ansicolorterminalappender.cs

精通SQL Server2005项目开发

		/// <remarks>
		/// <para>
		/// Writes the event to the console.
		/// </para>
		/// <para>
		/// The format of the output will depend on the appender's layout.
		/// </para>
		/// </remarks>
		override protected void Append(log4net.Core.LoggingEvent loggingEvent) 
		{
			string loggingMessage = RenderLoggingEvent(loggingEvent);

			// see if there is a specified lookup.
			LevelColors levelColors = m_levelMapping.Lookup(loggingEvent.Level) as LevelColors;
			if (levelColors != null)
			{
				// Prepend the Ansi Color code
				loggingMessage = levelColors.CombinedColor + loggingMessage;
			}

			// on most terminals there are weird effects if we don't clear the background color
			// before the new line.  This checks to see if it ends with a newline, and if
			// so, inserts the clear codes before the newline, otherwise the clear codes
			// are inserted afterwards.
			if (loggingMessage.Length > 1)
			{
				if (loggingMessage.EndsWith("\r\n") || loggingMessage.EndsWith("\n\r")) 
				{
					loggingMessage = loggingMessage.Insert(loggingMessage.Length - 2, PostEventCodes);
				} 
				else if (loggingMessage.EndsWith("\n") || loggingMessage.EndsWith("\r")) 
				{
					loggingMessage = loggingMessage.Insert(loggingMessage.Length - 1, PostEventCodes);
				} 
				else 
				{
					loggingMessage = loggingMessage + PostEventCodes;
				}
			}
			else
			{
				if (loggingMessage[0] == '\n' || loggingMessage[0] == '\r') 
				{
					loggingMessage = PostEventCodes + loggingMessage;
				} 
				else 
				{
					loggingMessage = loggingMessage + PostEventCodes;
				}
			}

#if NETCF
			// Write to the output stream
			Console.Write(loggingMessage);
#else
			if (m_writeToErrorStream)
			{
				// Write to the error stream
				Console.Error.Write(loggingMessage);
			}
			else
			{
				// Write to the output stream
				Console.Write(loggingMessage);
			}
#endif
		
		}

		/// <summary>
		/// This appender requires a <see cref="Layout"/> to be set.
		/// </summary>
		/// <value><c>true</c></value>
		/// <remarks>
		/// <para>
		/// This appender requires a <see cref="Layout"/> to be set.
		/// </para>
		/// </remarks>
		override protected bool RequiresLayout
		{
			get { return true; }
		}

		/// <summary>
		/// Initialize the options for this appender
		/// </summary>
		/// <remarks>
		/// <para>
		/// Initialize the level to color mappings set on this appender.
		/// </para>
		/// </remarks>
		public override void ActivateOptions()
		{
			base.ActivateOptions();
			m_levelMapping.ActivateOptions();
		}

		#endregion Override implementation of AppenderSkeleton

		#region Public Static Fields

		/// <summary>
		/// The <see cref="AnsiColorTerminalAppender.Target"/> to use when writing to the Console 
		/// standard output stream.
		/// </summary>
		/// <remarks>
		/// <para>
		/// The <see cref="AnsiColorTerminalAppender.Target"/> to use when writing to the Console 
		/// standard output stream.
		/// </para>
		/// </remarks>
		public const string ConsoleOut = "Console.Out";

		/// <summary>
		/// The <see cref="AnsiColorTerminalAppender.Target"/> to use when writing to the Console 
		/// standard error output stream.
		/// </summary>
		/// <remarks>
		/// <para>
		/// The <see cref="AnsiColorTerminalAppender.Target"/> to use when writing to the Console 
		/// standard error output stream.
		/// </para>
		/// </remarks>
		public const string ConsoleError = "Console.Error";

		#endregion Public Static Fields

		#region Private Instances Fields

		/// <summary>
		/// Flag to write output to the error stream rather than the standard output stream
		/// </summary>
		private bool m_writeToErrorStream = false;

		/// <summary>
		/// Mapping from level object to color value
		/// </summary>
		private LevelMapping m_levelMapping = new LevelMapping();

		/// <summary>
		/// Ansi code to reset terminal
		/// </summary>
		private const string PostEventCodes = "\x1b[0m";

		#endregion Private Instances Fields

		#region LevelColors LevelMapping Entry

		/// <summary>
		/// A class to act as a mapping between the level that a logging call is made at and
		/// the color it should be displayed as.
		/// </summary>
		/// <remarks>
		/// <para>
		/// Defines the mapping between a level and the color it should be displayed in.
		/// </para>
		/// </remarks>
		public class LevelColors : LevelMappingEntry
		{
			private AnsiColor m_foreColor;
			private AnsiColor m_backColor;
			private AnsiAttributes m_attributes;
			private string m_combinedColor = "";

			/// <summary>
			/// The mapped foreground color for the specified level
			/// </summary>
			/// <remarks>
			/// <para>
			/// Required property.
			/// The mapped foreground color for the specified level
			/// </para>
			/// </remarks>
			public AnsiColor ForeColor
			{
				get { return m_foreColor; }
				set { m_foreColor = value; }
			}

			/// <summary>
			/// The mapped background color for the specified level
			/// </summary>
			/// <remarks>
			/// <para>
			/// Required property.
			/// The mapped background color for the specified level
			/// </para>
			/// </remarks>
			public AnsiColor BackColor
			{
				get { return m_backColor; }
				set { m_backColor = value; }
			}

			/// <summary>
			/// The color attributes for the specified level
			/// </summary>
			/// <remarks>
			/// <para>
			/// Required property.
			/// The color attributes for the specified level
			/// </para>
			/// </remarks>
			public AnsiAttributes Attributes
			{
				get { return m_attributes; }
				set { m_attributes = value; }
			}

			/// <summary>
			/// Initialize the options for the object
			/// </summary>
			/// <remarks>
			/// <para>
			/// Combine the <see cref="ForeColor"/> and <see cref="BackColor"/> together
			/// and append the attributes.
			/// </para>
			/// </remarks>
			public override void ActivateOptions()
			{
				base.ActivateOptions();

				StringBuilder buf = new StringBuilder();

				// Reset any existing codes
				buf.Append("\x1b[0;");

				// set the foreground color
				buf.Append(30 + (int)m_foreColor);
				buf.Append(';');

				// set the background color
				buf.Append(40 + (int)m_backColor);

				// set the attributes
				if ((m_attributes & AnsiAttributes.Bright) > 0)
				{
					buf.Append(";1");
				}
				if ((m_attributes & AnsiAttributes.Dim) > 0)
				{
					buf.Append(";2");
				}
				if ((m_attributes & AnsiAttributes.Underscore) > 0)
				{
					buf.Append(";4");
				}
				if ((m_attributes & AnsiAttributes.Blink) > 0)
				{
					buf.Append(";5");
				}
				if ((m_attributes & AnsiAttributes.Reverse) > 0)
				{
					buf.Append(";7");
				}
				if ((m_attributes & AnsiAttributes.Hidden) > 0)
				{
					buf.Append(";8");
				}
				if ((m_attributes & AnsiAttributes.Strikethrough) > 0)
				{
					buf.Append(";9");
				}

				buf.Append('m');

				m_combinedColor = buf.ToString();
			}

			/// <summary>
			/// The combined <see cref="ForeColor"/>, <see cref="BackColor"/> and
			/// <see cref="Attributes"/> suitable for setting the ansi terminal color.
			/// </summary>
			internal string CombinedColor
			{
				get { return m_combinedColor; }
			}
		}

		#endregion // LevelColors LevelMapping Entry
	}
}