third_party/WebKit/Source/modules/accessibility/AXListBox.cpp

/*
 * Copyright (C) 2008 Apple 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
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#include "modules/accessibility/AXListBox.h"

#include "core/html/HTMLOptionElement.h"
#include "core/html/HTMLSelectElement.h"
#include "modules/accessibility/AXListBoxOption.h"
#include "modules/accessibility/AXObjectCacheImpl.h"

namespace blink {

using namespace HTMLNames;

AXListBox::AXListBox(LayoutObject* layoutObject,
                     AXObjectCacheImpl& axObjectCache)
    : AXLayoutObject(layoutObject, axObjectCache), m_activeIndex(-1) {
  activeIndexChanged();
}

AXListBox::~AXListBox() {}

AXListBox* AXListBox::create(LayoutObject* layoutObject,
                             AXObjectCacheImpl& axObjectCache) {
  return new AXListBox(layoutObject, axObjectCache);
}

AccessibilityRole AXListBox::determineAccessibilityRole() {
  if ((m_ariaRole = determineAriaRoleAttribute()) != UnknownRole)
    return m_ariaRole;

  return ListBoxRole;
}

AXObject* AXListBox::activeDescendant() {
  if (!isHTMLSelectElement(getNode()))
    return nullptr;

  HTMLSelectElement* select = toHTMLSelectElement(getNode());
  int activeIndex = select->activeSelectionEndListIndex();
  if (activeIndex >= 0 && activeIndex < static_cast<int>(select->length())) {
    HTMLOptionElement* option = select->item(m_activeIndex);
    return axObjectCache().get(option);
  }

  return nullptr;
}

void AXListBox::activeIndexChanged() {
  if (!isHTMLSelectElement(getNode()))
    return;

  HTMLSelectElement* select = toHTMLSelectElement(getNode());
  int activeIndex = select->activeSelectionEndListIndex();
  if (activeIndex == m_activeIndex)
    return;

  m_activeIndex = activeIndex;
  if (!select->isFocused())
    return;

  axObjectCache().postNotification(
      this, AXObjectCacheImpl::AXActiveDescendantChanged);
}

}  // namespace blink