Source/platform/exported/WebActiveGestureAnimation.h

/*
 * 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:
 *
 * 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 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 OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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 */

#ifndef WebActiveGestureAnimation_h
#define WebActiveGestureAnimation_h

#include "platform/PlatformExport.h"
#include "wtf/Noncopyable.h"
#include "wtf/OwnPtr.h"
#include "wtf/PassOwnPtr.h"

namespace WebKit {

class WebGestureCurve;
class WebGestureCurveTarget;

// Implements a gesture animation (fling scroll, etc.) using a curve with a generic interface
// to define the animation parameters as a function of time, and applies the animation
// to a target, again via a generic interface. It is assumed that animate() is called
// on a more-or-less regular basis by the owner.
class PLATFORM_EXPORT WebActiveGestureAnimation {
    WTF_MAKE_NONCOPYABLE(WebActiveGestureAnimation);
public:
    static PassOwnPtr<WebActiveGestureAnimation> createAtAnimationStart(PassOwnPtr<WebGestureCurve>, WebGestureCurveTarget*);
    static PassOwnPtr<WebActiveGestureAnimation> createWithTimeOffset(PassOwnPtr<WebGestureCurve>, WebGestureCurveTarget*, double startTime);
    ~WebActiveGestureAnimation();

    bool animate(double time);

private:
    // Assumes a valid WebGestureCurveTarget that outlives the animation.
    WebActiveGestureAnimation(PassOwnPtr<WebGestureCurve>, WebGestureCurveTarget*, double startTime, bool waitingForFirstTick);

    double m_startTime;
    bool m_waitingForFirstTick;
    OwnPtr<WebGestureCurve> m_curve;
    WebGestureCurveTarget* m_target;
};

} // namespace WebKit

#endif