bool AccessibilityObject::allowsTextRanges() const
{
// Check type for the AccessibilityObject.
if (isTextControl() || isWebArea() || isGroup() || isLink() || isHeading() || isListItem() || isTableCell())
return true;
// Check roles as the last fallback mechanism.
AccessibilityRole role = roleValue();
return role == ParagraphRole || role == LabelRole || role == DivRole || role == FormRole;
}
bool AccessibilitySVGElement::inheritsPresentationalRole() const
{
if (canSetFocusAttribute())
return false;
AccessibilityRole role = roleValue();
if (role != AccessibilityRole::SVGTextPath && role != AccessibilityRole::SVGTSpan)
return false;
for (AccessibilityObject* parent = parentObject(); parent; parent = parent->parentObject()) {
if (is<AccessibilityRenderObject>(*parent) && parent->element()->hasTagName(SVGNames::textTag))
return parent->roleValue() == AccessibilityRole::Presentational;
}
return false;
}
AccessibilityObjectInclusion AccessibilityObject::accessibilityPlatformIncludesObject() const
{
AccessibilityObject* parent = parentObject();
if (!parent)
return DefaultBehavior;
AccessibilityRole role = roleValue();
if (role == SplitterRole)
return IncludeObject;
// We expose the slider as a whole but not its value indicator.
if (role == SliderThumbRole)
return IgnoreObject;
// When a list item is made up entirely of children (e.g. paragraphs)
// the list item gets ignored. We need it.
if (isGroup() && parent->isList())
return IncludeObject;
// Entries and password fields have extraneous children which we want to ignore.
if (parent->isPasswordField() || parent->isTextControl())
return IgnoreObject;
// Include all tables, even layout tables. The AT can decide what to do with each.
if (role == CellRole || role == TableRole)
return IncludeObject;
// The object containing the text should implement AtkText itself.
if (role == StaticTextRole)
return IgnoreObject;
// Include all list items, regardless they have or not inline children
if (role == ListItemRole)
return IncludeObject;
// Bullets/numbers for list items shouldn't be exposed as AtkObjects.
if (role == ListMarkerRole)
return IgnoreObject;
// Never expose an unknown object, since AT's won't know what to
// do with them. This is what is done on the Mac as well.
if (role == UnknownRole)
return IgnoreObject;
return DefaultBehavior;
}
bool AccessibilitySVGElement::computeAccessibilityIsIgnored() const
{
// According to the SVG Accessibility API Mappings spec, items should be excluded if:
// * They would be excluded according to the Core Accessibility API Mappings.
// * They are neither perceivable nor interactive.
// * Their first mappable role is presentational, unless they have a global ARIA
// attribute (covered by Core AAM) or at least one 'title' or 'desc' child element.
// * They have an ancestor with Children Presentational: True (covered by Core AAM)
AccessibilityObjectInclusion decision = defaultObjectInclusion();
if (decision == AccessibilityObjectInclusion::IgnoreObject)
return true;
if (m_renderer->isSVGHiddenContainer())
return true;
// The SVG AAM states objects with at least one 'title' or 'desc' element MUST be included.
// At this time, the presence of a matching 'lang' attribute is not mentioned in the spec.
for (const auto& child : childrenOfType<SVGElement>(*element())) {
if ((is<SVGTitleElement>(child) || is<SVGDescElement>(child)))
return false;
}
if (roleValue() == AccessibilityRole::Presentational || inheritsPresentationalRole())
return true;
if (ariaRoleAttribute() != AccessibilityRole::Unknown)
return false;
// The SVG AAM states text elements should also be included, if they have content.
if (m_renderer->isSVGText() || m_renderer->isSVGTextPath()) {
for (auto& child : childrenOfType<RenderText>(downcast<RenderElement>(*m_renderer))) {
if (!child.isAllCollapsibleWhitespace())
return false;
}
}
// SVG shapes should not be included unless there's a concrete reason for inclusion.
// https://rawgit.com/w3c/aria/master/svg-aam/svg-aam.html#exclude_elements
if (m_renderer->isSVGShape())
return !(hasAttributesRequiredForInclusion() || canSetFocusAttribute() || element()->hasEventListeners());
return AccessibilityRenderObject::computeAccessibilityIsIgnored();
}
AccessibilityObjectInclusion AccessibilityObject::accessibilityPlatformIncludesObject() const
{
AccessibilityObject* parent = parentObject();
if (!parent)
return DefaultBehavior;
AccessibilityRole role = roleValue();
if (role == HorizontalRuleRole)
return IncludeObject;
// We expose the slider as a whole but not its value indicator.
if (role == SliderThumbRole)
return IgnoreObject;
// When a list item is made up entirely of children (e.g. paragraphs)
// the list item gets ignored. We need it.
if (isGroup() && parent->isList())
return IncludeObject;
// Entries and password fields have extraneous children which we want to ignore.
if (parent->isPasswordField() || parent->isTextControl())
return IgnoreObject;
// Include all tables, even layout tables. The AT can decide what to do with each.
if (role == CellRole || role == TableRole)
return IncludeObject;
// The object containing the text should implement AtkText itself.
if (role == StaticTextRole)
return IgnoreObject;
// Include all list items, regardless they have or not inline children
if (role == ListItemRole)
return IncludeObject;
// Bullets/numbers for list items shouldn't be exposed as AtkObjects.
if (role == ListMarkerRole)
return IgnoreObject;
// Never expose an unknown object, since AT's won't know what to
// do with them. This is what is done on the Mac as well.
if (role == UnknownRole)
return IgnoreObject;
// Given a paragraph or div containing a non-nested anonymous block, WebCore
// ignores the paragraph or div and includes the block. We want the opposite:
// ATs are expecting accessible objects associated with textual elements. They
// usually have no need for the anonymous block. And when the wrong objects
// get included or ignored, needed accessibility signals do not get emitted.
if (role == ParagraphRole || role == DivRole) {
// Don't call textUnderElement() here, because it's slow and it can
// crash when called while we're in the middle of a subtree being deleted.
if (!renderer()->firstChildSlow())
return DefaultBehavior;
if (!parent->renderer() || parent->renderer()->isAnonymousBlock())
return DefaultBehavior;
for (RenderObject* r = renderer()->firstChildSlow(); r; r = r->nextSibling()) {
if (r->isAnonymousBlock())
return IncludeObject;
}
}
// Block spans result in objects of ATK_ROLE_PANEL which are almost always unwanted.
// However, if we ignore block spans whose parent is the body, the child controls
// will become immediate children of the ATK_ROLE_DOCUMENT_FRAME and any text will
// become text within the document frame itself. This ultimately may be what we want
// and would largely be consistent with what we see from Gecko. However, ignoring
// spans whose parent is the body changes the current behavior we see from WebCore.
// Until we have sufficient time to properly analyze these cases, we will defer to
// WebCore. We only check that the parent is not aria because we do not expect
// anonymous blocks which are aria-related to themselves have an aria role, nor
// have we encountered instances where the parent of an anonymous block also lacked
// an aria role but the grandparent had one.
if (renderer() && renderer()->isAnonymousBlock() && !parent->renderer()->isBody()
&& parent->ariaRoleAttribute() == UnknownRole)
return IgnoreObject;
return DefaultBehavior;
}
