From 55b8eda9272b5913a438c4fc242c73d2418e6929 Mon Sep 17 00:00:00 2001
From: Martin Baulig <martin.baulig@xamarin.com>
Date: Tue, 5 Mar 2013 17:40:52 -0500
Subject: [PATCH] System.Progress

---
 mcs/class/corlib/System/Progress.cs | 72 +++++++++++++++++++++++++++++
 mcs/class/corlib/corlib.dll.sources |  1 +
 2 files changed, 73 insertions(+)
 create mode 100644 mcs/class/corlib/System/Progress.cs

diff --git a/mcs/class/corlib/System/Progress.cs b/mcs/class/corlib/System/Progress.cs
new file mode 100644
index 00000000000..75f896d67f3
--- /dev/null
+++ b/mcs/class/corlib/System/Progress.cs
@@ -0,0 +1,72 @@
+// Authors:
+//      Martin Baulig (martin.baulig@xamarin.com)
+//
+// Copyright 2012 Xamarin Inc. (http://www.xamarin.com)
+//
+//
+// Permission is hereby granted, free of charge, to any person obtaining
+// a copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to
+// permit persons to whom the Software is furnished to do so, subject to
+// the following conditions:
+// 
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+//
+#if NET_4_5
+using System.Threading;
+
+namespace System {
+	[MonoTODO ("Use SynchronizationContext / ThreadPool.")]
+	public class Progress<T> : IProgress<T> {
+		Action<T> handler;
+		SynchronizationContext ctx;
+
+		public Progress ()
+		{
+			ctx = SynchronizationContext.Current;
+		}
+
+		public Progress (Action<T> handler)
+		{
+			this.handler = handler;
+		}
+		
+		void Invoke (Action action)
+		{
+			if (ctx != null)
+				ctx.Post (_ => action (), null);
+			else
+				ThreadPool.QueueUserWorkItem (_ => action ());
+		}
+		
+		protected virtual void OnReport (T value)
+		{
+			Invoke (() => {
+				if (handler != null)
+					handler (value);
+				if (ProgressChanged != null)
+					ProgressChanged (this, value);
+			});
+		}
+		
+		void IProgress<T>.Report (T value)
+		{
+			OnReport (value);
+		}
+		
+		public event EventHandler<T> ProgressChanged;
+		
+	}
+}
+#endif
diff --git a/mcs/class/corlib/corlib.dll.sources b/mcs/class/corlib/corlib.dll.sources
index 5b5fcabd301..b954112040c 100644
--- a/mcs/class/corlib/corlib.dll.sources
+++ b/mcs/class/corlib/corlib.dll.sources
@@ -1570,6 +1570,7 @@ System/ArraySegment.cs
 System/Comparison.cs
 System/Converter.cs
 System/Predicate.cs
+System/Progress.cs
 System.Collections.Generic/Comparer.cs
 
 System.Threading.Tasks/ConcurrentExclusiveSchedulerPair.cs
-- 
2.25.1