nunit24/NUnitCore/core/TextCapture.cs

   1 // ****************************************************************
   2 // Copyright 2008, Charlie Poole
   3 // This is free software licensed under the NUnit license. You may
   4 // obtain a copy of the license at http://nunit.org/?p=license&r=2.4
   5 // ****************************************************************
   6
   7 using System.IO;
   8
   9 namespace NUnit.Core
  10 {
  11     /// <summary>
  12     /// Abstract base for classes that capture text output
  13     /// and redirect it to a TextWriter.
  14     /// </summary>
  15     public abstract class TextCapture
  16     {
  17         #region Private Fields
  18         /// <summary>
  19         /// True if capture is enabled
  20         /// </summary>
  21         private bool enabled;
  22
  23         /// <summary>
  24         /// The TextWriter to which text is redirected
  25         /// </summary>
  26         private TextWriter writer;
  27         #endregion
  28
  29         #region Properties
  30         /// <summary>
  31         /// The TextWriter to which text is redirected
  32         /// </summary>
  33         public TextWriter Writer
  34         {
  35             get { return writer; }
  36             set
  37             {
  38                 writer = value;
  39
  40                 if (writer != null && enabled)
  41                     StartCapture();
  42             }
  43         }
  44
  45         /// <summary>
  46         /// Controls whether text is captured or not
  47         /// </summary>
  48         public bool Enabled
  49         {
  50             get { return enabled; }
  51             set
  52             {
  53                 if (enabled != value)
  54                 {
  55                     if (writer != null && enabled)
  56                         StopCapture();
  57
  58                     enabled = value;
  59
  60                     if (writer != null && enabled && DefaultThreshold != "Off")
  61                         StartCapture();
  62                 }
  63             }
  64         }
  65
  66         /// <summary>
  67         /// Returns the default threshold value, which represents
  68         /// the degree of verbosity of the output text stream.
  69         /// Returns "None" in the base class. Derived classes that
  70         /// support verbosity levels should override it.
  71         /// </summary>
  72         public virtual string DefaultThreshold
  73         {
  74             get { return "None"; }
  75         }
  76         #endregion
  77
  78         #region Abstract Members
  79         /// <summary>
  80         /// Override this to perform whatever actions are needed
  81         /// to start capturing text and sending it to the Writer.
  82         /// </summary>
  83         protected abstract void StartCapture();
  84
  85         /// <summary>
  86         /// Override this to perform whatever actions are needed
  87         /// to flush remaining output and stop capturing text.
  88         /// The Writer should not be changed, allowing capture
  89         /// to be restarted at a future point.
  90         /// </summary>
  91         protected abstract void StopCapture();
  92         #endregion
  93     }
  94
  95 }