Merge pull request #207 from minami110/main

AddTo support for Godot Node

src/R3.Godot/addons/R3.Godot/GodotNodeExtensions.cs

@@ -0,0 +1,32 @@
+using System;
+using Godot;
+
+namespace R3;
+
+public static class GodotNodeExtensions
+{
+    /// <summary>
+    /// Dispose self on target node has bee tree exited.
+    /// </summary>
+    /// <param name="disposable"></param>
+    /// <param name="node"></param>
+    /// <typeparam name="T"></typeparam>
+    /// <returns>Self disposable</returns>
+    public static T AddTo<T>(this T disposable, Node node) where T : IDisposable
+    {
+        // Note: Dispose when tree exited, so if node is not inside tree, dispose immediately.
+        if (!node.IsInsideTree()) 
+        {
+            if (!node.IsNodeReady()) // Before enter tree
+            {
+                GD.PrintErr("AddTo does not support to use before enter tree.");
+            }
+
+            disposable.Dispose();
+            return disposable;
+        }
+
+        node.TreeExited += () => disposable.Dispose();
+        return disposable;
+    }
+}