# 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 **4** pages managed by a `ViewPager2` (`OnboardingPagerAdapter.kt:32-38`). The adapter returns `slides.size + 1` items — three text slides plus the security-setup page inserted at position 1. Tap-to-navigate on the page-indicator dots is disabled; the only forward motion is the bottom **Next** / **Get Started** button.

| Position | Fragment | Purpose |
|---|---|---|
| 0 | `OnboardingFragment` (welcome) | Language pick + welcome copy |
| 1 | `SecuritySetupFragment` | PIN or pattern setup |
| 2 | `OnboardingConfigureFragment` | Theme, accent, nav mode |
| 3 | `OnboardingFragment` (`isLast = true`) | Final screen with **Get Started** |

Each page has a gate that controls when the bottom button activates.

---

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

- Displays a welcome illustration and app name
- Language toggle group (`languageToggle` in `OnboardingActivity.kt:86-92`): **English** / **Dhivehi** only
- Selecting a language calls `AppCompatDelegate.setApplicationLocales()` immediately
- The language section is only visible while the user is on page 0

---

## 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.

---

## Final Slide — Get Started

The last page is another `OnboardingFragment` with `isLast = true`. After the user scrolls it to the bottom, a 5-second `CountDownTimer` (`OnboardingActivity.kt:95-97`, `155-164`) starts — the **Get Started** button is disabled until the timer reaches zero, with the remaining seconds shown in the button label.

---

## Completion

When the user taps **Get Started**, `OnboardingActivity` sets the `onboarding_done` flag, marks `app.isUnlocked = true`, and launches `LoginActivity` directly so the user does not have to re-authenticate immediately after setup.

---

 

---

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