SimpleEditorTableView.cs

/***
 * Copyright (c) 2024 Red Games
 * 
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLRDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USER OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

using System;
using System.Collections.Generic;
using System.Linq;
using UnityEditor;
using UnityEditor.IMGUI.Controls;
using UnityEngine;

namespace RedGame.Framework.EditorTools
{
    public class SimpleEditorTableView<TData>
    {
        private MultiColumnHeaderState _multiColumnHeaderState;
        private MultiColumnHeader _multiColumnHeader;
        private MultiColumnHeaderState.Column[] _columns;
        private readonly Color _lighterColor = Color.white * 0.3f;
        private readonly Color _darkerColor = Color.white * 0.1f;

        private Vector2 _scrollPosition;
        private bool _columnResized;
        private bool _sortingDirty;
        
        public delegate void DrawItem(Rect rect, TData item);
       
        public class ColumnDef
        {
            internal MultiColumnHeaderState.Column column;
            internal DrawItem onDraw;
            internal Comparison<TData> onSort;
            
            public ColumnDef SetMaxWidth(float maxWidth)
            {
                column.maxWidth = maxWidth;
                return this;
            }
            
            public ColumnDef SetTooltip(string tooltip)
            {
                column.headerContent.tooltip = tooltip;
                return this;
            }

            public ColumnDef SetAutoResize(bool autoResize)
            {
                column.autoResize = autoResize;
                return this;
            }

            public ColumnDef SetAllowToggleVisibility(bool allow)
            {
                column.allowToggleVisibility = allow;
                return this;
            }
            
            public ColumnDef SetSorting(Comparison<TData> onSort)
            {
                this.onSort = onSort;
                column.canSort = true;
                return this;
            }
        }

        private readonly List<ColumnDef> _columnDefs = new List<ColumnDef>();
        
        public void ClearColumns()
        {
            _columnDefs.Clear();
            _columnResized = true;
        }
        
        public ColumnDef AddColumn(string title, int minWidth, DrawItem onDrawItem)
        {
            ColumnDef columnDef = new ColumnDef()
            {
                column = new MultiColumnHeaderState.Column()
                {
                    allowToggleVisibility = false,
                    autoResize = true,
                    minWidth = minWidth,
                    canSort = false,
                    sortingArrowAlignment = TextAlignment.Right,
                    headerContent = new GUIContent(title),
                    headerTextAlignment = TextAlignment.Left,
                },
                onDraw = onDrawItem
            };
            
            _columnDefs.Add(columnDef);
            _columnResized = true;
            return columnDef;
        }

        private void ReBuild()
        {
            _columns = _columnDefs.Select((def) => def.column).ToArray();
            _multiColumnHeaderState = new MultiColumnHeaderState(_columns);
            _multiColumnHeader = new MultiColumnHeader(_multiColumnHeaderState);
            _multiColumnHeader.visibleColumnsChanged += (multiColumnHeader) => multiColumnHeader.ResizeToFit();
            _multiColumnHeader.sortingChanged += (multiColumnHeader) => _sortingDirty = true;
            _multiColumnHeader.ResizeToFit();
            _columnResized = false;
        }
        
        public void DrawTableGUI(TData[] data, float maxHeight = float.MaxValue, float rowHeight = -1)
        {
            if (_multiColumnHeader == null || _columnResized)
                ReBuild();
            
            float rowWidth = _multiColumnHeaderState.widthOfAllVisibleColumns;
            if (rowHeight < 0)
                rowHeight = EditorGUIUtility.singleLineHeight;
            
            Rect headerRect = GUILayoutUtility.GetRect(rowWidth, rowHeight);
            _multiColumnHeader!.OnGUI(headerRect, xScroll: 0.0f);

            float sumWidth = rowWidth;
            float sumHeight = rowHeight * data.Length + GUI.skin.horizontalScrollbar.fixedHeight;

            UpdateSorting(data);

            Rect scrollViewPos = GUILayoutUtility.GetRect(0, sumWidth, 0, maxHeight);
            Rect viewRect = new Rect(0, 0, sumWidth, sumHeight);
            
            _scrollPosition = GUI.BeginScrollView(
                position: scrollViewPos,
                scrollPosition: _scrollPosition,
                viewRect: viewRect,
                alwaysShowHorizontal: false,
                alwaysShowVertical: false
            );
            
            EditorGUILayout.BeginVertical();

            for (int row = 0; row < data.Length; row++)
            {
                Rect rowRect = new Rect(0, rowHeight * row, rowWidth, rowHeight);

                EditorGUI.DrawRect(rect: rowRect, color: row % 2 == 0 ? _darkerColor : _lighterColor);
                
                for (int col = 0; col < _columns.Length; col++)
                {
                    if (_multiColumnHeader.IsColumnVisible(col))
                    {
                        int visibleColumnIndex = _multiColumnHeader.GetVisibleColumnIndex(col);
                        Rect cellRect = _multiColumnHeader.GetCellRect(visibleColumnIndex, rowRect);
                        _columnDefs[col].onDraw(cellRect, data[row]);
                    }
                }
            }

            EditorGUILayout.EndVertical();
            GUI.EndScrollView(handleScrollWheel: true);
        }

        private void UpdateSorting(TData[] data)
        {
            if (_sortingDirty)
            {
                int sortIndex = _multiColumnHeader.sortedColumnIndex;
                if (sortIndex >= 0)
                {
                    var sortCompare = _columnDefs[sortIndex].onSort;
                    bool ascending = _multiColumnHeader.IsSortedAscending(sortIndex);

                    Array.Sort(data, ((a, b) =>
                    {
                        int r = sortCompare(a, b);
                        return ascending ? r : -r;
                    }));
                }

                _sortingDirty = false;
            }
        }
    }
}