XenoAtom.Terminal.UI

XenoAtom.Terminal.UI is a modern, reactive retained-mode terminal UI framework for .NET, built on top of XenoAtom.Terminal. It provides a rich set of controls (TextBox, TextArea, lists, tables, dialogs…), a consistent layout system, a styling/theming model, and a binding system designed for smooth live UIs.

✨ Features

• Two hosting models:
  • Inline widgets via Terminal.Write(...) and Terminal.Live(...)
  • Fullscreen apps via Terminal.Run(...) (alternate screen + input loop)
• Modern control library (60+ built-in controls):
  • Buttons, toggles, lists, tables, tabs, menus, dialogs/popups, toasts, charts, progress, spinners, tooltips…
  • Text editing: TextBox, TextArea, MaskedInput, NumberBox (undo/redo: Ctrl+Z / Ctrl+R)
  • Advanced widgets: LogControl, CommandPalette, BreakdownChart, ColorPicker
  • Mockup/empty-state widget: Placeholder (text + background surfaces, gradients)
  • Companion extension package: XenoAtom.Terminal.UI.Extensions.Markdown (MarkdownControl, MarkdownMarkupConverter with source-preserving highlight mode)
• Binding-first UI:
  • Bindable properties, State<T>, automatic dependency tracking, minimal boilerplate
• Layout system: consistent measure/arrange protocol (integer cell UI), panels and containers
• Styling, themes, and color schemes:
  • Theme + per-control styles, ColorScheme palettes (terminal-native and RGB themes)
  • Brush gradients for controls such as TextBlock, TextBox, and TextFiglet
  • RootLoops-powered color scheme generator (https://rootloops.sh) with many built-in schemes
• Input:
  • Keyboard, mouse, resize events; focus navigation; routed events where appropriate
• Commands & key hints:
  • Context-aware commands with single-stroke gestures and multi-stroke sequences
  • CommandBar control for discoverable shortcuts
• Rendering:
  • Cell-buffer renderer + diffing, efficient batched output, synchronized output (DEC 2026)
  • Alpha-aware colors (RGBA) with blending support for modern UI effects
• Generated glyph helpers:
  • NerdFont exposes the official Nerd Fonts catalog as Rune properties for easy use in TextBlock, Markup, and string interpolation
• Debug overlay:
  • Built-in performance overlay (toggle with F12) to inspect frame timings, invalidation, and diff output
• Cross-platform + AOT-friendly: net10.0 and NativeAOT-oriented design (built on XenoAtom.Terminal)

Note

XenoAtom.Terminal.UI depends on XenoAtom.Terminal. The two libraries are designed to be used together: Terminal handles safe ANSI/markup output and unified input events; Terminal.UI builds a widget/layout system on top.

Requirements (.NET 10 / C# 14)

XenoAtom.Terminal.UI targets net10.0 and requires the .NET 10 SDK (C# 14).

Rationale: the library integrates into XenoAtom.Terminal using C# 14 extension members, so you can write Terminal.Write(...), Terminal.Live(...), and Terminal.Run(...) even though Terminal is defined in the separate XenoAtom.Terminal package.

🚀 Quick start

using XenoAtom.Terminal;
using XenoAtom.Terminal.UI;
using XenoAtom.Terminal.UI.Controls;

Terminal.Write(new Group("Welcome")
    .Content(new VStack("Hello", "from", "Terminal.UI").Spacing(1))
);

Inline “live” widget (updates without clearing your output):

using XenoAtom.Terminal;
using XenoAtom.Terminal.UI;
using XenoAtom.Terminal.UI.Controls;

var work = new ProgressTask("Work");

Terminal.Live(
    new ProgressTaskGroup().Tasks([work]),
    onUpdate: () =>
    {
        work.Value = Math.Min(1, work.Value + 0.01);
        return work.Value < 1
            ? TerminalLoopResult.Continue
            : TerminalLoopResult.StopAndKeepVisual;
    });

Fullscreen app:

using XenoAtom.Terminal;
using XenoAtom.Terminal.UI;
using XenoAtom.Terminal.UI.Controls;

State<string?> text = new("Type here");
State<bool> exit = new(false);

Terminal.Run(
    new VStack(
        new TextBox(text),
        new TextBlock(() => $"The text typed is: {text.Value}"),
        new Button("Exit").Click(() => exit.Value = true)
    ),
    onUpdate: () => exit.Value
        ? TerminalLoopResult.StopAndKeepVisual 
        : TerminalLoopResult.Continue
    );

Brush gradient example:

using XenoAtom.Terminal.UI.Styling;

var brush = Brush.LinearGradient(
    new GradientPoint(0f, 0f),
    new GradientPoint(1f, 0f),
    [new GradientStop(0f, Colors.DeepSkyBlue), new GradientStop(1f, Colors.White)]);

Terminal.Write(
    new TextBlock("Gradient title")
        .Style(TextBlockStyle.Default with { ForegroundBrush = brush })
);

Nerd Font glyph example:

Terminal.Write(
    new Markup($"[accent]{NerdFont.MdHome}[/] Home  [primary]{NerdFont.PlBranch}[/] main  [success]{NerdFont.WeatherDaySunny}[/] Ready")
);

If your terminal/font combination renders Nerd Font glyphs as double-width, set WideRuneResolver = TerminalWideRuneResolvers.NerdFontDoubleWidth on TerminalRunOptions, TerminalLiveOptions, or TerminalAppOptions.

🧩 Controls included

The library ships with a large set of built-in controls. See Controls Reference for the full reference.

Highlights:

• Text input: TextBox, TextArea, MaskedInput, NumberBox, ValidationPresenter
• Lists: ListBox, OptionList, SelectionList, Select<T>, TreeView
• Data: Table, DataGridControl
• Layout: VStack, HStack, Grid, DockLayout, Splitters, Border, Group, Padder
• Overlays: Popup, Dialog, TooltipHost, Backdrop
• Toasts: Toast, ToastHost (overlay notifications)
• Visualization: BarChart, LineChart, Sparkline, Canvas, BreakdownChart, TextFiglet, Placeholder
• Progress: ProgressBar, ProgressTaskGroup, Spinner

📖 User guide

For details, see the dedicated website.

🧪 Samples

• samples/ControlsDemo: catalog-style demo of controls and styles.
• samples/FullscreenDemo: fullscreen UI showcase.
• samples/InlineLiveDemo: inline/live demo (interactive).

🪪 License

This software is released under the BSD-2-Clause license.

🤗 Author

Alexandre Mutel aka xoofx.