mcs/class/referencesource/System.Activities.Presentation/System.Activities.Presentation/System/Activities/Presentation/Base/Core/Internal/PropertyEditing/State/PropertyState.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.Diagnostics;
   8     using System.Diagnostics.CodeAnalysis;
   9     using System.Runtime;
  10
  11     // <summary>
  12     // Simple state object that knows how to remember state for a single property.
  13     // The only thing it currently remembers is whether the property's sub-properties
  14     // are expanded or collapsed.
  15     // </summary>
  16     internal class PropertyState : PersistedState
  17     {
  18
  19         private const bool DefaultSubPropertiesExpanded = false;
  20
  21         private string _propertyName;
  22         private bool _subPropertiesExpanded = DefaultSubPropertiesExpanded;
  23
  24         // <summary>
  25         // Basic ctor
  26         // </summary>
  27         // <param name="propertyName">Property to wrap around</param>
  28         [SuppressMessage("Microsoft.Performance", "CA1805:DoNotInitializeUnnecessarily")]
  29         public PropertyState(string propertyName)
  30         {
  31             Fx.Assert(!string.IsNullOrEmpty(propertyName), "Expected a full property name");
  32             _propertyName = propertyName;
  33         }
  34
  35         // <summary>
  36         // We key these state objects by their property names
  37         // </summary>
  38         public override object Key
  39         {
  40             get { return _propertyName; }
  41         }
  42
  43         // <summary>
  44         // Returns true if any of the contained values differ from the default
  45         // </summary>
  46         public override bool IsSignificant
  47         {
  48             get { return _subPropertiesExpanded != DefaultSubPropertiesExpanded; }
  49         }
  50
  51         // <summary>
  52         // Gets or sets a flag indicating whether the sub-properties of the contained
  53         // property have been expanded or collapsed.
  54         // </summary>
  55         public bool SubPropertiesExpanded
  56         {
  57             get { return _subPropertiesExpanded; }
  58             set { _subPropertiesExpanded = value; }
  59         }
  60
  61         // <summary>
  62         // Serializes this object into a simple string (AppDomains like strings).
  63         //
  64         // Format: PropertyName,SubPropertiesExpanded;NextPropertyName,SubPropertiesExpanded;...
  65         // Where bools are recorded as 0 = false and 1 = true
  66         // </summary>
  67         // <returns>Serialized version of this state object (may be null)</returns>
  68         protected override string SerializeCore()
  69         {
  70             return string.Concat(
  71                 PersistedStateUtilities.Escape(_propertyName),
  72                 ',',
  73                 PersistedStateUtilities.BoolToDigit(_subPropertiesExpanded));
  74         }
  75
  76         // <summary>
  77         // Attempts to deserialize a string into a PropertyState object
  78         // </summary>
  79         // <param name="propertyStateString">String to deserialize</param>
  80         // <returns>Instance of PropertyState if the serialized string was valid, null otherwise.</returns>
  81         public static PropertyState Deserialize(string propertyStateString)
  82         {
  83             string[] args = propertyStateString.Split(',');
  84             if (args == null || args.Length != 2)
  85             {
  86                 return null;
  87             }
  88
  89             bool? subPropertiesExpanded = PersistedStateUtilities.DigitToBool(args[1]);
  90             if (subPropertiesExpanded == null)
  91             {
  92                 return null;
  93             }
  94
  95             string propertyName = PersistedStateUtilities.Unescape(args[0]);
  96             if (string.IsNullOrEmpty(propertyName))
  97             {
  98                 return null;
  99             }
 100
 101             PropertyState propertyState = new PropertyState(propertyName);
 102             propertyState.SubPropertiesExpanded = (bool)subPropertiesExpanded;
 103             return propertyState;
 104         }
 105     }
 106 }