/*
 * 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:
 *
 *     * 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,
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef WebPrerenderingSupport_h
#define WebPrerenderingSupport_h

#include "WebCommon.h"

namespace blink {

class WebPrerender;

class WebPrerenderingSupport {
public:
    BLINK_PLATFORM_EXPORT static void initialize(WebPrerenderingSupport*);
    BLINK_PLATFORM_EXPORT static void shutdown();
    BLINK_PLATFORM_EXPORT static WebPrerenderingSupport* current();

    // A prerender link element is added when it is inserted into a document.
    virtual void add(const WebPrerender&) = 0;

    // A prerender is canceled when it is removed from a document.
    virtual void cancel(const WebPrerender&) = 0;

    // A prerender is abandoned when it's navigated away from or suspended in the page cache. This
    // is a weaker signal than cancel(), since the launcher hasn't indicated that the prerender isn't
    // wanted, and we may end up using it after, for instance, a short redirect chain.
    virtual void abandon(const WebPrerender&) = 0;

protected:
    WebPrerenderingSupport() { }
    virtual ~WebPrerenderingSupport() { }

private:
    static WebPrerenderingSupport* s_platform;
};

} // namespace blink

#endif // WebPrerenderingSupport_h