Move code files to src directory and add readme

src/.editorconfig

@@ -0,0 +1,4 @@
+[*.cs]
+
+# CS0067: The event 'HomeCommand.CanExecuteChanged' is never used
+dotnet_diagnostic.CS0067.severity = none

src/Markdowser.sln

@@ -0,0 +1,30 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.9.34616.47
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Markdowser", "Markdowser\Markdowser.csproj", "{98C02B25-7D7D-4F83-892D-5503FFF3D108}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{99E8E3C0-9FF5-4665-98DC-BD0C00FA8569}"
+	ProjectSection(SolutionItems) = preProject
+		.editorconfig = .editorconfig
+	EndProjectSection
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{98C02B25-7D7D-4F83-892D-5503FFF3D108}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{98C02B25-7D7D-4F83-892D-5503FFF3D108}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{98C02B25-7D7D-4F83-892D-5503FFF3D108}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{98C02B25-7D7D-4F83-892D-5503FFF3D108}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {93739FBA-8641-4D80-A0C5-64201ABD1B13}
+	EndGlobalSection
+EndGlobal

src/Markdowser/App.axaml

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+<Application xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             x:Class="Markdowser.App"
+             xmlns:local="using:Markdowser"
+             RequestedThemeVariant="Default">
+    <!-- "Default" ThemeVariant follows system theme variant. "Dark" or "Light" are other available options. -->
+
+    <Application.DataTemplates>
+        <local:ViewLocator />
+    </Application.DataTemplates>
+
+    <Application.Styles>
+        <StyleInclude Source="avares://Semi.Avalonia/Themes/Index.axaml" />
+    </Application.Styles>
+</Application>

src/Markdowser/App.axaml.cs

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+using Avalonia;
+using Avalonia.Controls.ApplicationLifetimes;
+using Avalonia.Markup.Xaml;
+using Avalonia.Styling;
+
+using Markdowser.Models;
+using Markdowser.ViewModels;
+using Markdowser.Views;
+
+namespace Markdowser;
+
+public partial class App : Application
+{
+    public override void Initialize()
+    {
+        AvaloniaXamlLoader.Load(this);
+    }
+
+    public override void OnFrameworkInitializationCompleted()
+    {
+        if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
+        {
+            desktop.MainWindow = new MainWindow
+            {
+                DataContext = new MainWindowViewModel(),
+            };
+
+            desktop.MainWindow.Closing += (sender, e) =>
+            {
+                Settings.SaveSettings();
+            };
+        }
+
+        base.OnFrameworkInitializationCompleted();
+
+        if (Current is not null)
+        {
+            Current.RequestedThemeVariant = Settings.Current.DarkMode ? ThemeVariant.Dark : ThemeVariant.Light;
+        }
+    }
+}

src/Markdowser/Commands/ChangeThemeCommand.cs

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+using Avalonia;
+using Avalonia.Styling;
+
+using Markdowser.Models;
+using Markdowser.Utilities;
+
+using System;
+using System.Windows.Input;
+
+namespace Markdowser.Commands;
+
+internal class ChangeThemeCommand : ICommand
+{
+#pragma warning disable CS0067 // The event 'ChangeThemeCommand.CanExecuteChanged' is never used
+
+    public event EventHandler? CanExecuteChanged;
+
+#pragma warning restore CS0067 // The event 'ChangeThemeCommand.CanExecuteChanged' is never used
+
+    public bool CanExecute(object? parameter)
+    {
+        return true;
+    }
+
+    public void Execute(object? parameter)
+    {
+        Application? app = Application.Current;
+        if (app is not null)
+        {
+            ThemeVariant theme = app.ActualThemeVariant;
+            app.RequestedThemeVariant = theme == ThemeVariant.Dark ? ThemeVariant.Light : ThemeVariant.Dark;
+            Settings.Current.DarkMode = app.RequestedThemeVariant == ThemeVariant.Dark;
+            GlobalState.ReloadContent(this);
+        }
+    }
+}

src/Markdowser/Commands/HomeCommand.cs

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+using Markdowser.Models;
+using Markdowser.Utilities;
+
+using System;
+using System.Windows.Input;
+
+namespace Markdowser.Commands;
+
+internal class HomeCommand : ICommand
+{
+#pragma warning disable CS0067 // The event 'HomeCommand.CanExecuteChanged' is never used
+
+    public event EventHandler? CanExecuteChanged;
+
+#pragma warning restore CS0067 // The event 'HomeCommand.CanExecuteChanged' is never used
+
+    public bool CanExecute(object? parameter)
+    {
+        return true;
+    }
+
+    public void Execute(object? parameter)
+    {
+        GlobalState.Url = Settings.Current.HomeUrl ?? string.Empty;
+    }
+}

src/Markdowser/Commands/HyperlinkCommand.cs

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+using Markdowser.Utilities;
+
+using System;
+using System.Diagnostics;
+using System.Windows.Input;
+
+namespace Markdowser.Commands;
+
+public class HyperlinkCommand : ICommand
+{
+#pragma warning disable CS0067 // The event 'HyperlinkCommand.CanExecuteChanged' is never used
+
+    public event EventHandler? CanExecuteChanged;
+
+#pragma warning restore CS0067 // The event 'HyperlinkCommand.CanExecuteChanged' is never used
+
+    public bool CanExecute(object? parameter)
+    {
+        return true;
+    }
+
+    public void Execute(object? parameter)
+    {
+        if (parameter is string url)
+        {
+            Debug.WriteLine($"Hyperlink clicked: {url}");
+
+            if (Uri.IsWellFormedUriString(url, UriKind.Absolute))
+            {
+                GlobalState.Url = url;
+            }
+            else if (Uri.IsWellFormedUriString(url, UriKind.Relative) || url.StartsWith('/'))
+            {
+                GlobalState.Url = new Uri(new Uri(GlobalState.Url), url).ToString();
+            }
+            else
+            {
+                Debug.WriteLine($"Invalid URL: {url}");
+            }
+        }
+    }
+}

src/Markdowser/GlobalSuppressions.cs

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+// This file is used by Code Analysis to maintain SuppressMessage
+// attributes that are applied to this project.
+// Project-level suppressions either have no target or are given
+// a specific target and scoped to a namespace, type, member, etc.
+
+using System.Diagnostics.CodeAnalysis;
+
+[assembly: SuppressMessage("Minor Code Smell", "S1075:URIs should not be hardcoded", Justification = "<Pending>")]
+[assembly: SuppressMessage("Minor Code Smell", "CS0067:The event 'ChangeThemeCommand.CanExecuteChanged' is never used", Justification = "<Pending>", Scope = "member", Target = "~N:Markdowser.Commands")]
+[assembly: SuppressMessage("Performance", "CA1822:Mark members as static", Justification = "<Pending>")]

src/Markdowser/Markdowser.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <BuiltInComInteropSupport>true</BuiltInComInteropSupport>
+    <ApplicationManifest>app.manifest</ApplicationManifest>
+    <AvaloniaUseCompiledBindingsByDefault>true</AvaloniaUseCompiledBindingsByDefault>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <AvaloniaResource Include="Assets\**" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <None Remove="Assets\Markdowser-Dark-Transparent.ico" />
+    <None Remove="Assets\Markdowser-Dark-Transparent.png" />
+    <None Remove="Assets\Markdowser-Dark.png" />
+    <None Remove="Assets\Markdowser-Light-Transparent.ico" />
+    <None Remove="Assets\Markdowser-Light-Transparent.png" />
+    <None Remove="Assets\Markdowser-Light.png" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Avalonia" Version="11.0.10" />
+    <PackageReference Include="Avalonia.Desktop" Version="11.0.10" />
+    <PackageReference Include="Avalonia.Themes.Fluent" Version="11.0.10" />
+    <PackageReference Include="Avalonia.Fonts.Inter" Version="11.0.10" />
+    <!--Condition below is needed to remove Avalonia.Diagnostics package from build output in Release configuration.-->
+    <PackageReference Condition="'$(Configuration)' == 'Debug'" Include="Avalonia.Diagnostics" Version="11.0.10" />
+    <PackageReference Include="Avalonia.ReactiveUI" Version="11.0.10" />
+    <PackageReference Include="Markdown.Avalonia" Version="11.0.2" />
+    <PackageReference Include="Projektanker.Icons.Avalonia" Version="9.1.2" />
+    <PackageReference Include="Projektanker.Icons.Avalonia.FontAwesome" Version="9.1.2" />
+    <PackageReference Include="Projektanker.Icons.Avalonia.MaterialDesign" Version="9.1.2" />
+    <PackageReference Include="ReverseMarkdown" Version="4.3.0" />
+    <PackageReference Include="Semi.Avalonia" Version="11.0.7.1" />
+  </ItemGroup>
+</Project>

src/Markdowser/Models/Settings.cs

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+using Markdowser.Utilities;
+
+using System.IO;
+using System.Text.Json;
+
+namespace Markdowser.Models;
+
+public class Settings
+{
+    public static Settings Current { get; set; } = LoadSettings();
+
+    public bool DarkMode { get; set; }
+
+    public string? HomeUrl { get; set; }
+
+    public static void SaveSettings()
+    {
+        if (!Directory.Exists(Configuration.ApplicationDataPath))
+        {
+            _ = Directory.CreateDirectory(Configuration.ApplicationDataPath);
+        }
+
+        File.WriteAllText(Configuration.SettingsFilePath, JsonSerializer.Serialize(Current));
+    }
+
+    private static Settings LoadSettings()
+    {
+        if (File.Exists(Configuration.SettingsFilePath))
+        {
+            return JsonSerializer.Deserialize<Settings>(File.ReadAllText(Configuration.SettingsFilePath)) ?? new Settings();
+        }
+        else
+        {
+            return new Settings();
+        }
+    }
+}

src/Markdowser/Program.cs

@@ -0,0 +1,37 @@
+using Avalonia;
+using Avalonia.ReactiveUI;
+
+using Projektanker.Icons.Avalonia;
+using Projektanker.Icons.Avalonia.FontAwesome;
+using Projektanker.Icons.Avalonia.MaterialDesign;
+
+using System;
+
+namespace Markdowser;
+
+internal static class Program
+{
+    // Initialization code. Don't use any Avalonia, third-party APIs or any
+    // SynchronizationContext-reliant code before AppMain is called: things aren't initialized
+    // yet and stuff might break.
+    [STAThread]
+    public static void Main(string[] args)
+    {
+        _ = BuildAvaloniaApp()
+        .StartWithClassicDesktopLifetime(args);
+    }
+
+    // Avalonia configuration, don't remove; also used by visual designer.
+    public static AppBuilder BuildAvaloniaApp()
+    {
+        _ = IconProvider.Current
+            .Register<FontAwesomeIconProvider>()
+            .Register<MaterialDesignIconProvider>();
+
+        return AppBuilder.Configure<App>()
+            .UsePlatformDetect()
+            .WithInterFont()
+            .LogToTrace()
+            .UseReactiveUI();
+    }
+}

src/Markdowser/Utilities/ColumnDefinition.cs

@@ -0,0 +1,35 @@
+using Avalonia;
+
+namespace Markdowser.Utilities;
+
+internal static class ColumnDefinition
+{
+    public static readonly AttachedProperty<bool> IsVisibleProperty = AvaloniaProperty.RegisterAttached<Avalonia.Controls.ColumnDefinition, bool>("IsVisible", typeof(ColumnDefinition), true, coerce: (element, visibility) =>
+    {
+        Avalonia.Controls.GridLength? lastWidth = element.GetValue(LastWidthProperty!);
+        if (visibility && lastWidth is { })
+        {
+            _ = element.SetValue(Avalonia.Controls.ColumnDefinition.WidthProperty, lastWidth);
+        }
+        else if (!visibility)
+        {
+            _ = element.SetValue(LastWidthProperty, element.GetValue(Avalonia.Controls.ColumnDefinition.WidthProperty));
+            _ = element.SetValue(Avalonia.Controls.ColumnDefinition.WidthProperty, ZeroWidth);
+        }
+        return visibility;
+    });
+
+    private static readonly Avalonia.Controls.GridLength ZeroWidth = new Avalonia.Controls.GridLength(0, Avalonia.Controls.GridUnitType.Pixel);
+
+    private static readonly AttachedProperty<Avalonia.Controls.GridLength?> LastWidthProperty = AvaloniaProperty.RegisterAttached<Avalonia.Controls.ColumnDefinition, Avalonia.Controls.GridLength?>("LastWidth", typeof(ColumnDefinition), default);
+
+    public static bool GetIsVisible(Avalonia.Controls.ColumnDefinition columnDefinition)
+    {
+        return columnDefinition.GetValue(IsVisibleProperty);
+    }
+
+    public static void SetIsVisible(Avalonia.Controls.ColumnDefinition columnDefinition, bool visibility)
+    {
+        _ = columnDefinition.SetValue(IsVisibleProperty, visibility);
+    }
+}

src/Markdowser/Utilities/Configuration.cs

@@ -0,0 +1,12 @@
+using System;
+using System.IO;
+
+namespace Markdowser.Utilities;
+
+internal static class Configuration
+{
+    public static string DownloadPath => Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
+    public static string ApplicationDataPath => Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), nameof(Markdowser));
+
+    public static string SettingsFilePath => Path.Combine(ApplicationDataPath, "settings.json");
+}

src/Markdowser/Utilities/GlobalState.cs

@@ -0,0 +1,51 @@
+using Avalonia.Controls;
+
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Diagnostics.CodeAnalysis;
+
+namespace Markdowser.Utilities;
+
+[SuppressMessage("Major Code Smell", "S4220:Events should have proper arguments", Justification = "<Pending>")]
+internal static class GlobalState
+{
+    public static event EventHandler<string>? UrlChanged;
+
+    public static event EventHandler? ContentReload;
+
+    private static string url = string.Empty;
+
+    public static Stack<string> BackHistory { get; } = new();
+
+    public static Stack<string> ForwardHistory { get; } = new();
+
+    public static string Url
+    {
+        get => url;
+        set
+        {
+            if (url != value)
+            {
+                BackHistory.Push(url);
+                ForwardHistory.Clear();
+            }
+
+            url = value;
+            UrlChanged?.Invoke(null, url);
+        }
+    }
+
+    public static ObservableCollection<TabItem> Tabs { get; internal set; } = [new TabItem() { Header = "New Tab" }];
+
+    internal static void SetUrl(object sender, string url)
+    {
+        GlobalState.url = url;
+        UrlChanged?.Invoke(sender, url);
+    }
+
+    internal static void ReloadContent(object sender)
+    {
+        ContentReload?.Invoke(sender, EventArgs.Empty);
+    }
+}

src/Markdowser/Utilities/HttpPathResolver.cs

@@ -0,0 +1,58 @@
+using Avalonia.Platform;
+
+using Markdown.Avalonia.Utils;
+using Markdowser.Models;
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Net.Http;
+using System.Threading.Tasks;
+
+namespace Markdowser.Utilities;
+
+public class HttpPathResolver : IPathResolver
+{
+    private readonly HttpClient httpClient = new();
+    public string? AssetPathRoot { get; set; }
+    public IEnumerable<string>? CallerAssemblyNames { get; set; }
+
+    public async Task<Stream?>? ResolveImageResource(string relativeOrAbsolutePath)
+    {
+        if (string.IsNullOrWhiteSpace(relativeOrAbsolutePath))
+        {
+            return GetLogo();
+        }
+
+        if (relativeOrAbsolutePath.StartsWith("avares://"))
+        {
+            return AssetLoader.Open(new Uri(relativeOrAbsolutePath))!;
+        }
+
+        if (!Uri.IsWellFormedUriString(relativeOrAbsolutePath, UriKind.Absolute))
+        {
+            relativeOrAbsolutePath = new Uri(new Uri(GlobalState.Url), relativeOrAbsolutePath).ToString();
+        }
+
+        Debug.WriteLine($"Resolving image: {relativeOrAbsolutePath}");
+
+        HttpResponseMessage httpResponseMessage = await httpClient.GetAsync(relativeOrAbsolutePath)!;
+
+        if (!httpResponseMessage.IsSuccessStatusCode)
+        {
+            return GetLogo();
+        }
+
+        return await httpResponseMessage.Content.ReadAsStreamAsync();
+    }
+
+    private static Stream GetLogo()
+    {
+        if (Settings.Current.DarkMode)
+        {
+            return AssetLoader.Open(new Uri("avares://Markdowser/Assets/Markdowser-Dark-Transparent.png"))!;
+        }
+
+        return AssetLoader.Open(new Uri("avares://Markdowser/Assets/Markdowser-Light-Transparent.png"))!;
+    }
+}

src/Markdowser/ViewLocator.cs

@@ -0,0 +1,34 @@
+using Avalonia.Controls;
+using Avalonia.Controls.Templates;
+
+using Markdowser.ViewModels;
+
+using System;
+
+namespace Markdowser;
+public class ViewLocator : IDataTemplate
+{
+
+    public Control? Build(object? data)
+    {
+        if (data is null)
+            return null;
+
+        var name = data.GetType().FullName!.Replace("ViewModel", "View", StringComparison.Ordinal);
+        var type = Type.GetType(name);
+
+        if (type != null)
+        {
+            var control = (Control)Activator.CreateInstance(type)!;
+            control.DataContext = data;
+            return control;
+        }
+
+        return new TextBlock { Text = "Not Found: " + name };
+    }
+
+    public bool Match(object? data)
+    {
+        return data is ViewModelBase;
+    }
+}

src/Markdowser/ViewModels/MainWindowViewModel.cs

@@ -0,0 +1,325 @@
+using Avalonia.Controls;
+using Avalonia.Threading;
+
+using HtmlAgilityPack;
+
+using Markdowser.Models;
+using Markdowser.Utilities;
+
+using ReactiveUI;
+
+using System;
+using System.Collections.ObjectModel;
+using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
+using System.IO;
+using System.Linq;
+using System.Net.Http;
+using System.Reflection;
+using System.Text;
+using System.Text.RegularExpressions;
+using System.Threading.Tasks;
+using System.Windows.Input;
+
+namespace Markdowser.ViewModels;
+
+public partial class MainWindowViewModel : ViewModelBase
+{
+    private readonly HttpClient httpClient = new(new HttpClientHandler() { AllowAutoRedirect = true });
+    private readonly ReverseMarkdown.Converter markdownConverter = new();
+
+    private readonly StringBuilder html = new();
+    private StringBuilder? content;
+    private TabItem currentTab = null!;
+    private bool showSidePanel;
+    private bool isBusy;
+    private int progress;
+    public ObservableCollection<TabItem> Tabs => GlobalState.Tabs;
+    public string Title => $"{nameof(Markdowser)} - {Assembly.GetExecutingAssembly().GetName().Version?.ToString()}";
+
+    public TabItem CurrentTab
+    {
+        get => currentTab;
+        set
+        {
+            if (currentTab is not null)
+            {
+                currentTab.Tag = Url;
+            }
+
+            _ = this.RaiseAndSetIfChanged(ref currentTab!, value);
+
+            Url = currentTab?.Tag?.ToString() ?? string.Empty;
+
+            FetchUrl();
+        }
+    }
+
+    public StringBuilder Content
+    {
+        get => content ?? DefaultContent;
+        set => this.RaiseAndSetIfChanged(ref content, value);
+    }
+
+    public string Url
+    {
+        get => GlobalState.Url;
+        set => GlobalState.SetUrl(this, value);
+    }
+
+    public bool ShowSidePanel
+    {
+        get => showSidePanel;
+        set => this.RaiseAndSetIfChanged(ref showSidePanel, value);
+    }
+
+    public bool IsBusy
+    {
+        get => isBusy;
+        set => this.RaiseAndSetIfChanged(ref isBusy, value);
+    }
+
+    public int Progress
+    {
+        get => progress;
+        set
+        {
+            _ = this.RaiseAndSetIfChanged(ref progress, value);
+            this.RaisePropertyChanged(nameof(ProgressIndeterminate));
+        }
+    }
+
+    public SettingsViewModel SettingsViewModel => new SettingsViewModel();
+    public RawHtmlViewModel RawHtmlViewModel => new RawHtmlViewModel(html);
+    public RawMarkdownViewModel RawMarkdownViewModel => new RawMarkdownViewModel(() => Content);
+    public bool CloseTabEnabled => Tabs.Count > 1;
+    public bool BackEnabled => GlobalState.BackHistory.Count > 0;
+    public bool ForwardEnabled => GlobalState.ForwardHistory.Count > 0;
+    public bool ProgressIndeterminate => Progress == 0;
+    public ICommand Browse => ReactiveCommand.Create(FetchUrl);
+
+    public ICommand Back => ReactiveCommand.Create(() =>
+    {
+        if (GlobalState.BackHistory.Count > 0)
+        {
+            GlobalState.ForwardHistory.Push(GlobalState.Url);
+            Url = GlobalState.BackHistory.Pop();
+            FetchUrl();
+
+            this.RaisePropertyChanged(nameof(BackEnabled));
+            this.RaisePropertyChanged(nameof(ForwardEnabled));
+        }
+    });
+
+    public ICommand Forward => ReactiveCommand.Create(() =>
+    {
+        if (GlobalState.ForwardHistory.Count > 0)
+        {
+            GlobalState.BackHistory.Push(GlobalState.Url);
+            Url = GlobalState.ForwardHistory.Pop();
+            FetchUrl();
+
+            this.RaisePropertyChanged(nameof(ForwardEnabled));
+            this.RaisePropertyChanged(nameof(BackEnabled));
+        }
+    });
+
+    public ICommand ToggleSidePanel => ReactiveCommand.Create(() => ShowSidePanel = !ShowSidePanel);
+
+    public ICommand CloseTab => ReactiveCommand.Create(() =>
+    {
+        if (Tabs.Count > 1)
+        {
+            int currentIndex = Tabs.IndexOf(CurrentTab);
+            _ = Tabs.Remove(CurrentTab);
+
+            CurrentTab = currentIndex > 0 ? Tabs[currentIndex - 1] : Tabs[0];
+            this.RaisePropertyChanged(nameof(CloseTabEnabled));
+        }
+    });
+
+    public ICommand NewTab => ReactiveCommand.Create(() =>
+    {
+        TabItem tab = new() { Header = "New Tab", Name = Guid.NewGuid().ToString() };
+        Tabs.Add(tab);
+        CurrentTab = tab;
+        this.RaisePropertyChanged(nameof(CloseTabEnabled));
+    });
+
+    private StringBuilder DefaultContent => new StringBuilder()
+        .AppendLine($"![Logo](avares://Markdowser/Assets/Markdowser-{(Settings.Current.DarkMode ? "Dark" : "Light")}-Transparent.png)")
+        .AppendLine()
+        .AppendLine($"{nameof(Markdowser)} {Assembly.GetExecutingAssembly().GetName().Version?.ToString()}\n")
+        .AppendLine("A markdown web browser.\n")
+        .AppendLine("[GitHub](https://github.me.stone-red.net/Markdowser)");
+
+    public MainWindowViewModel()
+    {
+        httpClient.DefaultRequestHeaders.UserAgent.ParseAdd($"{nameof(Markdowser)}/{Assembly.GetExecutingAssembly().GetName().Version?.ToString()}");
+        httpClient.Timeout = TimeSpan.FromSeconds(10);
+
+        markdownConverter.Config.UnknownTags = ReverseMarkdown.Config.UnknownTagsOption.Bypass;
+        markdownConverter.Config.SuppressDivNewlines = false;
+        markdownConverter.Config.SmartHrefHandling = false;
+
+        GlobalState.UrlChanged += (sender, url) =>
+        {
+            this.RaisePropertyChanged(nameof(ForwardEnabled));
+            this.RaisePropertyChanged(nameof(BackEnabled));
+            this.RaisePropertyChanged(nameof(Url));
+
+            if (sender == this)
+            {
+                return;
+            }
+
+            FetchUrl();
+        };
+
+        GlobalState.ContentReload += (sender, _) =>
+        {
+            this.RaisePropertyChanged(nameof(Content));
+        };
+    }
+
+    private static bool IsValidHttpUri(string uriString, [NotNullWhen(true)] out Uri? uri)
+    {
+        return Uri.TryCreate(uriString, UriKind.Absolute, out uri) && (uri.Scheme == Uri.UriSchemeHttp || uri.Scheme == Uri.UriSchemeHttps);
+    }
+
+    [GeneratedRegex("!\\[(.*?)\\]\\((.*?)\\)")]
+    private static partial Regex MarkdownImage();
+
+    private void FetchUrl()
+    {
+        if (string.IsNullOrWhiteSpace(Url))
+        {
+            content = null;
+            _ = html.Clear();
+            ContentChanged();
+            Debug.WriteLine("URL is empty.");
+            CurrentTab.Header = "New Tab";
+            return;
+        }
+
+        if (!IsValidHttpUri(Url, out _))
+        {
+            // Search with duckduckgo
+            Url = $"https://duckduckgo.com/html/?kd=-1&k1=-1&q={Uri.EscapeDataString(Url)}";
+        }
+
+        content ??= new StringBuilder();
+        _ = content.Clear();
+        _ = html.Clear();
+
+        IsBusy = true;
+        Progress = 0;
+
+        _ = Task.Run(async () =>
+        {
+            Debug.WriteLine("Fetching URL...");
+
+            try
+            {
+                HttpResponseMessage httpResponseMessage = await httpClient.GetAsync(Url);
+
+                Url = httpResponseMessage.RequestMessage?.RequestUri?.ToString() ?? Url;
+
+                if (!httpResponseMessage.IsSuccessStatusCode)
+                {
+                    IsBusy = false;
+                    _ = content.AppendLine($"# {(int)httpResponseMessage.StatusCode} {httpResponseMessage.StatusCode}");
+                    _ = content.AppendLine($"Failed to fetch URL: {httpResponseMessage.ReasonPhrase}");
+                    ContentChanged();
+                    return;
+                }
+
+                long length = httpResponseMessage.Content.Headers.ContentLength ?? 0;
+
+                using Stream contentStream = await httpResponseMessage.Content.ReadAsStreamAsync();
+                using StreamReader streamReader = new(contentStream);
+
+                while (!streamReader.EndOfStream)
+                {
+                    _ = html.AppendLine(await streamReader.ReadLineAsync());
+                    Progress = (int)((double)contentStream.Position / length * 100);
+                }
+
+                HtmlDocument htmlDoc = new HtmlDocument();
+                htmlDoc.LoadHtml(html.ToString());
+                string title = htmlDoc.DocumentNode.SelectSingleNode("html/head/title")?.InnerText ?? Url;
+
+                Dispatcher.UIThread.Post(() =>
+                {
+                    CurrentTab.Header = title?.Trim() ?? Url;
+                });
+            }
+            catch (HttpRequestException e)
+            {
+                IsBusy = false;
+
+                if (e.StatusCode is not null)
+                {
+                    _ = content.AppendLine($"# {(int)e.StatusCode} {e.StatusCode}");
+                }
+
+                _ = content.AppendLine($"# {e.HttpRequestError}");
+                _ = content.AppendLine($"Failed to fetch URL: {e.Message}");
+                ContentChanged();
+            }
+            catch (Exception e)
+            {
+                IsBusy = false;
+                _ = content.AppendLine($"# {e.GetType().Name}");
+                _ = content.AppendLine($"Failed to fetch URL: {e.Message}");
+                ContentChanged();
+            }
+
+            Progress = 0;
+
+            Debug.WriteLine("Converting HTML to markdown...");
+
+            string markdown = markdownConverter.Convert(html.ToString());
+
+            Debug.WriteLine("Processing markdown...");
+
+            int currentLine = 0;
+
+            string[] lines = markdown.Split('\n');
+            foreach (string line in lines)
+            {
+                Progress = (int)((double)currentLine / lines.Length * 100);
+                currentLine++;
+
+                string trimmedLine = line.Trim();
+
+                if (trimmedLine.All(c => c == '#'))
+                {
+                    _ = Content.Append(trimmedLine);
+                    continue;
+                }
+                else if (MarkdownImage().IsMatch(trimmedLine))
+                {
+                    _ = content.AppendLine()
+                    .Append(trimmedLine)
+                    .AppendLine()
+                    .AppendLine();
+                    continue;
+                }
+
+                _ = content.AppendLine(trimmedLine);
+            }
+
+            ContentChanged();
+
+            IsBusy = false;
+        });
+    }
+
+    private void ContentChanged()
+    {
+        this.RaisePropertyChanged(nameof(Content));
+        this.RaisePropertyChanged(nameof(RawHtmlViewModel));
+        this.RaisePropertyChanged(nameof(RawMarkdownViewModel));
+    }
+}

src/Markdowser/ViewModels/RawHtmlViewModel.cs

@@ -0,0 +1,8 @@
+using System.Text;
+
+namespace Markdowser.ViewModels;
+
+public class RawHtmlViewModel(StringBuilder html) : ViewModelBase
+{
+    public StringBuilder Html => html;
+}

src/Markdowser/ViewModels/RawMarkdownViewModel.cs

@@ -0,0 +1,9 @@
+using System;
+using System.Text;
+
+namespace Markdowser.ViewModels;
+
+public class RawMarkdownViewModel(Func<StringBuilder> markdown) : ViewModelBase
+{
+    public StringBuilder Markdown => markdown();
+}

src/Markdowser/ViewModels/SettingsViewModel.cs

@@ -0,0 +1,18 @@
+using Markdowser.Models;
+
+namespace Markdowser.ViewModels;
+
+public class SettingsViewModel : ViewModelBase
+{
+    public string? HomeUrl
+    {
+        get => Settings.Current.HomeUrl;
+        set => Settings.Current.HomeUrl = value;
+    }
+
+    public bool DarkMode
+    {
+        get => Settings.Current.DarkMode;
+        set => Settings.Current.DarkMode = value;
+    }
+}

src/Markdowser/ViewModels/ViewModelBase.cs

@@ -0,0 +1,6 @@
+using ReactiveUI;
+
+namespace Markdowser.ViewModels;
+public class ViewModelBase : ReactiveObject
+{
+}

src/Markdowser/Views/MainWindow.axaml

@@ -0,0 +1,138 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:vm="using:Markdowser.ViewModels"
+        xmlns:cmd="using:Markdowser.Commands"
+        xmlns:utils="using:Markdowser.Utilities"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        xmlns:md="https://github.com/whistyun/Markdown.Avalonia"
+        xmlns:ctxt="clr-namespace:ColorTextBlock.Avalonia;assembly=ColorTextBlock.Avalonia"
+        xmlns:i="https://github.com/projektanker/icons.avalonia"
+        mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
+        x:Class="Markdowser.Views.MainWindow"
+        x:DataType="vm:MainWindowViewModel"
+        Icon="/Assets/Markdowser-Light-Transparent.ico"
+        Title="{Binding Title}">
+
+    <Design.DataContext>
+        <!-- This only sets the DataContext for the previewer in an IDE,
+             to set the actual DataContext for runtime, set the DataContext property in code (look at App.axaml.cs) -->
+        <vm:MainWindowViewModel />
+    </Design.DataContext>
+
+    <Window.Resources>
+        <ResourceDictionary>
+            <ResourceDictionary.MergedDictionaries>
+                <ResourceDictionary>
+                    <utils:HttpPathResolver x:Key="HttpPathResolver" />
+                    <cmd:HyperlinkCommand x:Key="HyperlinkCommand" />
+                    <cmd:ChangeThemeCommand x:Key="ChangeThemeCommand" />
+                    <cmd:HomeCommand x:Key="HomeCommand" />
+                </ResourceDictionary>
+            </ResourceDictionary.MergedDictionaries>
+        </ResourceDictionary>
+    </Window.Resources>
+
+    <Grid RowDefinitions="Auto, *, Auto">
+        <Grid Grid.Row="0" ColumnDefinitions="*, Auto, Auto">
+            <TabControl Grid.Column="0" Theme="{DynamicResource ScrollTabControl}" SelectedItem="{Binding CurrentTab, Mode=TwoWay}" ItemsSource="{Binding Tabs}" />
+            <Button Grid.Column="1" Command="{Binding CloseTab}" IsEnabled="{Binding CloseTabEnabled}" HorizontalAlignment="Right" VerticalAlignment="Top" Height="32" i:Attached.Icon="fa-solid fa-xmark" />
+            <Button Grid.Column="2" Command="{Binding NewTab}" HorizontalAlignment="Right" VerticalAlignment="Top" Height="32" i:Attached.Icon="fa-solid fa-plus" />
+        </Grid>
+
+        <Grid Grid.Row="1">
+            <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="*" />
+                <ColumnDefinition Width="Auto" />
+                <ColumnDefinition Width="*" utils:ColumnDefinition.IsVisible="{Binding ShowSidePanel}" />
+            </Grid.ColumnDefinitions>
+
+            <md:MarkdownScrollViewer Margin="10 0 10 10" IsEnabled="{Binding !IsBusy}" Markdown="{Binding Content}">
+                <md:MarkdownScrollViewer.Styles>
+                    <Style Selector="ctxt|CTextBlock">
+                        <Setter Property="Foreground" Value="{DynamicResource SemiColorText0}" />
+                    </Style>
+                    <Style Selector="ctxt|CTextBlock.Heading1">
+                        <Setter Property="Foreground" Value="{DynamicResource SemiColorText0}" />
+                    </Style>
+                    <Style Selector="ctxt|CTextBlock.Heading2">
+                        <Setter Property="Foreground" Value="{DynamicResource SemiColorText0}" />
+                    </Style>
+                    <Style Selector="ctxt|CTextBlock.Heading3">
+                        <Setter Property="Foreground" Value="{DynamicResource SemiColorText0}" />
+                    </Style>
+                    <Style Selector="ctxt|CTextBlock.Heading4">
+                        <Setter Property="Foreground" Value="{DynamicResource SemiColorText0}" />
+                    </Style>
+                    <Style Selector="ctxt|CTextBlock.Heading5">
+                        <Setter Property="Foreground" Value="{DynamicResource SemiColorText0}" />
+                    </Style>
+                    <Style Selector="ctxt|CTextBlock.Heading6">
+                        <Setter Property="Foreground" Value="{DynamicResource SemiColorText0}" />
+                    </Style>
+                    <Style Selector="ctxt|CHyperlink">
+                        <Setter Property="Foreground" Value="{DynamicResource SemiColorLink}" />
+                    </Style>
+                    <Style Selector="ctxt|CHyperlink:pointerover">
+                        <Setter Property="Foreground" Value="{DynamicResource SemiColorLinkPointerover}" />
+                    </Style>
+                    <Style Selector="ctxt|CHyperlink:pressed">
+                        <Setter Property="Foreground" Value="{DynamicResource SemiColorLinkVisited}" />
+                    </Style>
+                    <Style Selector="ctxt|CImage">
+                        <Setter Property="FittingWhenProtrude" Value="True" />
+                        <Setter Property="LayoutWidth" Value="500" />
+                        <Setter Property="SaveAspectRatio" Value="True" />
+                    </Style>
+                </md:MarkdownScrollViewer.Styles>
+                <md:MarkdownScrollViewer.Plugins>
+                    <md:MdAvPlugins PathResolver="{StaticResource HttpPathResolver}" HyperlinkCommand="{StaticResource HyperlinkCommand}" />
+                </md:MarkdownScrollViewer.Plugins>
+            </md:MarkdownScrollViewer>
+            <GridSplitter Grid.Column="1" IsVisible="{Binding ShowSidePanel}" Background="{DynamicResource SemiColorTertiary}" ResizeDirection="Columns" />
+            <TabControl  Grid.Column="2" IsVisible="{Binding ShowSidePanel}" Margin="10">
+                <TabItem Header="Settings">
+                    <ScrollViewer>
+                        <ContentControl Margin="0 10 0 0" Content="{Binding SettingsViewModel}" />
+                    </ScrollViewer>
+                </TabItem>
+                <TabItem Header="Markdown">
+                    <ScrollViewer>
+                        <ContentControl Margin="0 10 0 0" Content="{Binding RawMarkdownViewModel}" />
+                    </ScrollViewer>
+                </TabItem>
+                <TabItem Header="HTML">
+                    <ScrollViewer>
+                        <ContentControl Margin="0 10 0 0" Content="{Binding RawHtmlViewModel}" />
+                    </ScrollViewer>
+                </TabItem>
+            </TabControl>
+        </Grid>
+
+        <Border Grid.Row="2" BorderThickness="0 2 0 0" CornerRadius="0" BorderBrush="{DynamicResource SemiColorTertiary}">
+            <Grid ColumnDefinitions="Auto, Auto, Auto, Auto, *, Auto">
+                <Button Grid.Column="0" i:Attached.Icon="fa-solid fa-caret-left" IsEnabled="{Binding BackEnabled}" Command="{Binding Back}" />
+                <Button Grid.Column="1" i:Attached.Icon="fa-solid fa-caret-right" IsEnabled="{Binding ForwardEnabled}" Command="{Binding Forward}" />
+                <Button Grid.Column="2" i:Attached.Icon="fa-solid fa-rotate-right" Command="{Binding Browse}" />
+                <Button Grid.Column="3" i:Attached.Icon="fa-solid fa-house" Command="{StaticResource HomeCommand}" />
+
+                <Grid Grid.Column="4">
+                    <TextBox x:Name="urlBar" IsVisible="{Binding !IsBusy}" Watermark="Search DuckDuckGo or type a URL" Text="{Binding Url}" BorderThickness="0">
+                        <TextBox.KeyBindings>
+                            <KeyBinding Gesture="Enter" Command="{Binding Browse}" />
+                        </TextBox.KeyBindings>
+                        <TextBox.Styles>
+                            <Style Selector="TextBox:focus /template/ Border#PART_BorderElement">
+                                <Setter Property="BorderThickness" Value="0" />
+                            </Style>
+                        </TextBox.Styles>
+                    </TextBox>
+
+                    <ProgressBar IsVisible="{Binding IsBusy}" IsIndeterminate="{Binding ProgressIndeterminate}" ShowProgressText="{Binding !ProgressIndeterminate}" Maximum="100" Height="32" Grid.Row="2" Value="{Binding Progress}" />
+                </Grid>
+
+                <Button Grid.Column="5" Command="{Binding ToggleSidePanel}" HorizontalAlignment="Right" i:Attached.Icon="fa-solid fa-table-columns" />
+            </Grid>
+        </Border>
+    </Grid>
+</Window>

src/Markdowser/Views/MainWindow.axaml.cs

@@ -0,0 +1,11 @@
+using Avalonia.Controls;
+
+namespace Markdowser.Views;
+
+public partial class MainWindow : Window
+{
+    public MainWindow()
+    {
+        InitializeComponent();
+    }
+}

src/Markdowser/Views/RawHtmlView.axaml

@@ -0,0 +1,10 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:vm="using:Markdowser.ViewModels"
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+             mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
+             x:DataType="vm:RawHtmlViewModel"
+             x:Class="Markdowser.Views.RawHtmlView">
+    <SelectableTextBlock Text="{Binding Html}" TextWrapping="Wrap" />
+</UserControl>

src/Markdowser/Views/RawHtmlView.axaml.cs

@@ -0,0 +1,11 @@
+using Avalonia.Controls;
+
+namespace Markdowser.Views;
+
+public partial class RawHtmlView : UserControl
+{
+    public RawHtmlView()
+    {
+        InitializeComponent();
+    }
+}

src/Markdowser/Views/RawMarkdownView.axaml

@@ -0,0 +1,10 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:vm="using:Markdowser.ViewModels"
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+             mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
+             x:DataType="vm:RawMarkdownViewModel"
+             x:Class="Markdowser.Views.RawMarkdownView">
+    <SelectableTextBlock Text="{Binding Markdown}" TextWrapping="Wrap" />
+</UserControl>

src/Markdowser/Views/RawMarkdownView.axaml.cs

@@ -0,0 +1,11 @@
+using Avalonia.Controls;
+
+namespace Markdowser.Views;
+
+public partial class RawMarkdownView : UserControl
+{
+    public RawMarkdownView()
+    {
+        InitializeComponent();
+    }
+}

src/Markdowser/Views/SettingsView.axaml

@@ -0,0 +1,29 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:vm="using:Markdowser.ViewModels"
+             xmlns:cmd="using:Markdowser.Commands"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+             xmlns:i="https://github.com/projektanker/icons.avalonia"
+             mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
+             x:DataType="vm:SettingsViewModel"
+             x:Class="Markdowser.Views.SettingsView">
+
+    <UserControl.Resources>
+        <ResourceDictionary>
+            <ResourceDictionary.MergedDictionaries>
+                <ResourceDictionary>
+                    <cmd:ChangeThemeCommand x:Key="ChangeThemeCommand" />
+                </ResourceDictionary>
+            </ResourceDictionary.MergedDictionaries>
+        </ResourceDictionary>
+    </UserControl.Resources>
+
+    <StackPanel Spacing="10">
+        <TextBlock Text="Dark Mode" />
+        <ToggleSwitch IsChecked="{Binding DarkMode}" Command="{StaticResource ChangeThemeCommand}" />
+
+        <TextBlock Text="Home URL" />
+        <TextBox Text="{Binding HomeUrl}" Watermark="URL, or leave empty to use default" />
+    </StackPanel>
+</UserControl>

src/Markdowser/Views/SettingsView.axaml.cs

@@ -0,0 +1,11 @@
+using Avalonia.Controls;
+
+namespace Markdowser.Views;
+
+public partial class SettingsView : UserControl
+{
+    public SettingsView()
+    {
+        InitializeComponent();
+    }
+}

src/Markdowser/app.manifest

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
+  <!-- This manifest is used on Windows only.
+       Don't remove it as it might cause problems with window transparency and embedded controls.
+       For more details visit https://learn.microsoft.com/en-us/windows/win32/sbscs/application-manifests -->
+  <assemblyIdentity version="1.0.0.0" name="Markdowser.Desktop"/>
+
+  <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
+    <application>
+      <!-- A list of the Windows versions that this application has been tested on
+           and is designed to work with. Uncomment the appropriate elements
+           and Windows will automatically select the most compatible environment. -->
+
+      <!-- Windows 10 -->
+      <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}" />
+    </application>
+  </compatibility>
+</assembly>