Source/core/html/HTMLImportChild.cpp

/*
 * Copyright (C) 2013 Google Inc. All rights reserved.
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 * 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.
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 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
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 * 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,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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#include "config.h"
#include "core/html/HTMLImportChild.h"

#include "core/dom/Document.h"
#include "core/html/HTMLImportChildClient.h"
#include "core/html/HTMLImportLoader.h"

namespace WebCore {

HTMLImportChild::HTMLImportChild(const KURL& url, HTMLImportChildClient* client)
    : m_url(url)
    , m_client(client)
{
}

HTMLImportChild::~HTMLImportChild()
{
    // importDestroyed() should be called before the destruction.
    ASSERT(!m_loader);
}

void HTMLImportChild::wasAlreadyLoadedAs(HTMLImportChild* found)
{
    ASSERT(!m_loader);
    ASSERT(m_client);
    shareLoader(found);
}

void HTMLImportChild::startLoading(const ResourcePtr<RawResource>& resource)
{
    ASSERT(!hasResource());
    ASSERT(!m_loader);

    HTMLImportResourceOwner::setResource(resource);

    // If the node is "document blocked", it cannot create HTMLImportLoader
    // even if there is no sharable one found, as there is possibility that
    // preceding imports load the sharable imports.
    // In that case preceding one should win because it comes first in the tree order.
    // See also didUnblockDocument().
    if (isDocumentBlocked())
        return;

    createLoader();
}

void HTMLImportChild::didFinish()
{
    if (m_client)
        m_client->didFinish();
    clearResource();
    root()->blockerGone();
}

Document* HTMLImportChild::importedDocument() const
{
    if (!m_loader)
        return 0;
    return m_loader->importedDocument();
}

void HTMLImportChild::importDestroyed()
{
    if (parent())
        parent()->removeChild(this);
    if (m_loader) {
        m_loader->removeClient(this);
        m_loader.clear();
    }
}

HTMLImportRoot* HTMLImportChild::root()
{
    return parent() ? parent()->root() : 0;
}

Document* HTMLImportChild::document() const
{
    return (m_loader && m_loader->isOwnedBy(this)) ? m_loader->document() : 0;
}

void HTMLImportChild::wasDetachedFromDocument()
{
    // For imported documens this shouldn't be called because Document::m_import is
    // cleared before Document is destroyed by HTMLImportChild::importDestroyed().
    ASSERT_NOT_REACHED();
}

void HTMLImportChild::didFinishParsing()
{
    ASSERT(m_loader->isOwnedBy(this));
    m_loader->didFinishParsing();
}

// Once all preceding imports are loaded and "document blocking" ends,
// HTMLImportChild can decide whether it should load the import by itself
// or it can share existing one.
void HTMLImportChild::didUnblockDocument()
{
    HTMLImport::didUnblockDocument();
    ASSERT(!isDocumentBlocked());
    ASSERT(!m_loader || !m_loader->isOwnedBy(this));

    if (m_loader)
        return;
    if (HTMLImportChild* found = root()->findLinkFor(m_url, this))
        shareLoader(found);
    else
        createLoader();
}

void HTMLImportChild::createLoader()
{
    ASSERT(!isDocumentBlocked());
    ASSERT(!m_loader);
    m_loader = HTMLImportLoader::create(this, parent()->document()->fetcher());
    m_loader->addClient(this);
    m_loader->startLoading(resource());
}

void HTMLImportChild::shareLoader(HTMLImportChild* loader)
{
    ASSERT(!m_loader);
    m_loader = loader->m_loader;
    m_loader->addClient(this);
    root()->blockerGone();
}

bool HTMLImportChild::isProcessing() const
{
    return m_loader && m_loader->isOwnedBy(this) && m_loader->isProcessing();
}

bool HTMLImportChild::isDone() const
{
    return m_loader && m_loader->isDone();
}

bool HTMLImportChild::isLoaded() const
{
    return m_loader->isLoaded();
}

} // namespace WebCore