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Source/Editor/Surface/Undo/MoveNodesAction.cs

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+// Copyright (c) 2012-2020 Wojciech Figat. All rights reserved.
+
+using System;
+using FlaxEngine;
+
+namespace FlaxEditor.Surface.Undo
+{
+    /// <summary>
+    /// Move Visject Surface nodes undo action.
+    /// </summary>
+    /// <seealso cref="FlaxEditor.IUndoAction" />
+    class MoveNodesAction : IUndoAction
+    {
+        private VisjectSurface _surface;
+        private ContextHandle _context;
+        private uint[] _nodeIds;
+        private readonly Vector2 _locationDelta;
+
+        public MoveNodesAction(VisjectSurfaceContext context, uint[] nodeIds, Vector2 locationDelta)
+        {
+            _surface = context.Surface;
+            _context = new ContextHandle(context);
+            _nodeIds = nodeIds;
+            _locationDelta = locationDelta;
+        }
+
+        /// <inheritdoc />
+        public string ActionString => "Move nodes";
+
+        /// <inheritdoc />
+        public void Do()
+        {
+            Apply(_locationDelta);
+        }
+
+        /// <inheritdoc />
+        public void Undo()
+        {
+            Apply(-_locationDelta);
+        }
+
+        private void Apply(Vector2 delta)
+        {
+            var context = _context.Get(_surface);
+            foreach (var nodeId in _nodeIds)
+            {
+                var node = context.FindNode(nodeId);
+                if (node == null)
+                    throw new Exception("Missing node.");
+
+                node.Location += delta;
+            }
+
+            context.MarkAsModified(false);
+        }
+
+        /// <inheritdoc />
+        public void Dispose()
+        {
+            _surface = null;
+            _nodeIds = null;
+        }
+    }
+}