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      1 /*
      2  * Copyright (c) 2011, Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are
      6  * met:
      7  *
      8  *     * Redistributions of source code must retain the above copyright
      9  * notice, this list of conditions and the following disclaimer.
     10  *     * Redistributions in binary form must reproduce the above
     11  * copyright notice, this list of conditions and the following disclaimer
     12  * in the documentation and/or other materials provided with the
     13  * distribution.
     14  *     * Neither the name of Google Inc. nor the names of its
     15  * contributors may be used to endorse or promote products derived from
     16  * this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #ifndef ScrollAnimatorNone_h
     32 #define ScrollAnimatorNone_h
     33 
     34 #include "platform/Timer.h"
     35 #include "platform/geometry/FloatPoint.h"
     36 #include "platform/scroll/ScrollAnimator.h"
     37 
     38 class ScrollAnimatorNoneTest;
     39 
     40 namespace blink {
     41 
     42 class PLATFORM_EXPORT ScrollAnimatorNone : public ScrollAnimator {
     43 public:
     44     explicit ScrollAnimatorNone(ScrollableArea*);
     45     virtual ~ScrollAnimatorNone();
     46 
     47     virtual bool scroll(ScrollbarOrientation, ScrollGranularity, float step, float delta) OVERRIDE;
     48     virtual void scrollToOffsetWithoutAnimation(const FloatPoint&) OVERRIDE;
     49 
     50     virtual void cancelAnimations() OVERRIDE;
     51     virtual void serviceScrollAnimations() OVERRIDE;
     52 
     53     virtual void willEndLiveResize() OVERRIDE;
     54     virtual void didAddVerticalScrollbar(Scrollbar*) OVERRIDE;
     55     virtual void didAddHorizontalScrollbar(Scrollbar*) OVERRIDE;
     56 
     57     enum Curve {
     58         Linear,
     59         Quadratic,
     60         Cubic,
     61         Quartic,
     62         Bounce
     63     };
     64 
     65     struct PLATFORM_EXPORT Parameters {
     66         Parameters();
     67         Parameters(bool isEnabled, double animationTime, double repeatMinimumSustainTime, Curve attackCurve, double attackTime, Curve releaseCurve, double releaseTime, Curve coastTimeCurve, double maximumCoastTime);
     68 
     69         // Note that the times can be overspecified such that releaseTime or releaseTime and attackTime are greater
     70         // than animationTime. animationTime takes priority over releaseTime, capping it. attackTime is capped at
     71         // whatever time remains, or zero if none.
     72         bool m_isEnabled;
     73         double m_animationTime;
     74         double m_repeatMinimumSustainTime;
     75 
     76         Curve m_attackCurve;
     77         double m_attackTime;
     78 
     79         Curve m_releaseCurve;
     80         double m_releaseTime;
     81 
     82         Curve m_coastTimeCurve;
     83         double m_maximumCoastTime;
     84     };
     85 
     86 protected:
     87     virtual void animationWillStart() { }
     88     virtual void animationDidFinish() { }
     89 
     90     Parameters parametersForScrollGranularity(ScrollGranularity) const;
     91 
     92     friend class ::ScrollAnimatorNoneTest;
     93 
     94     struct PLATFORM_EXPORT PerAxisData {
     95         PerAxisData(ScrollAnimatorNone* parent, float* currentPos, int visibleLength);
     96         void reset();
     97         bool updateDataFromParameters(float step, float delta, float scrollableSize, double currentTime, Parameters*);
     98         bool animateScroll(double currentTime);
     99         void updateVisibleLength(int visibleLength);
    100 
    101         static double curveAt(Curve, double t);
    102         static double attackCurve(Curve, double deltaT, double curveT, double startPos, double attackPos);
    103         static double releaseCurve(Curve, double deltaT, double curveT, double releasePos, double desiredPos);
    104         static double coastCurve(Curve, double factor);
    105 
    106         static double curveIntegralAt(Curve, double t);
    107         static double attackArea(Curve, double startT, double endT);
    108         static double releaseArea(Curve, double startT, double endT);
    109 
    110         double newScrollAnimationPosition(double deltaTime);
    111 
    112         float* m_currentPosition;
    113         double m_currentVelocity;
    114 
    115         double m_desiredPosition;
    116         double m_desiredVelocity;
    117 
    118         double m_startPosition;
    119         double m_startTime;
    120         double m_startVelocity;
    121 
    122         double m_animationTime;
    123         double m_lastAnimationTime;
    124 
    125         double m_attackPosition;
    126         double m_attackTime;
    127         Curve m_attackCurve;
    128 
    129         double m_releasePosition;
    130         double m_releaseTime;
    131         Curve m_releaseCurve;
    132 
    133         int m_visibleLength;
    134     };
    135 
    136     void startNextTimer();
    137     void animationTimerFired();
    138 
    139     void stopAnimationTimerIfNeeded();
    140     bool animationTimerActive();
    141     void updateVisibleLengths();
    142 
    143     PerAxisData m_horizontalData;
    144     PerAxisData m_verticalData;
    145 
    146     double m_startTime;
    147     bool m_animationActive;
    148 };
    149 
    150 } // namespace blink
    151 
    152 #endif // ScrollAnimatorNone_h
    153