ScrollAnimationKinetic.h [plain text]
#pragma once
#include "FloatPoint.h"
#include "ScrollAnimation.h"
#include <wtf/Optional.h>
#include <wtf/RunLoop.h>
namespace WebCore {
class PlatformWheelEvent;
class ScrollAnimationKinetic final : public ScrollAnimation {
private:
class PerAxisData {
public:
PerAxisData(double lower, double upper, double initialPosition, double initialVelocity);
double position() { return m_position; }
double velocity() { return m_velocity; }
bool animateScroll(Seconds timeDelta);
private:
double m_lower { 0 };
double m_upper { 0 };
double m_coef1 { 0 };
double m_coef2 { 0 };
Seconds m_elapsedTime;
double m_position { 0 };
double m_velocity { 0 };
};
public:
using ScrollExtentsCallback = WTF::Function<ScrollExtents(void)>;
using NotifyPositionChangedCallback = WTF::Function<void(FloatPoint&&)>;
ScrollAnimationKinetic(ScrollExtentsCallback&&, NotifyPositionChangedCallback&&);
virtual ~ScrollAnimationKinetic();
void appendToScrollHistory(const PlatformWheelEvent&);
void clearScrollHistory();
FloatPoint computeVelocity();
void start(const FloatPoint& initialPosition, const FloatPoint& velocity, bool mayHScroll, bool mayVScroll);
void stop() override;
bool isActive() const override;
private:
void animationTimerFired();
Seconds deltaToNextFrame();
ScrollExtentsCallback m_scrollExtentsFunction;
NotifyPositionChangedCallback m_notifyPositionChangedFunction;
Optional<PerAxisData> m_horizontalData;
Optional<PerAxisData> m_verticalData;
MonotonicTime m_startTime;
RunLoop::Timer<ScrollAnimationKinetic> m_animationTimer;
FloatPoint m_position;
Vector<PlatformWheelEvent> m_scrollHistory;
};
}