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

   1 //----------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.
   3 //----------------------------------------------------------------
   4
   5 namespace System.Activities.Presentation.Model
   6 {
   7
   8     using System;
   9     using System.Activities;
  10     using System.Diagnostics;
  11     using System.Linq;
  12     using System.Runtime;
  13     using System.Activities.Presentation.View;
  14     using System.Windows.Threading;
  15
  16     class GenericArgumentUpdater
  17     {
  18         EditingContext context;
  19         const string TypeArgumentPropertyName = "TypeArgument";
  20
  21         public GenericArgumentUpdater(EditingContext context)
  22         {
  23             this.context = context;
  24         }
  25
  26         public void AddSupportForUpdatingTypeArgument(Type modelItemType)
  27         {
  28             AttachedProperty<Type> typeArgumentProperty = new AttachedProperty<Type>
  29             {
  30                 Name = TypeArgumentPropertyName,
  31                 OwnerType = modelItemType,
  32                 Getter = (modelItem) => modelItem.Parent == null ? null : GetTypeArgument(modelItem),
  33                 Setter = (modelItem, value) => UpdateTypeArgument(modelItem, value),
  34                 IsBrowsable = true
  35             };
  36             this.context.Services.GetService<AttachedPropertiesService>().AddProperty(typeArgumentProperty);
  37         }
  38
  39         private static void UpdateTypeArgument(ModelItem modelItem, Type value)
  40         {
  41             if (value != null)
  42             {
  43                 Type oldModelItemType = modelItem.ItemType;
  44                 Fx.Assert(oldModelItemType.GetGenericArguments().Count() == 1, "we only support changing a single type parameter ?");
  45                 Type newModelItemType = oldModelItemType.GetGenericTypeDefinition().MakeGenericType(value);
  46                 Fx.Assert(newModelItemType != null, "New model item type needs to be non null or we cannot proceed further");
  47                 ModelItem newModelItem = ModelFactory.CreateItem(modelItem.GetEditingContext(), Activator.CreateInstance(newModelItemType));
  48                 MorphHelper.MorphObject(modelItem, newModelItem);
  49                 MorphHelper.MorphProperties(modelItem, newModelItem);
  50
  51                 if (oldModelItemType.IsSubclassOf(typeof(Activity)) && newModelItemType.IsSubclassOf(typeof(Activity)))
  52                 {
  53                     if (string.Equals((string)modelItem.Properties["DisplayName"].ComputedValue, GetActivityDefaultName(oldModelItemType), StringComparison.Ordinal))
  54                     {
  55                         newModelItem.Properties["DisplayName"].SetValue(GetActivityDefaultName(newModelItemType));
  56                     }
  57                 }
  58
  59                 DesignerView designerView = modelItem.GetEditingContext().Services.GetService<DesignerView>();
  60                 if (designerView != null)
  61                 {
  62                     Dispatcher.CurrentDispatcher.BeginInvoke(DispatcherPriority.Render, (Action)(() =>
  63                     {
  64                         if (designerView.RootDesigner != null && ((WorkflowViewElement)designerView.RootDesigner).ModelItem == modelItem)
  65                         {
  66                             designerView.MakeRootDesigner(newModelItem, true);
  67                         }
  68                         Selection.SelectOnly(modelItem.GetEditingContext(), newModelItem);
  69                     }));
  70                 }
  71             }
  72         }
  73
  74         private static Type GetTypeArgument(ModelItem modelItem)
  75         {
  76             Fx.Assert(modelItem.ItemType.GetGenericArguments().Count() == 1, "we only support changing a single type parameter ?");
  77             return modelItem.ItemType.GetGenericArguments()[0];
  78         }
  79
  80         private static string GetActivityDefaultName(Type activityType)
  81         {
  82             Fx.Assert(activityType.IsSubclassOf(typeof(Activity)), "activityType is not a subclass of System.Activities.Activity");
  83             Activity activity = (Activity)Activator.CreateInstance(activityType);
  84             return activity.DisplayName;
  85         }
  86     }
  87
  88
  89
  90 }