reemjd / urd

undo redo pattern for .NET

URD

#undo redo pattern for C# applications

this is a basic undo pattern for .NET applications. developed for use in GS subtitle project (not published) in this pattern when you want a undo / redo able action you will need to warp that action with using statement. as a example if you going to change a property you can do this

using (new PropertyChange(Object, "Property", "Property changed "))
{
  Object.Property="new value";
}

now the change you made to the "Property" property of the "Object" object is added to the drop out stack and it can undo or redo any time you want.

if you want a undoAble list change you can do it using same syntax

private void AddNewItem(<string>List list,string item,bool undoAble)
{
	using (undoAble?new ListChangeAddElement(list,item,"add new string to the string list"):null) //you can use a condition then you can minimize code
	{
		list.Add(item);
	}
}

Removing a Item

private void RemoveItem(list,item,bool undoAble)
{
	using(undoAble?new ListChangeRemoveElement(list,item,list.IndexOf(item)," remove "+item+" from the string list"))
	{
		list.Remove(item);
	}
}

so on.. (check the code)

benefits of this pattern

low CPU, Memory usage
undo only what you want

if you want to implement your own operation . only thing you need to do is create a class--> extend Change class and IUndoAble interface.