garden_client/Assets/Script/Tool/UI/BestfitText.cs

using System.Collections;
using System.Collections.Generic;

using UnityEngine;
using UnityEngine.UI;
using UnityEngine.Events;

public class BestfitText : Text
{
    #region

    protected string FormerText;
    
    #endregion

    protected void Update()
    {
                
    }

    protected override void OnPopulateMesh(VertexHelper toFill)
    {
        base.OnPopulateMesh(toFill);

        if (text != FormerText)
        {
            FormerText = text;

            StartCoroutine(DelayCall(Bestfit, 2));
        }
    }

    protected void Bestfit()
    {
        TextGenerationSettings textGenerationSettings = GetGenerationSettings(rectTransform.rect.size);

        bool shrink = false;
        bool expand = false;

        int antiCrush = 0;
        
        while (true)
        {
            antiCrush++;

            if (antiCrush > 100)
            {
                Debug.LogError("Crush");

                break;
            }

            int preferredLineHeight = Mathf.CeilToInt(cachedTextGenerator.GetPreferredHeight("1", textGenerationSettings));

            int preferredLineCount = Mathf.CeilToInt(cachedTextGenerator.GetPreferredHeight(text, textGenerationSettings)) / preferredLineHeight;

            int bestHeight = preferredLineHeight * preferredLineCount;
            
            if (bestHeight > rectTransform.rect.size.y)
            {
                textGenerationSettings.fontSize--;

                if (expand)
                {
                    break;
                }

                shrink = true;
            }
            else if (bestHeight < rectTransform.rect.size.y)
            {
                if (shrink)
                {
                    break;
                }

                textGenerationSettings.fontSize++;

                expand = true;
            }
            else if (bestHeight.Equal(rectTransform.rect.size.y))
            {
                break;
            }
        }

        fontSize = textGenerationSettings.fontSize;
    }

    protected IEnumerator DelayCall(UnityAction unityAction, int frame)
    {
        while (frame-- > 0)
        {
            yield return null;
        }

        unityAction.SafeInvoke();   
    }
}