Tri-Inspector/Editor/Elements/TriBoxGroupElement.cs

using TriInspector.Utilities;
using UnityEditor;
using UnityEngine;

namespace TriInspector.Elements
{
    public class TriBoxGroupElement : TriHeaderGroupBaseElement
    {
        private readonly GUIContent _headerLabel;

        public TriBoxGroupElement(DeclareBoxGroupAttribute attribute)
        {
            _headerLabel = attribute.Title == null
                ? GUIContent.none
                : new GUIContent(attribute.Title);
        }

        protected override float GetHeaderHeight(float width)
        {
            if (string.IsNullOrEmpty(_headerLabel.text))
            {
                return 0f;
            }

            return base.GetHeaderHeight(width);
        }

        protected override void DrawHeader(Rect position)
        {
            TriEditorGUI.DrawBox(position, TriEditorStyles.TabOnlyOne);

            var headerLabelRect = new Rect(position)
            {
                xMin = position.xMin + 6,
                xMax = position.xMax - 6,
                yMin = position.yMin + 2,
                yMax = position.yMax - 2,
            };

            EditorGUI.LabelField(headerLabelRect, _headerLabel);
        }
    }
}