# Onboarding

Shown once on first launch. Walks the user through language selection, security setup, and appearance configuration before creating any credentials.

---

## Activity — `OnboardingActivity`

`OnboardingActivity` hosts three sequential fragments managed by a `ViewPager2` with manual paging (swipe disabled). Progress dots are shown below the pager.

Each fragment has a **Continue** button that is only enabled after the user satisfies a completion requirement. Scrolling to the bottom of a slide is required before Continue activates on content slides.

---

## Slide 1 — Language & Welcome (`OnboardingFragment`)

- Displays a welcome illustration and app name
- Language selector chip group (English / Dhivehi)
- Selecting a language immediately updates the app locale
- Continue button becomes active once a language is selected (or immediately if system locale is already supported)

---

## Slide 2 — Security Setup (`SecuritySetupFragment`)

The user chooses a lock method to protect the app.

### Lock Methods

| Method | Description |
|---|---|
| PIN | 4–8 digit numeric PIN |
| Pattern | Grid pattern draw (minimum 4 nodes) |

### PIN Entry

- Two `EditText` fields: PIN + confirm PIN
- Continue activates only when both fields match and length ≥ 4

### Pattern Entry

- Custom `PatternView` widget
- Draws connecting lines between touched grid nodes in real time
- Two-phase: draw → confirm (must match first drawing)
- Continue activates after a valid matching pattern is confirmed

### Key Derivation

The chosen PIN or pattern string is hardened with **PBKDF2-HMAC-SHA256** (100 000 iterations, random 16-byte salt) before storage. The derived key is stored in encrypted `SharedPreferences` via `CredentialStore`.

### Biometric Option

After setting a PIN or pattern an optional **Enable Biometrics** toggle appears. If enabled, biometric authentication (fingerprint / face — `BIOMETRIC_WEAK`) can be used as an alternative to the PIN/pattern at the lock screen and optionally for transfer confirmation.

---

## Slide 3 — Configure (`OnboardingConfigureFragment`)

Appearance and navigation preferences, set before first login.

### Options

| Setting | Choices |
|---|---|
| Navigation mode | Drawer / Bottom Navigation |
| Theme | System default / Light / Dark |
| Accent colour | Chip selector (several Material colours) |

All preferences are written to `CredentialStore` / `SharedPreferences` immediately on selection so that `HomeActivity` inherits them on first launch.

---

## Completion

When the user taps Continue on slide 3, `OnboardingActivity` sets the `onboardingDone` flag and finishes. `MainActivity` then routes to `LoginActivity` (no credentials yet) on the next launch or immediately via `startActivity`.

---

 

---

[← App Overview](00-app-overview.md)     **Next →** [Lock Screen](02-lock-screen.md)