TextMeshProTeletypeEffect.cs

using System.Collections;
using System.Collections.Generic;
using Nrjwolf.Tools.AttachAttributes; // https://github.com/Nrjwolf/unity-auto-attach-component-attributes
using TMPro;
using UnityEngine;

[RequireComponent(typeof(TextMeshProUGUI))]
public class TextMeshProTeletypeEffect : MonoBehaviour
{
    [GetComponent] [SerializeField] private TextMeshProUGUI m_TextMeshProUGUI;
    public TextMeshProUGUI TextMeshProUGUI { get => m_TextMeshProUGUI; }

    [Range(0, 1)]
    [SerializeField]
    private float m_Value = 1;
    public float Value
    {
        get => m_Value;
        set
        {
            m_Value = value;
            TextMeshProUGUI.maxVisibleCharacters = (int)(TextMeshProUGUI.textInfo.characterCount * value);
        }
    }


#if UNITY_EDITOR
    void OnValidate()
    {
        if (!gameObject.activeInHierarchy)
            return;

        Value = m_Value;
    }
#endif
}