Meshtastic-Android/core/barcode

:core:barcode

Overview

The :core:barcode module provides barcode and QR code scanning capabilities using CameraX and flavor-specific decoding engines. It is used for scanning node configuration, pairing, and contact sharing.

The shared contract (BarcodeScanner interface + LocalBarcodeScannerProvider) lives in core:ui/commonMain, keeping this module Android-only.

Key Components

1. rememberBarcodeScanner

A Composable function (in main/) that provides camera permission handling, a full-screen scanner dialog with live preview and reticule overlay, and returns a BarcodeScanner instance.

• Technology: Uses CameraX for camera lifecycle management.
• Flavors: Barcode decoding is the only flavor-specific code:
  • google/ — ML Kit (BarcodeScanning + InputImage) via createBarcodeAnalyzer()
  • fdroid/ — ZXing (MultiFormatReader + PlanarYUVLuminanceSource) via createBarcodeAnalyzer()
• All shared UI (dialog, reticule, permissions, camera lifecycle) lives in main/.

Source Layout

src/
├── main/     BarcodeScannerProvider.kt (shared UI)
├── google/   BarcodeAnalyzerFactory.kt (ML Kit decoder)
├── fdroid/   BarcodeAnalyzerFactory.kt (ZXing decoder)
├── test/     Unit tests
└── androidTest/ Instrumented tests

Usage

// In a Composable (typically wired via LocalBarcodeScannerProvider in app/)
val scanner = rememberBarcodeScanner { result ->
    // Handle scanned QR code string (or null on dismiss)
}
scanner.startScan()

Module dependency graph

graph TB
  :core:barcode[barcode]:::compose-desktop-application
  :core:barcode -.-> :core:resources
  :core:barcode -.-> :core:ui

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classDef android-application-compose fill:#CAFFBF,stroke:#000,stroke-width:2px,color:#000;
classDef compose-desktop-application fill:#CAFFBF,stroke:#000,stroke-width:2px,color:#000;
classDef android-feature fill:#FFD6A5,stroke:#000,stroke-width:2px,color:#000;
classDef android-library fill:#9BF6FF,stroke:#000,stroke-width:2px,color:#000;
classDef android-library-compose fill:#9BF6FF,stroke:#000,stroke-width:2px,color:#000;
classDef android-test fill:#A0C4FF,stroke:#000,stroke-width:2px,color:#000;
classDef jvm-library fill:#BDB2FF,stroke:#000,stroke-width:2px,color:#000;
classDef kmp-library fill:#FFC1CC,stroke:#000,stroke-width:2px,color:#000;
classDef unknown fill:#FFADAD,stroke:#000,stroke-width:2px,color:#000;