CheckPass

CheckPass is an Android app designed to streamline passenger check-in for buses by enabling agents to quickly scan QR codes on tickets, instantly retrieving and displaying passenger details for check-in or cancellation.

Key Features

• Dual Scanning Support:

  • PDA Devices: Uses built-in scan hardware via a BroadcastReceiver implementation.
  • Camera Phones: Utilizes CameraX and MLKit for QR code scanning, leveraging setImageAnalysisAnalyzer for live code detection.

• Unified Codebase:

  • Scanning logic is abstracted via the ScannerManager interface:

    interface ScannerManager {
        val scannedCodes: SharedFlow<String>
        fun startScan()
        fun stopScan()
    }

  • Device detection at runtime chooses the appropriate implementation (BroadcastScannerManager for PDAs, CameraScannerManager for camera phones).

• Reactive Scanned Code Handling:

  • QR codes scanned are delivered using SharedFlow<String>, allowing the app to respond immediately and display passenger dialogs.

• Camera Permissions & Libraries:

  • Camera usage on phones is managed with explicit permissions in the manifest.
  • The Google Accompanist library is used for elegant runtime permission handling.

How It Works

1. Agent scans the QR code on the passenger's ticket (either with the PDA's physical button or the phone's camera).
2. Passenger details appear in a dialog; the agent can check in or cancel.
3. Core logic adapts to device type automatically.

App Demo

Code Highlights

• BroadcastReceiver for handling hardware scan events on PDA devices.
• CameraX’s setImageAnalysisAnalyzer for real-time QR detection on camera phones.
• Google Accompanist Permissions for runtime camera access.
• SharedFlow for propagating scanned QR codes to the UI.

CheckPass ensures a consistent, fast, and reliable check-in experience across device types by abstracting scanning logic and handling permissions gracefully.