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

    public int VerticalMinSize = 1;
    public int VerticalMaxSize = 29;

    protected string FormerText;
    
    #endregion

    protected void Update()
    {
                
    }

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

        if (text != FormerText)
        {
            FormerText = text;
            
            StartCoroutine(DelayCall(Bestfit, 1));
        }
    }

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

        bool shrink = false;
        bool expand = false;

        int antiCrush = 0;

        while (true)
        {
            antiCrush++;

            if (antiCrush > 1000)
            {
                Debug.LogError("Crush");

                break;
            }

            float bestHeight = cachedTextGenerator.GetPreferredHeight(text, textGenerationSettings);
            
            if (bestHeight > rectTransform.rect.size.y*canvas.scaleFactor)
            {
                textGenerationSettings.fontSize--;

                if (textGenerationSettings.fontSize < VerticalMinSize)
                {
                    textGenerationSettings.fontSize = VerticalMinSize;

                    break;
                }
                else if (textGenerationSettings.fontSize > VerticalMaxSize)
                {
                    textGenerationSettings.fontSize = VerticalMaxSize;
                }
                else
                {
                    if (expand)
                    {
                        break;
                    }
                    else
                    {
                        shrink = true;
                    }
                }
            }
            else if (bestHeight < rectTransform.rect.size.y * canvas.scaleFactor)
            {
                if (shrink)
                {
                    break;
                }
                
                textGenerationSettings.fontSize++;

                if (textGenerationSettings.fontSize < VerticalMinSize)
                {
                    textGenerationSettings.fontSize = VerticalMinSize;
                }
                else if (textGenerationSettings.fontSize >= VerticalMaxSize)
                {
                    textGenerationSettings.fontSize = VerticalMaxSize;

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

        fontSize = textGenerationSettings.fontSize;
    }

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

        unityAction.SafeInvoke();   
    }
}