mcs/class/referencesource/System.Activities.Presentation/System.Activities.Presentation/System/Activities/Presentation/Model/CollectionChange.cs

   1 //----------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.
   3 //----------------------------------------------------------------
   4
   5 namespace System.Activities.Presentation.Model
   6 {
   7     using System.Runtime;
   8     using System.Activities.Presentation.Services;
   9
  10     class CollectionChange : ModelChange
  11     {
  12         public ModelItemCollection Collection { get; set; }
  13
  14         public int Index { get; set; }
  15
  16         public ModelItem Item { get; set; }
  17
  18         public OperationType Operation { get; set; }
  19
  20         public ModelTreeManager ModelTreeManager { get; set; }
  21
  22         public override string Description
  23         {
  24             get
  25             {
  26                 return this.Operation == OperationType.Insert ? SR.CollectionAddEditingScopeDescription : SR.CollectionRemoveEditingScopeDescription;
  27             }
  28         }
  29
  30         public override bool Apply()
  31         {
  32             switch (this.Operation)
  33             {
  34                 case OperationType.Insert:
  35                     ApplyInsert();
  36                     break;
  37                 case OperationType.Delete:
  38                     ApplyDelete();
  39                     break;
  40                 default:
  41                     Fx.Assert("Operation should be Insert or Delete");
  42                     break;
  43
  44             }
  45             return true;
  46         }
  47
  48         private void ApplyDelete()
  49         {
  50             Fx.Assert(this.ModelTreeManager != null, "ModelTreeManager cannot be null.");
  51             Fx.Assert(this.Collection != null, "this.Collection cannot be null.");
  52
  53             if (this.Index >= 0)
  54             {
  55                 ((ModelItemCollectionImpl)this.Collection).RemoveAtCore(this.Index);
  56             }
  57             else
  58             {
  59                 Fx.Assert(this.Index == -1, "-1 must be used to indicate Remove(item)");
  60                 this.Index = this.Collection.IndexOf(this.Item);
  61                 ((ModelItemCollectionImpl)this.Collection).RemoveCore(this.Item);
  62             }
  63
  64             ModelChangeInfo changeInfo = ModelChangeInfoImpl.CreateCollectionItemRemoved(this.Collection, this.Item);
  65             this.ModelTreeManager.NotifyCollectionRemove(this.Item, changeInfo);
  66         }
  67
  68         private void ApplyInsert()
  69         {
  70             Fx.Assert(this.ModelTreeManager != null, "ModelTreeManager cannot be null.");
  71             Fx.Assert(this.Collection != null, "this.Collection cannot be null.");
  72
  73             if (this.Index >= 0)
  74             {
  75                 ((ModelItemCollectionImpl)this.Collection).InsertCore(this.Index, this.Item);
  76             }
  77             else
  78             {
  79                 Fx.Assert(this.Index == -1, "-1 must be used to indicate Add(item)");
  80                 this.Index = this.Collection.Count;
  81                 ((ModelItemCollectionImpl)this.Collection).AddCore(this.Item);
  82             }
  83
  84             ModelChangeInfo changeInfo = ModelChangeInfoImpl.CreateCollectionItemAdded(this.Collection, this.Item);
  85             this.ModelTreeManager.NotifyCollectionInsert(this.Item, changeInfo);
  86         }
  87
  88         public override Change GetInverse()
  89         {
  90             OperationType reverseOperation = this.Operation == OperationType.Insert ? OperationType.Delete : OperationType.Insert;
  91             return new CollectionChange()
  92                 {
  93                     Collection = this.Collection,
  94                     Operation = reverseOperation,
  95                     Item = this.Item,
  96                     ModelTreeManager = this.ModelTreeManager,
  97                     Index = this.Index
  98                 };
  99
 100         }
 101
 102         public enum OperationType
 103         {
 104             Insert, Delete
 105         }
 106     }
 107 }