-
Notifications
You must be signed in to change notification settings - Fork 0
/
IMemento.cs
77 lines (66 loc) · 3.41 KB
/
IMemento.cs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
#region license
/*
Copyright (c) 2007 Lu Yixiang
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, 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 FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.
*/
#endregion
using System;
namespace GenericUndoRedo
{
/// <summary>
/// The most generic interface of a memento class. A memento is a state that can be saved and restored.
/// See details on <b>Memento Design Pattern</b> concept
/// <a href="http://www.google.com/search?q=memento+design+pattern+&btnG=Search">here</a>.
/// </summary>
/// <remarks>
/// <b>Design Considerations:</b>
/// The common memento struture a state property and sometimes an action property.
/// In this design those properties are not explicitly , though essentially the
/// In this design, if a memento stores a state and doesn't has the ability to Restore the target to the state,
/// we have to introduce another class or a class per type of memento.
/// With the memento itslef supporting Retore of the states, the state and action are not necessary to be exposed as public properties.
/// And only one class for each type of memento is required, which is simpler to read and easier to maintain.
/// <b>NOTE</b> that every class that implements this interface should be serializable,
/// by either annotate it with "[Serializabl]" or manuallying implementing the serialization methods.
/// This requirement should be full filled in order to support the serialization of <see cref="UndoRedoHistory<T>"/>.
/// </remarks>
public interface IMemento<T>
{
/// <summary>
/// Restores target to the state memorized by this memento. Here shows an exapmle of usage.
/// <code>
/// public void TestMemento(IMemento<Object> memento, Object target)
/// {
/// Object oldObj = target.Clone();
/// IMemento<Object> previousState = memento.Restore(target);
/// Object newObj = previousState.Restore(target);
/// Debug.Assert(oldObj.Equals(newObj));
/// }
/// </code>
/// </summary>
/// <returns>A memento of the state before restoring, which is refered to as a <i>Inverse Memento</i> of this memento.</returns>
/// <remarks>
/// Being able to restore its own state, undo can be implemented using an undo stack. But that's not enough for implementing redo.
/// The returned inverse memento is the key to support redo.
/// </remarks>
IMemento<T> Restore(T target);
string GetName();
}
}