Improve pasting to support different copy sources

Filtration.ObjectModel/Commands/ItemFilterScript/PasteMultipleBlocksCommand.cs

@@ -0,0 +1,49 @@
+using System;
+using System.Collections.Generic;
+
+namespace Filtration.ObjectModel.Commands.ItemFilterScript
+{
+    public class PasteMultipleBlocksCommand : IUndoableCommand
+    {
+        private readonly IItemFilterScript _itemFilterScript;
+        private readonly List<IItemFilterBlockBase> _pastedItemFilterBlocks;
+        private readonly IItemFilterBlockBase _addAfterItemFilterBlock;
+
+        public PasteMultipleBlocksCommand(IItemFilterScript itemFilterScript, List<IItemFilterBlockBase> pastedItemFilterBlocks, IItemFilterBlockBase addAfterItemFilterBlock)
+        {
+            _itemFilterScript = itemFilterScript;
+            _pastedItemFilterBlocks = pastedItemFilterBlocks;
+            _addAfterItemFilterBlock = addAfterItemFilterBlock;
+        }
+
+        public void Execute()
+        {
+            if (_addAfterItemFilterBlock != null)
+            {
+                var lastAddedBlock = _addAfterItemFilterBlock;
+                foreach(var block in _pastedItemFilterBlocks)
+                {
+                    _itemFilterScript.ItemFilterBlocks.Insert(_itemFilterScript.ItemFilterBlocks.IndexOf(lastAddedBlock) + 1, block);
+                    lastAddedBlock = block;
+                }
+            }
+            else
+            {
+                foreach (var block in _pastedItemFilterBlocks)
+                {
+                    _itemFilterScript.ItemFilterBlocks.Add(block);
+                }
+            }
+        }
+
+        public void Undo()
+        {
+            foreach (var block in _pastedItemFilterBlocks)
+            {
+                _itemFilterScript.ItemFilterBlocks.Remove(block);
+            }
+        }
+
+        public void Redo() => Execute();
+    }
+}