AppleHillsProduction/Assets/Editor/TimelineEventMappingDrawer.cs

using UnityEngine;
using UnityEditor;
using Interactions;
using System;

[CustomPropertyDrawer(typeof(InteractionTimelineAction.TimelineEventMapping))]
public class TimelineEventMappingDrawer : PropertyDrawer
{
    public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
    {
        // Use default property drawer, but initialize values if needed
        InitializeDefaultValues(property);
        EditorGUI.PropertyField(position, property, label, true);
    }

    public override float GetPropertyHeight(SerializedProperty property, GUIContent label)
    {
        return EditorGUI.GetPropertyHeight(property, label, true);
    }

    // Called when property is created to initialize default values
    private void InitializeDefaultValues(SerializedProperty property)
    {
        // Check if this is a new/empty property that needs initialization
        SerializedProperty timelinesArray = property.FindPropertyRelative("timelines");
        if (timelinesArray != null && timelinesArray.arraySize == 0)
        {
            // This appears to be a new property, so initialize default values
            
            // Initialize timelines array with one empty element
            timelinesArray.ClearArray();
            timelinesArray.InsertArrayElementAtIndex(0);
            timelinesArray.GetArrayElementAtIndex(0).objectReferenceValue = null;
            
            // Set default binding values
            property.FindPropertyRelative("bindPlayerCharacter").boolValue = true;
            property.FindPropertyRelative("bindPulverCharacter").boolValue = true;
            property.FindPropertyRelative("playerTrackName").stringValue = "Player";
            property.FindPropertyRelative("pulverTrackName").stringValue = "Pulver";
            property.FindPropertyRelative("timeoutSeconds").floatValue = 30f;
            property.FindPropertyRelative("loopLast").boolValue = false;
            property.FindPropertyRelative("loopAll").boolValue = false;
            
            // Make sure to apply modifications
            property.serializedObject.ApplyModifiedProperties();
        }
    }
}