Counter App

In the previous section, we built a “hello world” TUI. In this tutorial, we’ll develop a simple counter application.

For the app, we’ll need a Paragraph to display the counter. We’ll also want to increment or decrement the counter when a key is pressed. Let’s increment and decrement the counter with j and k.

Initialization

Go ahead and set up a new rust project with

cargo new ratatui-counter-app
cd ratatui-counter-app

We are only going to use 3 dependencies in this tutorial:

cargo add ratatui crossterm anyhow

Tip

We opt to use the anyhow crate for easier error handling; it is not necessary to build apps with ratatui.

File structure

We are going to start off like in the previous “hello world” tutorial with one file like so:

tree .
├── Cargo.toml
├── LICENSE
└── src
   └── main.rs

but this time for the counter example, we will expand it out to multiple files like so:

tree .
├── Cargo.toml
├── LICENSE
└── src
   ├── app.rs
   ├── event.rs
   ├── lib.rs
   ├── main.rs
   ├── tui.rs
   ├── ui.rs
   └── update.rs