1 files changed, 90 insertions, 0 deletions
diff --git a/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimelineUndo.cs b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimelineUndo.cs
new file mode 100644
index 0000000..b6392f0
--- /dev/null
+++ b/Library/PackageCache/com.unity.timeline@1.2.13/Runtime/Utilities/TimelineUndo.cs
@@ -0,0 +1,90 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using UnityEngine.Playables;
+
+#if UNITY_EDITOR
+using UnityEditor;
+#endif
+
+namespace UnityEngine.Timeline
+{
+    static class TimelineUndo
+    {
+        public static void PushDestroyUndo(TimelineAsset timeline, Object thingToDirty, Object objectToDestroy, string operation)
+        {
+#if UNITY_EDITOR
+            if (objectToDestroy == null || !DisableUndoGuard.enableUndo)
+                return;
+
+            if (thingToDirty != null)
+                EditorUtility.SetDirty(thingToDirty);
+
+            if (timeline != null)
+                EditorUtility.SetDirty(timeline);
+
+            Undo.DestroyObjectImmediate(objectToDestroy);
+#else
+            if (objectToDestroy != null)
+                Object.Destroy(objectToDestroy);
+#endif
+        }
+
+        [Conditional("UNITY_EDITOR")]
+        public static void PushUndo(Object thingToDirty, string operation)
+        {
+#if UNITY_EDITOR
+            if (thingToDirty != null && DisableUndoGuard.enableUndo)
+            {
+                var track = thingToDirty as TrackAsset;
+                if (track != null)
+                    track.MarkDirty();
+
+                EditorUtility.SetDirty(thingToDirty);
+                Undo.RegisterCompleteObjectUndo(thingToDirty, "Timeline " + operation);
+            }
+#endif
+        }
+
+        [Conditional("UNITY_EDITOR")]
+        public static void RegisterCreatedObjectUndo(Object thingCreated, string operation)
+        {
+#if UNITY_EDITOR
+            if (DisableUndoGuard.enableUndo)
+            {
+                Undo.RegisterCreatedObjectUndo(thingCreated, "Timeline " + operation);
+            }
+#endif
+        }
+
+#if UNITY_EDITOR
+        public struct DisableUndoGuard : IDisposable
+        {
+            internal static bool enableUndo = true;
+            static readonly Stack<bool> m_UndoStateStack = new Stack<bool>();
+            bool m_Disposed;
+            public DisableUndoGuard(bool disable)
+            {
+                m_Disposed = false;
+                m_UndoStateStack.Push(enableUndo);
+                enableUndo = !disable;
+            }
+
+            public void Dispose()
+            {
+                if (!m_Disposed)
+                {
+                    if (m_UndoStateStack.Count == 0)
+                    {
+                        Debug.LogError("UnMatched DisableUndoGuard calls");
+                        enableUndo = true;
+                        return;
+                    }
+                    enableUndo = m_UndoStateStack.Pop();
+                    m_Disposed = true;
+                }
+            }
+        }
+#endif
+    }
+}