CnC_Remastered_Collection

Command and Conquer: Red Alert
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UndoRedoList.cs (3417B)

      1 //
      2 // Copyright 2020 Electronic Arts Inc.
      3 //
      4 // The Command & Conquer Map Editor and corresponding source code is free 
      5 // software: you can redistribute it and/or modify it under the terms of 
      6 // the GNU General Public License as published by the Free Software Foundation, 
      7 // either version 3 of the License, or (at your option) any later version.
      8 
      9 // The Command & Conquer Map Editor and corresponding source code is distributed 
     10 // in the hope that it will be useful, but with permitted additional restrictions 
     11 // under Section 7 of the GPL. See the GNU General Public License in LICENSE.TXT 
     12 // distributed with this program. You should have received a copy of the 
     13 // GNU General Public License along with permitted additional restrictions 
     14 // with this program. If not, see https://github.com/electronicarts/CnC_Remastered_Collection
     15 using System;
     16 using System.Collections.Generic;
     17 using System.Linq;
     18 using System.Text;
     19 using System.Threading.Tasks;
     20 
     21 namespace MobiusEditor.Utility
     22 {
     23     public class UndoRedoList<T>
     24     {
     25         private const int DefaultMaxUndoRedo = 50;
     26 
     27         private readonly List<(Action<T> Undo, Action<T> Redo)> undoRedoActions = new List<(Action<T> Undo, Action<T> Redo)>();
     28         private readonly int maxUndoRedo;
     29         private int undoRedoPosition = 0;
     30 
     31         public event EventHandler<EventArgs> Tracked;
     32         public event EventHandler<EventArgs> Undone;
     33         public event EventHandler<EventArgs> Redone;
     34 
     35         public bool CanUndo => undoRedoPosition > 0;
     36 
     37         public bool CanRedo => undoRedoActions.Count > undoRedoPosition;
     38 
     39         public UndoRedoList(int maxUndoRedo)
     40         {
     41             this.maxUndoRedo = maxUndoRedo;
     42         }
     43 
     44         public UndoRedoList()
     45             : this(DefaultMaxUndoRedo)
     46         {
     47         }
     48 
     49         public void Clear()
     50         {
     51             undoRedoActions.Clear();
     52             undoRedoPosition = 0;
     53             OnTracked();
     54         }
     55 
     56         public void Track(Action<T> undo, Action<T> redo)
     57         {
     58             if (undoRedoActions.Count > undoRedoPosition)
     59             {
     60                 undoRedoActions.RemoveRange(undoRedoPosition, undoRedoActions.Count - undoRedoPosition);
     61             }
     62 
     63             undoRedoActions.Add((undo, redo));
     64 
     65             if (undoRedoActions.Count > maxUndoRedo)
     66             {
     67                 undoRedoActions.RemoveRange(0, undoRedoActions.Count - maxUndoRedo);
     68             }
     69 
     70             undoRedoPosition = undoRedoActions.Count;
     71             OnTracked();
     72         }
     73 
     74         public void Undo(T context)
     75         {
     76             if (!CanUndo)
     77             {
     78                 throw new InvalidOperationException();
     79             }
     80 
     81             undoRedoPosition--;
     82             undoRedoActions[undoRedoPosition].Undo(context);
     83             OnUndone();
     84         }
     85 
     86         public void Redo(T context)
     87         {
     88             if (!CanRedo)
     89             {
     90                 throw new InvalidOperationException();
     91             }
     92 
     93             undoRedoActions[undoRedoPosition].Redo(context);
     94             undoRedoPosition++;
     95             OnRedone();
     96         }
     97 
     98         protected virtual void OnTracked()
     99         {
    100             Tracked?.Invoke(this, new EventArgs());
    101         }
    102 
    103         protected virtual void OnUndone()
    104         {
    105             Undone?.Invoke(this, new EventArgs());
    106         }
    107 
    108         protected virtual void OnRedone()
    109         {
    110             Redone?.Invoke(this, new EventArgs());
    111         }
    112     }
    113 }