Now minimum supported Android version is 6 (API level 23)

app/build.gradle

@@ -7,7 +7,7 @@ android {
     ndkVersion = '25.1.8937393'
     defaultConfig {
         applicationId = 'com.tutpro.baresip'
-        minSdkVersion 21
+        minSdkVersion 23
         targetSdkVersion 33
         versionCode = 275
         versionName = '53.2.3'
@@ -64,7 +64,7 @@ dependencies {
     implementation "androidx.swiperefreshlayout:swiperefreshlayout:1.1.0"
     implementation "androidx.preference:preference-ktx:1.2.0"
     implementation "androidx.exifinterface:exifinterface:1.3.6"
-    implementation "androidx.core:core-ktx:1.9.0"
+    implementation "androidx.core:core-ktx:1.10.0"
     implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.6.4'
     implementation "androidx.lifecycle:lifecycle-extensions:2.2.0"
     implementation "androidx.activity:activity-ktx:1.7.0"

app/src/main/kotlin/com/tutpro/baresip/BaresipService.kt

@@ -701,13 +701,9 @@ class BaresipService: Service() {
                             Log.d(TAG, "Incoming call $uap/$callp/$peerUri")
                             Call(callp, ua, peerUri, "in", "incoming", Utils.dtmfWatcher(callp)).add()
                             if (ua.account.answerMode == Api.ANSWERMODE_MANUAL) {
-                                if (VERSION.SDK_INT >= 23) {
                                 Log.d(TAG, "CurrentInterruptionFilter ${nm.currentInterruptionFilter}")
                                 if (nm.currentInterruptionFilter <= NotificationManager.INTERRUPTION_FILTER_ALL)
                                     startRinging()
-                                } else {
-                                    startRinging()
-                                }
                             } else {
                                 val newIntent = Intent(this, MainActivity::class.java)
                                 newIntent.flags = Intent.FLAG_ACTIVITY_SINGLE_TOP or Intent.FLAG_ACTIVITY_CLEAR_TOP or
@@ -719,10 +715,7 @@ class BaresipService: Service() {
                             }
                         }
                         if (!Utils.isVisible()) {
-                            val piFlags = if (VERSION.SDK_INT >= 23)
+                            val piFlags = PendingIntent.FLAG_IMMUTABLE or PendingIntent.FLAG_UPDATE_CURRENT
-                                PendingIntent.FLAG_IMMUTABLE or PendingIntent.FLAG_UPDATE_CURRENT
-                            else
-                                PendingIntent.FLAG_UPDATE_CURRENT
                             val intent = Intent(applicationContext, MainActivity::class.java)
                             intent.flags = Intent.FLAG_ACTIVITY_SINGLE_TOP or Intent.FLAG_ACTIVITY_CLEAR_TOP or
                                         Intent.FLAG_ACTIVITY_NEW_TASK
@@ -827,10 +820,7 @@ class BaresipService: Service() {
                     }
                     "call transfer" -> {
                         if (!Utils.isVisible()) {
-                            val piFlags = if (VERSION.SDK_INT >= 23)
+                            val piFlags = PendingIntent.FLAG_IMMUTABLE or PendingIntent.FLAG_UPDATE_CURRENT
-                                PendingIntent.FLAG_IMMUTABLE or PendingIntent.FLAG_UPDATE_CURRENT
-                            else
-                                PendingIntent.FLAG_UPDATE_CURRENT
                             val intent = Intent(applicationContext, MainActivity::class.java)
                             intent.flags = Intent.FLAG_ACTIVITY_SINGLE_TOP or
                                 Intent.FLAG_ACTIVITY_CLEAR_TOP or Intent.FLAG_ACTIVITY_NEW_TASK
@@ -917,10 +907,7 @@ class BaresipService: Service() {
                             }
                             if (!Utils.isVisible()) {
                                 if (missed) {
-                                    val piFlags = if (VERSION.SDK_INT >= 23)
+                                    val piFlags = PendingIntent.FLAG_IMMUTABLE or PendingIntent.FLAG_UPDATE_CURRENT
-                                        PendingIntent.FLAG_IMMUTABLE or PendingIntent.FLAG_UPDATE_CURRENT
-                                    else
-                                        PendingIntent.FLAG_UPDATE_CURRENT
                                     val caller = Utils.friendlyUri(this, call.peerUri, ua.account)
                                     val intent = Intent(applicationContext, MainActivity::class.java)
                                     intent.flags = Intent.FLAG_ACTIVITY_SINGLE_TOP or
@@ -935,10 +922,6 @@ class BaresipService: Service() {
                                             .setContentIntent(pi)
                                             .setCategory(Notification.CATEGORY_CALL)
                                             .setAutoCancel(true)
-                                    if (VERSION.SDK_INT < 23) {
-                                        nb.setContentTitle(getString(R.string.missed_call_from))
-                                        nb.setContentText(caller)
-                                    } else {
                                     var missedCalls = 0
                                     for (notification in nm.activeNotifications)
                                         if (notification.id == CALL_MISSED_NOTIFICATION_ID)
@@ -952,7 +935,6 @@ class BaresipService: Service() {
                                                 String.format(getString(R.string.missed_calls_count),
                                                         missedCalls + 1))
                                     }
-                                    }
                                     if (VERSION.SDK_INT < 26) {
                                         @Suppress("DEPRECATION")
                                         nb.setVibrate(LongArray(0))
@@ -1012,10 +994,7 @@ class BaresipService: Service() {
         Message.save()
         ua.account.unreadMessages = true
         if (!Utils.isVisible()) {
-            val piFlags = if (VERSION.SDK_INT >= 23)
+            val piFlags = PendingIntent.FLAG_IMMUTABLE or PendingIntent.FLAG_UPDATE_CURRENT
-                PendingIntent.FLAG_IMMUTABLE or PendingIntent.FLAG_UPDATE_CURRENT
-            else
-                PendingIntent.FLAG_UPDATE_CURRENT
             val intent = Intent(applicationContext, MainActivity::class.java)
             intent.flags = Intent.FLAG_ACTIVITY_SINGLE_TOP or Intent.FLAG_ACTIVITY_CLEAR_TOP or
                         Intent.FLAG_ACTIVITY_NEW_TASK
@@ -1062,11 +1041,8 @@ class BaresipService: Service() {
             nm.notify(MESSAGE_NOTIFICATION_ID, nb.build())
             return
         }
-        if (VERSION.SDK_INT >= 23) {
         if (nm.currentInterruptionFilter <= NotificationManager.INTERRUPTION_FILTER_ALL)
             nt.play()
-        } else
-            nt.play()
         postServiceEvent(ServiceEvent("message show", arrayListOf(uap, peerUri), System.nanoTime()))
     }
 
@@ -1098,7 +1074,6 @@ class BaresipService: Service() {
         Api.net_debug()
         postServiceEvent(ServiceEvent("started", arrayListOf(callActionUri), System.nanoTime()))
         callActionUri = ""
-        if (VERSION.SDK_INT >= 23)
         Log.d(TAG, "Battery optimizations are ignored: " +
                 "${pm.isIgnoringBatteryOptimizations(packageName)}")
         Log.d(TAG, "Partial wake lock/wifi lock is held: " +
@@ -1140,11 +1115,8 @@ class BaresipService: Service() {
         val intent = Intent(applicationContext, MainActivity::class.java)
                 .setAction(Intent.ACTION_MAIN)
                 .addCategory(Intent.CATEGORY_LAUNCHER)
-        val pi = if (VERSION.SDK_INT >= 23)
+        val pi = PendingIntent.getActivity(applicationContext, STATUS_REQ_CODE, intent,
-            PendingIntent.getActivity(applicationContext, STATUS_REQ_CODE, intent,
             PendingIntent.FLAG_IMMUTABLE)
-        else
-            PendingIntent.getActivity(applicationContext, STATUS_REQ_CODE, intent, 0)
         val notificationLayout = RemoteViews(packageName, R.layout.status_notification)
         snb.setVisibility(NotificationCompat.VISIBILITY_PUBLIC)
                 .setSmallIcon(R.drawable.ic_stat)
@@ -1240,12 +1212,8 @@ class BaresipService: Service() {
                 true
             } else {
                 if (am.getStreamVolume(AudioManager.STREAM_RING) != 0) {
-                    if (VERSION.SDK_INT >= Build.VERSION_CODES.M) /* M == 23 */ {
                     @Suppress("DEPRECATION")
                     Settings.System.getInt(contentResolver, Settings.System.VIBRATE_WHEN_RINGING, 0) == 1
-                    } else {
-                        true
-                    }
                 } else {
                     false
                 }
@@ -1370,7 +1338,7 @@ class BaresipService: Service() {
                     removed++
             }
 
-        val active = activeNetwork()
+        val active = cm.activeNetwork
         Log.d(TAG, "Added/Removed/Active = $added/$removed/$active")
 
         if (added > 0 || removed > 0 || active != activeNetwork) {
@@ -1430,7 +1398,7 @@ class BaresipService: Service() {
             return
         val servers = mutableListOf<InetAddress>()
         // Use DNS servers first from active network (if available)
-        val activeNetwork = activeNetwork()
+        val activeNetwork = cm.activeNetwork
         if (activeNetwork != null) {
             val linkProps = cm.getLinkProperties(activeNetwork)
             if (linkProps != null)
@@ -1438,7 +1406,7 @@ class BaresipService: Service() {
         }
         // Then add DNS servers from the other networks
         for (n in allNetworks) {
-            if (isNetworkActive(n)) continue
+            if (n == cm.activeNetwork) continue
             val linkProps = cm.getLinkProperties(n)
             if (linkProps != null)
                 for (server in linkProps.dnsServers)
@@ -1455,25 +1423,6 @@ class BaresipService: Service() {
         }
     }
 
-    private fun activeNetwork(): Network? {
-        return if (VERSION.SDK_INT >= 23)
-            cm.activeNetwork
-        else {
-            for (n in allNetworks)
-                if (isNetworkActive(n)) return n
-            return null
-        }
-    }
-
-    private fun isNetworkActive(network: Network): Boolean {
-        if (VERSION.SDK_INT >= 23)
-            return network == cm.activeNetwork
-        @Suppress("DEPRECATION")
-        if ((cm.activeNetworkInfo != null) && (cm.getNetworkInfo(network) != null))
-            return cm.activeNetworkInfo!!.toString() == cm.getNetworkInfo(network)!!.toString()
-        return false
-    }
-
     private fun registerContentObserver() {
         if (!contentObserverRegistered)
             try {

app/src/main/kotlin/com/tutpro/baresip/BootCompletedReceiver.kt

@@ -45,11 +45,8 @@ class BootCompletedReceiver : BroadcastReceiver() {
                 val channel = NotificationChannel("default", "default",
                         NotificationManager.IMPORTANCE_DEFAULT)
                 nm.createNotificationChannel(channel)
-                val pi = if (Build.VERSION.SDK_INT >= 23)
+                val pi = PendingIntent.getActivity(context, 0, i,
-                    PendingIntent.getActivity(context, 0, i,
                     PendingIntent.FLAG_IMMUTABLE or PendingIntent.FLAG_ONE_SHOT)
-                else
-                    PendingIntent.getActivity(context, 0, i, PendingIntent.FLAG_ONE_SHOT)
                 with(NotificationCompat.Builder(context, "default")) {
                     setSmallIcon(R.drawable.ic_stat)
                     setContentTitle(context.getString(R.string.app_name))

app/src/main/kotlin/com/tutpro/baresip/ConfigActivity.kt

@@ -93,7 +93,6 @@ class ConfigActivity : AppCompatActivity() {
         oldAutoStart = if (asCv.size == 0) "no" else asCv[0]
         autoStart.isChecked = oldAutoStart == "yes"
 
-        if (Build.VERSION.SDK_INT >= 23) {
         val pm = getSystemService(Context.POWER_SERVICE) as PowerManager
         val androidSettingsRequest = registerForActivityResult(
                 ActivityResultContracts.StartActivityForResult()
@@ -109,9 +108,6 @@ class ConfigActivity : AppCompatActivity() {
                     Log.e(TAG, "ActivityNotFound exception: $e")
             }
         }
-        } else {
-            binding.Battery.visibility = View.GONE
-        }
 
         listenAddr = binding.ListenAddress
         val laCv = Config.variable("sip_listen")
@@ -352,8 +348,7 @@ class ConfigActivity : AppCompatActivity() {
         contactsSpinner.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
             override fun onItemSelected(parent: AdapterView<*>, view: View, position: Int, id: Long) {
                 contactsMode = contactsModeKeys[position]
-                if (contactsMode != "baresip" && Build.VERSION.SDK_INT >= 23 &&
+                if (contactsMode != "baresip" && !Utils.checkPermissions(applicationContext, contactsPermissions))
-                        !Utils.checkPermissions(applicationContext, contactsPermissions))
                     with(MaterialAlertDialogBuilder(this@ConfigActivity, R.style.AlertDialogTheme)) {
                         setTitle(getText(R.string.consent_request))
                         setMessage(getText(R.string.contacts_consent))

app/src/main/kotlin/com/tutpro/baresip/MainActivity.kt

@@ -1215,8 +1215,7 @@ class MainActivity : AppCompatActivity() {
                     if (acc.missedCalls)
                         callsButton.setImageResource(R.drawable.calls_missed)
                 }
-                if ((Build.VERSION.SDK_INT >= 22 && kgm.isDeviceLocked) ||
+                if (kgm.isDeviceLocked)
-                        (Build.VERSION.SDK_INT < 22 && kgm.isKeyguardLocked && kgm.isKeyguardSecure))
                     Utils.setShowWhenLocked(this, false)
             }
             "message", "message show", "message reply" -> {

app/src/main/kotlin/com/tutpro/baresip/Utils.kt

@@ -476,8 +476,6 @@ object Utils {
     }
 
     fun checkPermissions(ctx: Context, permissions: Array<String>) : Boolean {
-        if (Build.VERSION.SDK_INT < 23)
-            return true
         for (p in permissions) {
             if (ContextCompat.checkSelfPermission(ctx, p) != PackageManager.PERMISSION_GRANTED) {
                 Log.d(TAG, "Permission $p is denied")