UndoOperationGroup.cs

// Copyright (c) 2014 AlphaSierraPapa for the SharpDevelop Team
// 
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// 
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// substantial portions of the Software.
// 
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// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
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using System;
using System.Diagnostics;
using Unity.CodeEditor.Utils;

namespace Unity.CodeEditor.Document
{
	/// <summary>
	/// This class stacks the last x operations from the undostack and makes
	/// one undo/redo operation from it.
	/// </summary>
	internal sealed class UndoOperationGroup : IUndoableOperationWithContext
	{
	    private readonly IUndoableOperation[] _undolist;
		
		internal UndoOperationGroup(Deque<IUndoableOperation> stack, int numops)
		{
			if (stack == null)  {
				throw new ArgumentNullException(nameof(stack));
			}
			
			Debug.Assert(numops > 0 , "UndoOperationGroup : numops should be > 0");
			Debug.Assert(numops <= stack.Count);
			
			_undolist = new IUndoableOperation[numops];
			for (var i = 0; i < numops; ++i) {
				_undolist[i] = stack.PopBack();
			}
		}
		
		public void Undo()
		{
		    foreach (var t in _undolist)
		    {
		        t.Undo();
		    }
		}
		
		public void Undo(UndoStack stack)
		{
		    foreach (var t in _undolist)
		    {
		        stack.RunUndo(t);
		    }
		}
		
		public void Redo()
		{
			for (var i = _undolist.Length - 1; i >= 0; --i) {
				_undolist[i].Redo();
			}
		}
		
		public void Redo(UndoStack stack)
		{
			for (var i = _undolist.Length - 1; i >= 0; --i) {
				stack.RunRedo(_undolist[i]);
			}
		}
	}
}