mcs/class/referencesource/System.Activities.Presentation/System.Activities.Presentation/System/Activities/Presentation/ErrorActivity.cs

   1 //----------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.
   3 //----------------------------------------------------------------
   4
   5
   6 namespace System.Activities.Presentation
   7 {
   8     using System;
   9     using System.Activities;
  10     using System.Activities.Presentation.View;
  11     using System.ComponentModel;
  12     using System.Runtime;
  13     using System.Xaml;
  14     using XamlDeferLoad = System.Windows.Markup.XamlDeferLoadAttribute;
  15
  16     [Designer(typeof(ErrorActivity.ErrorActivityView))]
  17     internal class ErrorActivity : Activity
  18     {
  19         static readonly AttachableMemberIdentifier HasErrorActivitiesProperty =
  20             new AttachableMemberIdentifier(typeof(ErrorActivity), "HasErrorActivities");
  21         internal const string ErrorNodesProperty = "ErrorNodes";
  22
  23         [Browsable(false)]
  24         [XamlDeferLoad(typeof(NodeListLoader), typeof(object))]
  25         public XamlNodeList ErrorNodes { get; set; }
  26
  27         internal static bool GetHasErrorActivities(object target)
  28         {
  29             object result;
  30             if (AttachablePropertyServices.TryGetProperty(target, HasErrorActivitiesProperty, out result))
  31             {
  32                 return (bool)result;
  33             }
  34             return false;
  35         }
  36
  37         internal static void SetHasErrorActivities(object target, bool value)
  38         {
  39             AttachablePropertyServices.SetProperty(target, HasErrorActivitiesProperty, value);
  40         }
  41
  42         internal static void WriteNodeList(XamlWriter writer, XamlNodeList nodeList)
  43         {
  44             // We need to pass the ErrorNodes contents through as a NodeList, because XOW doesn't
  45             // currently support unknown types, even inside a DeferLoad block.
  46             // But if a NodeList is written to XOW as a Value, XOW will unpack, forcing us to re-buffer
  47             // the nodes in our deferring loader. So we wrap the NodeList value inside a dummy StartObject.
  48             writer.WriteStartObject(XamlLanguage.Object);
  49             writer.WriteStartMember(XamlLanguage.Initialization);
  50             writer.WriteValue(nodeList);
  51             writer.WriteEndMember();
  52             writer.WriteEndObject();
  53         }
  54
  55         internal class NodeListLoader : XamlDeferringLoader
  56         {
  57             public override object Load(XamlReader xamlReader, IServiceProvider serviceProvider)
  58             {
  59                 // Expects a nodestream produced by WriteNodesList
  60                 xamlReader.Read();
  61                 xamlReader.Read();
  62                 xamlReader.Read();
  63                 Fx.Assert(xamlReader.NodeType == XamlNodeType.Value, "Expected Value node");
  64                 return (XamlNodeList)xamlReader.Value;
  65             }
  66
  67             public override XamlReader Save(object value, IServiceProvider serviceProvider)
  68             {
  69                 return ((XamlNodeList)value).GetReader();
  70             }
  71         }
  72
  73         internal class ErrorActivityView : WorkflowViewElement
  74         {
  75             public ErrorActivityView()
  76             {
  77                 WorkflowViewService.ShowErrorInViewElement(this, SR.ActivityLoadError, null);
  78             }
  79         }
  80     }
  81
  82     [Designer(typeof(ErrorActivity.ErrorActivityView))]
  83     internal class ErrorActivity<T> : Activity<T>
  84     {
  85         [Browsable(false)]
  86         [XamlDeferLoad(typeof(ErrorActivity.NodeListLoader), typeof(object))]
  87         public XamlNodeList ErrorNodes { get; set; }
  88     }
  89 }