feat: Add tablet landscape orientation support (#490)

- Tablets now support landscape mode, phones remain portrait-only
- Add OrientationAwareActivity base class for orientation management
- Add DeviceUtils.isTablet() for runtime device detection
- Update MainActivity and GeohashPickerActivity to extend OrientationAwareActivity
- Uses multiple detection criteria (screen size, density, configuration)
Fixes #480

app/src/main/AndroidManifest.xml

@@ -64,14 +64,12 @@
             android:name=".ui.GeohashPickerActivity"
             android:exported="false"
             android:theme="@style/Theme.BitchatAndroid"
-            android:screenOrientation="portrait"
             android:windowSoftInputMode="adjustResize" />
         <activity
             android:name=".MainActivity"
             android:exported="true"
             android:label="@string/app_name"
             android:theme="@style/Theme.BitchatAndroid"
-            android:screenOrientation="portrait"
             android:windowSoftInputMode="adjustResize"
             android:launchMode="singleTop">
             <intent-filter>

app/src/main/java/com/bitchat/android/MainActivity.kt

@@ -3,7 +3,6 @@ package com.bitchat.android
 import android.content.Intent
 import android.os.Bundle
 import android.util.Log
-import androidx.activity.ComponentActivity
 import androidx.activity.OnBackPressedCallback
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
@@ -15,7 +14,6 @@ import androidx.compose.material3.Scaffold
 import androidx.compose.runtime.*
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
-import androidx.compose.ui.unit.dp
 import androidx.lifecycle.lifecycleScope
 import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.repeatOnLifecycle
@@ -39,12 +37,13 @@ import com.bitchat.android.onboarding.PermissionExplanationScreen
 import com.bitchat.android.onboarding.PermissionManager
 import com.bitchat.android.ui.ChatScreen
 import com.bitchat.android.ui.ChatViewModel
+import com.bitchat.android.ui.OrientationAwareActivity
 import com.bitchat.android.ui.theme.BitchatTheme
 import com.bitchat.android.nostr.PoWPreferenceManager
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
 
-class MainActivity : ComponentActivity() {
+class MainActivity : OrientationAwareActivity() {
 
     private lateinit var permissionManager: PermissionManager
     private lateinit var onboardingCoordinator: OnboardingCoordinator

app/src/main/java/com/bitchat/android/ui/GeohashPickerActivity.kt

@@ -11,7 +11,6 @@ import android.webkit.WebChromeClient
 import android.webkit.WebSettings
 import android.webkit.WebView
 import android.webkit.WebViewClient
-import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.compose.foundation.layout.*
 import androidx.compose.foundation.shape.RoundedCornerShape
@@ -45,7 +44,7 @@ import com.bitchat.android.geohash.LocationChannelManager
 import com.bitchat.android.ui.theme.BASE_FONT_SIZE
 
 @OptIn(ExperimentalMaterial3Api::class)
-class GeohashPickerActivity : ComponentActivity() {
+class GeohashPickerActivity : OrientationAwareActivity() {
 
     companion object {
         const val EXTRA_INITIAL_GEOHASH = "initial_geohash"

app/src/main/java/com/bitchat/android/ui/OrientationAwareActivity.kt

@@ -0,0 +1,28 @@
+package com.bitchat.android.ui
+
+import android.content.pm.ActivityInfo
+import android.os.Bundle
+import androidx.activity.ComponentActivity
+import com.bitchat.android.utils.DeviceUtils
+
+/**
+ * Base activity that automatically sets orientation based on device type.
+ * Tablets can rotate to landscape, phones are locked to portrait.
+ */
+abstract class OrientationAwareActivity : ComponentActivity() {
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setOrientationBasedOnDeviceType()
+    }
+
+    private fun setOrientationBasedOnDeviceType() {
+        requestedOrientation = if (DeviceUtils.isTablet(this)) {
+            // Allow all orientations on tablets
+            ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED
+        } else {
+            // Lock to portrait on phones
+            ActivityInfo.SCREEN_ORIENTATION_PORTRAIT
+        }
+    }
+}

app/src/main/java/com/bitchat/android/utils/DeviceUtils.kt

@@ -0,0 +1,39 @@
+package com.bitchat.android.utils
+
+import android.content.Context
+import android.content.res.Configuration
+import android.util.DisplayMetrics
+import android.view.WindowManager
+import androidx.core.content.getSystemService
+import kotlin.math.sqrt
+
+object DeviceUtils {
+
+    /**
+     * Determines if the current device is a tablet based on screen size and density.
+     * Uses multiple criteria to accurately detect tablets vs phones.
+     */
+    fun isTablet(context: Context): Boolean {
+        val windowManager = context.getSystemService<WindowManager>()
+        val displayMetrics = DisplayMetrics()
+        windowManager?.defaultDisplay?.getMetrics(displayMetrics)
+
+        // Calculate screen size in inches
+        val widthInches = displayMetrics.widthPixels / displayMetrics.xdpi
+        val heightInches = displayMetrics.heightPixels / displayMetrics.ydpi
+        val diagonalInches = sqrt((widthInches * widthInches) + (heightInches * heightInches))
+
+        // Check if device has tablet configuration
+        val configuration = context.resources.configuration
+        val isLargeScreen = (configuration.screenLayout and Configuration.SCREENLAYOUT_SIZE_MASK) >= Configuration.SCREENLAYOUT_SIZE_LARGE
+        val isXLargeScreen = (configuration.screenLayout and Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_XLARGE
+
+        // A device is considered a tablet if:
+        // 1. Screen diagonal is 7 inches or larger, OR
+        // 2. Configuration indicates large or xlarge screen, OR
+        // 3. Smallest width is 600dp or more (sw600dp)
+        val smallestWidthDp = context.resources.configuration.smallestScreenWidthDp
+
+        return diagonalInches >= 7.0 || isLargeScreen || isXLargeScreen || smallestWidthDp >= 600
+    }
+}