Hex1b

Hex1b is a .NET library for building TUI apps using an approachable code-first API.

Installation

dotnet add package Hex1b

Quick Start

Hello World

A minimal application that displays text and a quit button:

using Hex1b;

using var app = new Hex1bApp(ctx =>
    ctx.VStack(b => [
        b.Text("Hello, Terminal!"),
        b.Button("Quit").OnClick(e => e.Context.RequestStop())
    ])
);

await app.RunAsync();

Counter with State

An interactive counter demonstrating mutable state across renders:

using Hex1b;

// State persists outside the builder function
var count = 0;

using var app = new Hex1bApp(ctx =>
    ctx.VStack(b => [
        b.Text($"Count: {count}"),
        b.Button("Increment").OnClick(_ => count++),
        b.Button("Decrement").OnClick(_ => count--),
        b.Text(""),
        b.Button("Quit").OnClick(e => e.Context.RequestStop())
    ])
);

await app.RunAsync();

Counter with Custom Key Bindings

A counter controlled with custom keyboard shortcuts (Ctrl+A to increment, Ctrl+D to decrement):

using Hex1b;
using Hex1b.Input;

var count = 0;

using var app = new Hex1bApp(ctx =>
    ctx.VStack(b => [
        b.Text($"Count: {count}"),
        b.Text(""),
        b.Text("Ctrl+A: Increment"),
        b.Text("Ctrl+D: Decrement"),
        b.Text("Ctrl+Q: Quit")
    ]).InputBindings(bindings =>
    {
        bindings.Ctrl().Key(Hex1bKey.A).Action(() => count++, "Increment counter");
        bindings.Ctrl().Key(Hex1bKey.D).Action(() => count--, "Decrement counter");
        bindings.Ctrl().Key(Hex1bKey.Q).Action(ctx => ctx.RequestStop(), "Quit");
    })
);

await app.RunAsync();

Layout System

Hex1b uses a constraint-based layout system with size hints:

// Vertical stack with flexible sizing
new VStackWidget(
    children: [contentWidget, statusBarWidget],
    sizeHints: [SizeHint.Fill, SizeHint.Content]
);

Size Hints:

• SizeHint.Fill – Expand to fill available space
• SizeHint.Content – Size to fit content
• SizeHint.Fixed(n) – Fixed size of n units
• SizeHint.Weighted(n) – Proportional sizing with weight n

Widgets

Input Bindings

Define keyboard shortcuts using the fluent builder API:

widget.InputBindings(bindings =>
{
    // Simple key
    bindings.Key(Hex1bKey.Delete).Action(() => DeleteItem());
    
    // Modifier keys (any combination)
    bindings.Ctrl().Key(Hex1bKey.S).Action(() => Save(), "Save");
    bindings.Shift().Key(Hex1bKey.Tab).Action(() => FocusPrevious(), "Previous");
    bindings.Ctrl().Shift().Key(Hex1bKey.S).Action(() => SaveAs(), "Save as");
    
    // Multi-step chords
    bindings.Ctrl().Key(Hex1bKey.K)
        .Then().Key(Hex1bKey.C)
        .Action(() => CommentLine(), "Comment line");
});

Theming

Apply built-in themes or create your own:

using Hex1b.Theming;

using var app = new Hex1bApp(
    builder,
    new Hex1bAppOptions { Theme = Hex1bThemes.Sunset }
);

Documentation

• GitHub Repository
• Sample Applications
• API Documentation

License

Hex1b is licensed under the MIT License.