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Terminal User Guide

XenoAtom.Terminal.UI is a modern retained-mode terminal UI framework built on top of XenoAtom.Terminal. It supports both:

  • Inline widgets that render as part of normal terminal output (Terminal.Write, Terminal.Live)
  • Fullscreen applications (alternate screen, focus navigation, routed input, dialogs, etc.)

This guide documents the concepts, features, and controls of the library.

Fullscreen demo screenshot

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 the hosting APIs are available as Terminal.Write(...), Terminal.Live(...), and Terminal.Run(...) on the Terminal type coming from the XenoAtom.Terminal package.

Quick start

Ecosystem

Terminal.UI is built on:

  • XenoAtom.Terminal - terminal I/O, input events, hosting (inline + fullscreen)
  • XenoAtom.Ansi - ANSI/VT primitives and markup used by the Markup control and parsers

See also:

Hosting & integration

  • Hosting (inline vs fullscreen, update loops)
  • Prompts (inline prompts built on top of Terminal.Live)

Core concepts

  • Visual Tree (Visuals, fluent API, dynamic composition)
  • Binding (State<T>, bindable properties, dependency tracking)
  • Data Templating (DataTemplates, DataPresenter, item templates)
  • Culture (culture-aware value formatting)
  • Layout (layout protocol, alignment, margin/padding)
  • Input (keyboard/mouse, focus, routed events, capture)
  • Commands (commands, key sequences, key hints with CommandBar)
  • Styling (Theme, styles, environment, brushes/gradients)
  • Rendering (cell buffer, diff renderer, performance)
  • Scrolling (ScrollViewer, scroll models, scrollbars)
  • Text Editing (TextBox/TextArea/MaskedInput and the text subsystem)
  • Undo/Redo (undo/redo for text editors)
  • Markup (markup syntax, semantic tokens, MarkupTextParser)
  • Overlays (dialogs, popups, backdrops, tooltips, toasts)
  • Nerd Font icons (generated Rune helpers for official Nerd Fonts glyphs)
  • Debugging (debug overlay, performance metrics)

Controls reference

Samples

The samples folder contains end-to-end demos:

  • Demos (screenshots, videos, and GitHub links)
  • samples/FullscreenDemo: fullscreen UI showcase.
  • samples/ControlsDemo: catalog-style demo.
  • samples/InlineLiveDemo: inline/live example (interactive).

Specs and design notes

The site/docs/specs folder contains deeper design documents and implementation notes used during development: