FancyScrollView

openupm add jp.setchi.fancyscrollview

{
  "dependencies": {
    "jp.setchi.fancyscrollview": "https://github.com/setchi/FancyScrollView.git#upm"
  }
}

class ItemData
{
    public string Message { get; }

    public ItemData(string message)
    {
        Message = message;
    }
}

using UnityEngine;
using UnityEngine.UI;
using FancyScrollView;

class MyCell : FancyCell<ItemData>
{
    [SerializeField] Text message = default;

    public override void UpdateContent(ItemData itemData)
    {
        message.text = itemData.Message;
    }

    public override void UpdatePosition(float position)
    {
        // position は 0.0 ~ 1.0 の値です
        // position に基づいてスクロールの外観を自由に制御できます
    }
}

using UnityEngine;
using System.Linq;
using FancyScrollView;

class MyScrollView : FancyScrollView<ItemData>
{
    [SerializeField] Scroller scroller = default;
    [SerializeField] GameObject cellPrefab = default;

    protected override GameObject CellPrefab => cellPrefab;

    void Start()
    {
        scroller.OnValueChanged(base.UpdatePosition);
    }

    public void UpdateData(IList<ItemData> items)
    {
        base.UpdateContents(items);
        scroller.SetTotalCount(items.Count);
    }
}

using UnityEngine;
using System.Linq;

class EntryPoint : MonoBehaviour
{
    [SerializeField] MyScrollView myScrollView = default;

    void Start()
    {
        var items = Enumerable.Range(0, 20)
            .Select(i => new ItemData($"Cell {i}"))
            .ToArray();

        myScrollView.UpdateData(items);
    }
}