Add SVG encoder

src/Spectre.Console.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 16
-VisualStudioVersion = 16.0.30225.117
+# Visual Studio Version 17
+VisualStudioVersion = 17.0.31903.59
 MinimumVisualStudioVersion = 15.0.26124.0
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Spectre.Console", "Spectre.Console\Spectre.Console.csproj", "{80DCBEF3-99D6-46C0-9C5B-42B4534D9113}"
 EndProject

src/Spectre.Console/AnsiConsole.Recording.cs

@@ -44,6 +44,20 @@ public static string ExportHtml()
         return _recorder.ExportHtml();
     }
 
+    /// <summary>
+    /// Exports all recorded console output as SVG text.
+    /// </summary>
+    /// <returns>The recorded output as SVG text.</returns>
+    public static string ExportSvg()
+    {
+        if (_recorder == null)
+        {
+            throw new InvalidOperationException("Cannot export SVG since a recording hasn't been started.");
+        }
+
+        return _recorder.ExportSvg();
+    }
+
     /// <summary>
     /// Exports all recorded console output using a custom encoder.
     /// </summary>
@@ -53,7 +67,7 @@ public static string ExportCustom(IAnsiConsoleEncoder encoder)
     {
         if (_recorder == null)
         {
-            throw new InvalidOperationException("Cannot export HTML since a recording hasn't been started.");
+            throw new InvalidOperationException("Cannot export since a recording hasn't been started.");
         }
 
         if (encoder is null)

src/Spectre.Console/Color.cs

@@ -242,6 +242,23 @@ public static Color FromConsoleColor(ConsoleColor color)
         };
     }
 
+    /// <summary>
+    /// Converts a hexadecimal format string to a <see cref="Color"/>.
+    /// </summary>
+    /// <param name="hex">The hexadecimal format string to parse.</param>
+    /// <returns>A <see cref="Color"/> representing the hexadecimal format string.</returns>
+    public static Color FromHex(string hex)
+    {
+        var color = StyleParser.ParseHexColor(hex, out var error);
+        if (color == null || error != null)
+        {
+            error ??= "Could not parse hex color";
+            throw new InvalidOperationException(error);
+        }
+
+        return color.Value;
+    }
+
     /// <summary>
     /// Converts the color to a markup string.
     /// </summary>

src/Spectre.Console/Extensions/RecorderExtensions.cs

@@ -37,4 +37,21 @@ public static string ExportHtml(this Recorder recorder)
 
         return recorder.Export(_htmlEncoder);
     }
+
+    /// <summary>
+    /// Exports the recorded content as SVG.
+    /// </summary>
+    /// <param name="recorder">The recorder.</param>
+    /// <returns>The recorded content as HTML.</returns>
+    public static string ExportSvg(this Recorder recorder)
+    {
+        if (recorder is null)
+        {
+            throw new ArgumentNullException(nameof(recorder));
+        }
+
+        return recorder.Export(
+            new SvgEncoder(
+                new SvgEncoderSettings()));
+    }
 }

src/Spectre.Console/Internal/Text/Encoding/HtmlEncoder.cs

@@ -1,3 +1,5 @@
+using System.Web;
+
 namespace Spectre.Console.Internal;
 
 internal sealed class HtmlEncoder : IAnsiConsoleEncoder
@@ -42,7 +44,7 @@ public string Encode(IAnsiConsole console, IEnumerable<IRenderable> renderables)
                     }
 
                     builder.Append('>');
-                    builder.Append(line);
+                    builder.Append(HttpUtility.HtmlEncode(line));
                     builder.Append("</span>");
 
                     if (parts.Length > 1 && !last)

src/Spectre.Console/Internal/Text/Encoding/Svg/SvgCssBuilder.cs

@@ -0,0 +1,62 @@
+namespace Spectre.Console.Internal;
+
+internal static class SvgCssBuilder
+{
+    public static string BuildCss(SvgTheme theme, Style style)
+    {
+        var css = new List<string>();
+
+        var foreground = theme.GetColor(style.Foreground);
+        var background = theme.GetColor(style.Background);
+
+        if ((style.Decoration & Decoration.Invert) != 0)
+        {
+            var temp = foreground;
+            foreground = background;
+            background = temp;
+        }
+
+        if ((style.Decoration & Decoration.Dim) != 0)
+        {
+            var blender = background;
+            if (blender.Equals(Color.Default))
+            {
+                blender = Color.White;
+            }
+
+            foreground = foreground.Blend(blender, 0.5f);
+        }
+
+        if (!foreground.Equals(Color.Default))
+        {
+            css.Add($"color: #{foreground.ToHex()}");
+        }
+
+        if (!background.Equals(Color.Default))
+        {
+            css.Add($"background-color: #{background.ToHex()}");
+        }
+
+        if ((style.Decoration & Decoration.Bold) != 0)
+        {
+            css.Add("font-weight: bold");
+        }
+
+        if ((style.Decoration & Decoration.Bold) != 0)
+        {
+            css.Add("font-style: italic");
+        }
+
+        if ((style.Decoration & Decoration.Underline) != 0)
+        {
+            css.Add("text-decoration: underline");
+        }
+
+        if ((style.Decoration & Decoration.Strikethrough) != 0)
+        {
+            css.Add("text-decoration: line-through");
+        }
+
+        return string.Join(";", css);
+    }
+}

src/Spectre.Console/Internal/Text/Encoding/Svg/SvgEncoder.cs

@@ -0,0 +1,90 @@
+using System.Web;
+
+namespace Spectre.Console.Internal;
+
+internal sealed class SvgEncoder : IAnsiConsoleEncoder
+{
+    private readonly SvgEncoderSettings _settings;
+
+    public SvgEncoder(SvgEncoderSettings settings)
+    {
+        _settings = settings ?? throw new ArgumentNullException(nameof(settings));
+    }
+
+    public string Encode(IAnsiConsole console, IEnumerable<IRenderable> renderable)
+    {
+        var template = GetTemplate();
+        if (template == null)
+        {
+            throw new InvalidOperationException("Template could not be found");
+        }
+
+        var context = new RenderContext(new EncoderCapabilities(ColorSystem.TrueColor));
+        var segmentLines = Segment.SplitLines(
+            renderable.SelectMany(r => r.Render(context, console.Profile.Width)));
+
+        var lines = new List<string>();
+        foreach (var segmentLine in segmentLines)
+        {
+            var line = new List<string>();
+
+            foreach (var segment in segmentLine)
+            {
+                if (segment.IsControlCode)
+                {
+                    continue;
+                }
+
+                var text = HttpUtility.HtmlEncode(segment.Text);
+
+                if (segment.Style != Style.Plain)
+                {
+                    var rule = SvgCssBuilder.BuildCss(_settings.Theme, segment.Style);
+                    text = $"<span style=\"color: #{_settings.Theme.ForegroundColor.ToHex()};{rule}; \">{text}</span>";
+                }
+                else
+                {
+                    text = $"<span style=\"color: #{_settings.Theme.ForegroundColor.ToHex()}; \">{text}</span>";
+                }
+
+                line.Add(text);
+            }
+
+            lines.Add($"<div>{string.Concat(line)}</div>");
+        }
+
+        var terminalPadding = 12;
+        var requiredCodeHeight = _settings.LineHeight * segmentLines.Count;
+        var terminalHeight = requiredCodeHeight + 60;
+        var terminalWidth =
+            (int)((console.Profile.Width * _settings.FontWidthScale * _settings.FontSize)
+            + (2 * terminalPadding)
+            + console.Profile.Width);
+
+        var totalHeight = terminalHeight + (2 * _settings.Margin);
+        var totalWidth = terminalWidth + (2 * _settings.Margin);
+
+        return template
+            .Replace("@(total_width)", totalWidth.ToString())
+            .Replace("@(total_height)", totalHeight.ToString())
+            .Replace("@(font_size)", _settings.FontSize.ToString())
+            .Replace("@(theme_background_color)", "#" + _settings.Theme.BackgroundColor.ToHex())
+            .Replace("@(theme_foreground_color)", "#" + _settings.Theme.ForegroundColor.ToHex())
+            .Replace("@(line_height)", _settings.LineHeight.ToString())
+            .Replace("@(code)", string.Concat(lines));
+    }
+
+    private static string? GetTemplate()
+    {
+        var stream = typeof(SvgEncoder).Assembly.GetManifestResourceStream("Spectre.Console.Svg.Templates.Simple.svg");
+        if (stream != null)
+        {
+            using (var reader = new StreamReader(stream))
+            {
+                return reader.ReadToEnd();
+            }
+        }
+
+        return null;
+    }
+}

src/Spectre.Console/Internal/Text/Encoding/Svg/SvgEncoderSettings.cs

@@ -0,0 +1,35 @@
+namespace Spectre.Console.Internal;
+
+/// <summary>
+/// Represents settings for the SVG encoder.
+/// </summary>
+internal sealed class SvgEncoderSettings
+{
+    /// <summary>
+    /// Gets or sets the font size.
+    /// Default value is 18.
+    /// </summary>
+    public int FontSize { get; set; } = 18;
+
+    /// <summary>
+    /// Gets or sets the line height.
+    /// Default value is 22.
+    /// </summary>
+    public int LineHeight { get; set; } = 22;
+
+    /// <summary>
+    /// Gets or sets the font width scale.
+    /// Default value is 0.6.
+    /// </summary>
+    public float FontWidthScale { get; set; } = 0.6f;
+
+    /// <summary>
+    /// Gets or sets the margin (in pixels).
+    /// </summary>
+    public int Margin { get; set; } = 140;
+
+    /// <summary>
+    /// Gets or sets the theme to use.
+    /// </summary>
+    public SvgTheme Theme { get; set; } = new DefaultTheme();
+}

src/Spectre.Console/Internal/Text/Encoding/Svg/SvgTheme.cs

@@ -0,0 +1,87 @@
+namespace Spectre.Console.Internal;
+
+/// <summary>
+/// Represents a theme used for SVG rendering.
+/// </summary>
+internal abstract class SvgTheme
+{
+    private readonly Dictionary<Color, Color> _lookup;
+    private readonly Dictionary<byte, Color> _lookupNumbers;
+    private readonly Dictionary<string, Color> _lookupNames;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="SvgTheme"/> class.
+    /// </summary>
+    protected SvgTheme()
+    {
+        _lookup = new Dictionary<Color, Color>();
+        _lookupNumbers = new Dictionary<byte, Color>();
+        _lookupNames = new Dictionary<string, Color>();
+    }
+
+    /// <summary>
+    /// Gets the background color.
+    /// </summary>
+    public abstract Color BackgroundColor { get; }
+
+    /// <summary>
+    /// Gets the foreground color.
+    /// </summary>
+    public abstract Color ForegroundColor { get; }
+
+    /// <summary>
+    /// Overrides a color with the specified one.
+    /// </summary>
+    /// <param name="color">The color to override.</param>
+    /// <param name="newColor">The color to use instead of the overridden color.</param>
+    protected void Override(Color color, Color newColor)
+    {
+        if (color.Number != null)
+        {
+            _lookupNumbers[color.Number.Value] = newColor;
+
+            var name = ColorTable.GetName(color.Number.Value);
+            if (name != null)
+            {
+                _lookupNames[name] = newColor;
+            }
+        }
+
+        _lookup[color] = newColor;
+    }
+
+    internal Color GetColor(Color color)
+    {
+        if (color.IsDefault)
+        {
+            return color;
+        }
+
+        if (color.Number != null)
+        {
+            // Found by number?
+            if (_lookupNumbers.TryGetValue(color.Number.Value, out var numberResult))
+            {
+                return numberResult;
+            }
+
+            // Found by name?
+            var name = ColorTable.GetName(color.Number.Value);
+            if (name != null)
+            {
+                if (_lookupNames.TryGetValue(name, out var namedResult))
+                {
+                    return namedResult;
+                }
+            }
+        }
+
+        // Exact match?
+        if (_lookup.TryGetValue(color, out var result))
+        {
+            return result;
+        }
+
+        return color;
+    }
+}