/src/NUnit/UiException/Controls/CodeBox.cs

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

// This is free software licensed under the NUnit license. You may

// obtain a copy of the license at http://nunit.org

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



using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using NUnit.UiException.CodeFormatters;

using System.Diagnostics;



/// This control could have been replaced by a standard RichTextBox control, but

/// it turned out that RichTextBox:

///     - was hard to configure

///     - was hard to set the viewport

///     - doesn't use double buffer optimization

///     - scrolls text one line at a time without be configurable.

/// 

/// CodeBox has been written to address these specific issues in order to display

/// C# source code where exceptions occured.



namespace NUnit.UiException.Controls

{

    /// <summary>

    /// A control that implements ICodeView.

    /// </summary>

    public class CodeBox : UserControl, ICodeView

    {

        protected CodeRenderingContext _workingContext;

        protected FormattedCode _formattedCode;



        private IFormatterCatalog _formatter;

        private ICodeRenderer _renderer;

        private string _language;



        private bool _showCurrentLine;

        private int _currentLine;

        

        public CodeBox() :

            this(new GeneralCodeFormatter(), new DefaultCodeRenderer()) { }



        #region ICodeView Members



        public override string Text

        {

            get { return (_formattedCode.Text); }

            set

            {

                if (value == null)

                    value = "";



                SizeF docSize;



                _formattedCode = _formatter.Format(value, _language);

                docSize = _renderer.GetDocumentSize(

                    _formattedCode, _workingContext.Graphics, _workingContext.Font);

                AutoScrollMinSize = new Size((int)docSize.Width, (int)docSize.Height);



                Invalidate();



                return;

            }

        }



        public string Language

        {

            get { return (_language); }

            set

            {

                if (value == null)

                    value = "";

                if (_language == value)

                    return;



                _language = value;

                Text = Text;

            }

        }



        public int CurrentLine

        {

            get { return (_currentLine); }

            set

            {

                float y = _renderer.LineIndexToYCoordinate(value,

                    _workingContext.Graphics, _workingContext.Font);



                y -= Height / 2;



                _currentLine = value;

                AutoScrollPosition = new Point(0, (int)y);



                Invalidate();

            }

        }



        public IFormatterCatalog Formatter

        {

            get { return (_formatter); }

        }



        #endregion



        /// <summary>

        /// Gets or sets a value telling whether or not displaying a special

        /// feature for the current line at drawing time.

        /// </summary>        

        public bool ShowCurrentLine

        {

            get { return (_showCurrentLine); }

            set { _showCurrentLine = value; }

        }



        /// <summary>

        /// If ShowCurrentLine is set, this set the current line's background color.

        /// </summary>

        public Color CurrentLineBackColor

        {

            get { return (_workingContext.CurrentLineBackColor); }

            set { 

                _workingContext.CurrentLineBackColor = value;

                Invalidate();

            }

        }



        /// <summary>

        /// If ShowCurrentLine is set, this set current line's foreground color.

        /// </summary>

        public Color CurrentLineForeColor

        {

            get { return (_workingContext.CurrentLineForeColor); }

            set { 

                _workingContext.CurrentLineForeColor = value;

                Invalidate();

            }

        }

       

        protected CodeBox(IFormatterCatalog formatter, ICodeRenderer renderer)

        {

            SetStyle(ControlStyles.AllPaintingInWmPaint, true);

            SetStyle(ControlStyles.UserPaint, true);

            DoubleBuffered = true;



            _formatter = formatter;

            _formattedCode = FormattedCode.Empty;



            _renderer = renderer;



            _currentLine = -1;

            _showCurrentLine = false;



            _language = "";



            this.Font = new Font(FontFamily.GenericMonospace, 8);

            this.BackColor = Color.White;



            createGraphics();

            AutoScroll = true;



            return;

        }



        protected override void OnMouseHover(EventArgs e)

        {

            base.OnMouseHover(e);

            Focus();

        }



        protected override void OnPaint(PaintEventArgs e)

        {

            Graphics backup;



            base.OnPaint(e);



            backup = _workingContext.Graphics;

            _workingContext.Graphics = e.Graphics;

            _workingContext.CurrentLine = (_showCurrentLine ? _currentLine : -1);



            _renderer.DrawToGraphics(_formattedCode, _workingContext,

                new Rectangle(-AutoScrollPosition.X, -AutoScrollPosition.Y, Width, Height));



            _workingContext.Graphics = backup;



            return;

        }



        protected override void OnFontChanged(EventArgs e)

        {

            base.OnFontChanged(e);



            if (_workingContext != null)

            {

                _workingContext.Font = Font;

                Text = Text;

            }



            return;

        }



        private void createGraphics()

        {

            Graphics gCurrent = CreateGraphics();

            Image img = new Bitmap(10, 10, gCurrent);

            Graphics gImg = Graphics.FromImage(img);



            gCurrent.Dispose();



            _workingContext = new CodeRenderingContext();

            _workingContext.Graphics = gImg;

            _workingContext.Font = Font;



            _workingContext.CurrentLine = -1;

            _workingContext.BackgroundColor = Color.White;

            _workingContext.CurrentLineBackColor = Color.Red;

            _workingContext.CurrentLineForeColor = Color.White;

            _workingContext.CodeColor = Color.Black;

            _workingContext.CommentColor = Color.Green;

            _workingContext.KeywordColor = Color.Blue;

            _workingContext.StringColor = Color.Red;



            return;

        }

    }    

}