InertialScrollManager.h

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// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "Containers/Array.h"
#include "CoreMinimal.h"
 
class FInertialScrollManager
{
 
public:
    SLATE_API FInertialScrollManager(double SampleTimeout = 0.1f);
 
    SLATE_API void AddScrollSample(float Delta, double CurrentTime);
 
    SLATE_API void UpdateScrollVelocity(const float InDeltaTime);
 
    SLATE_API void ClearScrollVelocity(bool bInShouldStopScrollNow = false);
 
    float GetScrollVelocity() const { return ScrollVelocity; }
 
    bool GetShouldStopScrollNow() const { return bShouldStopScrollNow; }
 
    void ResetShouldStopScrollNow() { bShouldStopScrollNow = false; }
 
private:
    struct FScrollSample
    {
        double Time;
        float Delta;
 
        FScrollSample(float InDelta, double InTime)
            : Time(InTime)
            , Delta(InDelta)
        {}
    };
 
    TArray<FScrollSample> ScrollSamples;
 
    float ScrollVelocity;
 
    bool bShouldStopScrollNow = false;
 
    double SampleTimeout;
};