CPF/CPF.ReoGrid/Common/ActionManager.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;

namespace CPF.ReoGrid.Common
{
	internal sealed class ActionManager
	{
		public List<IUndoableAction> UndoStack
		{
			get
			{
				return this.undoStack;
			}
		}

		public Stack<IUndoableAction> RedoStack
		{
			get
			{
				return this.redoStack;
			}
		}

		public void DoAction(IAction action)
		{
			this.DoAction(action, true);
		}

		public void AddAction(IAction action)
		{
			this.DoAction(action, false);
		}

		private void DoAction(IAction action, bool perform)
		{
			this.Do(action, perform, action is IUndoableAction);
		}

		private void Do(IAction action, bool perform, bool isCanUndo)
		{
			Logger.Log(ActionManager.LOGKEY, string.Format("{0} action: {1}[{2}]", perform ? "do" : "add", action.GetType().Name, action.GetName()));
			bool flag = this.BeforePerformAction != null;
			if (flag)
			{
				ActionEventArgs actionEventArgs = new ActionEventArgs(action, ActionBehavior.Do);
				this.BeforePerformAction(this, actionEventArgs);
				bool cancel = actionEventArgs.Cancel;
				if (cancel)
				{
					return;
				}
			}
			if (perform)
			{
				action.Do();
			}
			bool flag2 = action is IUndoableAction && isCanUndo;
			if (flag2)
			{
				this.redoStack.Clear();
				this.undoStack.Add(action as IUndoableAction);
				bool flag3 = this.undoStack.Count<IUndoableAction>() > this.capacity;
				if (flag3)
				{
					int count = this.undoStack.Count<IUndoableAction>() - this.capacity;
					this.undoStack.RemoveRange(0, count);
					Logger.Log(ActionManager.LOGKEY, "action stack full. remove " + count.ToString() + " action(s).");
				}
			}
			EventHandler<ActionEventArgs> afterPerformAction = this.AfterPerformAction;
			if (afterPerformAction != null)
			{
				afterPerformAction(this, new ActionEventArgs(action, ActionBehavior.Do));
			}
		}

		public void Reset()
		{
			this.redoStack.Clear();
			this.undoStack.Clear();
		}

		public bool CanUndo()
		{
			return this.undoStack.Count > 0;
		}

		public bool CanRedo()
		{
			return this.redoStack.Count<IUndoableAction>() > 0;
		}

		public IAction Undo()
		{
			bool flag = this.undoStack.Count<IUndoableAction>() > 0;
			IAction result;
			if (flag)
			{
				IUndoableAction undoableAction = null;
				while (this.undoStack.Count > 0)
				{
					undoableAction = this.undoStack.Last<IUndoableAction>();
					Logger.Log(ActionManager.LOGKEY, "undo action: " + undoableAction.ToString());
					bool flag2 = this.BeforePerformAction != null;
					if (flag2)
					{
						ActionEventArgs actionEventArgs = new ActionEventArgs(undoableAction, ActionBehavior.Undo);
						this.BeforePerformAction(this, new ActionEventArgs(undoableAction, ActionBehavior.Undo));
						bool cancel = actionEventArgs.Cancel;
						if (cancel)
						{
							break;
						}
					}
					this.undoStack.Remove(undoableAction);
					undoableAction.Undo();
					this.redoStack.Push(undoableAction);
					EventHandler<ActionEventArgs> afterPerformAction = this.AfterPerformAction;
					if (afterPerformAction != null)
					{
						afterPerformAction(this, new ActionEventArgs(undoableAction, ActionBehavior.Undo));
					}
					bool flag3 = !(undoableAction is ISerialUndoAction);
					if (flag3)
					{
						break;
					}
				}
				result = undoableAction;
			}
			else
			{
				result = null;
			}
			return result;
		}

		public IAction Redo()
		{
			bool flag = this.redoStack.Count > 0;
			IAction result;
			if (flag)
			{
				IUndoableAction undoableAction = null;
				while (this.redoStack.Count > 0)
				{
					undoableAction = this.redoStack.Pop();
					Logger.Log(ActionManager.LOGKEY, "redo action: " + undoableAction.ToString());
					bool flag2 = this.BeforePerformAction != null;
					if (flag2)
					{
						ActionEventArgs actionEventArgs = new ActionEventArgs(undoableAction, ActionBehavior.Redo);
						this.BeforePerformAction(this, actionEventArgs);
						bool cancel = actionEventArgs.Cancel;
						if (cancel)
						{
							break;
						}
					}
					undoableAction.Redo();
					this.undoStack.Add(undoableAction);
					EventHandler<ActionEventArgs> afterPerformAction = this.AfterPerformAction;
					if (afterPerformAction != null)
					{
						afterPerformAction(this, new ActionEventArgs(undoableAction, ActionBehavior.Redo));
					}
					bool flag3 = !(undoableAction is ISerialUndoAction);
					if (flag3)
					{
						break;
					}
				}
				result = undoableAction;
			}
			else
			{
				result = null;
			}
			return result;
		}

		//[DebuggerBrowsable(DebuggerBrowsableState.Never)]
		public event EventHandler<ActionEventArgs> BeforePerformAction;

		//[DebuggerBrowsable(DebuggerBrowsableState.Never)]
		public event EventHandler<ActionEventArgs> AfterPerformAction;

		private static readonly string LOGKEY = "actionmanager";

		private List<IUndoableAction> undoStack = new List<IUndoableAction>();

		private Stack<IUndoableAction> redoStack = new Stack<IUndoableAction>();

		private int capacity = 30;
	}
}