Source/core/history/BackForwardController.h

/*
 * Copyright (C) 2010 Apple 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 INC. 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 INC. 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.
 */

#ifndef BackForwardController_h
#define BackForwardController_h

#include "wtf/Forward.h"
#include "wtf/Noncopyable.h"
#include "wtf/RefPtr.h"

namespace WebCore {

class BackForwardClient;
class HistoryItem;
class Page;

// FIXME: Why does this class exist? It seems to delegate almost entirely to Page, and perhaps should be part of Page's implementation.
class BackForwardController {
    WTF_MAKE_NONCOPYABLE(BackForwardController); WTF_MAKE_FAST_ALLOCATED;
public:
    ~BackForwardController();

    static PassOwnPtr<BackForwardController> create(Page*, BackForwardClient*);

    BackForwardClient* client() const { return m_client; }

    bool goBackOrForward(int distance);
    bool goBack() { return goBackOrForward(-1); }
    bool goForward() { return goBackOrForward(1); }

    void addItem(PassRefPtr<HistoryItem>);
    void setCurrentItem(HistoryItem*);
    HistoryItem* currentItem() { return m_currentItem.get(); }

    int count() const;
    int backCount() const;
    int forwardCount() const;

private:
    BackForwardController(Page*, BackForwardClient*);

    Page* m_page;
    BackForwardClient* m_client;

    // FIXME: Ideally, we could derive this from HistoryController, but the rules for setting it are non-obvious.
    RefPtr<HistoryItem> m_currentItem;
};

} // namespace WebCore

#endif // BackForwardController_h