Chrome

Caution

Under heavy development. Not production-ready. The API can break without notice. Use at your own risk.

The eight themed components xpui asks a backend to paint — a list, a dialog, a slider, a progress bar, a header, a sub-header, a button-hint bar and a scroll indicator — painted from drawing primitives alone. A backend sitting on a drawing library has nothing to answer xpui's Chrome trait with, and would otherwise have to write a widget toolkit before it could show anything; this crate is that toolkit, once, for all of them. no_std, and it depends on xpui and nothing else.

Every document in this repository is listed in docs/README.md.

Using it

TOML

[dependencies]
xpui-chrome = { git = "https://github.com/XPUI-Framework/xpui-chrome", branch = "main" }

Your backend implements Canvas, TextMetrics, InputSource and Clock — the contract is docs/host.md — and one macro writes the whole of the fifth, Chrome:

Rust

use xpui_chrome::{KeyRow, Labels, Metrics};

static METRICS: Metrics = Metrics::DEFAULT;
static LABELS: Labels = Labels::ENGLISH;
static KEYS: KeyRow = KeyRow::READER;

xpui_chrome::plain_chrome! {
  for MyBackend,
  metrics: |_backend| &METRICS,
  labels: |_backend| &LABELS,
  keys: |_backend| &KEYS,
  request_update: |backend| backend.flush(),
}

Four things go in because four parties own them: the metrics come from whoever knows the panel, the labels from whoever knows the user's language, the key row from the hardware, and request_update from the one thing that can get pixels onto a panel — the backend. docs/reference/plain-chrome.md says what each is and why they are closures, and docs/reference.md is the whole API. Nothing is on crates.io yet, which is why the dependency above is a git URL.

Checking it

Shell

./build-and-test.sh

The checks themselves are in xtask/ — this repository's own list, in Rust, holding nothing it does not run. ./build-and-test.sh fix formats in place first. How a change is reviewed is in docs/contributing.md.

Where it sits

Every arrow is a dependency in a Cargo.toml, and they all point inward toward xpui, which depends on nothing at all. That is the rule the organisation is arranged around: a backend can be written without the framework knowing it exists, and a firmware reaches whatever it needs directly rather than through whoever happens to sit above it.