Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/System.Workflow.Activities/ActivityTrace.cs

@@ -0,0 +1,60 @@
+namespace System.Workflow.Activities
+{
+    using System;
+    using System.Diagnostics;
+
+
+    internal static class WorkflowActivityTrace
+    {
+        static TraceSource activity;
+        static TraceSource rules;
+
+        internal static TraceSource Activity
+        {
+            get { return activity; }
+        }
+
+        internal static TraceSource Rules
+        {
+            get { return rules; }
+        }
+
+        /// <summary>
+        /// Statically set up trace sources
+        /// 
+        /// To enable logging to a file, add lines like the following to your app config file.
+        /*
+            <system.diagnostics>
+                <switches>
+                    <add name="System.Workflow LogToFile" value="1" />
+                </switches>
+            </system.diagnostics>
+        */
+        /// To enable tracing to default trace listeners, add lines like the following
+        /*
+            <system.diagnostics>
+                <switches>
+                    <add name="System.Workflow LogToTraceListener" value="1" />
+                </switches>
+            </system.diagnostics>
+        */
+        /// </summary>
+        static WorkflowActivityTrace()
+        {
+            activity = new TraceSource("System.Workflow.Activities");
+            activity.Switch = new SourceSwitch("System.Workflow.Activities", SourceLevels.Off.ToString());
+
+            rules = new TraceSource("System.Workflow.Activities.Rules");
+            rules.Switch = new SourceSwitch("System.Workflow.Activities.Rules", SourceLevels.Off.ToString());
+
+            foreach (TraceListener listener in Trace.Listeners)
+            {
+                if (!(listener is DefaultTraceListener))
+                {
+                    activity.Listeners.Add(listener);
+                    rules.Listeners.Add(listener);
+                }
+            }
+        }
+    }
+}