mcs/class/referencesource/System.Activities.Presentation/System.Activities.Presentation/System/Activities/Presentation/DictionaryItemsCollection.cs

   1 //-----------------------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.
   3 //-----------------------------------------------------------------------------
   4
   5 namespace System.Activities.Presentation
   6 {
   7     using System.Activities.Presentation.Model;
   8     using System.Collections.Generic;
   9     using System.Collections.ObjectModel;
  10     using System.Runtime;
  11
  12     class DictionaryItemsCollection<TKey, TValue> : Collection<ModelItemKeyValuePair<TKey, TValue>>, IItemsCollection
  13     {
  14         IDictionary<TKey, TValue> dictionary;
  15         public bool ShouldUpdateDictionary { get; set; }
  16         public ModelItemDictionaryImpl ModelDictionary { get; set; }
  17
  18         public DictionaryItemsCollection(object dictionary)
  19         {
  20             this.ShouldUpdateDictionary = true;
  21             this.dictionary = dictionary as IDictionary<TKey, TValue>;
  22             Fx.Assert(this.dictionary != null, "dictionary should be instantiated");
  23             foreach (KeyValuePair<TKey, TValue> kvpair in this.dictionary)
  24             {
  25                 ModelItemKeyValuePair<TKey, TValue> item = new ModelItemKeyValuePair<TKey, TValue>(kvpair.Key, kvpair.Value);
  26                 item.collection = this;
  27                 base.InsertItem(this.Count, item);
  28             }
  29         }
  30
  31         internal void PostUpdateKey()
  32         {
  33             this.UpdateDictionary();
  34         }
  35
  36         internal void PreUpdateKey(TKey oldKey, TKey newKey)
  37         {
  38             this.dictionary.Remove(oldKey);
  39             if (this.dictionary.ContainsKey(newKey))
  40             {
  41                 this.UpdateDictionary();
  42                 throw FxTrace.Exception.AsError(new ArgumentException(SR.DuplicateKey));
  43             }
  44             if (this.ModelDictionary != null)
  45             {
  46                 this.ModelDictionary.UpdateKey(oldKey, newKey);
  47             }
  48         }
  49
  50         internal void UpdateValue(TKey key, TValue value)
  51         {
  52             if (ShouldUpdateDictionary)
  53             {
  54                 this.dictionary[key] = value;
  55                 if (this.ModelDictionary != null)
  56                 {
  57                     this.ModelDictionary.UpdateValue(key, value);
  58                 }
  59             }
  60         }
  61
  62         protected override void ClearItems()
  63         {
  64             if (ShouldUpdateDictionary)
  65             {
  66                 this.dictionary.Clear();
  67             }
  68             base.ClearItems();
  69         }
  70
  71         protected override void InsertItem(int index, ModelItemKeyValuePair<TKey, TValue> item)
  72         {
  73             if (item == null)
  74             {
  75                 throw FxTrace.Exception.AsError(new ArgumentNullException("item"));
  76             }
  77
  78             if (ShouldUpdateDictionary && this.dictionary.ContainsKey(item.Key))
  79             {
  80                 throw FxTrace.Exception.AsError(new ArgumentException(SR.DuplicateKey));
  81             }
  82
  83             item.collection = this;
  84             base.InsertItem(index, item);
  85
  86             this.UpdateDictionary();
  87         }
  88
  89         protected override void RemoveItem(int index)
  90         {
  91             ModelItemKeyValuePair<TKey, TValue> item = this[index];
  92             Fx.Assert(item != null, "Item should not be null.");
  93             if (ShouldUpdateDictionary)
  94             {
  95                 this.dictionary.Remove(item.Key);
  96             }
  97
  98             base.RemoveItem(index);
  99         }
 100
 101         protected override void SetItem(int index, ModelItemKeyValuePair<TKey, TValue> item)
 102         {
 103             if (item == null)
 104             {
 105                 throw FxTrace.Exception.AsError(new ArgumentNullException("item"));
 106             }
 107             item.collection = this;
 108             ModelItemKeyValuePair<TKey, TValue> oldItem = this[index];
 109             Fx.Assert(oldItem != null, "Item should not be null.");
 110             this.PreUpdateKey(oldItem.Key, item.Key);
 111             base.SetItem(index, item);
 112             this.PostUpdateKey();
 113         }
 114
 115         void UpdateDictionary()
 116         {
 117             if (ShouldUpdateDictionary)
 118             {
 119                 // Make sure the order of KVPairs in the dictionary is the same as the order of items in the collection
 120                 this.dictionary.Clear();
 121                 foreach (ModelItemKeyValuePair<TKey, TValue> item in this)
 122                 {
 123                     this.dictionary.Add(new KeyValuePair<TKey, TValue>(item.Key, item.Value));
 124                 }
 125             }
 126         }
 127
 128     }
 129 }