/IronPython_2_0/Src/Microsoft.Scripting/Hosting/Shell/BasicConsole.cs

/* ****************************************************************************

 *

 * Copyright (c) Microsoft Corporation. 

 *

 * This source code is subject to terms and conditions of the Microsoft Public License. A 

 * copy of the license can be found in the License.html file at the root of this distribution. If 

 * you cannot locate the  Microsoft Public License, please send an email to 

 * dlr@microsoft.com. By using this source code in any fashion, you are agreeing to be bound 

 * by the terms of the Microsoft Public License.

 *

 * You must not remove this notice, or any other, from this software.

 *

 *

 * ***************************************************************************/



using System; using Microsoft;

using System.IO;

using Microsoft.Scripting;

using Microsoft.Scripting.Utils;

using System.Threading;



namespace Microsoft.Scripting.Hosting.Shell {



    public class BasicConsole : IConsole, IDisposable {



        private TextWriter _output;

        private TextWriter _errorOutput;

        private AutoResetEvent _ctrlCEvent;

        private Thread _creatingThread;



        public TextWriter Output {

            get { return _output; }

            set {

                ContractUtils.RequiresNotNull(value, "value");

                _output = value;

            }

        }



        public TextWriter ErrorOutput {

            get { return _errorOutput; }

            set {

                ContractUtils.RequiresNotNull(value, "value");

                _errorOutput = value;

            }

        }



        protected AutoResetEvent CtrlCEvent {

            get { return _ctrlCEvent; }

            set { _ctrlCEvent = value; }

        }



        protected Thread CreatingThread {

            get { return _creatingThread; }

            set { _creatingThread = value; }

        }



        private ConsoleColor _promptColor;

        private ConsoleColor _outColor;

        private ConsoleColor _errorColor;

        private ConsoleColor _warningColor;



        public BasicConsole(bool colorful) {            

            _output = System.Console.Out;

            _errorOutput = System.Console.Error;

            SetupColors(colorful);



            _creatingThread = Thread.CurrentThread;            



#if !SILVERLIGHT // ConsoleCancelEventHandler

            Console.CancelKeyPress += new ConsoleCancelEventHandler(delegate(object sender, ConsoleCancelEventArgs e) {

                if (e.SpecialKey == ConsoleSpecialKey.ControlC) {

                    e.Cancel = true;

                    _ctrlCEvent.Set();

                    _creatingThread.Abort(new KeyboardInterruptException(""));

                }

            });

#endif

            _ctrlCEvent = new AutoResetEvent(false);

        }



        private void SetupColors(bool colorful) {



            if (colorful) {

                _promptColor = PickColor(ConsoleColor.Gray, ConsoleColor.White);

                _outColor = PickColor(ConsoleColor.Green, ConsoleColor.White);

                _errorColor = PickColor(ConsoleColor.Red, ConsoleColor.White);

                _warningColor = PickColor(ConsoleColor.Yellow, ConsoleColor.White);

            } else {

#if !SILVERLIGHT

                _promptColor = _outColor = _errorColor = _warningColor = Console.ForegroundColor;

#endif

            }

        }



        private static ConsoleColor PickColor(ConsoleColor best, ConsoleColor other) {

#if SILVERLIGHT

            return best;

#else

            if (Console.BackgroundColor != best) {

                return best;

            }



            return other;

#endif

        }



        protected void WriteColor(TextWriter output, string str, ConsoleColor c) {

#if !SILVERLIGHT // Console.ForegroundColor

            ConsoleColor origColor = Console.ForegroundColor;

            Console.ForegroundColor = c;

#endif

            output.Write(str);

            output.Flush();



#if !SILVERLIGHT // Console.ForegroundColor

            Console.ForegroundColor = origColor;

#endif

        }



        #region IConsole Members



        public virtual string ReadLine(int autoIndentSize) {

            Write("".PadLeft(autoIndentSize), Style.Prompt);



            string res = Console.In.ReadLine();

            if (res == null) {

                // we have a race - the Ctrl-C event is delivered

                // after ReadLine returns.  We need to wait for a little

                // bit to see which one we got.  This will cause a slight

                // delay when shutting down the process via ctrl-z, but it's

                // not really perceptible.  In the ctrl-C case we will return

                // as soon as the event is signaled.

#if SILVERLIGHT

                if (_ctrlCEvent != null && _ctrlCEvent.WaitOne(100))

#else

                if (_ctrlCEvent != null && _ctrlCEvent.WaitOne(100, false))

#endif

 {

                    // received ctrl-C

                    return "";

                } else {

                    // received ctrl-Z

                    return null;

                }

            }

            return "".PadLeft(autoIndentSize) + res;

        }



        public virtual void Write(string text, Style style) {

            switch (style) {

                case Style.Prompt: WriteColor(_output, text, _promptColor); break;

                case Style.Out: WriteColor(_output, text, _outColor); break;

                case Style.Error: WriteColor(_errorOutput, text, _errorColor); break;

                case Style.Warning: WriteColor(_errorOutput, text, _warningColor); break;

            }

        }



        public void WriteLine(string text, Style style) {

            Write(text + Environment.NewLine, style);

        }



        public void WriteLine() {

            Write(Environment.NewLine, Style.Out);

        }



        #endregion



        #region IDisposable Members



        public void Dispose() {

            if (_ctrlCEvent != null) {

                _ctrlCEvent.Close();

            }



            GC.SuppressFinalize(this);

        }



        #endregion

    }



}