easy buttons property drawer version

easybuttons_propertydrawer.cs

using UnityEngine;
using UnityEditor;
using System.Reflection;
using System.Linq;

using EasyButtons;
using System;
using System.Collections.Generic;
using System.Collections;

public class EasyButtonsPropertyDrawer<T> : PropertyDrawer
{
    // Needed to extract the index frop the property path that looks like foo.bar.myList[5];
    static int GetIndexFromPropertyPath(string propertyPath)
    {
        return Convert.ToInt32(new string(propertyPath.Where(c => char.IsDigit(c)).ToArray()));
    }

    // Lazily return the objects this property is referencing.  
    // Only handles basic types, lists and arrays for now.
    IEnumerable<System.Object> GetObjects(SerializedProperty property)
    {
        foreach(var targetObject in property.serializedObject.targetObjects)
        {
            var obj = this.fieldInfo.GetValue( targetObject);
            if (obj.GetType().IsArray)
            {
                var index = GetIndexFromPropertyPath(property.propertyPath);
                obj = ((T[])obj)[index];
            }
            else if(obj is IList)
            {
                var index = GetIndexFromPropertyPath(property.propertyPath);
                IList asList = ((IList)obj);
                
                obj = (T)( asList[index] );
            }
            yield return obj;
        }
    }

    // Unity adds annoying padding at the start, and since we're using gui layouts we can just say we take up no space
    // and let the normal layout junk do it's magic.
    public override float GetPropertyHeight(SerializedProperty property, GUIContent label) { return -2f; }
    public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
    {
        property.isExpanded = EditorGUILayout.Foldout(property.isExpanded, label);

        if(property.isExpanded)
        {
            // Loop through all methods with no parameters
            var methods = typeof(T)
                .GetMethods(BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic)
                .Where(m => m.GetParameters().Length == 0);

            foreach (var method in methods)
            {
                // Get the ButtonAttribute on the method (if any)
                var ba = (ButtonAttribute)Attribute.GetCustomAttribute(method, typeof(ButtonAttribute));

                if (ba != null)
                {
                    // Determine whether the button should be enabled based on its mode
                    var wasEnabled = GUI.enabled;
                    GUI.enabled = ba.Mode == ButtonMode.AlwaysEnabled
                        || (EditorApplication.isPlaying ? ba.Mode == ButtonMode.EnabledInPlayMode : ba.Mode == ButtonMode.DisabledInPlayMode);


                    if (((int)ba.Spacing & (int)ButtonSpacing.Before) != 0) EditorGUILayout.Space(10);
                    
                    // Draw a button which invokes the method
                    var buttonName = String.IsNullOrEmpty(ba.Name) ? ObjectNames.NicifyVariableName(method.Name) : ba.Name;
                    using(new GUILayout.HorizontalScope())
                    {
                        GUILayout.Space(EditorGUI.indentLevel*30);
                        if (GUILayout.Button(buttonName))
                        {
                            foreach(var t in GetObjects(property))
                            {
                                method.Invoke(t, null);
                            }
                        }
                    }

                    if (((int)ba.Spacing & (int)ButtonSpacing.After) != 0) EditorGUILayout.Space(10);
                    
                    GUI.enabled = wasEnabled;
                }
            }

            EditorGUI.indentLevel++;

            var propertyIterator = property.Copy();
            var siblingProperty = property.Copy();
            siblingProperty.Next(false);

            bool bOnceThrough = false;

            while( propertyIterator.NextVisible(!bOnceThrough) // First time through, enter children (!bOnceThrough), otherwise don't
            &&  !SerializedProperty.EqualContents(propertyIterator, siblingProperty) // We haven't entered a sibling 
            )
            {
                bOnceThrough = true;
                // Default
                EditorGUILayout.PropertyField(propertyIterator, includeChildren: true);
            }
            EditorGUI.indentLevel--;
        }

    }
}

// Users can implement the property drawer like this.  Not as nice as 
[CustomPropertyDrawer(typeof(MyCustomType))]
public class CCA_Parameters_PropertyDrawer : EasyButtonsPropertyDrawer<MyCustomType>
{
}