@angadie/chittie-react-native

The React Native backend for chittie — a Nitro module that rasterizes non-Latin text (Sinhala/Tamil/Arabic) natively (CoreText on iOS, android.graphics on Android) and exposes it as chittie's TextRasterizer. No Skia.

Dev client / bare RN only — it's a native module, so it can't run in Expo Go. (Your printer transport — BLE/USB — needs a dev client anyway, so this costs you nothing extra.) See the RFC: docs/rfc/rn-native.md.

Install

npm i @angadie/chittie-react-native @angadie/chittie react-native-nitro-modules
cd ios && pod install     # iOS
# Android autolinks; rebuild the dev client.

The Nitro bindings (nitrogen/) are generated and shipped — you only re-run npm run codegen if you change the .nitro.ts spec. Built with react-native-builder-bob (lib/commonjs|module| typescript). Requires React Native's new architecture.

Use

Pass the native rasterizer to render() — everything else is the same chittie API:

import { render, Printer, Text, Row } from '@angadie/chittie';
import { createNativeRasterizer } from '@angadie/chittie-react-native';

const rasterizer = createNativeRasterizer();

const bytes = render(
  <Printer width={32}>
    <Text align="center" bold>ආයුබෝවන්</Text>
    <Row left="තේ" right="Rs. 250" />
  </Printer>,
  { dotWidth: 384, rasterizer }   // 58mm
);
// send `bytes` over your transport (BLE/USB/TCP)

The native side returns an RGBA bitmap sized to the text (dims padded to /8), which chittie packs to ESC/POS raster unchanged.

Architecture

TS:   createNativeRasterizer()  →  makeRasterizer(native)  →  chittie TextRasterizer
      (src/index.ts)               (src/adapter.ts, pure)     (ImageData → render())
Nitro spec: src/specs/ChittieRasterizer.nitro.ts  (rasterize → RasterBitmap{data,width,height})
Native:  ios/HybridChittieRasterizer.swift   (UIKit/CoreText)
         android/.../HybridChittieRasterizer.kt  (StaticLayout/Canvas)

makeRasterizer is pure and dependency-free (no Nitro import) so it's unit-testable off-device; createNativeRasterizer wires the real Nitro HybridObject.

What's verified vs gated

• Verified (off-device): nitro-codegen runs and the bindings are committed under nitrogen/; the TS adapter spike (native bitmap → ImageData → chittie's padTo8, spikes/adapter.spike.mts); bob build (commonjs/module/typescript) + typecheck in the monorepo gate.
• Gated (needs Xcode/Android Studio + a device): the native Swift/Kotlin compile and an on-device snapshot of the rendered glyphs. The iOS/Android build files mirror the proven react-native-nitro-haptics template; the device build validates them.

Roadmap (per the RFC)

• Phase 1 — rasterizer (this).
• Phase 2 — read-capable BLE transport (status via DLE EOT notify; see chittie-transport's queryStatus).
• Phase 3 — USB (Android host) + TCP transports.

Notes

• Complex shaping + bidi come from the platform engines for free (UIKit/StaticLayout), so Arabic joins and reorders correctly. For RTL rows, also pass rtl to <Row> (see docs/i18n.md).
• For font selection, the native side uses the system font (which has Sinhala/Tamil/Arabic fallbacks); custom-font support is a future option.