mcs/class/referencesource/System.Activities.Presentation/System.Activities.Presentation/System/Activities/Presentation/Base/Core/Internal/PropertyEditing/FromExpression/Framework/UIThreadDispatcher.cs

   1 // -------------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation. All Rights Reserved.
   3 // -------------------------------------------------------------------
   4 //From \\authoring\Sparkle\Source\1.0.1083.0\Common\Source\Framework
   5 namespace System.Activities.Presentation.Internal.PropertyEditing.FromExpression.Framework
   6 {
   7     using System;
   8     using System.Diagnostics;
   9     using System.Windows.Threading;
  10     using System.Runtime;
  11
  12     // <summary>
  13     // A class to execute a method on the UI thread. This must be constructed on the UI thread,
  14     // usually by calling UIThreadDispatcher.InitializeDispatcher(). Derive from this and
  15     // install your own on UIThreadDispatcher if you want to.
  16     // </summary>
  17     internal class UIThreadDispatcher
  18     {
  19
  20         static UIThreadDispatcher dispatcher;
  21         // fields
  22         private Dispatcher uiThreadDispatcher;
  23
  24         // Singleton Management
  25
  26         public UIThreadDispatcher()
  27         {
  28             this.uiThreadDispatcher = Dispatcher.CurrentDispatcher;
  29         }
  30
  31         public static UIThreadDispatcher Instance
  32         {
  33             get
  34             {
  35                 Fx.Assert(dispatcher != null, "Instance getter called before Instance is initialized");
  36
  37                 return dispatcher;
  38             }
  39             set
  40             {
  41                 dispatcher = value;
  42             }
  43         }
  44
  45
  46         public static void InitializeInstance()
  47         {
  48             Instance = new UIThreadDispatcher();
  49         }
  50
  51         public virtual void BeginInvoke(DispatcherPriority priority, Delegate method)
  52         {
  53             if (!this.uiThreadDispatcher.HasShutdownStarted)
  54             {
  55                 this.uiThreadDispatcher.BeginInvoke(priority, method);
  56             }
  57         }
  58
  59         public virtual void BeginInvoke(DispatcherPriority priority, Delegate method, object arg)
  60         {
  61             if (!this.uiThreadDispatcher.HasShutdownStarted)
  62             {
  63                 this.uiThreadDispatcher.BeginInvoke(priority, method, arg);
  64             }
  65         }
  66
  67         public virtual void BeginInvoke(DispatcherPriority priority, Delegate method, object arg, params object[] args)
  68         {
  69             if (!this.uiThreadDispatcher.HasShutdownStarted)
  70             {
  71                 this.uiThreadDispatcher.BeginInvoke(priority, method, arg, args);
  72             }
  73         }
  74
  75         public virtual void Invoke(DispatcherPriority priority, Delegate method)
  76         {
  77             if (!this.uiThreadDispatcher.HasShutdownStarted)
  78             {
  79                 this.uiThreadDispatcher.Invoke(priority, method);
  80             }
  81         }
  82
  83         public virtual void Invoke(DispatcherPriority priority, Delegate method, object arg)
  84         {
  85             if (!this.uiThreadDispatcher.HasShutdownStarted)
  86             {
  87                 this.uiThreadDispatcher.Invoke(priority, method, arg);
  88             }
  89         }
  90
  91         public virtual void Invoke(DispatcherPriority priority, Delegate method, object arg, params object[] args)
  92         {
  93             if (!this.uiThreadDispatcher.HasShutdownStarted)
  94             {
  95                 this.uiThreadDispatcher.Invoke(priority, method, arg, args);
  96             }
  97         }
  98     }
  99 }
 100