// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)

using System;

namespace ICSharpCode.SharpDevelop.Editor
{
	/// <summary>
	/// Describes a change of the document text.
	/// This class is thread-safe.
	/// </summary>
	public class TextChangeEventArgs : EventArgs
	{
		/// <summary>
		/// The offset at which the change occurs.
		/// </summary>
		public int Offset { get; private set; }
		
		/// <summary>
		/// The text that was inserted.
		/// </summary>
		public string RemovedText { get; private set; }
		
		/// <summary>
		/// The number of characters removed.
		/// </summary>
		public int RemovalLength {
			get { return RemovedText.Length; }
		}
		
		/// <summary>
		/// The text that was inserted.
		/// </summary>
		public string InsertedText { get; private set; }
		
		/// <summary>
		/// The number of characters inserted.
		/// </summary>
		public int InsertionLength {
			get { return InsertedText.Length; }
		}
		
		/// <summary>
		/// Creates a new TextChangeEventArgs object.
		/// </summary>
		public TextChangeEventArgs(int offset, string removedText, string insertedText)
		{
			this.Offset = offset;
			this.RemovedText = removedText ?? string.Empty;
			this.InsertedText = insertedText ?? string.Empty;
		}
	}
}