YiScrollController.h

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// © You i Labs Inc. 2000-2017. All rights reserved.
#ifndef _YI_SCROLL_CONTROLLER_H_
#define _YI_SCROLL_CONTROLLER_H_

#include "animation/YiAnimation.h"
#include "binding/YiScriptableObject.h"
#include "framework/YiPredef.h"

class CYIInputInterpreter;

struct YI_SCROLLED_INFO
{
    YI_SCROLLED_INFO();

    float fDelta;
    float fSpeed;
    float fEventPos;
    int32_t nPageBefore;
    int32_t nPageAfter;
    bool       bReachedStart;
    bool       bReachedEnd;
};

class CYIScrollController : public CYIAnimation::Listener, public CYIScriptableObject
{
public:

    class ScrollListener
    {
    public:
        virtual ~ScrollListener() {}
        virtual void OnScrollStarted(CYIScrollController * /*pControl*/) {};
        virtual void OnScrollEnded(CYIScrollController * /*pControl*/) {};
        virtual void OnScrollAuto(CYIScrollController * /*pControl*/) {};
        virtual void OnScrolled(CYIScrollController * /*pControl*/, YI_SCROLLED_INFO /*scrolledInfo*/) {};
    };
    
    class OutOfRangeListener
    {
    public:
        virtual ~OutOfRangeListener() {}

        virtual void OnOutOfRangeAtStart(CYIScrollController * /*pControl*/, float /*fOutOfRange*/, float /*fDelta*/){};
        virtual void OnOutOfRangeAtEnd(CYIScrollController * /*pControl*/, float /*fOutOfRange*/, float /*fDelta*/){};

        virtual void OnOutOfRangeAtStartDirectionChanged(CYIScrollController * /*pControl*/, float /*fOutOfRange*/, float /*fDelta*/){};
        virtual void OnOutOfRangeAtEndDirectionChanged(CYIScrollController * /*pControl*/, float /*fOutOfRange*/, float /*fDelta*/){};
        virtual void OnOutOfRangeAtStartSnapBack(CYIScrollController * /*pControl*/, float /*fOutOfRange*/){};
        virtual void OnOutOfRangeAtEndSnapBack(CYIScrollController * /*pControl*/, float /*fOutOfRange*/){};
        virtual void OnOutOfRangeAtStartBegan(CYIScrollController * /*pControl*/, float /*fOutOfRange*/, float /*fDelta*/){};
        virtual void OnOutOfRangeAtEndBegan(CYIScrollController * /*pControl*/, float /*fOutOfRange*/, float /*fDelta*/){};
        virtual void OnOutOfRangeAtStartFinished(CYIScrollController * /*pControl*/) {};
        virtual void OnOutOfRangeAtEndFinished  (CYIScrollController * /*pControl*/) {};
    };

    CYIScrollController();
    virtual                   ~CYIScrollController() override;

    void SetSnapBackDur(uint64_t uSnapBackDur);
    uint64_t GetSnapBackDur() const;

    void SetFrictionCoeff(float fFrictionCoefficient);
    void SetMaxVelocityCoeff(float fMaxVelocityCoefficient);

    void SetScrollListener(ScrollListener *pListener);
    void SetOutOfRangeListener(OutOfRangeListener *pListener);

    void GetDataRange(float *pStart, float *pSize) const;
    void SetDataRange(float fDataStart, float fDataSize, bool bAnimate = true);
    void SetMagnetRules(bool bSnapBack, float fSnapBackStart, float fSnapBackEnd, float fMaxOutOfRangeStart, float fMaxOutOfRangeEnd);

    void SetCarousel(bool bCarousel);

    void MoveBy(float fDelta, float fEventPos = 0, bool bAllowOutOfRange = false, bool bNotifyListener = true);

    void MoveByAnimate(float fDelta, uint64_t uDur, CYITimeInterpolator *pInterpolator = nullptr, bool bAllowOutOfRange = true);
    void MoveToPercentage(float fPercentage, bool bNotifyListener = true);
    void MoveToPercentageAnimate(float fPercentage, uint64_t uDur, CYITimeInterpolator *pInterpolator = nullptr);
    void StopScrolling();
    bool IsScrolling() const;
    float GetPctPos() const;
    int64_t GetCurrentVelocity() const;
    void GetCurrentWindowPos(float *pStart, float *pEnd) const;
    float GetDataStart() const;

    float GetScrollStartPos() const;
    void Reset();

    void SetPageSize(float fPageSize, bool bAlwaysCenterOnPage = false, bool bSwipeToNextPage = false);
    float GetPageSize() const;
    bool GetAlwaysCenterOnPage() const;
    int32_t GetCurPage() const;
    int32_t GetPageCount() const;
    float CalculatePageOffset(int32_t nPage) const;
    float CalculateOffsetToNearestPage(float fMoveBy) const;

    float CalculateCenterOffset() const;

    virtual float CalculateSnapBackOffset() const;

    void GestureStart(float fPos, uint64_t uEventTimeMs);
    void GestureMove(float fPos, uint64_t uEventTimeMs);
    void GestureEnd(float fPos, uint64_t uEventTimeMs);

    void SetDecelerationDuration(uint32_t uDurationMs);

    virtual uint32_t GetDecelerationDuration() const;

    float GetScrollDelta() const;

    float GetCompletedScrollDelta() const;

protected:

    virtual bool AdjustMoveBy(float *pMoveBy, const float &fDataEnd) const;
    virtual bool AdjustMoveByNoOutOfRange(float *pMoveBy) const;
    virtual bool AdjustMoveByNoOutOfRangeDuringDecelerate(float *pMoveBy, int32_t nDir);

    void AnimateMoveBy(float fDelta, uint64_t uDur, bool bCanCancel, CYITimeInterpolator *pInterpolator = nullptr);
    void Decelerate();
    void FinishMoveBy();
    bool SnapBack(bool bAnimate = true);

    virtual void OnAnimate(CYIAnimation *pAnim, float fDataPosition) override;
    virtual void OnAnimationBegin(CYIAnimation *pAnim) override;

    virtual void OnAnimationEnd(CYIAnimation *pAnim) override;

    void StartScroll(bool bAlreadyScrolling);
    void EndScroll();
    void AutoScroll();

    float GetDataEnd() const;

    bool IsOutOfRange(float fOffset = 0.0f) const;

    float CalculateSnapBackOffset(float fDataStart) const;

    float m_fDataStart;
    float m_fDataSize;
    float m_fAnticipatedDataStart;
    float m_fAnticipatedDataEnd;

    float m_fScrollStartPos;
    bool                    m_bIsScrolling;

    int32_t m_nOutOfRangeDirection;

    bool                    m_bAlwaysCenterOnPage;
    bool                    m_bSwipeToNextPage;
    bool                    m_bSnapBack;
    float m_fSnapBackStart;
    float m_fSnapBackEnd;
    float m_fMaxOutOfRangeStart;
    float m_fMaxOutOfRangeEnd;
    float m_fPageSize;
    bool                       m_bCarousel;

    uint64_t m_uSnapBackDur;
    float m_fFrictionCoeff;
    uint32_t m_uDecelerationDuration;

    bool                    m_bGestureStarted;
    int32_t m_nPageAtGestureStart;
    float m_fGestureEndPos;

    CYIAnimation               *m_pMoveByAnim;
    float m_fMoveByTarget;
    float m_fMoveByDone;
    bool                    m_bMoveByCanCancel;
    bool                    m_bAllowOutOfRangeOnAnimateMoveBy;

    ScrollListener             *m_pScrollListener;
    OutOfRangeListener         *m_pOutOfRangeListener;

    CYIInputInterpreter        *m_pGestureData;

private:
    YI_DISALLOW_COPY_AND_ASSIGN(CYIScrollController)
};

#endif // _YI_SCROLL_CONTROLLER_H_