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Demos

Every demo in the repository runs in your terminal and in the browser from the same source. Start with the live showcase, then explore the code behind it.

Try the live showcase

Open your terminal and run:

sh
ssh ratcn.com

No Rust installation or account needed. Browse the component catalog, switch themes, drag cards across the Kanban board, and try the larger demo apps with your keyboard and mouse. The showcase runs real Ratatui interfaces remotely and displays them in your terminal.

The hosted sandbox leaves out the network-dependent Effects demo. Run the showcase locally or use the browser demos to explore the complete collection.

Run a demo locally

Clone the repository and run any demo by name:

sh
git clone https://github.com/kristoferlund/ratcn
cd ratcn
cargo run -p ledger93

The live previews on the component pages are these same demos, compiled to WebAssembly.

Browsing them all

sh
cargo run -p showcase

Three views bring the site into your terminal: the landing page, a scrolling Getting started guide, and a catalog with the selected demo running beside its navigation list. Showcase embeds the demo crates rather than reimplementing them.

Reading the source

  • Start with a small demo such as select/src/lib.rs for state, messages, and component declarations.
  • demos/shared/src/lib.rs defines the single Demo::draw(&mut Buffer, area, theme) contract and the shared native/browser host. The host supplies the frame's buffer and area, routes events, and schedules redraws and wakeups.
  • showcase/src/main.rs owns view navigation, scroll offsets, chrome focus, and input ownership. catalog.rs adapts demos for hosting; instances are constructed lazily and keep their own state and runtime.
  • The Getting started view renders getting_started.md with tui-markdown inside a ScrollArea. Edit the document, not a collection of Rust widgets; code highlighting is disabled.

Catalog demos draw directly into their pane. Interactive demos pass that area to Ratcn::render_into; paint-only demos use ordinary widgets. Pointer coordinates remain screen-absolute. Only the scrolling landing preview uses an offscreen buffer, copies visible rows, and translates pointer coordinates. The host owns allocation and clearing; the buffer contract carries no cursor metadata and does not sandbox arbitrary base paint.

Showcase routes input to the active demo, saves and restores chrome focus, and cancels pointer interaction when a demo loses its input session or painted area. Its small focus-reveal helper keeps the separately painted landing preview aligned: ScrollArea focus reveal does not emit its effective offset to the app.

Full applications

Start here if you want to see how the pieces fit together at real size. All three are worth reading as source, not just running.

DemoShows
ledger93A nineties double-entry bookkeeping terminal. The largest example: several screens, per-screen state and messages, and a keyboard-first workflow.
landingA responsive grid of live components, and how one app splits state and messages across independent tiles. This is the demo embedded on the home page.
wizardA four-step wizard that walks through starting a ratcn app. Buttons that move between steps, a select and a list that record choices, and one screen module per step. This is the demo embedded on Getting started.

Patterns

Each of these shows one technique end to end.

DemoShows
kanbanDrag and drop between columns, with cards keeping their identity as they move. See Dragging.
dragThe smallest possible drag: one block, moved anywhere inside the frame.
panelsTwo focusable panels, each grouping its own children — scopes and Tab boundaries. See Structuring a larger app.
effectsFetching data without blocking the UI, and feeding the result back in as a message. See State and messages.

Components

One demo per feature, so a docs page can show several side by side. These are the previews embedded on the component pages.

ComponentDemos
Buttonbutton-small, button-large — the five variants at each size
Listlist (cursor and selection kept separate), list-multi (checkbox multi-selection), list-people (two-line custom rows)
ScrollAreascroll-area — ten buttons in a viewport three of them tall
Selectselect — the dropdown panel
Tabstabs-basic (manual activation), tabs-automatic (focus selects), tabs-disabled (skipped by traversal), tabs-large
Dialogdialog — a modal layer with actions, draggable by its border
Toasttoast — transient notifications your app owns
Tooltiptooltip — hover or Tab to a button and its bubble floats above
Checkboxcheckbox — one component as checkbox, ASCII checklist, and switch
Cyclecycle — settings rows with the value cycling in place
Progressprogress — a bare bar, a downloading label-and-percentage pair, and a finished one
BarChartbarchart, barchart-horizontal — a paint-only widget, no runtime needed

Running them in the browser

The demos are also the source of the previews on this site. Building them needs Trunk:

sh
cd demos/ledger93
trunk serve

Each demo's lib.rs is its reusable entry point; larger demos split their implementation across modules. The main.rs Trunk builds is the same one that runs natively. Each demo's Cargo.toml adds ratcn's ratzilla feature for wasm32, and the host they all share, demos/shared, enables ratcn's termina feature for the native build. See Host integration for how that wiring works.