Aurum · Biometric Unlock
Aurum · Biometric Unlock is a production-ready Web3 Flutter screen from FlutterKit — free, with full source code.
The biometric app-lock gate for the Aurum self-custody wallet, on a near-black #0B0E11 canvas. A 160px fingerprint sits centred, drawn entirely by a _FingerprintPainter whose ridges fill from slate-grey (#2B3139) up to brand gold (#F0B90B) as a single 1700ms AnimationController drives its progress from 0 to 1. While scanning, a bold 'Scanning…' title sits over the muted line 'Hold still while we verify your fingerprint'; on completion the painter flips to a green (#2EBD85) success tick and the copy swaps to 'Unlocked' / 'Welcome back to Aurum'. The print is tappable to restart a scan, and a gold 'Use passcode instead' TextButton offers a fallback. A status listener fires the injected onUnlocked callback 650ms after the scan completes — via a cancellable Timer that is torn down in dispose() so nothing leaks. Pure Flutter with a bundled Inter font, forced dark theme, one CustomPainter and no network images, wired only through onUnlocked and onUsePasscode callbacks so it drops into any auth flow.
Full tutorial coming soon.
The step-by-step walkthrough and complete Dart source for this screen haven't been published yet. They'll be free when they are — no sign-up, no payment. In the meantime, browse the screens that already have their tutorial.
What's included
- ✓_FingerprintPainter — a 160px custom-painted fingerprint whose ridges fill slate→gold by animation progress and flip to a green success tick
- ✓Single AnimationController (1700ms) with a status listener that drives the scan and the done state
- ✓Cancellable Timer firing onUnlocked 650ms after the scan completes, cleaned up in dispose() for a leak-free teardown
- ✓Tap-to-rescan GestureDetector plus a gold 'Use passcode instead' TextButton fallback
- ✓State-driven copy that swaps 'Scanning… / Hold still…' for 'Unlocked / Welcome back to Aurum'
- ✓onUnlocked and onUsePasscode VoidCallback hooks, bundled Inter font and forced dark theme — self-contained route
Use cases
- ✓Biometric app-lock gate for a self-custody crypto or web3 wallet
- ✓Face/Touch-ID-style re-authentication when the app returns to foreground
- ✓Secure re-entry step before revealing balances or signing a transaction
- ✓Reusable fingerprint-scan animation for any dark-themed fintech app
