feat: system language + navigation (#32)

* feat: add apis (systemLanguage, navigationMode)

* feat: add kotlin, swift impl

* feat: showcase app

* docs: add docs (device-info, navigation mode)

* fix: ktlintFormat

Author: l2hyunwoo

android/src/main/java/com/margelo/nitro/nitrodeviceinfo/DeviceInfo.kt

@@ -44,11 +44,10 @@ import kotlinx.coroutines.suspendCancellableCoroutine
 import java.net.Inet4Address
 import java.net.NetworkInterface
 import java.security.KeyStore
+import java.util.Locale
 import kotlin.coroutines.resume
 
-/**
- * Build information cache to avoid repeated Build.* lookups
- */
+/** Build information cache to avoid repeated Build.* lookups */
 private data class BuildInfoCache(
     val serialNumber: String,
     val androidId: String,
@@ -115,16 +114,15 @@ class DeviceInfo : HybridDeviceInfoSpec() {
     }
 
     /**
-     * Get serial number with permission check
-     * Requires READ_PHONE_STATE permission on Android 8.0+
+     * Get serial number with permission check Requires READ_PHONE_STATE permission on Android 8.0+
      */
     @SuppressLint("MissingPermission")
     private fun getSerialNumberInternal(): String {
         return try {
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                 // Android 8.0+ requires READ_PHONE_STATE permission
-                if (context.checkSelfPermission(android.Manifest.permission.READ_PHONE_STATE)
-                    == PackageManager.PERMISSION_GRANTED
+                if (context.checkSelfPermission(android.Manifest.permission.READ_PHONE_STATE) ==
+                    PackageManager.PERMISSION_GRANTED
                 ) {
                     Build.getSerial()
                 } else {
@@ -147,7 +145,8 @@ class DeviceInfo : HybridDeviceInfoSpec() {
                 Settings.Secure.getString(
                     context.contentResolver,
                     Settings.Secure.ANDROID_ID,
-                ) ?: "unknown",
+                )
+                    ?: "unknown",
             securityPatch = Build.VERSION.SECURITY_PATCH,
             bootloader = Build.BOOTLOADER,
             codename = Build.VERSION.CODENAME,
@@ -168,9 +167,7 @@ class DeviceInfo : HybridDeviceInfoSpec() {
 
     /** Cached system features list */
     private val systemFeatures: List<String> by lazy {
-        context.packageManager.systemAvailableFeatures
-            .mapNotNull { it.name }
-            .sorted()
+        context.packageManager.systemAvailableFeatures.mapNotNull { it.name }.sorted()
     }
 
     /** Cached supported media types */
@@ -179,9 +176,7 @@ class DeviceInfo : HybridDeviceInfoSpec() {
             val codecList = MediaCodecList(MediaCodecList.ALL_CODECS)
             val types = mutableSetOf<String>()
             codecList.codecInfos?.forEach { codecInfo ->
-                codecInfo.supportedTypes.forEach { type ->
-                    types.add(type)
-                }
+                codecInfo.supportedTypes.forEach { type -> types.add(type) }
             }
 
             types.sorted()
@@ -259,7 +254,8 @@ class DeviceInfo : HybridDeviceInfoSpec() {
         get() = false
 
     /**
-     * Check if device has Dynamic Island Android devices don't have Dynamic Island (iOS-only feature)
+     * Check if device has Dynamic Island Android devices don't have Dynamic Island (iOS-only
+     * feature)
      */
     override val hasDynamicIsland: Boolean
         get() = false
@@ -329,7 +325,6 @@ class DeviceInfo : HybridDeviceInfoSpec() {
                 when {
                     batteryManager.getIntProperty(BatteryManager.BATTERY_PROPERTY_STATUS) ==
                         BatteryManager.BATTERY_STATUS_FULL -> BatteryState.FULL
-
                     isCharging -> BatteryState.CHARGING
                     else -> BatteryState.UNPLUGGED
                 }
@@ -502,7 +497,8 @@ class DeviceInfo : HybridDeviceInfoSpec() {
     override val hasGms: Boolean
         get() {
             return try {
-                val result = GoogleApiAvailability.getInstance().isGooglePlayServicesAvailable(context)
+                val result =
+                    GoogleApiAvailability.getInstance().isGooglePlayServicesAvailable(context)
                 result == ConnectionResult.SUCCESS
             } catch (e: Exception) {
                 Log.w(NAME, "GMS not available or GMS library not found", e)
@@ -600,7 +596,8 @@ class DeviceInfo : HybridDeviceInfoSpec() {
         get() {
             return try {
                 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
-                    context.packageManager.getInstallSourceInfo(context.packageName).installingPackageName
+                    context.packageManager.getInstallSourceInfo(context.packageName)
+                        .installingPackageName
                         ?: "unknown"
                 } else {
                     @Suppress("DEPRECATION")
@@ -644,7 +641,6 @@ class DeviceInfo : HybridDeviceInfoSpec() {
                                         continuation.resume("unknown")
                                     }
                                 }
-
                                 else -> {
                                     referrerClient.endConnection()
                                     continuation.resume("unknown")
@@ -787,7 +783,8 @@ class DeviceInfo : HybridDeviceInfoSpec() {
                 val locationManager =
                     context.getSystemService(Context.LOCATION_SERVICE) as LocationManager
 
-                locationManager.allProviders
+                locationManager
+                    .allProviders
                     .filter { locationManager.isProviderEnabled(it) }
                     .toTypedArray()
             } catch (e: Exception) {
@@ -835,9 +832,7 @@ class DeviceInfo : HybridDeviceInfoSpec() {
 
     /** Get device token (iOS-specific, throws error on Android) */
     override fun getDeviceToken(): Promise<String> {
-        return Promise.async {
-            throw Exception("getDeviceToken() is only available on iOS")
-        }
+        return Promise.async { throw Exception("getDeviceToken() is only available on iOS") }
     }
 
     /** Get IP address with 5-second cache */
@@ -938,8 +933,8 @@ class DeviceInfo : HybridDeviceInfoSpec() {
     override val isLiquidGlassAvailable: Boolean = false
 
     /**
-     * Check if hardware-backed key storage is available
-     * Android KeyStore is always hardware-backed on API 23+ (TEE or StrongBox)
+     * Check if hardware-backed key storage is available Android KeyStore is always hardware-backed
+     * on API 23+ (TEE or StrongBox)
      */
     override val isHardwareKeyStoreAvailable: Boolean
         get() {
@@ -1007,6 +1002,32 @@ class DeviceInfo : HybridDeviceInfoSpec() {
             }
         }
 
+    // MARK: - Localization & Navigation
+
+    /** Get device system language in BCP 47 format */
+    override val systemLanguage: String
+        get() = Locale.getDefault().toLanguageTag()
+
+    /** Get Android navigation mode Values: 0 = 3-button, 1 = 2-button, 2 = gesture */
+    override val navigationMode: NavigationMode
+        get() {
+            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
+                // Pre-Android 10 only has 3-button navigation
+                return NavigationMode.BUTTONS
+            }
+            return try {
+                when (Settings.Secure.getInt(context.contentResolver, "navigation_mode", 0)) {
+                    0 -> NavigationMode.BUTTONS // 3-button navigation
+                    1 -> NavigationMode.TWOBUTTONS // 2-button navigation
+                    2 -> NavigationMode.GESTURE // Gesture navigation
+                    else -> NavigationMode.UNKNOWN
+                }
+            } catch (e: Exception) {
+                Log.w(NAME, "Failed to get navigation mode", e)
+                NavigationMode.UNKNOWN
+            }
+        }
+
     companion object {
         const val NAME = "NitroDeviceInfo"
     }

docs/docs/api/device-info.md

@@ -486,6 +486,87 @@ const deviceName = DeviceInfoModule.deviceName;
 
 ---
 
+## Localization & Navigation
+
+### `systemLanguage: string`
+
+Get device system language in BCP 47 format.
+
+```typescript
+const language = DeviceInfoModule.systemLanguage;
+// iOS: "en-US", "ko-KR", "ja-JP", "zh-Hans-CN"
+// Android: "en-US", "ko-KR", "ja-JP", "zh-Hans-CN"
+```
+
+**Platform**: iOS, Android
+
+**Examples**:
+
+| Language | Code |
+|----------|------|
+| English (US) | `en-US` |
+| Korean | `ko-KR` |
+| Japanese | `ja-JP` |
+| Simplified Chinese | `zh-Hans-CN` |
+| French (France) | `fr-FR` |
+| German | `de-DE` |
+
+**Use Case**:
+
+```typescript
+const language = DeviceInfoModule.systemLanguage;
+
+if (language.startsWith('ko')) {
+  console.log('Korean device detected');
+} else if (language.startsWith('ja')) {
+  console.log('Japanese device detected');
+}
+```
+
+### `navigationMode: NavigationMode`
+
+Get Android navigation mode.
+
+```typescript
+const navMode = DeviceInfoModule.navigationMode;
+// Android with gesture nav → "gesture"
+// Android with 3-button nav → "buttons"
+// Android with 2-button nav → "twobuttons"
+// iOS → "unknown"
+```
+
+**Type**: `'gesture' | 'buttons' | 'twobuttons' | 'unknown'`
+
+**Platform**: Android only (returns "unknown" on iOS)
+
+**Values**:
+
+| Value | Description |
+|-------|-------------|
+| `gesture` | Full gesture navigation (swipe-based) |
+| `buttons` | Traditional 3-button navigation (Back, Home, Recent) |
+| `twobuttons` | 2-button navigation (Back, Home with swipe up) |
+| `unknown` | Cannot determine (always on iOS) |
+
+**Use Case**:
+
+```typescript
+const navMode = DeviceInfoModule.navigationMode;
+
+if (navMode === 'gesture') {
+  // Avoid bottom gesture conflicts
+  // Add extra bottom padding for bottom sheets
+  console.log('Using gesture navigation - add extra padding');
+} else if (navMode === 'buttons') {
+  // Traditional navigation bar is present
+  console.log('Using button navigation');
+}
+```
+
+**Note**: Navigation mode detection requires Android 10 (API 29) or later. On older Android versions, returns `"buttons"` since gesture navigation was not available.
+
+---
+
 ## Platform-Specific Properties
 
 ### `apiLevel: number`
@@ -903,6 +984,8 @@ This provides fast access while keeping data reasonably fresh.
 | Battery info            | ✅  | ✅      | Low power mode iOS only             |
 | System resources        | ✅  | ✅      | All platforms                       |
 | Network info            | ✅  | ✅      | MAC hardcoded on iOS 7+             |
+| System language         | ✅  | ✅      | BCP 47 format                       |
+| Navigation mode         | ❌  | ✅      | Android only (API 29+)              |
 | Android Build info      | ❌  | ✅      | Android only                        |
 | hasNotch/Dynamic Island | ✅  | ❌      | iOS only                            |
 | Hardware KeyStore       | ✅  | ✅      | All platforms                       |

docs/docs/api/types.md

@@ -10,6 +10,7 @@ import type {
   PowerState,
   BatteryState,
   DeviceType,
+  NavigationMode,
 } from 'react-native-nitro-device-info';
 ```
 
@@ -92,6 +93,49 @@ switch (powerState.batteryState) {
 }
 ```
 
+### NavigationMode
+
+Android navigation mode types.
+
+```typescript
+type NavigationMode = 'gesture' | 'buttons' | 'twobuttons' | 'unknown';
+```
+
+**Values**:
+
+- **gesture**: Full gesture navigation (swipe-based)
+- **buttons**: Traditional 3-button navigation (Back, Home, Recent)
+- **twobuttons**: 2-button navigation (Back, Home with swipe up)
+- **unknown**: Cannot determine (always returns this on iOS)
+
+**Usage**:
+
+```typescript
+const navMode = DeviceInfoModule.navigationMode;
+
+switch (navMode) {
+  case 'gesture':
+    console.log('Device uses gesture navigation');
+    // Add extra bottom padding for gesture conflicts
+    break;
+  case 'buttons':
+    console.log('Device uses 3-button navigation');
+    break;
+  case 'twobuttons':
+    console.log('Device uses 2-button navigation');
+    break;
+  case 'unknown':
+    console.log('Navigation mode unknown (iOS)');
+    break;
+}
+```
+
+**Platform Behavior**:
+
+- **Android API 29+**: Returns actual navigation mode
+- **Android API < 29**: Returns `"buttons"` (gesture nav didn't exist)
+- **iOS**: Always returns `"unknown"`
+
 ### DeviceType
 
 Device category classification.
@@ -242,6 +286,10 @@ interface DeviceInfo extends HybridObject {
   // Installation Methods
   getInstallReferrer(): Promise<string>;
 
+  // Localization & Navigation Properties
+  readonly systemLanguage: string;
+  readonly navigationMode: NavigationMode;
+
   // Advanced Capability Properties
   readonly isWiredHeadphonesConnected: boolean;
   readonly isBluetoothHeadphonesConnected: boolean;

example/showcase/ios/Podfile.lock

@@ -8,7 +8,7 @@ PODS:
   - hermes-engine (0.81.1):
     - hermes-engine/Pre-built (= 0.81.1)
   - hermes-engine/Pre-built (0.81.1)
-  - NitroDeviceInfo (1.1.0):
+  - NitroDeviceInfo (1.2.1):
     - NitroModules
     - React-callinvoker
     - React-Core
@@ -2528,7 +2528,7 @@ SPEC CHECKSUMS:
   fmt: a40bb5bd0294ea969aaaba240a927bd33d878cdd
   glog: 5683914934d5b6e4240e497e0f4a3b42d1854183
   hermes-engine: 4f8246b1f6d79f625e0d99472d1f3a71da4d28ca
-  NitroDeviceInfo: 6e2e20647d7020d463dd3c80a45b947966777bea
+  NitroDeviceInfo: d7178fee34161c1e7aa640410d51242192f42e54
   NitroModules: 5f474732a91ef6a48e7788fb73b355bcb52999ee
   RCT-Folly: 59ec0ac1f2f39672a0c6e6cecdd39383b764646f
   RCTDeprecation: c4b9e2fd0ab200e3af72b013ed6113187c607077

example/showcase/src/config/propertyCategories.ts

@@ -297,7 +297,27 @@ export const PROPERTY_CONFIGS: Omit<DeviceProperty, 'value' | 'errorState'>[] =
   },
 
   // ==========================================================================
-  // CATEGORY 8: Platform Capabilities
+  // CATEGORY 8: Localization & Navigation
+  // ==========================================================================
+  {
+    key: 'systemLanguage',
+    label: 'System Language',
+    category: PropertyCategory.LOCALIZATION_NAVIGATION,
+    type: PropertyType.STRING,
+    platform: PlatformAvailability.ALL,
+    isSync: true,
+  },
+  {
+    key: 'navigationMode',
+    label: 'Navigation Mode',
+    category: PropertyCategory.LOCALIZATION_NAVIGATION,
+    type: PropertyType.STRING,
+    platform: PlatformAvailability.ALL,
+    isSync: true,
+  },
+
+  // ==========================================================================
+  // CATEGORY 9: Platform Capabilities
   // ==========================================================================
   {
     key: 'apiLevel',

example/showcase/src/types/index.ts

@@ -22,6 +22,7 @@ export enum PropertyCategory {
   SYSTEM_RESOURCES = 'System Resources',
   APP_METADATA = 'Application Metadata',
   NETWORK_CONNECTIVITY = 'Network & Connectivity',
+  LOCALIZATION_NAVIGATION = 'Localization & Navigation',
   PLATFORM_CAPABILITIES = 'Platform Capabilities',
   ANDROID_BUILD_INFO = 'Android Build Information',
   ADVANCED_FEATURES = 'Advanced Features',