/*
 * Copyright (C) 2009 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:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of Google Inc. 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 THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
 * OWNER OR 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 "public/web/WebAXObject.h"

#include "SkMatrix44.h"
#include "core/HTMLNames.h"
#include "core/css/CSSPrimitiveValueMappings.h"
#include "core/dom/Document.h"
#include "core/dom/Node.h"
#include "core/editing/markers/DocumentMarker.h"
#include "core/frame/FrameHost.h"
#include "core/frame/FrameView.h"
#include "core/frame/VisualViewport.h"
#include "core/input/KeyboardEventManager.h"
#include "core/style/ComputedStyle.h"
#include "core/page/Page.h"
#include "modules/accessibility/AXObject.h"
#include "modules/accessibility/AXObjectCacheImpl.h"
#include "modules/accessibility/AXTable.h"
#include "modules/accessibility/AXTableCell.h"
#include "modules/accessibility/AXTableColumn.h"
#include "modules/accessibility/AXTableRow.h"
#include "public/platform/WebFloatRect.h"
#include "public/platform/WebPoint.h"
#include "public/platform/WebRect.h"
#include "public/platform/WebString.h"
#include "public/platform/WebURL.h"
#include "public/web/WebDocument.h"
#include "public/web/WebElement.h"
#include "public/web/WebNode.h"
#include "web/WebLocalFrameImpl.h"
#include "web/WebViewImpl.h"
#include "wtf/text/StringBuilder.h"

namespace blink {

#if DCHECK_IS_ON()
// It's not safe to call some WebAXObject APIs if a layout is pending.
// Clients should call updateLayoutAndCheckValidity first.
static bool isLayoutClean(Document* document) {
  if (!document || !document->view())
    return false;
  return document->lifecycle().state() >= DocumentLifecycle::LayoutClean ||
         ((document->lifecycle().state() == DocumentLifecycle::StyleClean ||
           document->lifecycle().state() ==
               DocumentLifecycle::LayoutSubtreeChangeClean) &&
          !document->view()->needsLayout());
}
#endif

WebScopedAXContext::WebScopedAXContext(WebDocument& rootDocument)
    : m_private(ScopedAXObjectCache::create(*rootDocument.unwrap<Document>())) {
}

WebScopedAXContext::~WebScopedAXContext() {
  m_private.reset(0);
}

WebAXObject WebScopedAXContext::root() const {
  return WebAXObject(static_cast<AXObjectCacheImpl*>(m_private->get())->root());
}

void WebAXObject::reset() {
  m_private.reset();
}

void WebAXObject::assign(const WebAXObject& other) {
  m_private = other.m_private;
}

bool WebAXObject::equals(const WebAXObject& n) const {
  return m_private.get() == n.m_private.get();
}

bool WebAXObject::isDetached() const {
  if (m_private.isNull())
    return true;

  return m_private->isDetached();
}

int WebAXObject::axID() const {
  if (isDetached())
    return -1;

  return m_private->axObjectID();
}

int WebAXObject::generateAXID() const {
  if (isDetached())
    return -1;

  return m_private->axObjectCache().platformGenerateAXID();
}

bool WebAXObject::updateLayoutAndCheckValidity() {
  if (!isDetached()) {
    Document* document = m_private->getDocument();
    if (!document || !document->view())
      return false;
    document->view()->updateLifecycleToCompositingCleanPlusScrolling();
  }

  // Doing a layout can cause this object to be invalid, so check again.
  return !isDetached();
}

WebString WebAXObject::actionVerb() const {
  if (isDetached())
    return WebString();

  return m_private->actionVerb();
}

bool WebAXObject::canDecrement() const {
  if (isDetached())
    return false;

  return m_private->isSlider();
}

bool WebAXObject::canIncrement() const {
  if (isDetached())
    return false;

  return m_private->isSlider();
}

bool WebAXObject::canPress() const {
  if (isDetached())
    return false;

  return m_private->actionElement() || m_private->isButton() ||
         m_private->isMenuRelated();
}

bool WebAXObject::canSetFocusAttribute() const {
  if (isDetached())
    return false;

  return m_private->canSetFocusAttribute();
}

bool WebAXObject::canSetValueAttribute() const {
  if (isDetached())
    return false;

  return m_private->canSetValueAttribute();
}

unsigned WebAXObject::childCount() const {
  if (isDetached())
    return 0;

  return m_private->children().size();
}

WebAXObject WebAXObject::childAt(unsigned index) const {
  if (isDetached())
    return WebAXObject();

  if (m_private->children().size() <= index)
    return WebAXObject();

  return WebAXObject(m_private->children()[index]);
}

WebAXObject WebAXObject::parentObject() const {
  if (isDetached())
    return WebAXObject();

  return WebAXObject(m_private->parentObject());
}

bool WebAXObject::canSetSelectedAttribute() const {
  if (isDetached())
    return false;

  return m_private->canSetSelectedAttribute();
}

bool WebAXObject::isAnchor() const {
  if (isDetached())
    return false;

  return m_private->isAnchor();
}

bool WebAXObject::isAriaReadOnly() const {
  if (isDetached())
    return false;

  return equalIgnoringASCIICase(
      m_private->getAttribute(HTMLNames::aria_readonlyAttr), "true");
}

WebString WebAXObject::ariaAutoComplete() const {
  if (isDetached())
    return WebString();

  return m_private->ariaAutoComplete();
}

WebAXAriaCurrentState WebAXObject::ariaCurrentState() const {
  if (isDetached())
    return WebAXAriaCurrentStateUndefined;

  return static_cast<WebAXAriaCurrentState>(m_private->ariaCurrentState());
}

bool WebAXObject::isButtonStateMixed() const {
  if (isDetached())
    return false;

  return m_private->checkboxOrRadioValue() == ButtonStateMixed;
}

bool WebAXObject::isChecked() const {
  if (isDetached())
    return false;

  return m_private->isChecked();
}

bool WebAXObject::isClickable() const {
  if (isDetached())
    return false;

  return m_private->isClickable();
}

bool WebAXObject::isCollapsed() const {
  if (isDetached())
    return false;

  return m_private->isCollapsed();
}

bool WebAXObject::isControl() const {
  if (isDetached())
    return false;

  return m_private->isControl();
}

bool WebAXObject::isEnabled() const {
  if (isDetached())
    return false;

  return m_private->isEnabled();
}

WebAXExpanded WebAXObject::isExpanded() const {
  if (isDetached())
    return WebAXExpandedUndefined;

  return static_cast<WebAXExpanded>(m_private->isExpanded());
}

bool WebAXObject::isFocused() const {
  if (isDetached())
    return false;

  return m_private->isFocused();
}

bool WebAXObject::isHovered() const {
  if (isDetached())
    return false;

  return m_private->isHovered();
}

bool WebAXObject::isLinked() const {
  if (isDetached())
    return false;

  return m_private->isLinked();
}

bool WebAXObject::isLoaded() const {
  if (isDetached())
    return false;

  return m_private->isLoaded();
}

bool WebAXObject::isMultiSelectable() const {
  if (isDetached())
    return false;

  return m_private->isMultiSelectable();
}

bool WebAXObject::isOffScreen() const {
  if (isDetached())
    return false;

  return m_private->isOffScreen();
}

bool WebAXObject::isPasswordField() const {
  if (isDetached())
    return false;

  return m_private->isPasswordField();
}

bool WebAXObject::isPressed() const {
  if (isDetached())
    return false;

  return m_private->isPressed();
}

bool WebAXObject::isReadOnly() const {
  if (isDetached())
    return false;

  return m_private->isReadOnly();
}

bool WebAXObject::isRequired() const {
  if (isDetached())
    return false;

  return m_private->isRequired();
}

bool WebAXObject::isSelected() const {
  if (isDetached())
    return false;

  return m_private->isSelected();
}

bool WebAXObject::isSelectedOptionActive() const {
  if (isDetached())
    return false;

  return m_private->isSelectedOptionActive();
}

bool WebAXObject::isVisible() const {
  if (isDetached())
    return false;

  return m_private->isVisible();
}

bool WebAXObject::isVisited() const {
  if (isDetached())
    return false;

  return m_private->isVisited();
}

WebString WebAXObject::accessKey() const {
  if (isDetached())
    return WebString();

  return WebString(m_private->accessKey());
}

unsigned WebAXObject::backgroundColor() const {
  if (isDetached())
    return 0;

  // RGBA32 is an alias for unsigned int.
  return m_private->backgroundColor();
}

unsigned WebAXObject::color() const {
  if (isDetached())
    return 0;

  // RGBA32 is an alias for unsigned int.
  return m_private->color();
}

// Deprecated.
void WebAXObject::colorValue(int& r, int& g, int& b) const {
  if (isDetached())
    return;

  unsigned color = m_private->colorValue();
  r = (color >> 16) & 0xFF;
  g = (color >> 8) & 0xFF;
  b = color & 0xFF;
}

unsigned WebAXObject::colorValue() const {
  if (isDetached())
    return 0;

  // RGBA32 is an alias for unsigned int.
  return m_private->colorValue();
}

WebAXObject WebAXObject::ariaActiveDescendant() const {
  if (isDetached())
    return WebAXObject();

  return WebAXObject(m_private->activeDescendant());
}

bool WebAXObject::ariaControls(WebVector<WebAXObject>& controlsElements) const {
  if (isDetached())
    return false;

  AXObject::AXObjectVector controls;
  m_private->ariaControlsElements(controls);

  WebVector<WebAXObject> result(controls.size());
  for (size_t i = 0; i < controls.size(); i++)
    result[i] = WebAXObject(controls[i]);
  controlsElements.swap(result);

  return true;
}

bool WebAXObject::ariaHasPopup() const {
  if (isDetached())
    return false;

  return m_private->ariaHasPopup();
}

bool WebAXObject::ariaFlowTo(WebVector<WebAXObject>& flowToElements) const {
  if (isDetached())
    return false;

  AXObject::AXObjectVector flowTo;
  m_private->ariaFlowToElements(flowTo);

  WebVector<WebAXObject> result(flowTo.size());
  for (size_t i = 0; i < flowTo.size(); i++)
    result[i] = WebAXObject(flowTo[i]);
  flowToElements.swap(result);

  return true;
}

bool WebAXObject::isEditable() const {
  if (isDetached())
    return false;

  return m_private->isEditable();
}

bool WebAXObject::isMultiline() const {
  if (isDetached())
    return false;

  return m_private->isMultiline();
}

bool WebAXObject::isRichlyEditable() const {
  if (isDetached())
    return false;

  return m_private->isRichlyEditable();
}

int WebAXObject::posInSet() const {
  if (isDetached())
    return 0;

  return m_private->posInSet();
}

int WebAXObject::setSize() const {
  if (isDetached())
    return 0;

  return m_private->setSize();
}

bool WebAXObject::isInLiveRegion() const {
  if (isDetached())
    return false;

  return 0 != m_private->liveRegionRoot();
}

bool WebAXObject::liveRegionAtomic() const {
  if (isDetached())
    return false;

  return m_private->liveRegionAtomic();
}

bool WebAXObject::liveRegionBusy() const {
  if (isDetached())
    return false;

  return m_private->liveRegionBusy();
}

WebString WebAXObject::liveRegionRelevant() const {
  if (isDetached())
    return WebString();

  return m_private->liveRegionRelevant();
}

WebString WebAXObject::liveRegionStatus() const {
  if (isDetached())
    return WebString();

  return m_private->liveRegionStatus();
}

WebAXObject WebAXObject::liveRegionRoot() const {
  if (isDetached())
    return WebAXObject();

  AXObject* liveRegionRoot = m_private->liveRegionRoot();
  if (liveRegionRoot)
    return WebAXObject(liveRegionRoot);
  return WebAXObject();
}

bool WebAXObject::containerLiveRegionAtomic() const {
  if (isDetached())
    return false;

  return m_private->containerLiveRegionAtomic();
}

bool WebAXObject::containerLiveRegionBusy() const {
  if (isDetached())
    return false;

  return m_private->containerLiveRegionBusy();
}

WebString WebAXObject::containerLiveRegionRelevant() const {
  if (isDetached())
    return WebString();

  return m_private->containerLiveRegionRelevant();
}

WebString WebAXObject::containerLiveRegionStatus() const {
  if (isDetached())
    return WebString();

  return m_private->containerLiveRegionStatus();
}

bool WebAXObject::ariaOwns(WebVector<WebAXObject>& ownsElements) const {
  // aria-owns rearranges the accessibility tree rather than just
  // exposing an attribute.

  // FIXME(dmazzoni): remove this function after we stop calling it
  // from Chromium.  http://crbug.com/489590

  return false;
}

WebString WebAXObject::fontFamily() const {
  if (isDetached())
    return WebString();

  return m_private->fontFamily();
}

float WebAXObject::fontSize() const {
  if (isDetached())
    return 0.0f;

  return m_private->fontSize();
}

bool WebAXObject::canvasHasFallbackContent() const {
  if (isDetached())
    return false;

  return m_private->canvasHasFallbackContent();
}

WebAXInvalidState WebAXObject::invalidState() const {
  if (isDetached())
    return WebAXInvalidStateUndefined;

  return static_cast<WebAXInvalidState>(m_private->getInvalidState());
}

// Only used when invalidState() returns WebAXInvalidStateOther.
WebString WebAXObject::ariaInvalidValue() const {
  if (isDetached())
    return WebString();

  return m_private->ariaInvalidValue();
}

double WebAXObject::estimatedLoadingProgress() const {
  if (isDetached())
    return 0.0;

  return m_private->estimatedLoadingProgress();
}

int WebAXObject::headingLevel() const {
  if (isDetached())
    return 0;

  return m_private->headingLevel();
}

int WebAXObject::hierarchicalLevel() const {
  if (isDetached())
    return 0;

  return m_private->hierarchicalLevel();
}

// FIXME: This method passes in a point that has page scale applied but assumes
// that (0, 0) is the top left of the visual viewport. In other words, the
// point has the VisualViewport scale applied, but not the VisualViewport
// offset. crbug.com/459591.
WebAXObject WebAXObject::hitTest(const WebPoint& point) const {
  if (isDetached())
    return WebAXObject();

  IntPoint contentsPoint =
      m_private->documentFrameView()->soonToBeRemovedUnscaledViewportToContents(
          point);
  AXObject* hit = m_private->accessibilityHitTest(contentsPoint);

  if (hit)
    return WebAXObject(hit);

  if (m_private->getBoundsInFrameCoordinates().contains(contentsPoint))
    return *this;

  return WebAXObject();
}

WebString WebAXObject::keyboardShortcut() const {
  if (isDetached())
    return WebString();

  String accessKey = m_private->accessKey();
  if (accessKey.isNull())
    return WebString();

  DEFINE_STATIC_LOCAL(String, modifierString, ());
  if (modifierString.isNull()) {
    unsigned modifiers = KeyboardEventManager::kAccessKeyModifiers;
    // Follow the same order as Mozilla MSAA implementation:
    // Ctrl+Alt+Shift+Meta+key. MSDN states that keyboard shortcut strings
    // should not be localized and defines the separator as "+".
    StringBuilder modifierStringBuilder;
    if (modifiers & WebInputEvent::ControlKey)
      modifierStringBuilder.append("Ctrl+");
    if (modifiers & WebInputEvent::AltKey)
      modifierStringBuilder.append("Alt+");
    if (modifiers & WebInputEvent::ShiftKey)
      modifierStringBuilder.append("Shift+");
    if (modifiers & WebInputEvent::MetaKey)
      modifierStringBuilder.append("Win+");
    modifierString = modifierStringBuilder.toString();
  }

  return String(modifierString + accessKey);
}

WebString WebAXObject::language() const {
  if (isDetached())
    return WebString();

  return m_private->language();
}

bool WebAXObject::performDefaultAction() const {
  if (isDetached())
    return false;

  return m_private->performDefaultAction();
}

bool WebAXObject::increment() const {
  if (isDetached())
    return false;

  if (canIncrement()) {
    m_private->increment();
    return true;
  }
  return false;
}

bool WebAXObject::decrement() const {
  if (isDetached())
    return false;

  if (canDecrement()) {
    m_private->decrement();
    return true;
  }
  return false;
}

WebAXOrientation WebAXObject::orientation() const {
  if (isDetached())
    return WebAXOrientationUndefined;

  return static_cast<WebAXOrientation>(m_private->orientation());
}

bool WebAXObject::press() const {
  if (isDetached())
    return false;

  return m_private->press();
}

WebAXRole WebAXObject::role() const {
  if (isDetached())
    return WebAXRoleUnknown;

  return static_cast<WebAXRole>(m_private->roleValue());
}

void WebAXObject::selection(WebAXObject& anchorObject,
                            int& anchorOffset,
                            WebAXTextAffinity& anchorAffinity,
                            WebAXObject& focusObject,
                            int& focusOffset,
                            WebAXTextAffinity& focusAffinity) const {
  if (isDetached()) {
    anchorObject = WebAXObject();
    anchorOffset = -1;
    anchorAffinity = WebAXTextAffinityDownstream;
    focusObject = WebAXObject();
    focusOffset = -1;
    focusAffinity = WebAXTextAffinityDownstream;
    return;
  }

  AXObject::AXRange axSelection = m_private->selection();
  anchorObject = WebAXObject(axSelection.anchorObject);
  anchorOffset = axSelection.anchorOffset;
  anchorAffinity = static_cast<WebAXTextAffinity>(axSelection.anchorAffinity);
  focusObject = WebAXObject(axSelection.focusObject);
  focusOffset = axSelection.focusOffset;
  focusAffinity = static_cast<WebAXTextAffinity>(axSelection.focusAffinity);
  return;
}

void WebAXObject::setSelection(const WebAXObject& anchorObject,
                               int anchorOffset,
                               const WebAXObject& focusObject,
                               int focusOffset) const {
  if (isDetached())
    return;

  AXObject::AXRange axSelection(anchorObject, anchorOffset,
                                TextAffinity::Upstream, focusObject,
                                focusOffset, TextAffinity::Downstream);
  m_private->setSelection(axSelection);
  return;
}

unsigned WebAXObject::selectionEnd() const {
  if (isDetached())
    return 0;

  AXObject::AXRange axSelection = m_private->selectionUnderObject();
  if (axSelection.focusOffset < 0)
    return 0;

  return axSelection.focusOffset;
}

unsigned WebAXObject::selectionStart() const {
  if (isDetached())
    return 0;

  AXObject::AXRange axSelection = m_private->selectionUnderObject();
  if (axSelection.anchorOffset < 0)
    return 0;

  return axSelection.anchorOffset;
}

unsigned WebAXObject::selectionEndLineNumber() const {
  if (isDetached())
    return 0;

  VisiblePosition position = m_private->visiblePositionForIndex(selectionEnd());
  int lineNumber = m_private->lineForPosition(position);
  if (lineNumber < 0)
    return 0;

  return lineNumber;
}

unsigned WebAXObject::selectionStartLineNumber() const {
  if (isDetached())
    return 0;

  VisiblePosition position =
      m_private->visiblePositionForIndex(selectionStart());
  int lineNumber = m_private->lineForPosition(position);
  if (lineNumber < 0)
    return 0;

  return lineNumber;
}

void WebAXObject::setFocused(bool on) const {
  if (!isDetached())
    m_private->setFocused(on);
}

void WebAXObject::setSelectedTextRange(int selectionStart,
                                       int selectionEnd) const {
  if (isDetached())
    return;

  m_private->setSelection(AXObject::AXRange(selectionStart, selectionEnd));
}

void WebAXObject::setSequentialFocusNavigationStartingPoint() const {
  if (isDetached())
    return;

  m_private->setSequentialFocusNavigationStartingPoint();
}

void WebAXObject::setValue(WebString value) const {
  if (isDetached())
    return;

  m_private->setValue(value);
}

void WebAXObject::showContextMenu() const {
  if (isDetached())
    return;

  Node* node = m_private->getNode();
  if (!node)
    return;

  Element* element = nullptr;
  if (node->isElementNode()) {
    element = toElement(node);
  } else if (node->isDocumentNode()) {
    element = node->document().documentElement();
  } else {
    node->updateDistribution();
    ContainerNode* parent = FlatTreeTraversal::parent(*node);
    if (!parent)
      return;
    SECURITY_DCHECK(parent->isElementNode());
    element = toElement(parent);
  }

  if (!element)
    return;

  LocalFrame* frame = element->document().frame();
  if (!frame)
    return;

  WebViewImpl* view = WebLocalFrameImpl::fromFrame(frame)->viewImpl();
  if (!view)
    return;

  view->showContextMenuForElement(WebElement(element));
}

WebString WebAXObject::stringValue() const {
  if (isDetached())
    return WebString();

  return m_private->stringValue();
}

WebAXTextDirection WebAXObject::textDirection() const {
  if (isDetached())
    return WebAXTextDirectionLR;

  return static_cast<WebAXTextDirection>(m_private->textDirection());
}

WebAXTextStyle WebAXObject::textStyle() const {
  if (isDetached())
    return WebAXTextStyleNone;

  return static_cast<WebAXTextStyle>(m_private->getTextStyle());
}

WebURL WebAXObject::url() const {
  if (isDetached())
    return WebURL();

  return m_private->url();
}

WebString WebAXObject::name(WebAXNameFrom& outNameFrom,
                            WebVector<WebAXObject>& outNameObjects) const {
  if (isDetached())
    return WebString();

  AXNameFrom nameFrom = AXNameFromUninitialized;
  HeapVector<Member<AXObject>> nameObjects;
  WebString result = m_private->name(nameFrom, &nameObjects);
  outNameFrom = static_cast<WebAXNameFrom>(nameFrom);

  WebVector<WebAXObject> webNameObjects(nameObjects.size());
  for (size_t i = 0; i < nameObjects.size(); i++)
    webNameObjects[i] = WebAXObject(nameObjects[i]);
  outNameObjects.swap(webNameObjects);

  return result;
}

WebString WebAXObject::name() const {
  if (isDetached())
    return WebString();

  AXNameFrom nameFrom;
  HeapVector<Member<AXObject>> nameObjects;
  return m_private->name(nameFrom, &nameObjects);
}

WebString WebAXObject::description(
    WebAXNameFrom nameFrom,
    WebAXDescriptionFrom& outDescriptionFrom,
    WebVector<WebAXObject>& outDescriptionObjects) const {
  if (isDetached())
    return WebString();

  AXDescriptionFrom descriptionFrom = AXDescriptionFromUninitialized;
  HeapVector<Member<AXObject>> descriptionObjects;
  String result = m_private->description(static_cast<AXNameFrom>(nameFrom),
                                         descriptionFrom, &descriptionObjects);
  outDescriptionFrom = static_cast<WebAXDescriptionFrom>(descriptionFrom);

  WebVector<WebAXObject> webDescriptionObjects(descriptionObjects.size());
  for (size_t i = 0; i < descriptionObjects.size(); i++)
    webDescriptionObjects[i] = WebAXObject(descriptionObjects[i]);
  outDescriptionObjects.swap(webDescriptionObjects);

  return result;
}

WebString WebAXObject::placeholder(WebAXNameFrom nameFrom,
                                   WebAXDescriptionFrom descriptionFrom) const {
  if (isDetached())
    return WebString();

  return m_private->placeholder(
      static_cast<AXNameFrom>(nameFrom),
      static_cast<AXDescriptionFrom>(descriptionFrom));
}

bool WebAXObject::supportsRangeValue() const {
  if (isDetached())
    return false;

  return m_private->supportsRangeValue();
}

WebString WebAXObject::valueDescription() const {
  if (isDetached())
    return WebString();

  return m_private->valueDescription();
}

float WebAXObject::valueForRange() const {
  if (isDetached())
    return 0.0;

  return m_private->valueForRange();
}

float WebAXObject::maxValueForRange() const {
  if (isDetached())
    return 0.0;

  return m_private->maxValueForRange();
}

float WebAXObject::minValueForRange() const {
  if (isDetached())
    return 0.0;

  return m_private->minValueForRange();
}

WebNode WebAXObject::node() const {
  if (isDetached())
    return WebNode();

  Node* node = m_private->getNode();
  if (!node)
    return WebNode();

  return WebNode(node);
}

WebDocument WebAXObject::document() const {
  if (isDetached())
    return WebDocument();

  Document* document = m_private->getDocument();
  if (!document)
    return WebDocument();

  return WebDocument(document);
}

bool WebAXObject::hasComputedStyle() const {
  if (isDetached())
    return false;

  Document* document = m_private->getDocument();
  if (document)
    document->updateStyleAndLayoutTree();

  Node* node = m_private->getNode();
  if (!node)
    return false;

  return node->ensureComputedStyle();
}

WebString WebAXObject::computedStyleDisplay() const {
  if (isDetached())
    return WebString();

  Document* document = m_private->getDocument();
  if (document)
    document->updateStyleAndLayoutTree();

  Node* node = m_private->getNode();
  if (!node)
    return WebString();

  const ComputedStyle* computedStyle = node->ensureComputedStyle();
  if (!computedStyle)
    return WebString();

  return WebString(
      CSSIdentifierValue::create(computedStyle->display())->cssText());
}

bool WebAXObject::accessibilityIsIgnored() const {
  if (isDetached())
    return false;

  return m_private->accessibilityIsIgnored();
}

bool WebAXObject::lineBreaks(WebVector<int>& result) const {
  if (isDetached())
    return false;

  Vector<int> lineBreaksVector;
  m_private->lineBreaks(lineBreaksVector);

  size_t vectorSize = lineBreaksVector.size();
  WebVector<int> lineBreaksWebVector(vectorSize);
  for (size_t i = 0; i < vectorSize; i++)
    lineBreaksWebVector[i] = lineBreaksVector[i];
  result.swap(lineBreaksWebVector);

  return true;
}

unsigned WebAXObject::columnCount() const {
  if (isDetached())
    return false;

  if (!m_private->isAXTable())
    return 0;

  return toAXTable(m_private.get())->columnCount();
}

unsigned WebAXObject::rowCount() const {
  if (isDetached())
    return false;

  if (!m_private->isAXTable())
    return 0;

  return toAXTable(m_private.get())->rowCount();
}

WebAXObject WebAXObject::cellForColumnAndRow(unsigned column,
                                             unsigned row) const {
  if (isDetached())
    return WebAXObject();

  if (!m_private->isAXTable())
    return WebAXObject();

  AXTableCell* cell =
      toAXTable(m_private.get())->cellForColumnAndRow(column, row);
  return WebAXObject(static_cast<AXObject*>(cell));
}

WebAXObject WebAXObject::headerContainerObject() const {
  if (isDetached())
    return WebAXObject();

  if (!m_private->isAXTable())
    return WebAXObject();

  return WebAXObject(toAXTable(m_private.get())->headerContainer());
}

WebAXObject WebAXObject::rowAtIndex(unsigned rowIndex) const {
  if (isDetached())
    return WebAXObject();

  if (!m_private->isAXTable())
    return WebAXObject();

  const AXObject::AXObjectVector& rows = toAXTable(m_private.get())->rows();
  if (rowIndex < rows.size())
    return WebAXObject(rows[rowIndex]);

  return WebAXObject();
}

WebAXObject WebAXObject::columnAtIndex(unsigned columnIndex) const {
  if (isDetached())
    return WebAXObject();

  if (!m_private->isAXTable())
    return WebAXObject();

  const AXObject::AXObjectVector& columns =
      toAXTable(m_private.get())->columns();
  if (columnIndex < columns.size())
    return WebAXObject(columns[columnIndex]);

  return WebAXObject();
}

unsigned WebAXObject::rowIndex() const {
  if (isDetached())
    return 0;

  if (!m_private->isTableRow())
    return 0;

  return toAXTableRow(m_private.get())->rowIndex();
}

WebAXObject WebAXObject::rowHeader() const {
  if (isDetached())
    return WebAXObject();

  if (!m_private->isTableRow())
    return WebAXObject();

  return WebAXObject(toAXTableRow(m_private.get())->headerObject());
}

void WebAXObject::rowHeaders(WebVector<WebAXObject>& rowHeaderElements) const {
  if (isDetached())
    return;

  if (!m_private->isAXTable())
    return;

  AXObject::AXObjectVector headers;
  toAXTable(m_private.get())->rowHeaders(headers);

  size_t headerCount = headers.size();
  WebVector<WebAXObject> result(headerCount);

  for (size_t i = 0; i < headerCount; i++)
    result[i] = WebAXObject(headers[i]);

  rowHeaderElements.swap(result);
}

unsigned WebAXObject::columnIndex() const {
  if (isDetached())
    return 0;

  if (m_private->roleValue() != ColumnRole)
    return 0;

  return toAXTableColumn(m_private.get())->columnIndex();
}

WebAXObject WebAXObject::columnHeader() const {
  if (isDetached())
    return WebAXObject();

  if (m_private->roleValue() != ColumnRole)
    return WebAXObject();

  return WebAXObject(toAXTableColumn(m_private.get())->headerObject());
}

void WebAXObject::columnHeaders(
    WebVector<WebAXObject>& columnHeaderElements) const {
  if (isDetached())
    return;

  if (!m_private->isAXTable())
    return;

  AXObject::AXObjectVector headers;
  toAXTable(m_private.get())->columnHeaders(headers);

  size_t headerCount = headers.size();
  WebVector<WebAXObject> result(headerCount);

  for (size_t i = 0; i < headerCount; i++)
    result[i] = WebAXObject(headers[i]);

  columnHeaderElements.swap(result);
}

unsigned WebAXObject::cellColumnIndex() const {
  if (isDetached())
    return 0;

  if (!m_private->isTableCell())
    return 0;

  std::pair<unsigned, unsigned> columnRange;
  toAXTableCell(m_private.get())->columnIndexRange(columnRange);
  return columnRange.first;
}

unsigned WebAXObject::cellColumnSpan() const {
  if (isDetached())
    return 0;

  if (!m_private->isTableCell())
    return 0;

  std::pair<unsigned, unsigned> columnRange;
  toAXTableCell(m_private.get())->columnIndexRange(columnRange);
  return columnRange.second;
}

unsigned WebAXObject::cellRowIndex() const {
  if (isDetached())
    return 0;

  if (!m_private->isTableCell())
    return 0;

  std::pair<unsigned, unsigned> rowRange;
  toAXTableCell(m_private.get())->rowIndexRange(rowRange);
  return rowRange.first;
}

unsigned WebAXObject::cellRowSpan() const {
  if (isDetached())
    return 0;

  if (!m_private->isTableCell())
    return 0;

  std::pair<unsigned, unsigned> rowRange;
  toAXTableCell(m_private.get())->rowIndexRange(rowRange);
  return rowRange.second;
}

WebAXSortDirection WebAXObject::sortDirection() const {
  if (isDetached())
    return WebAXSortDirectionUndefined;

  return static_cast<WebAXSortDirection>(m_private->getSortDirection());
}

void WebAXObject::loadInlineTextBoxes() const {
  if (isDetached())
    return;

  m_private->loadInlineTextBoxes();
}

WebAXObject WebAXObject::nextOnLine() const {
  if (isDetached())
    return WebAXObject();

  return WebAXObject(m_private.get()->nextOnLine());
}

WebAXObject WebAXObject::previousOnLine() const {
  if (isDetached())
    return WebAXObject();

  return WebAXObject(m_private.get()->previousOnLine());
}

void WebAXObject::markers(WebVector<WebAXMarkerType>& types,
                          WebVector<int>& starts,
                          WebVector<int>& ends) const {
  if (isDetached())
    return;

  Vector<DocumentMarker::MarkerType> markerTypes;
  Vector<AXObject::AXRange> markerRanges;
  m_private->markers(markerTypes, markerRanges);
  DCHECK_EQ(markerTypes.size(), markerRanges.size());

  WebVector<WebAXMarkerType> webMarkerTypes(markerTypes.size());
  WebVector<int> startOffsets(markerRanges.size());
  WebVector<int> endOffsets(markerRanges.size());
  for (size_t i = 0; i < markerTypes.size(); ++i) {
    webMarkerTypes[i] = static_cast<WebAXMarkerType>(markerTypes[i]);
    DCHECK(markerRanges[i].isSimple());
    startOffsets[i] = markerRanges[i].anchorOffset;
    endOffsets[i] = markerRanges[i].focusOffset;
  }

  types.swap(webMarkerTypes);
  starts.swap(startOffsets);
  ends.swap(endOffsets);
}

void WebAXObject::characterOffsets(WebVector<int>& offsets) const {
  if (isDetached())
    return;

  Vector<int> offsetsVector;
  m_private->textCharacterOffsets(offsetsVector);

  size_t vectorSize = offsetsVector.size();
  WebVector<int> offsetsWebVector(vectorSize);
  for (size_t i = 0; i < vectorSize; i++)
    offsetsWebVector[i] = offsetsVector[i];
  offsets.swap(offsetsWebVector);
}

void WebAXObject::wordBoundaries(WebVector<int>& starts,
                                 WebVector<int>& ends) const {
  if (isDetached())
    return;

  Vector<AXObject::AXRange> wordBoundaries;
  m_private->wordBoundaries(wordBoundaries);

  WebVector<int> wordStartOffsets(wordBoundaries.size());
  WebVector<int> wordEndOffsets(wordBoundaries.size());
  for (size_t i = 0; i < wordBoundaries.size(); ++i) {
    DCHECK(wordBoundaries[i].isSimple());
    wordStartOffsets[i] = wordBoundaries[i].anchorOffset;
    wordEndOffsets[i] = wordBoundaries[i].focusOffset;
  }

  starts.swap(wordStartOffsets);
  ends.swap(wordEndOffsets);
}

bool WebAXObject::isScrollableContainer() const {
  if (isDetached())
    return false;

  return m_private->isScrollableContainer();
}

WebPoint WebAXObject::scrollOffset() const {
  if (isDetached())
    return WebPoint();

  return m_private->scrollOffset();
}

WebPoint WebAXObject::minimumScrollOffset() const {
  if (isDetached())
    return WebPoint();

  return m_private->minimumScrollOffset();
}

WebPoint WebAXObject::maximumScrollOffset() const {
  if (isDetached())
    return WebPoint();

  return m_private->maximumScrollOffset();
}

void WebAXObject::setScrollOffset(const WebPoint& offset) const {
  if (isDetached())
    return;

  m_private->setScrollOffset(offset);
}

void WebAXObject::getRelativeBounds(WebAXObject& offsetContainer,
                                    WebFloatRect& boundsInContainer,
                                    SkMatrix44& containerTransform) const {
  if (isDetached())
    return;

#if DCHECK_IS_ON()
  DCHECK(isLayoutClean(m_private->getDocument()));
#endif

  AXObject* container = nullptr;
  FloatRect bounds;
  m_private->getRelativeBounds(&container, bounds, containerTransform);
  offsetContainer = WebAXObject(container);
  boundsInContainer = WebFloatRect(bounds);
}

void WebAXObject::scrollToMakeVisible() const {
  if (!isDetached())
    m_private->scrollToMakeVisible();
}

void WebAXObject::scrollToMakeVisibleWithSubFocus(
    const WebRect& subfocus) const {
  if (!isDetached())
    m_private->scrollToMakeVisibleWithSubFocus(subfocus);
}

void WebAXObject::scrollToGlobalPoint(const WebPoint& point) const {
  if (!isDetached())
    m_private->scrollToGlobalPoint(point);
}

WebAXObject::WebAXObject(AXObject* object) : m_private(object) {}

WebAXObject& WebAXObject::operator=(AXObject* object) {
  m_private = object;
  return *this;
}

WebAXObject::operator AXObject*() const {
  return m_private.get();
}

}  // namespace blink