mcs/class/referencesource/System.Activities.Presentation/System.Activities.Presentation/System/Activities/Presentation/Xaml/ActivityBuilderHelper.cs

   1 //----------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.
   3 //----------------------------------------------------------------
   4
   5 namespace System.Activities.Presentation.Xaml
   6 {
   7     using System.Activities.Presentation.Model;
   8     using System.Collections.Generic;
   9
  10     internal static class ActivityBuilderHelper
  11     {
  12         internal static bool IsActivityBuilderType(ModelItem modelItem)
  13         {
  14             if (null == modelItem)
  15             {
  16                 throw FxTrace.Exception.AsError(new ArgumentNullException("modelItem"));
  17             }
  18             return modelItem.ItemType.IsAssignableFrom(typeof(ActivityBuilder));
  19         }
  20
  21         internal static List<Variable> GetVariables(object input)
  22         {
  23             if (null == input)
  24             {
  25                 throw FxTrace.Exception.AsError(new ArgumentNullException("input"));
  26             }
  27             ModelItem astAsModelItem = input as ModelItem;
  28             ActivityBuilder instance = input as ActivityBuilder;
  29             if (null != astAsModelItem)
  30             {
  31                 if (!astAsModelItem.ItemType.IsAssignableFrom(typeof(ActivityBuilder)))
  32                 {
  33                     throw FxTrace.Exception.AsError(new InvalidCastException(astAsModelItem.ItemType.FullName));
  34                 }
  35                 instance = (ActivityBuilder)astAsModelItem.GetCurrentValue();
  36             }
  37             else if (null == instance)
  38             {
  39                 throw FxTrace.Exception.AsError(new InvalidCastException(input.GetType().FullName));
  40             }
  41
  42             List<Variable> variables = new List<Variable>();
  43             foreach (DynamicActivityProperty property in instance.Properties)
  44             {
  45                 if (property != null)
  46                 {
  47                     Variable autoVariable = GetVariableFromProperty(property);
  48                     if (autoVariable != null)
  49                     {
  50                         variables.Add(autoVariable);
  51                     }
  52                 }
  53             }
  54             return variables;
  55         }
  56
  57         internal static Variable GetVariableFromProperty(DynamicActivityProperty property)
  58         {
  59             Type variableType = null;
  60             Variable autoVariable = null;
  61
  62             if (property.Type != null)
  63             {
  64                 Type propertyType = property.Type;
  65
  66                 // if the property is an Argument<T> create a variable of type T
  67                 if (propertyType != null && typeof(Argument).IsAssignableFrom(propertyType))
  68                 {
  69                     if (propertyType.IsGenericType)
  70                     {
  71                         variableType = propertyType.GetGenericArguments()[0];
  72                     }
  73                     else
  74                     {
  75                         variableType = typeof(object);
  76                     }
  77                 }
  78             }
  79             if (variableType != null)
  80             {
  81                 autoVariable = Variable.Create(property.Name, variableType, VariableModifiers.None);
  82                 Argument argument = property.Value as Argument;
  83                 if (argument != null)
  84                 {
  85                     autoVariable.Default = argument.Expression;
  86                 }
  87             }
  88             return autoVariable;
  89         }
  90     }
  91 }