Source/WebCore/dom/UserGestureIndicator.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 UserGestureIndicator_h
#define UserGestureIndicator_h

#include <wtf/Noncopyable.h>
#include <wtf/RefCounted.h>
#include <wtf/RefPtr.h>

namespace WebCore {

enum ProcessingUserGestureState {
    DefinitelyProcessingUserGesture,
    PossiblyProcessingUserGesture,
    DefinitelyNotProcessingUserGesture
};

class UserGestureIndicator {
    WTF_MAKE_NONCOPYABLE(UserGestureIndicator);
public:
    class Token : public RefCounted<Token> {
    public:
        virtual ~Token() { }
    };

    static bool processingUserGesture();
    static bool consumeUserGesture();
    static Token* currentToken();

    explicit UserGestureIndicator(ProcessingUserGestureState);
    explicit UserGestureIndicator(PassRefPtr<Token>);
    ~UserGestureIndicator();


private:
    static ProcessingUserGestureState s_state;
    static UserGestureIndicator* s_topmostIndicator;
    ProcessingUserGestureState m_previousState;
    RefPtr<Token> m_token;
};

}

#endif