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/*
* Copyright (C) 2008 Apple Ltd.
* Copyright (C) 2008 Alp Toker <alp@atoker.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include "config.h"
#include "AccessibilityObject.h"
#include "HTMLSpanElement.h"
#include "RenderBlock.h"
#include "RenderInline.h"
#include "RenderIterator.h"
#include "RenderTableCell.h"
#include "RenderText.h"
#include "TextControlInnerElements.h"
#include <glib-object.h>
#if HAVE(ACCESSIBILITY)
namespace WebCore {
bool AccessibilityObject::accessibilityIgnoreAttachment() const
{
return false;
}
AccessibilityObjectInclusion AccessibilityObject::accessibilityPlatformIncludesObject() const
{
AccessibilityObject* parent = parentObject();
if (!parent)
return DefaultBehavior;
// If the author has provided a role, platform-specific inclusion likely doesn't apply.
if (ariaRoleAttribute() != UnknownRole)
return DefaultBehavior;
AccessibilityRole role = roleValue();
// 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 || role == ColumnHeaderRole || role == RowHeaderRole)
return IncludeObject;
// The object containing the text should implement AtkText itself.
// However, WebCore also maps ARIA's "text" role to the StaticTextRole.
if (role == StaticTextRole)
return ariaRoleAttribute() != UnknownRole ? DefaultBehavior : 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;
if (role == InlineRole)
return IncludeObject;
// Lines past this point only make sense for AccessibilityRenderObjects.
RenderObject* renderObject = renderer();
if (!renderObject)
return DefaultBehavior;
// We always want to include paragraphs that have rendered content.
// WebCore Accessibility does so unless there is a RenderBlock child.
if (role == ParagraphRole) {
auto child = childrenOfType<RenderBlock>(downcast<RenderElement>(*renderObject)).first();
return child ? IncludeObject : DefaultBehavior;
}
// We always want to include table cells (layout and CSS) that have rendered text content.
if (is<RenderTableCell>(renderObject)) {
for (const auto& child : childrenOfType<RenderObject>(downcast<RenderElement>(*renderObject))) {
if (is<RenderInline>(child) || is<RenderText>(child) || is<HTMLSpanElement>(child.node()))
return IncludeObject;
}
return DefaultBehavior;
}
if (renderObject->isAnonymousBlock()) {
// The text displayed by an ARIA menu item is exposed through the accessible name.
if (parent->isMenuItem())
return IgnoreObject;
// The text displayed in headings is typically exposed in the heading itself.
if (parent->isHeading())
return IgnoreObject;
// The text displayed in list items is typically exposed in the list item itself.
if (parent->isListItem())
return IgnoreObject;
// The text displayed in links is typically exposed in the link itself.
if (parent->isLink())
return IgnoreObject;
// FIXME: This next one needs some further consideration. But paragraphs are not
// typically huge (like divs). And ignoring anonymous block children of paragraphs
// will preserve existing behavior.
if (parent->roleValue() == ParagraphRole)
return IgnoreObject;
return DefaultBehavior;
}
Node* node = renderObject->node();
if (!node)
return DefaultBehavior;
// We don't want <span> elements to show up in the accessibility hierarchy unless
// we have good reasons for that (e.g. focusable or visible because of containing
// a meaningful accessible name, maybe set through ARIA), so we can use
// atk_component_grab_focus() to set the focus to it.
if (is<HTMLSpanElement>(node) && !canSetFocusAttribute() && !hasAttributesRequiredForInclusion() && !supportsARIAAttributes())
return IgnoreObject;
// If we include TextControlInnerTextElement children, changes to those children
// will result in focus and text notifications that suggest the user is no longer
// in the control. This can be especially problematic for screen reader users with
// key echo enabled when typing in a password input.
if (is<TextControlInnerTextElement>(node))
return IgnoreObject;
return DefaultBehavior;
}
AccessibilityObjectWrapper* AccessibilityObject::wrapper() const
{
return m_wrapper;
}
void AccessibilityObject::setWrapper(AccessibilityObjectWrapper* wrapper)
{
if (wrapper == m_wrapper)
return;
if (m_wrapper)
g_object_unref(m_wrapper);
m_wrapper = wrapper;
if (m_wrapper)
g_object_ref(m_wrapper);
}
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 || role == PreRole;
}
unsigned AccessibilityObject::getLengthForTextRange() const
{
unsigned textLength = text().length();
if (textLength)
return textLength;
// Gtk ATs need this for all text objects; not just text controls.
Node* node = this->node();
RenderObject* renderer = node ? node->renderer() : nullptr;
if (is<RenderText>(renderer))
textLength = downcast<RenderText>(*renderer).textLength();
// Get the text length from the elements under the
// accessibility object if the value is still zero.
if (!textLength && allowsTextRanges())
textLength = textUnderElement(AccessibilityTextUnderElementMode(AccessibilityTextUnderElementMode::TextUnderElementModeIncludeAllChildren)).length();
return textLength;
}
} // namespace WebCore
#endif // HAVE(ACCESSIBILITY)
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