mcs/class/referencesource/System.Activities.Presentation/System.Activities.Presentation/System/Activities/Presentation/Base/Core/Internal/PropertyEditing/Editors/PropertyValueToDisplayNameConverter.cs

   1 //----------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.
   3 //----------------------------------------------------------------
   4 namespace System.Activities.Presentation.Internal.PropertyEditing.Editors
   5 {
   6     using System;
   7     using System.Collections.Generic;
   8     using System.Diagnostics;
   9     using System.Globalization;
  10     using System.Text;
  11     using System.Windows.Data;
  12
  13     using System.Activities.Presentation.PropertyEditing;
  14     using System.Activities.Presentation;
  15
  16     using System.Activities.Presentation.Internal.PropertyEditing.Model;
  17     using System.Activities.Presentation.Internal.Properties;
  18
  19     // <summary>
  20     // ValueConverter that takes an instance of PropertyValue and returns a display name for
  21     // it.  The returned name consists of the value Type name as well as its x:Name property
  22     // if it is defined.
  23     // </summary>
  24     internal class PropertyValueToDisplayNameConverter : IValueConverter
  25     {
  26
  27         private static PropertyValueToDisplayNameConverter _instance;
  28
  29         // <summary>
  30         // Static instance accessor for all non-XAML related conversion needs
  31         // </summary>
  32         public static PropertyValueToDisplayNameConverter Instance
  33         {
  34             get {
  35                 if (_instance == null)
  36                 {
  37                     _instance = new PropertyValueToDisplayNameConverter();
  38                 }
  39
  40                 return _instance;
  41             }
  42         }
  43
  44         // Converts an instance of PropertyValue to its appropriate display name
  45         public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
  46         {
  47
  48             if (typeof(string).IsAssignableFrom(targetType))
  49             {
  50
  51                 PropertyValue propertyValue = value as PropertyValue;
  52                 if (propertyValue != null)
  53                 {
  54
  55                     ModelPropertyEntryBase propertyEntry = propertyValue.ParentProperty as ModelPropertyEntryBase;
  56
  57                     // Figure out the value type name
  58                     string valueTypeName = string.Empty;
  59                     if (propertyEntry != null)
  60                     {
  61                         valueTypeName = propertyEntry.CommonValueType == null ? string.Empty : propertyEntry.CommonValueType.Name;
  62                     }
  63                     else
  64                     {
  65                         Debug.Fail("PropertyValueToDisplayNameConverter is being used for something other than ModelPropertyValues.  Re-evaluate the correctness of its logic.");
  66
  67                         // Fallback mechanism
  68                         object rawPropertyValue = propertyValue.Value;
  69                         if (rawPropertyValue != null)
  70                         {
  71                             valueTypeName = rawPropertyValue.GetType().Name;
  72                         }
  73                     }
  74
  75                     // See if there is a regular name
  76                     string propertyName = ModelUtilities.GetPropertyName(propertyValue);
  77
  78                     if (string.IsNullOrEmpty(propertyName))
  79                     {
  80                         // Type only
  81                         return string.Format(
  82                             culture,
  83                             Resources.PropertyEditing_CollectionItemDisplayFormatType,
  84                             valueTypeName);
  85                     }
  86                     else
  87                     {
  88                         // Type and name
  89                         return string.Format(
  90                             culture,
  91                             Resources.PropertyEditing_CollectionItemDisplayFormatTypeAndName,
  92                             valueTypeName,
  93                             propertyName);
  94                     }
  95                 }
  96             }
  97
  98             return string.Empty;
  99         }
 100
 101         // This class is only a one-way converter
 102         public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
 103         {
 104             throw FxTrace.Exception.AsError(new NotImplementedException());
 105         }
 106     }
 107 }