root/Source/core/dom/shadow/ShadowRoot.cpp

DEFINITIONS

1. m_descendantInsertionPointsIsValid
2. dispose
3. olderShadowRootForBindings
4. isOldestAuthorShadowRoot
5. cloneNode
6. innerHTML
7. setInnerHTML
8. recalcStyle
9. setApplyAuthorStyles
10. attach
11. insertedInto
12. removedFrom
13. childrenChanged
14. registerScopedHTMLStyleChild
15. unregisterScopedHTMLStyleChild
16. ensureShadowRootRareData
17. containsShadowElements
18. containsContentElements
19. containsShadowRoots
20. descendantShadowElementCount
21. shadowInsertionPointOfYoungerShadowRoot
22. setShadowInsertionPointOfYoungerShadowRoot
23. didAddInsertionPoint
24. didRemoveInsertionPoint
25. addChildShadowRoot
26. removeChildShadowRoot
27. childShadowRootCount
28. invalidateDescendantInsertionPoints
29. descendantInsertionPoints
30. styleSheets

/*
 * Copyright (C) 2011 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.
 *     * 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 "config.h"
#include "core/dom/shadow/ShadowRoot.h"

#include "bindings/v8/ExceptionState.h"
#include "core/css/StyleSheetList.h"
#include "core/css/resolver/StyleResolver.h"
#include "core/css/resolver/StyleResolverParentScope.h"
#include "core/dom/ElementTraversal.h"
#include "core/dom/StyleEngine.h"
#include "core/dom/Text.h"
#include "core/dom/shadow/ElementShadow.h"
#include "core/dom/shadow/InsertionPoint.h"
#include "core/dom/shadow/ShadowRootRareData.h"
#include "core/editing/markup.h"
#include "core/html/HTMLShadowElement.h"
#include "public/platform/Platform.h"

namespace WebCore {

struct SameSizeAsShadowRoot : public DocumentFragment, public TreeScope, public DoublyLinkedListNode<ShadowRoot> {
    void* pointers[3];
    unsigned countersAndFlags[1];
};

COMPILE_ASSERT(sizeof(ShadowRoot) == sizeof(SameSizeAsShadowRoot), shadowroot_should_stay_small);

ShadowRoot::ShadowRoot(Document& document, ShadowRootType type)
    : DocumentFragment(0, CreateShadowRoot)
    , TreeScope(*this, document)
    , m_prev(0)
    , m_next(0)
    , m_numberOfStyles(0)
    , m_applyAuthorStyles(false)
    , m_type(type)
    , m_registeredWithParentShadowRoot(false)
    , m_descendantInsertionPointsIsValid(false)
{
    ScriptWrappable::init(this);
}

ShadowRoot::~ShadowRoot()
{
    ASSERT(!m_prev);
    ASSERT(!m_next);

    if (m_shadowRootRareData && m_shadowRootRareData->styleSheets())
        m_shadowRootRareData->styleSheets()->detachFromDocument();

    document().styleEngine()->didRemoveShadowRoot(this);

    // We cannot let ContainerNode destructor call willBeDeletedFromDocument()
    // for this ShadowRoot instance because TreeScope destructor
    // clears Node::m_treeScope thus ContainerNode is no longer able
    // to access it Document reference after that.
    willBeDeletedFromDocument();

    // We must remove all of our children first before the TreeScope destructor
    // runs so we don't go through TreeScopeAdopter for each child with a
    // destructed tree scope in each descendant.
    removeDetachedChildren();

    // We must call clearRareData() here since a ShadowRoot class inherits TreeScope
    // as well as Node. See a comment on TreeScope.h for the reason.
    if (hasRareData())
        clearRareData();
}

void ShadowRoot::dispose()
{
    removeDetachedChildren();
}

ShadowRoot* ShadowRoot::olderShadowRootForBindings() const
{
    ShadowRoot* older = olderShadowRoot();
    while (older && !older->shouldExposeToBindings())
        older = older->olderShadowRoot();
    ASSERT(!older || older->shouldExposeToBindings());
    return older;
}

bool ShadowRoot::isOldestAuthorShadowRoot() const
{
    if (type() != AuthorShadowRoot)
        return false;
    if (ShadowRoot* older = olderShadowRoot())
        return older->type() == UserAgentShadowRoot;
    return true;
}

PassRefPtr<Node> ShadowRoot::cloneNode(bool, ExceptionState& exceptionState)
{
    exceptionState.throwDOMException(DataCloneError, "ShadowRoot nodes are not clonable.");
    return nullptr;
}

String ShadowRoot::innerHTML() const
{
    return createMarkup(this, ChildrenOnly);
}

void ShadowRoot::setInnerHTML(const String& markup, ExceptionState& exceptionState)
{
    if (isOrphan()) {
        exceptionState.throwDOMException(InvalidAccessError, "The ShadowRoot does not have a host.");
        return;
    }

    if (RefPtr<DocumentFragment> fragment = createFragmentForInnerOuterHTML(markup, host(), AllowScriptingContent, "innerHTML", exceptionState))
        replaceChildrenWithFragment(this, fragment.release(), exceptionState);
}

void ShadowRoot::recalcStyle(StyleRecalcChange change)
{
    // ShadowRoot doesn't support custom callbacks.
    ASSERT(!hasCustomStyleCallbacks());

    StyleResolverParentScope parentScope(*this);

    if (styleChangeType() >= SubtreeStyleChange)
        change = Force;

    if (change < Force && hasRareData() && childNeedsStyleRecalc())
        checkForChildrenAdjacentRuleChanges();

    // There's no style to update so just calling recalcStyle means we're updated.
    clearNeedsStyleRecalc();

    // FIXME: This doesn't handle :hover + div properly like Element::recalcStyle does.
    Text* lastTextNode = 0;
    for (Node* child = lastChild(); child; child = child->previousSibling()) {
        if (child->isTextNode()) {
            toText(child)->recalcTextStyle(change, lastTextNode);
            lastTextNode = toText(child);
        } else if (child->isElementNode()) {
            if (child->shouldCallRecalcStyle(change))
                toElement(child)->recalcStyle(change, lastTextNode);
            if (child->renderer())
                lastTextNode = 0;
        }
    }

    clearChildNeedsStyleRecalc();
}

void ShadowRoot::setApplyAuthorStyles(bool value)
{
    if (isOrphan())
        return;

    if (applyAuthorStyles() == value)
        return;

    m_applyAuthorStyles = value;

    ASSERT(host());
    ASSERT(host()->shadow());
    if (host()->shadow()->didAffectApplyAuthorStyles())
        host()->setNeedsStyleRecalc(SubtreeStyleChange);

    // Since styles in shadow trees can select shadow hosts, set shadow host's needs-recalc flag true.
    // FIXME: host->setNeedsStyleRecalc() should take care of all elements in its shadow tree.
    // However, when host's recalcStyle is skipped (i.e. host's parent has no renderer),
    // no recalc style is invoked for any elements in its shadow tree.
    // This problem occurs when using getComputedStyle() API.
    // So currently host and shadow root's needsStyleRecalc flags are set to be true.
    setNeedsStyleRecalc(SubtreeStyleChange);
}

void ShadowRoot::attach(const AttachContext& context)
{
    StyleResolverParentScope parentScope(*this);
    DocumentFragment::attach(context);
}

Node::InsertionNotificationRequest ShadowRoot::insertedInto(ContainerNode* insertionPoint)
{
    DocumentFragment::insertedInto(insertionPoint);

    if (!insertionPoint->inDocument() || !isOldest())
        return InsertionDone;

    // FIXME: When parsing <video controls>, insertedInto() is called many times without invoking removedFrom.
    // For now, we check m_registeredWithParentShadowroot. We would like to ASSERT(!m_registeredShadowRoot) here.
    // https://bugs.webkit.org/show_bug.cig?id=101316
    if (m_registeredWithParentShadowRoot)
        return InsertionDone;

    if (ShadowRoot* root = host()->containingShadowRoot()) {
        root->addChildShadowRoot();
        m_registeredWithParentShadowRoot = true;
    }

    return InsertionDone;
}

void ShadowRoot::removedFrom(ContainerNode* insertionPoint)
{
    if (insertionPoint->inDocument() && m_registeredWithParentShadowRoot) {
        ShadowRoot* root = host()->containingShadowRoot();
        if (!root)
            root = insertionPoint->containingShadowRoot();
        if (root)
            root->removeChildShadowRoot();
        m_registeredWithParentShadowRoot = false;
    }

    DocumentFragment::removedFrom(insertionPoint);
}

void ShadowRoot::childrenChanged(bool changedByParser, Node* beforeChange, Node* afterChange, int childCountDelta)
{
    ContainerNode::childrenChanged(changedByParser, beforeChange, afterChange, childCountDelta);
    if (InsertionPoint* point = shadowInsertionPointOfYoungerShadowRoot()) {
        if (ShadowRoot* root = point->containingShadowRoot())
            root->owner()->setNeedsDistributionRecalc();
    }
}

void ShadowRoot::registerScopedHTMLStyleChild()
{
    ++m_numberOfStyles;
    setHasScopedHTMLStyleChild(true);
}

void ShadowRoot::unregisterScopedHTMLStyleChild()
{
    ASSERT(hasScopedHTMLStyleChild() && m_numberOfStyles > 0);
    --m_numberOfStyles;
    setHasScopedHTMLStyleChild(m_numberOfStyles > 0);
}

ShadowRootRareData* ShadowRoot::ensureShadowRootRareData()
{
    if (m_shadowRootRareData)
        return m_shadowRootRareData.get();

    m_shadowRootRareData = adoptPtr(new ShadowRootRareData);
    return m_shadowRootRareData.get();
}

bool ShadowRoot::containsShadowElements() const
{
    return m_shadowRootRareData ? m_shadowRootRareData->containsShadowElements() : 0;
}

bool ShadowRoot::containsContentElements() const
{
    return m_shadowRootRareData ? m_shadowRootRareData->containsContentElements() : 0;
}

bool ShadowRoot::containsShadowRoots() const
{
    return m_shadowRootRareData ? m_shadowRootRareData->containsShadowRoots() : 0;
}

unsigned ShadowRoot::descendantShadowElementCount() const
{
    return m_shadowRootRareData ? m_shadowRootRareData->descendantShadowElementCount() : 0;
}

HTMLShadowElement* ShadowRoot::shadowInsertionPointOfYoungerShadowRoot() const
{
    return m_shadowRootRareData ? m_shadowRootRareData->shadowInsertionPointOfYoungerShadowRoot() : 0;
}

void ShadowRoot::setShadowInsertionPointOfYoungerShadowRoot(PassRefPtr<HTMLShadowElement> shadowInsertionPoint)
{
    if (!m_shadowRootRareData && !shadowInsertionPoint)
        return;
    ensureShadowRootRareData()->setShadowInsertionPointOfYoungerShadowRoot(shadowInsertionPoint);
}

void ShadowRoot::didAddInsertionPoint(InsertionPoint* insertionPoint)
{
    ensureShadowRootRareData()->didAddInsertionPoint(insertionPoint);
    invalidateDescendantInsertionPoints();
}

void ShadowRoot::didRemoveInsertionPoint(InsertionPoint* insertionPoint)
{
    m_shadowRootRareData->didRemoveInsertionPoint(insertionPoint);
    invalidateDescendantInsertionPoints();
}

void ShadowRoot::addChildShadowRoot()
{
    ensureShadowRootRareData()->didAddChildShadowRoot();
}

void ShadowRoot::removeChildShadowRoot()
{
    // FIXME: Why isn't this an ASSERT?
    if (!m_shadowRootRareData)
        return;
    m_shadowRootRareData->didRemoveChildShadowRoot();
}

unsigned ShadowRoot::childShadowRootCount() const
{
    return m_shadowRootRareData ? m_shadowRootRareData->childShadowRootCount() : 0;
}

void ShadowRoot::invalidateDescendantInsertionPoints()
{
    m_descendantInsertionPointsIsValid = false;
    m_shadowRootRareData->clearDescendantInsertionPoints();
}

const Vector<RefPtr<InsertionPoint> >& ShadowRoot::descendantInsertionPoints()
{
    DEFINE_STATIC_LOCAL(const Vector<RefPtr<InsertionPoint> >, emptyList, ());

    if (m_shadowRootRareData && m_descendantInsertionPointsIsValid)
        return m_shadowRootRareData->descendantInsertionPoints();

    m_descendantInsertionPointsIsValid = true;

    if (!containsInsertionPoints())
        return emptyList;

    Vector<RefPtr<InsertionPoint> > insertionPoints;
    for (Element* element = ElementTraversal::firstWithin(*this); element; element = ElementTraversal::next(*element, this)) {
        if (element->isInsertionPoint())
            insertionPoints.append(toInsertionPoint(element));
    }

    ensureShadowRootRareData()->setDescendantInsertionPoints(insertionPoints);

    return m_shadowRootRareData->descendantInsertionPoints();
}

StyleSheetList* ShadowRoot::styleSheets()
{
    if (!ensureShadowRootRareData()->styleSheets())
        m_shadowRootRareData->setStyleSheets(StyleSheetList::create(this));

    return m_shadowRootRareData->styleSheets();
}

}