/* * Copyright (c) Contributors, http://opensimulator.org/ * See CONTRIBUTORS.TXT for a full list of copyright holders. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * Neither the name of the OpenSimulator Project nor the * names of its contributors may be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ using System; using System.Collections.Generic; namespace OpenSim.Framework { /// <summary> /// Undo stack. Deletes entries beyond a certain capacity /// </summary> /// <typeparam name="T"></typeparam> [Serializable] public class UndoStack<T> { private List<T> m_undolist; private int m_max; public UndoStack(int capacity) { m_undolist = new List<T>(); m_max = capacity; } public bool IsFull { get { return m_undolist.Count >= m_max; } } public int Capacity { get { return m_max; } } public int Count { get { return m_undolist.Count; } } public void Push(T item) { if (IsFull) { m_undolist.RemoveAt(0); } m_undolist.Add(item); } public T Pop() { if (m_undolist.Count > 0) { int ind = m_undolist.Count - 1; T item = m_undolist[ind]; m_undolist.RemoveAt(ind); return item; } else throw new InvalidOperationException("Cannot pop from empty stack"); } public T Peek() { if (m_undolist.Count > 0) { return m_undolist[m_undolist.Count - 1]; } else { return default(T); } } public void Clear() { m_undolist.Clear(); } } }