
related_objects);
for (auto& member_element : elements_from_attribute)
ids.push_back(member_element->GetIdAttribute());
TokenVectorFromAttribute(element, ids, html_names::kAriaDescribedbyAttr);
AXObjectCache().UpdateReverseTextRelations(this, ids);
if (!description.IsNull()) {
if (description_sources) {
DescriptionSource& source = description_sources->back();
source.type = description_from;
source.related_objects = *related_objects;
source.text = description;
found_description = true;
} else {
return description;
}
} else if (description_sources) {
description_sources->back().invalid = true;
}
}
// aria-description overrides any HTML-based accessible description,
// but not aria-describedby.
const AtomicString& aria_desc =
GetAOMPropertyOrARIAAttribute(AOMStringProperty::kDescription);
if (!aria_desc.IsNull()) {
description_from = ax::mojom::blink::DescriptionFrom::kAriaDescription;
description = aria_desc;
if (description_sources) {
found_description = true;
description_sources->back().text = description;
} else {
return description;
}
}
// SVG-AAM specifies additional description sources when ARIA sources have not
// been found. https://w3c.github.io/svg-aam/#mapping_additional_nd
if (IsA<SVGElement>(GetNode())) {
return SVGDescription(name_from, description_from, description_sources,
related_objects);
}
const auto* input_element = DynamicTo<HTMLInputElement>(GetNode());
// value, 5.2.2 from: https://www.w3.org/TR/html-aam-1.0/
if (name_from != ax::mojom::blink::NameFrom::kValue && input_element &&
input_element->IsTextButton()) {
description_from = ax::mojom::blink::DescriptionFrom::kButtonLabel;
if (description_sources) {
description_sources->push_back(
DescriptionSource(found_description, kValueAttr));
description_sources->back().type = description_from;
}
String value = input_element->Value();
if (!value.IsNull()) {
description = value;
if (description_sources) {
DescriptionSource& source = description_sources->back();
source.text = description;
found_description = true;
} else {
return description;
}
}
}
if (RoleValue() == ax::mojom::blink::Role::kRuby) {
description_from = ax::mojom::blink::DescriptionFrom::kRubyAnnotation;
if (description_sources) {
description_sources->push_back(DescriptionSource(found_description));
description_sources->back().type = description_from;
description_sources->back().native_source =
kAXTextFromNativeHTMLRubyAnnotation;
}
AXObject* ruby_annotation_ax_object = nullptr;
for (const auto& child : children_) {
if (child->RoleValue() == ax::mojom::blink::Role::kRubyAnnotation &&
child->GetNode() && IsA<HTMLRTElement>(child->GetNode())) {
ruby_annotation_ax_object = child;
break;
}
}
if (ruby_annotation_ax_object) {
AXObjectSet visited;
description =
RecursiveTextAlternative(*ruby_annotation_ax_object, this, visited);
if (related_objects) {
related_objects->push_back(
MakeGarbageCollected<NameSourceRelatedObject>(
ruby_annotation_ax_object, description));
}
if (description_sources) {
DescriptionSource& source = description_sources->back();
source.related_objects = *related_objects;
source.text = description;
found_description = true;
} else {
return description;
}
}
}
// table caption, 5.9.2 from: https://www.w3.org/TR/html-aam-1.0/
auto* table_element = DynamicTo<HTMLTableElement>(element);
if (name_from != ax::mojom::blink::NameFrom::kCaption && table_element) {
description_from = ax::mojom::blink::DescriptionFrom::kTableCaption;
if (description_sources) {
description_sources->push_back(DescriptionSource(found_description));
description_sources->back().type = description_from;
description_sources->back().native_source =
kAXTextFromNativeHTMLTableCaption;
}
HTMLTableCaptionElement* caption = table_element->caption();
if (caption) {
AXObject* caption_ax_object = AXObjectCache().GetOrCreate(caption);
if (caption_ax_object) {
AXObjectSet visited;
description =
RecursiveTextAlternative(*caption_ax_object, nullptr, visited);
if (related_objects) {
related_objects->push_back(
MakeGarbageCollected<NameSourceRelatedObject>(caption_ax_object,
description));
}
if (description_sources) {
DescriptionSource& source = description_sources->back();
source.related_objects = *related_objects;
source.text = description;
found_description = true;
} else {
return description;
}
}
}
}
// summary, 5.8.2 from: https://www.w3.org/TR/html-aam-1.0/
if (name_from != ax::mojom::blink::NameFrom::kContents &&
IsA<HTMLSummaryElement>(GetNode())) {
description_from = ax::mojom::blink::DescriptionFrom::kSummary;
if (description_sources) {
description_sources->push_back(DescriptionSource(found_description));
description_sources->back().type = description_from;
}
AXObjectSet visited;
description = TextFromDescendants(visited, nullptr, false);
if (!description.empty()) {
if (description_sources) {
found_description = true;
description_sources->back().text = description;
} else {
return description;
}
}
}
// title attribute, from: https://www.w3.org/TR/html-aam-1.0/
if (name_from != ax::mojom::blink::NameFrom::kTitle) {
description_from = ax::mojom::blink::DescriptionFrom::kTitle;
if (description_sources) {
description_sources->push_back(
DescriptionSource(found_description, kTitleAttr));
description_sources->back().type = description_from;
}
const AtomicString& title = GetAttribute(kTitleAttr);
if (!title.empty()) {
description = title;
if (description_sources) {
found_description = true;
description_sources->back().text = description;
} else {
return description;
}
}
}
description_from = ax::mojom::blink::DescriptionFrom::kNone;
if (found_description) {
DCHECK(description_sources)
<< "Should only reach here if description_sources are tracked";
// Use the first non-null description.
// TODO(accessibility) Why do we need to check superceded if that will
// always be the first one?
for (DescriptionSource& description_source : *description_sources) {
if (!description_source.text.IsNull() && !description_source.superseded) {
description_from = description_source.type;
if (!description_source.related_objects.empty())
*related_objects = description_source.related_objects;
return description_source.text;
}
}
}
return String();
}
String AXNodeObject::SVGDescription(
ax::mojom::blink::NameFrom name_from,
ax::mojom::blink::DescriptionFrom& description_from,
DescriptionSources* description_sources,
AXRelatedObjectVector* related_objects) const {
DCHECK(IsA<SVGElement>(GetNode()));
String description;
bool found_description = false;
Element* element = GetElement();
description_from = ax::mojom::blink::DescriptionFrom::kSvgDescElement;
if (description_sources) {
description_sources->push_back(DescriptionSource(found_description));
description_sources->back().type = description_from;
description_sources->back().native_source = kAXTextFromNativeSVGDescElement;
}
if (Element* desc = ElementTraversal::FirstChild(
*element, HasTagName(svg_names::kDescTag))) {
// TODO(accessibility): In most cases <desc> and <title> can participate in
// the recursive text alternative calculation. However when the <desc> or
// <title> is the child of a <use>, |AXObjectCache::GetOrCreate| will fail
// when |AXObject::ComputeNonARIAParent| returns null because the <use>
// element's subtree isn't visited by LayoutTreeBuilderTraversal. In
// addition, while aria-label and other text alternative sources are are
// technically valid on SVG <desc> and <title>, it is not clear if user
// agents must expose their values. Therefore until we hear otherwise, just
// use the inner text. See https://github.com/w3c/svgwg/issues/867
description = desc->GetInnerTextWithoutUpdate();
if (!description.empty()) {
if (description_sources) {
DescriptionSource& source = description_sources->back();
source.related_objects = *related_objects;
source.text = description;
found_description = true;
} else {
return description;
}
}
}
// If we haven't found a description source yet and the title is present,
// SVG-AAM states to use the <title> if ARIA label attributes are used to
// provide the accessible name.
if (IsNameFromAriaAttribute(element)) {
description_from = ax::mojom::blink::DescriptionFrom::kTitle;
if (description_sources) {
description_sources->push_back(DescriptionSource(found_description));
description_sources->back().type = description_from;
description_sources->back().native_source = kAXTextFromNativeTitleElement;
}
if (Element* title = ElementTraversal::FirstChild(
*element, HasTagName(svg_names::kTitleTag))) {
// TODO(accessibility): In most cases <desc> and <title> can participate
// in the recursive text alternative calculation. However when the <desc>
// or <title> is the child of a <use>, |AXObjectCache::GetOrCreate| will
// fail when |AXObject::ComputeNonARIAParent| returns null because the
// <use> element's subtree isn't visited by LayoutTreeBuilderTraversal. In
// addition, while aria-label and other text alternative sources are are
// technically valid on SVG <desc> and <title>, it is not clear if user
// agents must expose their values. Therefore until we hear otherwise,
// just use the inner text. See https://github.com/w3c/svgwg/issues/867
description = title->GetInnerTextWithoutUpdate();
if (!description.empty()) {
if (description_sources) {
DescriptionSource& source = description_sources->back();
source.related_objects = *related_objects;
source.text = description;
found_description = true;
} else {
return description;
}
}
}
}
// In the case of an SVG <a>, the last description source is the xlink:title
// attribute, if it didn't serve as the name source.
if (IsA<SVGAElement>(GetNode()) &&
name_from != ax::mojom::blink::NameFrom::kAttribute) {
description_from = ax::mojom::blink::DescriptionFrom::kTitle;
const AtomicString& title_attr =
DynamicTo<Element>(GetNode())->FastGetAttribute(
xlink_names::kTitleAttr);
if (!title_attr.empty()) {
description = title_attr;
if (description_sources) {
found_description = true;
description_sources->back().text = description;
} else {
return description;
}
}
}
return String();
}
String AXNodeObject::Placeholder(ax::mojom::blink::NameFrom name_from) const {
if (name_from == ax::mojom::blink::NameFrom::kPlaceholder)
return String();
Node* node = GetNode();
if (!node || !node->IsHTMLElement())
return String();
String native_placeholder = PlaceholderFromNativeAttribute();
if (!native_placeholder.empty())
return native_placeholder;
const AtomicString& aria_placeholder =
GetAOMPropertyOrARIAAttribute(AOMStringProperty::kPlaceholder);
if (!aria_placeholder.empty())
return aria_placeholder;
return String();
}
String AXNodeObject::Title(ax::mojom::blink::NameFrom name_from) const {
if (name_from == ax::mojom::blink::NameFrom::kTitle)
return String(); // Already exposed the title in the name field.
return GetTitle(GetElement());
}
String AXNodeObject::PlaceholderFromNativeAttribute() const {
Node* node = GetNode();
if (!node || !blink::IsTextControl(*node))
return String();
return ToTextControl(node)->StrippedPlaceholder();
}
String AXNodeObject::GetValueContributionToName(AXObjectSet& visited) const {
if (IsTextField())
return SlowGetValueForControlIncludingContentEditable();
if (IsRangeValueSupported()) {
const AtomicString& aria_valuetext =
GetAOMPropertyOrARIAAttribute(AOMStringProperty::kValueText);
if (!aria_valuetext.IsNull())
return aria_valuetext.GetString();
float value;
if (ValueForRange(&value))
return String::Number(value);
}
// "If the embedded control has role combobox or listbox, return the text
// alternative of the chosen option."
if (UseNameFromSelectedOption()) {
StringBuilder accumulated_text;
AXObjectVector selected_options;
SelectedOptions(selected_options);
for (const auto& child : selected_options) {
if (visited.insert(child).is_new_entry) {
if (accumulated_text.length())
accumulated_text.Append(" ");
accumulated_text.Append(child->ComputedName());
}
}
return accumulated_text.ToString();
}
return String();
}
bool AXNodeObject::UseNameFromSelectedOption() const {
// Assumes that the node was reached via recursion in the name calculation.
switch (RoleValue()) {
// Step 2E from: http://www.w3.org/TR/accname-aam-1.1
case ax::mojom::blink::Role::kComboBoxGrouping:
case ax::mojom::blink::Role::kComboBoxMenuButton:
case ax::mojom::blink::Role::kComboBoxSelect:
case ax::mojom::blink::Role::kListBox:
return true;
default:
return false;
}
}
void AXNodeObject::Trace(Visitor* visitor) const {
visitor->Trace(node_);
AXObject::Trace(visitor);
}
} // namespace blink