nctui - C++20 Terminal UI Framework

This is an Text User Interface (TUI) framework which provides a rich set of widgets for building sophisticated text-based user interfaces in the terminal. This framework leverages notcurses for rendering.

It is a C++20 port of a Terminal UI framework originally created for the Mono project as part of MonoCurses by Miguel de Icaza (see his original blog post). Later it was - still using ncurses - ported to D.

Overview

nctui is a C++20 module-based framework. It offers:

• Module-based architecture using C++20's module system
• Comprehensive widget library including buttons, labels, text entries, dialogs, menus, and more
• Event-driven input handling with keyboard and mouse support
• Main loop integration for application lifecycle management
• Container-based layout system for building complex UIs

Features

Widgets

Widget	Description
Button	Clickable button with customizable text
Label	Static text display
TrimLabel	Label with automatic text trimming
Docbrowser	AsciiDoc document browser
Checkbox	Toggleable checkbox
Entry	Single-line text input
Combobox	Multi-select that shows selection
TextView	Multi-line text display and editing
ListView	Scrollable list of items
ProgressBar	Visual progress indicator
Frame	Container with border and title
Dialog	Modal dialog windows
MessageBox	Pre-configured message dialogs
MenuBar	Drop-down menu system
RadioGroup	Group of mutually exclusive radio buttons
Container	Base class for custom widget containers

Requirements

• C++20 compliant compiler (GCC 11+, Clang 14+, MSVC 19.29+)
• notcurses (via notcurses++ C++ bindings)
• xmake build system

Quick Start

Building

The project uses xmake as its build system:

# Install dependencies (notcurses and notcurses++)# On Ubuntu/Debian:
sudo apt-get install libnotcurses-dev notcurses++-dev
# Build the library and examples
xmake
# Run a specific example
xmake run simple_example
xmake run mainloop_example
xmake run menu_example
xmake run tui_example

Examples

The examples/ directory contains several examples demonstrating various features of nctui:

Example	Description	Widgets Used
simple.cpp	Minimal nctui application showing basic widget usage	Container, Label, Entry
mainloop.cpp	Demonstrates the MainLoop class with timer-based events	MainLoop (no UI widgets)
menu.cpp	Shows a menu bar with drop-down menus and a read-only text viewer	MenuBar, MenuBarItem, MenuItem, Frame, TextView, Dialog, DocBrowser, Button
tui.cpp	Full torrent-manager-style TUI with resizable multi-pane layout	Container, Frame, Button, ListView, Label, TrimLabel, ProgressBar, Entry, RadioGroup, ComboBox, Dialog, plus custom LogWidget

Example Highlights

• simple.cpp: Perfect starting point. Creates a container with a label and an editable entry field.
• mainloop.cpp: Demonstrates timer management with addTimeout() for scheduled callbacks.
• menu.cpp: Features a complete menu system with File (Exit) and Help (About, Index) menus. The Index menu opens a DocBrowser dialog to view AsciiDoc documentation, and this README.md is displayed in a read-only TextView in the main window.
• tui.cpp: A comprehensive demo showcasing advanced features including:
  • Multi-pane layout with draggable resizable frames
  • Status panel with ProgressBar and multiple Label widgets
  • Options dialog with Entry fields, RadioGroup, and ComboBox for theme selection
  • Live theme switching with preview
  • Input validation for dialog fields
  • Custom LogWidget demonstrating how to create custom widgets
  • Timer-based status updates and logging
  • Add dialog for file selection with validation

For detailed usage information, module imports, input handling, focus management, dialogs, and menu system documentation, please refer to the AsciiDoc documentation in the docs/ folder.

Documentation

The docs/ directory contains comprehensive AsciiDoc documentation covering:

• Usage: Project setup, module imports, and requirements
• Widgets: Complete widget reference with examples
• Input Handling: Key processing phases and hot keys
• Focus Management: Widget focus and navigation
• Dialogs: Message boxes and dialog widgets
• Menu System: Menu bar and drop-down menus
• Themes: Color themes and styling

License

MIT License - see project root for full text.

Contributing

Contributions are welcome! Please ensure:

• Code follows the existing style and conventions
• C++20 features are used appropriately
• Module interfaces are clean and well-organized