dezhou_client/wb_unity_pro/Assets/Scripts/LuaHelper/CustomScrollView.cs

using UnityEngine;

public class CustomScrollView : MonoBehaviour
{
    public RectTransform rectStopUp;
    public RectTransform rectStopDown;
    public RectTransform rectTitle;
    public RectTransform rectCenter;

    public RectTransform rectCenterLimitUp;
    public RectTransform rectCenterLimitDown;
    public RectTransform rectCenterSubUp;
    public RectTransform rectCenterSubDown;

    // <20><><EFBFBD><EFBFBD>Ч<EFBFBD><D0A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
    private float damping = 0.9f; // <20><><EFBFBD><EFBFBD>ϵ<EFBFBD><CFB5><EFBFBD><EFBFBD>ֵԽС<D4BD><D0A1><EFBFBD><EFBFBD>Խ<EFBFBD><D4BD>
    private float minVelocity = 0.1f; // <20><>С<EFBFBD>ٶ<EFBFBD><D9B6><EFBFBD>ֵ

    private Vector3 vecStart;
    private Vector3 vecStartCenter;
    private Vector3 vecStartTitle;
    private Vector3 velocity = Vector3.zero; // <20><>ǰ<EFBFBD>ٶ<EFBFBD>
    private bool isDragging = false;
    private float lastMouseY;
    private bool shouldStopScrollUp = false; // <20>Ƿ<EFBFBD>Ӧ<EFBFBD><D3A6>ֹͣ<CDA3><D6B9><EFBFBD>ϻ<EFBFBD><CFBB><EFBFBD>
    private bool shouldStopScrollDown = false; // <20>Ƿ<EFBFBD>Ӧ<EFBFBD><D3A6>ֹͣ<CDA3><D6B9><EFBFBD>»<EFBFBD><C2BB><EFBFBD>

    void Update()
    {
        if (Input.GetMouseButtonDown(0))
        {
            StartDragging();
        }

        if (Input.GetMouseButtonUp(0))
        {
            StopDragging();
        }

        if (Input.GetMouseButton(0))
        {
            HandleDragging();
        }

        // Ӧ<>û<EFBFBD><C3BB><EFBFBD>Ч<EFBFBD><D0A7>
        ApplyInertia();
    }

    private void StartDragging()
    {
        vecStart = Input.mousePosition;
        vecStartCenter = rectCenter.position;
        vecStartTitle = rectTitle.position;
        lastMouseY = Input.mousePosition.y;
        velocity = Vector3.zero;
        isDragging = true;
        shouldStopScrollUp = false;
        shouldStopScrollDown = false;
    }

    private void StopDragging()
    {
        isDragging = false;
    }

    private void HandleDragging()
    {
        if (!isDragging) return;

        Vector3 currentMousePos = Input.mousePosition;

        // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Yֵ<59>ƶ<EFBFBD><C6B6><EFBFBD><EFBFBD>Ļ<EFBFBD><C4BB><EFBFBD>
        float deltaY = currentMousePos.y - vecStart.y;
        Vector3 newPosition = vecStartCenter + new Vector3(0, deltaY, 0);

        // <20><><EFBFBD><EFBFBD><EFBFBD>߽<EFBFBD><DFBD><EFBFBD><EFBFBD><EFBFBD>
        CheckScrollLimits(deltaY);

        // <20><><EFBFBD>ݱ߽<DDB1><DFBD><EFBFBD><EFBFBD>ƾ<EFBFBD><C6BE><EFBFBD><EFBFBD>Ƿ<EFBFBD><C7B7><EFBFBD><EFBFBD><EFBFBD>rectCenterλ<72><CEBB>
        if (!(deltaY > 0 && shouldStopScrollDown) && !(deltaY < 0 && shouldStopScrollUp))
        {
            // ֱ<><D6B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>rectCenter<65><72>λ<EFBFBD><CEBB>
            rectCenter.position = newPosition;

            // <20><><EFBFBD><EFBFBD>rectTitleӦ<65><D3A6><EFBFBD>ƶ<EFBFBD><C6B6><EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD><CEBB>
            Vector3 newTitlePosition = vecStartTitle + new Vector3(0, deltaY, 0);

            // <20><><EFBFBD><EFBFBD>rectTitle<6C><65>λ<EFBFBD>ã<EFBFBD><C3A3><EFBFBD><EFBFBD>ܳ<EFBFBD><DCB3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>±߽<C2B1>
            float minY = rectStopDown.position.y;
            float maxY = rectStopUp.position.y;
            newTitlePosition.y = Mathf.Clamp(newTitlePosition.y, minY, maxY);

            // <20><><EFBFBD><EFBFBD>rectTitle<6C><65>λ<EFBFBD><CEBB>
            rectTitle.position = newTitlePosition;
        }

        // <20><><EFBFBD>㵱ǰ<E3B5B1>ٶȣ<D9B6><C8A3><EFBFBD><EFBFBD>ڻ<EFBFBD><DABB><EFBFBD>Ч<EFBFBD><D0A7><EFBFBD><EFBFBD>
        float currentDeltaY = currentMousePos.y - lastMouseY;
        velocity = new Vector3(0, currentDeltaY / Time.deltaTime, 0);
        lastMouseY = currentMousePos.y;
    }

    private void ApplyInertia()
    {
        if (!isDragging && velocity.magnitude > minVelocity)
        {
            // <20><><EFBFBD><EFBFBD><EFBFBD>߽<EFBFBD><DFBD><EFBFBD><EFBFBD><EFBFBD>
            CheckScrollLimits(velocity.y * Time.deltaTime);

            // <20><><EFBFBD><EFBFBD><EFBFBD>Ƿ<EFBFBD>Ӧ<EFBFBD><D3A6>ֹͣ<CDA3><D6B9><EFBFBD>Ի<EFBFBD><D4BB><EFBFBD>
            bool shouldStopInertia = (velocity.y > 0 && shouldStopScrollDown) || (velocity.y < 0 && shouldStopScrollUp);

            if (!shouldStopInertia)
            {
                // ʹ<><CAB9>ָ<EFBFBD><D6B8>˥<EFBFBD><CBA5><EFBFBD>Ļ<EFBFBD><C4BB><EFBFBD>
                float deceleration = Mathf.Pow(damping, Time.deltaTime * 60f);
                velocity *= deceleration;

                // rectCenter<65><72><EFBFBD><EFBFBD><EFBFBD>ƶ<EFBFBD>
                rectCenter.position += velocity * Time.deltaTime;

                // rectTitle<6C><65><EFBFBD><EFBFBD>rectCenter<65>ƶ<EFBFBD><C6B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ܱ߽<DCB1><DFBD><EFBFBD><EFBFBD><EFBFBD>
                Vector3 newTitlePosition = rectTitle.position + velocity * Time.deltaTime;
                float minY = rectStopDown.position.y;
                float maxY = rectStopUp.position.y;
                newTitlePosition.y = Mathf.Clamp(newTitlePosition.y, minY, maxY);
                rectTitle.position = newTitlePosition;
            }
            else
            {
                // <20><><EFBFBD><EFBFBD>Ӧ<EFBFBD><D3A6>ֹͣ<CDA3><D6B9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ټ<EFBFBD><D9BC><EFBFBD>
                velocity *= 0.5f;
            }

            if (velocity.magnitude <= minVelocity)
            {
                velocity = Vector3.zero;
            }
        }
        else if (!isDragging && velocity.magnitude <= minVelocity)
        {
            // <20><><EFBFBD>ٶȺ<D9B6>Сʱ<D0A1><CAB1>ȷ<EFBFBD><C8B7>rectTitle<6C><65><EFBFBD>ڱ߽<DAB1><DFBD><EFBFBD>
            Vector3 currentTitlePos = rectTitle.position;
            float minY = rectStopDown.position.y;
            float maxY = rectStopUp.position.y;
            currentTitlePos.y = Mathf.Clamp(currentTitlePos.y, minY, maxY);
            rectTitle.position = currentTitlePos;
        }
    }

    // <20><><EFBFBD>黬<EFBFBD><E9BBAC><EFBFBD>߽<EFBFBD><DFBD><EFBFBD><EFBFBD><EFBFBD>
    private void CheckScrollLimits(float deltaY)
    {
        // <20><><EFBFBD>ñ<EFBFBD>־
        shouldStopScrollUp = false;
        shouldStopScrollDown = false;

        // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>»<EFBFBD><C2BB><EFBFBD>ʱrectCenterSubUp<55><70><EFBFBD>ܵ<EFBFBD><DCB5><EFBFBD>rectCenterLimitUp
        if (deltaY < 0) // <20><><EFBFBD>ϻ<EFBFBD><CFBB><EFBFBD><EFBFBD><EFBFBD>rectCenter<65><72><EFBFBD><EFBFBD><EFBFBD>ƶ<EFBFBD><C6B6><EFBFBD>
        {
            if (rectCenterSubUp != null && rectCenterLimitUp != null)
            {
                // <20><><EFBFBD><EFBFBD>rectCenterSubUp<55>ĵײ<C4B5><D7B2>Ƿ<EFBFBD><C7B7><EFBFBD><EFBFBD><EFBFBD>rectCenterLimitUp<55>Ķ<EFBFBD><C4B6><EFBFBD>
                float subUpBottom = rectCenterSubUp.position.y - rectCenterSubUp.rect.height / 2;
                float limitUpTop = rectCenterLimitUp.position.y + rectCenterLimitUp.rect.height / 2;

                if (subUpBottom < limitUpTop)
                {
                    shouldStopScrollUp = true;
                }
            }
        }

        // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϻ<EFBFBD><CFBB><EFBFBD>ʱrectCenterSubDown<77><6E><EFBFBD>ܸ<EFBFBD><DCB8><EFBFBD>rectCenterLimitDown
        if (deltaY > 0) // <20><><EFBFBD>»<EFBFBD><C2BB><EFBFBD><EFBFBD><EFBFBD>rectCenter<65><72><EFBFBD><EFBFBD><EFBFBD>ƶ<EFBFBD><C6B6><EFBFBD>
        {
            if (rectCenterSubDown != null && rectCenterLimitDown != null)
            {
                // <20><><EFBFBD><EFBFBD>rectCenterSubDown<77>Ķ<EFBFBD><C4B6><EFBFBD><EFBFBD>Ƿ<EFBFBD><C7B7><EFBFBD><EFBFBD><EFBFBD>rectCenterLimitDown<77>ĵײ<C4B5>
                float subDownTop = rectCenterSubDown.position.y + rectCenterSubDown.rect.height / 2;
                float limitDownBottom = rectCenterLimitDown.position.y - rectCenterLimitDown.rect.height / 2;

                if (subDownTop > limitDownBottom)
                {
                    shouldStopScrollDown = true;
                }
            }
        }
    }

    // <20>ⲿ<EFBFBD><E2B2BF><EFBFBD>Ե<EFBFBD><D4B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӷ<EFBFBD><D3B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ٶȣ<D9B6><C8A3><EFBFBD><EFBFBD>練<EFBFBD><E7B7B4>Ч<EFBFBD><D0A7><EFBFBD><EFBFBD>
    public void AddVelocity(Vector3 additionalVelocity)
    {
        velocity += additionalVelocity;
    }

    // <20><><EFBFBD>û<EFBFBD><C3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
    public void SetDamping(float newDamping)
    {
        damping = Mathf.Clamp(newDamping, 0.1f, 0.99f);
    }

    // <20><>ȡ<EFBFBD><C8A1>ǰ<EFBFBD>ٶ<EFBFBD>
    public Vector3 GetCurrentVelocity()
    {
        return velocity;
    }

    // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǿ<EFBFBD>Ƹ<EFBFBD><C6B8><EFBFBD>rectTitleλ<65>õ<EFBFBD><C3B5>߽<EFBFBD><DFBD>ڣ<EFBFBD><DAA3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڱ<EFBFBD>Ҫʱ<D2AA><CAB1><EFBFBD>ã<EFBFBD>
    public void ClampTitlePosition()
    {
        Vector3 currentTitlePos = rectTitle.position;
        float minY = rectStopDown.position.y;
        float maxY = rectStopUp.position.y;
        currentTitlePos.y = Mathf.Clamp(currentTitlePos.y, minY, maxY);
        rectTitle.position = currentTitlePos;
    }
}