third_party/WebKit/Source/core/html/HTMLDialogElement.cpp

/*
 * 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.
 *
 * 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.
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#include "core/html/HTMLDialogElement.h"

#include "bindings/core/v8/ExceptionState.h"
#include "core/dom/AXObjectCache.h"
#include "core/dom/ExceptionCode.h"
#include "core/dom/NodeTraversal.h"
#include "core/events/Event.h"
#include "core/frame/FrameView.h"
#include "core/frame/UseCounter.h"
#include "core/html/HTMLFormControlElement.h"
#include "core/style/ComputedStyle.h"

namespace blink {

using namespace HTMLNames;

// This function chooses the focused element when show() or showModal() is
// invoked, as described in their spec.
static void setFocusForDialog(HTMLDialogElement* dialog) {
  Element* focusableDescendant = 0;
  Node* next = 0;
  for (Node* node = dialog->firstChild(); node; node = next) {
    if (isHTMLDialogElement(*node))
      next = NodeTraversal::nextSkippingChildren(*node, dialog);
    else
      next = NodeTraversal::next(*node, dialog);

    if (!node->isElementNode())
      continue;
    Element* element = toElement(node);
    if (element->isFormControlElement()) {
      HTMLFormControlElement* control = toHTMLFormControlElement(node);
      if (control->isAutofocusable() && control->isFocusable()) {
        control->focus();
        return;
      }
    }
    if (!focusableDescendant && element->isFocusable())
      focusableDescendant = element;
  }

  if (focusableDescendant) {
    focusableDescendant->focus();
    return;
  }

  if (dialog->isFocusable()) {
    dialog->focus();
    return;
  }

  dialog->document().clearFocusedElement();
}

static void inertSubtreesChanged(Document& document) {
  // When a modal dialog opens or closes, nodes all over the accessibility
  // tree can change inertness which means they must be added or removed from
  // the tree. The most foolproof way is to clear the entire tree and rebuild
  // it, though a more clever way is probably possible.
  document.clearAXObjectCache();
  if (AXObjectCache* cache = document.axObjectCache())
    cache->childrenChanged(&document);
}

inline HTMLDialogElement::HTMLDialogElement(Document& document)
    : HTMLElement(dialogTag, document),
      m_centeringMode(NotCentered),
      m_centeredPosition(0),
      m_returnValue("") {
  UseCounter::count(document, UseCounter::DialogElement);
}

DEFINE_NODE_FACTORY(HTMLDialogElement)

void HTMLDialogElement::close(const String& returnValue,
                              ExceptionState& exceptionState) {
  if (!fastHasAttribute(openAttr)) {
    exceptionState.throwDOMException(InvalidStateError,
                                     "The element does not have an 'open' "
                                     "attribute, and therefore cannot be "
                                     "closed.");
    return;
  }
  closeDialog(returnValue);
}

void HTMLDialogElement::closeDialog(const String& returnValue) {
  if (!fastHasAttribute(openAttr))
    return;
  setBooleanAttribute(openAttr, false);

  HTMLDialogElement* activeModalDialog = document().activeModalDialog();
  document().removeFromTopLayer(this);
  if (activeModalDialog == this)
    inertSubtreesChanged(document());

  if (!returnValue.isNull())
    m_returnValue = returnValue;

  scheduleCloseEvent();
}

void HTMLDialogElement::forceLayoutForCentering() {
  m_centeringMode = NeedsCentering;
  document().updateStyleAndLayoutIgnorePendingStylesheets();
  if (m_centeringMode == NeedsCentering)
    setNotCentered();
}

void HTMLDialogElement::scheduleCloseEvent() {
  Event* event = Event::create(EventTypeNames::close);
  event->setTarget(this);
  document().enqueueAnimationFrameEvent(event);
}

void HTMLDialogElement::show() {
  if (fastHasAttribute(openAttr))
    return;
  setBooleanAttribute(openAttr, true);

  // The layout must be updated here because setFocusForDialog calls
  // Element::isFocusable, which requires an up-to-date layout.
  document().updateStyleAndLayoutIgnorePendingStylesheets();

  setFocusForDialog(this);
}

void HTMLDialogElement::showModal(ExceptionState& exceptionState) {
  if (fastHasAttribute(openAttr)) {
    exceptionState.throwDOMException(InvalidStateError,
                                     "The element already has an 'open' "
                                     "attribute, and therefore cannot be "
                                     "opened modally.");
    return;
  }
  if (!isConnected()) {
    exceptionState.throwDOMException(InvalidStateError,
                                     "The element is not in a Document.");
    return;
  }

  document().addToTopLayer(this);
  setBooleanAttribute(openAttr, true);

  // Throw away the AX cache first, so the subsequent steps don't have a chance
  // of queuing up AX events on objects that would be invalidated when the cache
  // is thrown away.
  inertSubtreesChanged(document());

  forceLayoutForCentering();
  setFocusForDialog(this);
}

void HTMLDialogElement::removedFrom(ContainerNode* insertionPoint) {
  HTMLElement::removedFrom(insertionPoint);
  setNotCentered();
  // FIXME: We should call inertSubtreesChanged() here.
}

void HTMLDialogElement::setCentered(LayoutUnit centeredPosition) {
  DCHECK_EQ(m_centeringMode, NeedsCentering);
  m_centeredPosition = centeredPosition;
  m_centeringMode = Centered;
}

void HTMLDialogElement::setNotCentered() {
  m_centeringMode = NotCentered;
}

bool HTMLDialogElement::isPresentationAttribute(
    const QualifiedName& name) const {
  // FIXME: Workaround for <https://bugs.webkit.org/show_bug.cgi?id=91058>:
  // modifying an attribute for which there is an attribute selector in html.css
  // sometimes does not trigger a style recalc.
  if (name == openAttr)
    return true;

  return HTMLElement::isPresentationAttribute(name);
}

void HTMLDialogElement::defaultEventHandler(Event* event) {
  if (event->type() == EventTypeNames::cancel) {
    closeDialog();
    event->setDefaultHandled();
    return;
  }
  HTMLElement::defaultEventHandler(event);
}

}  // namespace blink