Added threaded action to wrap sub-actions a view model can perform (this can either be scheduled individually or on the parent threaded view model); added missing copyright statement; more unit tests

git-svn-id: file:///srv/devel/repo-conversion/nuwi@45 d2e56fa2-650e-0410-a79f-9358c0239efd

Source/NullActiveWindowTracker.cs

@@ -0,0 +1,37 @@
+#region CPL License
+/*
+Nuclex Framework
+Copyright (C) 2002-2019 Nuclex Development Labs
+
+This library is free software; you can redistribute it and/or
+modify it under the terms of the IBM Common Public License as
+published by the IBM Corporation; either version 1.0 of the
+License, or (at your option) any later version.
+
+This library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+IBM Common Public License for more details.
+
+You should have received a copy of the IBM Common Public
+License along with this library
+*/
+#endregion
+
+using System;
+using System.Windows.Forms;
+
+namespace Nuclex.Windows.Forms {
+
+  /// <summary>Dummy implementation of the active window tracker service</summary>
+  internal class NullActiveWindowTracker : IActiveWindowTracker {
+
+    /// <summary>The default instance of the dummy window tracker</summary>
+    public static readonly NullActiveWindowTracker Default = new NullActiveWindowTracker();
+
+    /// <summary>The currently active top-level or modal window</summary>
+    public Form ActiveWindow { get { return null; } }
+
+  }
+
+} // namespace Nuclex.Windows.Forms