mcs/class/referencesource/System.Activities.Presentation/System.Activities.Presentation/System/Activities/Presentation/Base/Core/Internal/PropertyEditing/State/PropertyViewManagerStateContainer.cs

   1 //----------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.
   3 //----------------------------------------------------------------
   4 namespace System.Activities.Presentation.Internal.PropertyEditing.State
   5 {
   6     using System;
   7     using System.Collections.Generic;
   8     using System.Diagnostics;
   9     using System.Text;
  10     using System.Activities.Presentation.Internal.PropertyEditing.Views;
  11     using System.Activities.Presentation;
  12
  13     // <summary>
  14     // StateContainer for current selection of IPropertyViewManager
  15     // </summary>
  16     internal class PropertyViewManagerStateContainer : IStateContainer
  17     {
  18
  19         public static readonly PropertyViewManagerStateContainer Instance = new PropertyViewManagerStateContainer();
  20
  21         public const string RootPropertyInspectorPersistenceId = "RootPropertyInspector";
  22
  23         private Dictionary<string, string> _persistenceIdToManagerTypeNameMap;
  24         private PropertyViewManagerStateContainer()
  25         {
  26         }
  27
  28         // <summary>
  29         // Event fired when the internal state is scrapped and restored from
  30         // some saved value
  31         // </summary>
  32         public event EventHandler ContentRestored;
  33
  34         // <summary>
  35         // Gets the instance of IPropertyViewManager stored under the specified
  36         // persistence ID.
  37         // </summary>
  38         // <param name="persistenceId">ID to look up</param>
  39         // <returns>Instance of IPropertyViewManager stored under the specified
  40         // persistence ID.  If not found, an instance of the default IPropertyViewManager
  41         // is returned.</returns>
  42         public IPropertyViewManager GetPropertyViewManager(string persistenceId)
  43         {
  44             string propertyViewManagerTypeName;
  45             if (_persistenceIdToManagerTypeNameMap == null ||
  46                 !_persistenceIdToManagerTypeNameMap.TryGetValue(persistenceId, out propertyViewManagerTypeName))
  47             {
  48
  49                 // If we don't have any state stored, default to the value of the
  50                 // root PropertyInspector, unless that state is not stored either
  51                 // in which case default to category view.
  52                 //
  53                 if (persistenceId != RootPropertyInspectorPersistenceId)
  54                 {
  55                     return GetPropertyViewManager(RootPropertyInspectorPersistenceId);
  56                 }
  57                 else
  58                 {
  59                     return ByCategoryViewManager.Instance;
  60                 }
  61             }
  62
  63             if (string.Equals(propertyViewManagerTypeName, typeof(ByCategoryViewManager).Name))
  64             {
  65                 return ByCategoryViewManager.Instance;
  66             }
  67             else if (string.Equals(propertyViewManagerTypeName, typeof(AlphabeticalViewManager).Name))
  68             {
  69                 return AlphabeticalViewManager.Instance;
  70             }
  71
  72             Debug.Fail("Unknown IPropertyViewManager type: " + (propertyViewManagerTypeName ?? "null"));
  73             return ByCategoryViewManager.Instance;
  74         }
  75
  76         // <summary>
  77         // Stores the specified IPropertyViewManager under the specified persistenceId.
  78         // </summary>
  79         // <param name="persistenceId">ID to store under</param>
  80         // <param name="manager">IPropertyViewManager to store</param>
  81         public void StorePropertyViewManager(string persistenceId, IPropertyViewManager manager)
  82         {
  83             if (persistenceId == null)
  84             {
  85                 throw FxTrace.Exception.ArgumentNull("persistenceId");
  86             }
  87
  88             if (manager == null && _persistenceIdToManagerTypeNameMap == null)
  89             {
  90                 return;
  91             }
  92
  93             if (manager == null)
  94             {
  95                 _persistenceIdToManagerTypeNameMap.Remove(persistenceId);
  96             }
  97             else
  98             {
  99                 if (_persistenceIdToManagerTypeNameMap == null)
 100                 {
 101                     _persistenceIdToManagerTypeNameMap = new Dictionary<string, string>();
 102                 }
 103
 104                 _persistenceIdToManagerTypeNameMap[persistenceId] = manager.GetType().Name;
 105             }
 106         }
 107
 108         // IStateContainer Members
 109
 110         // <summary>
 111         // Retrieves all stored IPropertyViewManager types under all persistence IDs
 112         // </summary>
 113         // <returns>All stored IPropertyViewManager types under all persistence IDs</returns>
 114         public object RetrieveState()
 115         {
 116             if (_persistenceIdToManagerTypeNameMap == null || _persistenceIdToManagerTypeNameMap.Count == 0)
 117             {
 118                 return null;
 119             }
 120
 121             StringBuilder sb = new StringBuilder();
 122             foreach (KeyValuePair<string, string> pair in _persistenceIdToManagerTypeNameMap)
 123             {
 124                 if (sb.Length > 0)
 125                 {
 126                     sb.Append(';');
 127                 }
 128
 129                 sb.Append(PersistedStateUtilities.Escape(pair.Key));
 130                 sb.Append(';');
 131                 sb.Append(pair.Value);
 132             }
 133
 134             return sb.ToString();
 135         }
 136
 137         // <summary>
 138         // Attempts to restore the persisted state
 139         // </summary>
 140         // <param name="state"></param>
 141         public void RestoreState(object state)
 142         {
 143             if (state == null)
 144             {
 145                 return;
 146             }
 147
 148             string serializedState = state as string;
 149             if (serializedState == null)
 150             {
 151                 Debug.Fail("Invalid PropertyViewManager state: " + state.ToString());
 152                 return;
 153             }
 154
 155             string[] items = serializedState.Split(';');
 156             if ((items.Length % 2) != 0)
 157             {
 158                 Debug.Fail("Invalid PropertyViewManager state: " + state.ToString());
 159                 return;
 160             }
 161
 162             if (_persistenceIdToManagerTypeNameMap == null)
 163             {
 164                 _persistenceIdToManagerTypeNameMap = new Dictionary<string, string>();
 165             }
 166
 167             for (int i = 0; i < items.Length;)
 168             {
 169                 _persistenceIdToManagerTypeNameMap[items[i++]] = items[i++];
 170             }
 171
 172             if (ContentRestored != null)
 173             {
 174                 ContentRestored(this, EventArgs.Empty);
 175             }
 176         }
 177
 178     }
 179 }