Add "Dirt" plugin

Assets/Scripts/Editor/Dirt/Modification.cs

@@ -0,0 +1,127 @@
+using System.Linq;
+
+using UnityEditor;
+using UnityEngine;
+
+namespace Dirt
+{
+    public class Modification
+    {
+        public string propertyPath;
+
+        public ModificationReference instance;
+        public ModificationReference prefab;
+        public bool excluded;
+        bool appliedOrReverted;
+
+        public Modification(GameObject prefabOwner, GameObject instanceOwner, PropertyModification propertyModification)
+        {
+            propertyPath = propertyModification.propertyPath;
+
+            prefab = new(prefabOwner, propertyModification.target);
+
+            var componentIndex = prefab.Setup(this);
+
+            var settings = DirtWindowSettings.instance;
+
+            excluded = settings.IsExcluded(this);
+
+            if (excluded && !settings.visibility.HasFlag(VisibilityMask.Exclusions))
+                return;
+
+            var instanceTransform = instanceOwner.transform;
+            instance = new(instanceOwner, instanceTransform);
+
+            var target = instanceTransform;
+
+            if (prefab.targetPath != string.Empty)
+                target = target.Find(prefab.targetPath);
+
+            if (!target)
+            {
+                target = instanceTransform;
+                var indexed = prefab.targetIndexedPath.ToList();
+                while (target && indexed.Count > 0)
+                {
+                    var i = indexed[0];
+                    target = i < target.childCount ? target.GetChild(i) : null;
+                    indexed.RemoveAt(0);
+                }
+            }
+
+            if (target)
+            {
+
+                if (prefab.GetTarget() is GameObject)
+                    instance.SetTarget(target.gameObject);
+                else if (componentIndex > -1)
+                {
+                    var components = target.GetComponents<Component>();
+                    if (componentIndex < components.Length)
+                        instance.SetTarget(components[componentIndex]);
+                }
+            }
+
+            instance.Setup(this);
+        }
+
+        public bool IsUnchangedButDirty()
+        {
+            if (appliedOrReverted)
+                return false;
+
+            if (prefab.isNothing && instance.isNothing)
+                return true;
+
+            if (!prefab.hasValue)
+                return false;
+
+            if (!instance.hasValue)
+                return false;
+
+            if (prefab.targetPropertyValue != instance.targetPropertyValue)
+                return false;
+
+            if (prefab.targetPropertyObjectValue != instance.targetPropertyObjectValue)
+                return false;
+
+            return true;
+        }
+
+        public void Apply()
+        {
+            appliedOrReverted = true;
+
+            PrefabUtility.ApplyPropertyOverride(
+                instance.GetTargetProperty(this),
+                AssetDatabase.GetAssetPath(prefab.GetOwner()),
+                InteractionMode.UserAction
+            );
+        }
+
+        public void Revert()
+        {
+            appliedOrReverted = true;
+
+            var p = instance.GetTargetProperty(this);
+            if (p is not null)
+            {
+                try
+                {
+                    PrefabUtility.RevertPropertyOverride(p, InteractionMode.UserAction);
+                }
+                catch (System.ArgumentException ex)
+                {
+                    Debug.LogWarning(ex);
+                }
+                return;
+            }
+
+            PrefabUtility.RemoveUnusedOverrides(
+                new[] { instance.GetOwner() },
+                InteractionMode.UserAction
+            );
+        }
+    }
+
+}