HoHCI-BikeSteering/Assets/Editor/RoutesEditor.cs

using UnityEditor;
using UnityEngine;


[CustomEditor(typeof(Routes.Routes))]
[CanEditMultipleObjects]
// ReSharper disable once CheckNamespace
public class RoutesEditor : Editor
{
    private bool showListContent;
    
    public override void OnInspectorGUI()
    {
        serializedObject.Update();
        RoutesList(serializedObject.FindProperty("routes"));
        //EditorGUILayout.PropertyField(routes.FindPropertyRelative("arraySize"), true);
        EditorGUILayout.Space();
        EditorGUILayout.PropertyField(serializedObject.FindProperty("selectedRoute"), true);
        serializedObject.ApplyModifiedProperties();
    }

    private void RoutesList(SerializedProperty list)
    {
        showListContent = EditorGUILayout.BeginFoldoutHeaderGroup(showListContent, $"{list.displayName} (Length = {list.arraySize})");
        if (showListContent)
        {
            EditorGUI.indentLevel += 1;
            EditorGUILayout.PropertyField(list.FindPropertyRelative("Array.size"));
            for (var i = 0; i < list.arraySize; i++) {
                RouteDrawer.PropertyField(list.GetArrayElementAtIndex(i));
            }
            EditorGUI.indentLevel -= 1;
        }
        
        EditorGUILayout.EndFoldoutHeaderGroup();
        
    }
}