refactor: Set minSdk to 32 and remove legacy code

This commit increases the minimum SDK version to 32 (Android 12L), allowing for the removal of compatibility code for older Android versions.

Key changes include:
*   Updated `MIN_SDK` from 26 to 32.
*   Removed conditional logic for API levels below 32, particularly for permissions, foreground services, and UI components.
*   Simplified Bluetooth permission handling to only target modern APIs.
*   Cleaned up AndroidManifest by removing legacy permission tags.

Signed-off-by: James Rich <2199651+jamesarich@users.noreply.github.com>

app/src/main/AndroidManifest.xml

@@ -28,17 +28,10 @@
         android:name="android.hardware.location.gps"
         android:required="false" />
 
-    <!-- Request legacy Bluetooth permissions on older devices -->
-    <uses-permission android:name="android.permission.BLUETOOTH"
-        android:maxSdkVersion="30" />
-    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"
-        android:maxSdkVersion="30" />
-
-    <!-- API 31+ Bluetooth permissions -->
+    <!-- API 31+ Bluetooth permissions (Min SDK is 32) -->
     <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
     <uses-permission android:name="android.permission.BLUETOOTH_SCAN"
-        android:usesPermissionFlags="neverForLocation"
-        tools:targetApi="s" />
+        android:usesPermissionFlags="neverForLocation" />
 
     <!-- API 33+ Notification runtime permissions -->
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />

app/src/main/java/com/geeksville/mesh/MainActivity.kt

@@ -23,7 +23,6 @@ import android.content.Intent
 import android.graphics.Color
 import android.hardware.usb.UsbManager
 import android.net.Uri
-import android.os.Build
 import android.os.Bundle
 import androidx.activity.SystemBarStyle
 import androidx.activity.compose.setContent
@@ -67,14 +66,9 @@ class MainActivity : AppCompatActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         installSplashScreen()
-        enableEdgeToEdge(
-            // Disable three-button navbar scrim on pre-Q devices
-            navigationBarStyle = SystemBarStyle.auto(Color.TRANSPARENT, Color.TRANSPARENT),
-        )
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
-            // Disable three-button navbar scrim
-            window.setNavigationBarContrastEnforced(false)
-        }
+        enableEdgeToEdge(navigationBarStyle = SystemBarStyle.auto(Color.TRANSPARENT, Color.TRANSPARENT))
+        // Disable three-button navbar scrim (unconditional on API 32+)
+        window.setNavigationBarContrastEnforced(false)
 
         super.onCreate(savedInstanceState)
 

app/src/main/java/com/geeksville/mesh/service/MeshService.kt

@@ -23,7 +23,6 @@ import android.app.Service
 import android.content.Context
 import android.content.Intent
 import android.content.pm.ServiceInfo
-import android.os.Build
 import android.os.IBinder
 import android.os.RemoteException
 import android.util.Log
@@ -477,14 +476,10 @@ class MeshService : Service() {
                 this,
                 SERVICE_NOTIFY_ID,
                 notification,
-                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
-                    if (hasLocationPermission()) {
-                        ServiceInfo.FOREGROUND_SERVICE_TYPE_MANIFEST
-                    } else {
-                        ServiceInfo.FOREGROUND_SERVICE_TYPE_CONNECTED_DEVICE
-                    }
+                if (hasLocationPermission()) {
+                    ServiceInfo.FOREGROUND_SERVICE_TYPE_MANIFEST
                 } else {
-                    0 // No specific type needed for older Android versions
+                    ServiceInfo.FOREGROUND_SERVICE_TYPE_CONNECTED_DEVICE
                 },
             )
         } catch (ex: Exception) {
@@ -1359,7 +1354,7 @@ class MeshService : Service() {
         val failure =
             when {
                 address == null -> "no_active_address"
-                myNodeNum == null -> "no_my_node"
+                myNodeInfo == null -> "no_my_node"
                 else -> null
             }
         if (failure != null) {
@@ -1368,7 +1363,7 @@ class MeshService : Service() {
         }
 
         val safeAddress = address!!
-        val myNum = myNodeNum!!
+        val myNum = myNodeNum
         val storeForwardConfig = moduleConfig.storeForward
         val lastRequest = meshPrefs.getStoreForwardLastRequest(safeAddress)
         val (window, max) =

app/src/main/java/com/geeksville/mesh/service/MeshServiceStarter.kt

@@ -19,7 +19,6 @@ package com.geeksville.mesh.service
 
 import android.app.ForegroundServiceStartNotAllowedException
 import android.content.Context
-import android.os.Build
 import co.touchlab.kermit.Logger
 import com.geeksville.mesh.BuildConfig
 
@@ -36,13 +35,9 @@ fun MeshService.Companion.startService(context: Context) {
     Logger.i { "Trying to start service debug=${BuildConfig.DEBUG}" }
 
     val intent = createIntent(context)
-    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
-        try {
-            context.startForegroundService(intent)
-        } catch (ex: ForegroundServiceStartNotAllowedException) {
-            Logger.e { "Unable to start service: ${ex.message}" }
-        }
-    } else {
+    try {
         context.startForegroundService(intent)
+    } catch (ex: ForegroundServiceStartNotAllowedException) {
+        Logger.e { "Unable to start service: ${ex.message}" }
     }
 }

app/src/main/java/com/geeksville/mesh/ui/connections/ConnectionsScreen.kt

@@ -18,8 +18,6 @@
 package com.geeksville.mesh.ui.connections
 
 import android.net.InetAddresses
-import android.os.Build
-import android.util.Patterns
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
@@ -93,12 +91,7 @@ import org.meshtastic.feature.settings.radio.RadioConfigViewModel
 import org.meshtastic.feature.settings.radio.component.PacketResponseStateDialog
 import org.meshtastic.proto.ConfigProtos
 
-fun String?.isIPAddress(): Boolean = if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {
-    @Suppress("DEPRECATION")
-    this != null && Patterns.IP_ADDRESS.matcher(this).matches()
-} else {
-    InetAddresses.isNumericAddress(this.toString())
-}
+fun String?.isIPAddress(): Boolean = InetAddresses.isNumericAddress(this.toString())
 
 /**
  * Composable screen for managing device connections (BLE, TCP, USB). It handles permission requests for location and

app/src/main/java/com/geeksville/mesh/ui/connections/components/BLEDevices.kt

@@ -19,7 +19,6 @@ package com.geeksville.mesh.ui.connections.components
 
 import android.Manifest
 import android.content.Intent
-import android.os.Build
 import android.provider.Settings.ACTION_BLUETOOTH_SETTINGS
 import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.result.contract.ActivityResultContracts
@@ -40,7 +39,6 @@ import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
-import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.alpha
@@ -52,8 +50,6 @@ import com.geeksville.mesh.model.DeviceListEntry
 import com.google.accompanist.permissions.ExperimentalPermissionsApi
 import com.google.accompanist.permissions.MultiplePermissionsState
 import com.google.accompanist.permissions.rememberMultiplePermissionsState
-import com.google.accompanist.permissions.rememberPermissionState
-import kotlinx.coroutines.launch
 import org.jetbrains.compose.resources.stringResource
 import org.meshtastic.core.service.ConnectionState
 import org.meshtastic.core.strings.Res
@@ -63,11 +59,9 @@ import org.meshtastic.core.strings.bluetooth_paired_devices
 import org.meshtastic.core.strings.grant_permissions
 import org.meshtastic.core.strings.no_ble_devices
 import org.meshtastic.core.strings.open_settings
-import org.meshtastic.core.strings.permission_missing
 import org.meshtastic.core.strings.permission_missing_31
 import org.meshtastic.core.strings.scan
 import org.meshtastic.core.strings.scanning_bluetooth
-import org.meshtastic.core.ui.util.showToast
 
 /**
  * Composable that displays a list of Bluetooth Low Energy (BLE) devices and allows scanning. It handles Bluetooth
@@ -91,54 +85,21 @@ fun BLEDevices(
     scanModel: BTScanModel,
     bluetoothEnabled: Boolean,
 ) {
-    LocalContext.current // Used implicitly by stringResource
     val isScanning by scanModel.spinner.collectAsStateWithLifecycle(false)
 
-    // Define permissions needed for Bluetooth scanning based on Android version.
+    // Bluetooth permissions for Android 12+ (Min SDK is 32)
     val bluetoothPermissionsList = remember {
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
-            listOf(Manifest.permission.BLUETOOTH_SCAN, Manifest.permission.BLUETOOTH_CONNECT)
-        } else {
-            listOf(
-                Manifest.permission.BLUETOOTH,
-                Manifest.permission.ACCESS_FINE_LOCATION,
-                Manifest.permission.ACCESS_COARSE_LOCATION,
-            )
-        }
+        listOf(Manifest.permission.BLUETOOTH_SCAN, Manifest.permission.BLUETOOTH_CONNECT)
     }
 
-    val context = LocalContext.current
-    val permsMissing =
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
-            stringResource(Res.string.permission_missing_31)
-        } else {
-            stringResource(Res.string.permission_missing)
-        }
-    val coroutineScope = rememberCoroutineScope()
-
-    val singlePermissionState =
-        rememberPermissionState(
-            permission = Manifest.permission.ACCESS_BACKGROUND_LOCATION,
-            onPermissionResult = { granted ->
-                scanModel.refreshPermissions()
-                scanModel.startScan()
-            },
-        )
-
     val permissionsState =
         rememberMultiplePermissionsState(
             permissions = bluetoothPermissionsList,
             onPermissionsResult = { permissions ->
                 val granted = permissions.values.all { it }
-                if (permissions.getOrDefault(Manifest.permission.ACCESS_COARSE_LOCATION, false)) {
-                    coroutineScope.launch { context.showToast(permsMissing) }
-                    singlePermissionState.launchPermissionRequest()
-                }
                 if (granted) {
                     scanModel.refreshPermissions()
                     scanModel.startScan()
-                } else {
-                    coroutineScope.launch { context.showToast(permsMissing) }
                 }
             },
         )
@@ -231,12 +192,7 @@ fun BLEDevices(
         } else {
             // Show a message and a button to grant permissions if not all granted
             EmptyStateContent(
-                text =
-                if (permissionsState.shouldShowRationale) {
-                    stringResource(Res.string.permission_missing)
-                } else {
-                    stringResource(Res.string.permission_missing_31)
-                },
+                text = stringResource(Res.string.permission_missing_31),
                 actionButton = {
                     Button(onClick = { checkPermissionsAndScan(permissionsState, scanModel, bluetoothEnabled) }) {
                         Text(text = stringResource(Res.string.grant_permissions))

config.properties

@@ -20,7 +20,7 @@ VERSION_CODE_OFFSET=29314197
 
 # Application and SDK versions
 APPLICATION_ID=com.geeksville.mesh
-MIN_SDK=26
+MIN_SDK=32
 TARGET_SDK=36
 COMPILE_SDK=36
 

core/common/src/androidMain/kotlin/org/meshtastic/core/common/ContextServices.kt

@@ -21,7 +21,6 @@ import android.Manifest
 import android.content.Context
 import android.content.pm.PackageManager
 import android.location.LocationManager
-import android.os.Build
 import androidx.core.content.ContextCompat
 
 /** Checks if the device has a GPS receiver. */
@@ -44,22 +43,12 @@ fun Context.gpsDisabled(): Boolean {
  * Determines the list of Bluetooth permissions that are currently missing. Internal helper for
  * [hasBluetoothPermission].
  *
- * For Android S (API 31) and above, this includes [Manifest.permission.BLUETOOTH_SCAN] and
- * [Manifest.permission.BLUETOOTH_CONNECT]. For older versions, it includes [Manifest.permission.ACCESS_FINE_LOCATION]
- * as it is required for Bluetooth scanning.
+ * This includes [Manifest.permission.BLUETOOTH_SCAN] and [Manifest.permission.BLUETOOTH_CONNECT].
  *
  * @return Array of missing Bluetooth permission strings. Empty if all are granted.
  */
 private fun Context.getBluetoothPermissions(): Array<String> {
-    val requiredPermissions = mutableListOf<String>()
-
-    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
-        requiredPermissions.add(Manifest.permission.BLUETOOTH_SCAN)
-        requiredPermissions.add(Manifest.permission.BLUETOOTH_CONNECT)
-    } else {
-        // ACCESS_FINE_LOCATION is required for Bluetooth scanning on pre-S devices.
-        requiredPermissions.add(Manifest.permission.ACCESS_FINE_LOCATION)
-    }
+    val requiredPermissions = listOf(Manifest.permission.BLUETOOTH_SCAN, Manifest.permission.BLUETOOTH_CONNECT)
     return requiredPermissions
         .filter { ContextCompat.checkSelfPermission(this, it) != PackageManager.PERMISSION_GRANTED }
         .toTypedArray()

core/data/src/main/kotlin/org/meshtastic/core/data/repository/LocationRepository.kt

@@ -77,7 +77,7 @@ constructor(
 
         val providerList = buildList {
             val providers = allProviders
-            if (android.os.Build.VERSION.SDK_INT >= 31 && LocationManager.FUSED_PROVIDER in providers) {
+            if (LocationManager.FUSED_PROVIDER in providers) {
                 add(LocationManager.FUSED_PROVIDER)
             } else {
                 if (LocationManager.GPS_PROVIDER in providers) add(LocationManager.GPS_PROVIDER)

core/model/src/main/kotlin/org/meshtastic/core/model/util/DistanceExtensions.kt

@@ -33,20 +33,9 @@ enum class DistanceUnit(val symbol: String, val multiplier: Float, val system: I
 
     companion object {
         fun getFromLocale(locale: Locale = Locale.getDefault()): DisplayUnits =
-            if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.P) {
-                when (LocaleData.getMeasurementSystem(ULocale.forLocale(locale))) {
-                    LocaleData.MeasurementSystem.SI -> DisplayUnits.METRIC
-                    else -> DisplayUnits.IMPERIAL
-                }
-            } else {
-                when (locale.country.uppercase(locale)) {
-                    "US",
-                    "LR",
-                    "MM",
-                    "GB",
-                    -> DisplayUnits.IMPERIAL
-                    else -> DisplayUnits.METRIC
-                }
+            when (LocaleData.getMeasurementSystem(ULocale.forLocale(locale))) {
+                LocaleData.MeasurementSystem.SI -> DisplayUnits.METRIC
+                else -> DisplayUnits.IMPERIAL
             }
     }
 }

core/ui/src/main/kotlin/org/meshtastic/core/ui/theme/Theme.kt

@@ -19,7 +19,6 @@
 
 package org.meshtastic.core.ui.theme
 
-import android.os.Build
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
 import androidx.compose.material3.MaterialExpressiveTheme
@@ -283,7 +282,7 @@ fun AppTheme(
 ) {
     val colorScheme =
         when {
-            dynamicColor && Build.VERSION.SDK_INT >= Build.VERSION_CODES.S -> {
+            dynamicColor -> {
                 val context = LocalContext.current
                 if (darkTheme) dynamicDarkColorScheme(context) else dynamicLightColorScheme(context)
             }