/*
 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
 *           (C) 1999 Antti Koivisto (koivisto@kde.org)
 *           (C) 2001 Dirk Mueller (mueller@kde.org)
 * Copyright (C) 2004, 2005, 2006, 2010 Apple Inc. All rights reserved.
 *           (C) 2006 Alexey Proskuryakov (ap@nypop.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 "HTMLFieldSetElement.h"

#include "ElementIterator.h"
#include "HTMLCollection.h"
#include "HTMLLegendElement.h"
#include "HTMLNames.h"
#include "HTMLObjectElement.h"
#include "RenderFieldset.h"
#include <wtf/StdLibExtras.h>

namespace WebCore {

using namespace HTMLNames;

inline HTMLFieldSetElement::HTMLFieldSetElement(const QualifiedName& tagName, Document* document, HTMLFormElement* form)
    : HTMLFormControlElement(tagName, document, form)
    , m_documentVersion(0)
{
    ASSERT(hasTagName(fieldsetTag));
}

HTMLFieldSetElement::~HTMLFieldSetElement()
{
    if (hasAttribute(disabledAttr))
        document()->removeDisabledFieldsetElement();
}

PassRefPtr<HTMLFieldSetElement> HTMLFieldSetElement::create(const QualifiedName& tagName, Document* document, HTMLFormElement* form)
{
    return adoptRef(new HTMLFieldSetElement(tagName, document, form));
}

static void updateFromControlElementsAncestorDisabledStateUnder(HTMLElement& startNode, bool isDisabled)
{
    HTMLFormControlElement* control;
    if (isHTMLFormControlElement(startNode))
        control = &toHTMLFormControlElement(startNode);
    else
        control = Traversal<HTMLFormControlElement>::firstWithin(&startNode);
    while (control) {
        control->setAncestorDisabled(isDisabled);
        // Don't call setAncestorDisabled(false) on form contorls inside disabled fieldsets.
        if (isHTMLFieldSetElement(control) && control->hasAttribute(disabledAttr))
            control = Traversal<HTMLFormControlElement>::nextSkippingChildren(control, &startNode);
        else
            control = Traversal<HTMLFormControlElement>::next(control, &startNode);
    }
}

void HTMLFieldSetElement::disabledAttributeChanged()
{
    if (hasAttribute(disabledAttr))
        document()->addDisabledFieldsetElement();
    else
        document()->removeDisabledFieldsetElement();

    HTMLFormControlElement::disabledAttributeChanged();
}

void HTMLFieldSetElement::disabledStateChanged()
{
    // This element must be updated before the style of nodes in its subtree gets recalculated.
    HTMLFormControlElement::disabledStateChanged();

    if (disabledByAncestorFieldset())
        return;

    bool thisFieldsetIsDisabled = hasAttribute(disabledAttr);
    bool hasSeenFirstLegendElement = false;
    for (HTMLElement* control = Traversal<HTMLElement>::firstChild(this); control; control = Traversal<HTMLElement>::nextSibling(control)) {
        if (!hasSeenFirstLegendElement && isHTMLLegendElement(control)) {
            hasSeenFirstLegendElement = true;
            updateFromControlElementsAncestorDisabledStateUnder(*control, false /* isDisabled */);
            continue;
        }
        updateFromControlElementsAncestorDisabledStateUnder(*control, thisFieldsetIsDisabled);
    }
}

void HTMLFieldSetElement::childrenChanged(const ChildChange& change)
{
    HTMLFormControlElement::childrenChanged(change);
    if (!hasAttribute(disabledAttr))
        return;

    HTMLLegendElement* legend = Traversal<HTMLLegendElement>::firstChild(this);
    if (!legend)
        return;

    // We only care about the first legend element (in which form contorls are not disabled by this element) changing here.
    updateFromControlElementsAncestorDisabledStateUnder(*legend, false /* isDisabled */);
    while ((legend = Traversal<HTMLLegendElement>::nextSibling(legend)))
        updateFromControlElementsAncestorDisabledStateUnder(*legend, true);
}

void HTMLFieldSetElement::didMoveToNewDocument(Document* oldDocument)
{
    HTMLFormControlElement::didMoveToNewDocument(oldDocument);
    if (hasAttribute(disabledAttr)) {
        if (oldDocument)
            oldDocument->removeDisabledFieldsetElement();
        document()->addDisabledFieldsetElement();
    }
}

bool HTMLFieldSetElement::matchesValidPseudoClass() const
{
    return m_invalidDescendants.isEmpty();
}

bool HTMLFieldSetElement::matchesInvalidPseudoClass() const
{
    return !m_invalidDescendants.isEmpty();
}

bool HTMLFieldSetElement::supportsFocus() const
{
    return HTMLElement::supportsFocus();
}

const AtomicString& HTMLFieldSetElement::formControlType() const
{
    DEFINE_STATIC_LOCAL_ATOMICSTRING(fieldset, ("fieldset", AtomicString::ConstructFromLiteral));
    return fieldset;
}

RenderElement* HTMLFieldSetElement::createElementRenderer(PassRefPtr<RenderStyle> style, const RenderTreePosition&)
{
    return new RenderFieldset(*this, style);
}

HTMLLegendElement* HTMLFieldSetElement::legend() const
{
    return const_cast<HTMLLegendElement*>(childrenOfType<HTMLLegendElement>(this).first());
}

PassRefPtr<HTMLCollection> HTMLFieldSetElement::elements()
{
    return ensureCachedHTMLCollection(FormControls);
}

void HTMLFieldSetElement::refreshElementsIfNeeded() const
{
    uint64_t docVersion = document()->domTreeVersion();
    if (m_documentVersion == docVersion)
        return;

    m_documentVersion = docVersion;

    m_associatedElements.clear();

    for (Element* element = ElementTraversal::firstWithin(this); element; element = ElementTraversal::next(element, this)) {
        if (element->hasTagName(objectTag)) {
            m_associatedElements.append(static_cast<HTMLObjectElement*>(element));
            continue;
        }

        if (!element->isFormControlElement())
            continue;

        m_associatedElements.append(static_cast<HTMLFormControlElement*>(element));
    }
}

const Vector<FormAssociatedElement*>& HTMLFieldSetElement::associatedElements() const
{
    refreshElementsIfNeeded();
    return m_associatedElements;
}

unsigned HTMLFieldSetElement::length() const
{
    refreshElementsIfNeeded();
    unsigned len = 0;
    for (unsigned i = 0; i < m_associatedElements.size(); ++i)
        if (m_associatedElements[i]->isEnumeratable())
            ++len;
    return len;
}

void HTMLFieldSetElement::addInvalidDescendant(const HTMLFormControlElement& invalidFormControlElement)
{
    ASSERT_WITH_MESSAGE(!is<HTMLFieldSetElement>(invalidFormControlElement), "FieldSet are never candidates for constraint validation.");
    ASSERT(static_cast<const Element&>(invalidFormControlElement).matchesInvalidPseudoClass());
    ASSERT_WITH_MESSAGE(!m_invalidDescendants.contains(&invalidFormControlElement), "Updating the fieldset on validity change is not an efficient operation, it should only be done when necessary.");

    if (m_invalidDescendants.isEmpty())
        setNeedsStyleRecalc();
    m_invalidDescendants.add(&invalidFormControlElement);
}

void HTMLFieldSetElement::removeInvalidDescendant(const HTMLFormControlElement& formControlElement)
{
    ASSERT_WITH_MESSAGE(!is<HTMLFieldSetElement>(formControlElement), "FieldSet are never candidates for constraint validation.");
    ASSERT_WITH_MESSAGE(m_invalidDescendants.contains(&formControlElement), "Updating the fieldset on validity change is not an efficient operation, it should only be done when necessary.");

    m_invalidDescendants.remove(&formControlElement);
    if (m_invalidDescendants.isEmpty())
        setNeedsStyleRecalc();
}

} // namespace
