ichni_Creator_Studio/Assets/Scripts/DynamicUI/Hierarchy/HierarchyTab.cs

using System.Collections;
using System.Collections.Generic;
using Ichni.RhythmGame;
using TMPro;
using UnityEngine;
using UnityEngine.UI;

namespace Ichni.Editor
{
    public partial class HierarchyTab : MonoBehaviour
    {
        public GameObject indentationLinePrefab;
        
        public GameElement connectedGameElement;
        public HierarchyTab parentTab;
        public List<HierarchyTab> childTabList;

        public int tabLayer;
        public bool isSelected;
        public bool isExpanded;

        public RectTransform tabRect;
        public LayoutElement layoutElement;
        public RectTransform tabMainRect;
        public Button tabButton;
        public Button expandButton;
        public Button gotoButton;
        public TMP_Text tabButtonText;
        

        public void SetTab(GameElement targetElement, GameElement parentElement)
        {
            tabButtonText.text = targetElement.elementName;
            targetElement.connectedTab = this;
            this.isExpanded = false;
            this.isSelected = false;
            this.childTabList = new List<HierarchyTab>();

            if (parentElement == null)
            {
                this.tabLayer = 0;
                this.parentTab = null;
                this.transform.SetAsLastSibling();
            }
            else
            {
                this.parentTab = parentElement.connectedTab;
                this.tabLayer = this.parentTab.tabLayer + 1;

                this.parentTab.childTabList.Add(this);
                this.transform.SetSiblingIndex(this.parentTab.transform.GetSiblingIndex() +
                                               GetAllChildrenCount(this.parentTab));

                if (!this.parentTab.isExpanded)
                {
                    this.isExpanded = false;
                    SetExpansion(false);
                }

                for (int i = 1; i <= this.tabLayer; i++)
                {
                    float lineX = 10 * i;
                    Instantiate(indentationLinePrefab, tabRect).GetComponent<RectTransform>().anchoredPosition = new Vector2(lineX, 0);
                }
            }

            float posX = -25 + 10 * tabLayer;
            tabMainRect.anchoredPosition = new Vector2(posX, tabMainRect.anchoredPosition.y);

            expandButton.onClick.AddListener(ExpandOrFold);
        }
    }

    public partial class HierarchyTab
    {
        private int GetAllChildrenCount(HierarchyTab tab)
        {
            int c = tab.childTabList.Count;

            for (int i = 0; i < tab.childTabList.Count; i++)
            {
                c += GetAllChildrenCount(tab.childTabList[i]);
            }

            return c;
        }
        
        private void ExpandOrFold()
        {
            this.childTabList.RemoveAll(s => s == null);
            bool op = !isExpanded;

            for (int i = 0; i < childTabList.Count; i++)
            {
                childTabList[i].SetExpansion(op);
            }

            isExpanded = op;
        }

        private void SetExpansion(bool expand)
        {
            if (!(expand == true && isExpanded == false))
            {
                foreach (var tab in childTabList)
                {
                    tab.SetExpansion(expand);
                }
            }

            if (expand)
            {
                gameObject.SetActive(true);
                tabRect.localScale = Vector3.one;
                layoutElement.ignoreLayout = false;
            }
            else
            {
                tabRect.localScale = Vector3.zero;
                layoutElement.ignoreLayout = true;
                gameObject.SetActive(false);
            }
        }
    }
}