Fix boot start: run the boost in a foreground service instead of launching the UI

README.md

@@ -18,6 +18,40 @@ BoostX is a minimal yet powerful sound enhancement tool that allows users to boo
 - Adjustable volume and boost sliders.
 - Boost slider has two modes, discrete (default) and continuous (gradual) control. 
 - Real-time audio insights displaying output device details.
+- Optional **Start on Boot** — the boost is restored automatically after a reboot and stays
+  active in the background, without the app UI being open.
+
+## Start on Boot
+
+Enable **Start on Boot** in the app to have your saved boost and volume reapplied
+automatically after the device restarts.
+
+When the toggle is on (or a boost is active), BoostX runs a small foreground service that owns
+the audio effects, so the boost survives the UI being closed or swept out of recents. While it
+is running you'll see a persistent low-priority notification — *"BoostX active — Keeping volume
+boost at N%"* — which Android requires for any foreground service. Dismissing the boost from
+the app stops the service and the notification with it.
+
+Notes:
+
+- On Android 13+ the app asks for the notification permission the first time it needs to show
+  the service notification. If you deny it, the service still runs, but the notification is
+  hidden.
+- The service is declared as a `specialUse` foreground service. `mediaPlayback` is not usable
+  here because Android 15 forbids starting that type from `BOOT_COMPLETED`.
+- Some vendor ROMs aggressively kill background apps. If the boost doesn't come back after a
+  reboot, exempt BoostX from battery optimisation in the system settings.
+
+## Troubleshooting
+
+**The boost stops working when I play music (LineageOS / AudioFX ROMs).**
+
+System equalizers such as LineageOS' AudioFX attach their own effect to a music app's audio
+session. When they do, AudioFlinger *suspends* global (session 0) effects — which is where
+BoostX applies its boost — so the slider still shows a boost that you can no longer hear.
+
+This is platform behaviour rather than a BoostX bug. Disabling AudioFX (or whatever system
+equalizer your ROM ships) restores the boost.
 
 ## Screenshots
 

app/src/main/AndroidManifest.xml

@@ -8,6 +8,9 @@
     <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
     <uses-permission android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS"/>
     <uses-permission android:name="android.permission.WAKE_LOCK" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE"/>
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_SPECIAL_USE"/>
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
 
     <application
         android:allowBackup="true"
@@ -37,9 +40,19 @@
             <intent-filter>
                 <action android:name="android.intent.action.BOOT_COMPLETED" />
                 <action android:name="android.intent.action.QUICKBOOT_POWERON" />
+                <action android:name="com.htc.intent.action.QUICKBOOT_POWERON" />
             </intent-filter>
         </receiver>
 
+        <service
+            android:name=".BoostService"
+            android:exported="false"
+            android:foregroundServiceType="specialUse">
+            <property
+                android:name="android.app.PROPERTY_SPECIAL_USE_FGS_SUBTYPE"
+                android:value="Maintains a persistent system-wide audio loudness boost selected by the user" />
+        </service>
+
     </application>
 
 </manifest>

app/src/main/java/com/example/boostx/ActivityMain.kt

@@ -2,6 +2,7 @@ package com.example.boostx
 
 import android.Manifest
 import android.content.Context
+import android.content.SharedPreferences
 import android.content.pm.PackageManager
 import androidx.core.app.ActivityCompat
 import androidx.core.content.ContextCompat
@@ -46,6 +47,7 @@ class MainActivity : AppCompatActivity() {
     private lateinit var outputDeviceTextView: TextView
 
     private lateinit var audioController: AudioController
+    private lateinit var prefs: SharedPreferences
 
     private val handler = Handler(Looper.getMainLooper())
     private val updateRunnable = object : Runnable {
@@ -62,7 +64,8 @@ class MainActivity : AppCompatActivity() {
 
         checkPermissions()
 
-        audioController = AudioController(this)
+        audioController = AudioController.getInstance(this)
+        prefs = getSharedPreferences("BoostXPrefs", Context.MODE_PRIVATE)
 
         boostSlider = findViewById(R.id.boostSlider)
         volumeSlider = findViewById(R.id.volumeSlider)
@@ -84,13 +87,15 @@ class MainActivity : AppCompatActivity() {
         )
         gradualBoostSwitch.setOnCheckedChangeListener { _, isChecked ->
             handleGradualBoostSwitch(isChecked, originalBoostSliderProperties)
+            prefs.edit().putBoolean("gradual_boost", isChecked).apply()
         }
 
         bootStartSwitch.setOnCheckedChangeListener { _, isChecked ->
             handleBootStartSwitch(isChecked)
+            prefs.edit().putBoolean("boot_start", isChecked).apply()
+            updateServiceState()
         }
 
-        val prefs = getSharedPreferences("BoostXPrefs", Context.MODE_PRIVATE)
         val savedBoost = prefs.getFloat("boost_value", 0f)
         val savedVolume = prefs.getFloat("volume_value", 100f)
         val savedGradual = prefs.getBoolean("gradual_boost", false)
@@ -120,8 +125,14 @@ class MainActivity : AppCompatActivity() {
         applyBoost(validatedBoost.toInt())
         applyVolume(savedVolume.toInt())
 
-        boostSlider.addOnChangeListener { _, value, _ -> applyBoost(value.toInt()) }
-        volumeSlider.addOnChangeListener { _, value, _ -> applyVolume(value.toInt()) }
+        boostSlider.addOnChangeListener { _, value, _ ->
+            applyBoost(value.toInt())
+            prefs.edit().putFloat("boost_value", value).apply()
+        }
+        volumeSlider.addOnChangeListener { _, value, _ ->
+            applyVolume(value.toInt())
+            prefs.edit().putFloat("volume_value", value).apply()
+        }
 
         findViewById<TextView>(R.id.infoIcon).setOnClickListener {
             showAppInfo()
@@ -131,8 +142,17 @@ class MainActivity : AppCompatActivity() {
     }
 
     private fun checkPermissions() {
+        val permissions = mutableListOf<String>()
         if (ContextCompat.checkSelfPermission(this, Manifest.permission.RECORD_AUDIO) != PackageManager.PERMISSION_GRANTED) {
-            ActivityCompat.requestPermissions(this, arrayOf(Manifest.permission.RECORD_AUDIO), 1001)
+            permissions.add(Manifest.permission.RECORD_AUDIO)
+        }
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            if (ContextCompat.checkSelfPermission(this, Manifest.permission.POST_NOTIFICATIONS) != PackageManager.PERMISSION_GRANTED) {
+                permissions.add(Manifest.permission.POST_NOTIFICATIONS)
+            }
+        }
+        if (permissions.isNotEmpty()) {
+            ActivityCompat.requestPermissions(this, permissions.toTypedArray(), 1001)
         }
     }
 
@@ -291,6 +311,16 @@ class MainActivity : AppCompatActivity() {
         }
     }
 
+    private fun updateServiceState() {
+        val boostActive = boostSlider.value > 0f
+        val bootStart = bootStartSwitch.isChecked
+        if (boostActive || bootStart) {
+            BoostService.start(this)
+        } else if (BoostService.isRunning) {
+            BoostService.stop(this)
+        }
+    }
+
     override fun onResume() {
         super.onResume()
         handler.post(updateRunnable)
@@ -300,19 +330,21 @@ class MainActivity : AppCompatActivity() {
         super.onPause()
         handler.removeCallbacks(updateRunnable)
 
-        val prefs = getSharedPreferences("BoostXPrefs", Context.MODE_PRIVATE)
         prefs.edit().apply {
             putFloat("boost_value", boostSlider.value)
             putFloat("volume_value", volumeSlider.value)
             putBoolean("gradual_boost", gradualBoostSwitch.isChecked)
             putBoolean("boot_start", bootStartSwitch.isChecked)
             apply()
         }
+        updateServiceState()
     }
 
     override fun onDestroy() {
         super.onDestroy()
-        audioController.release()
+        if (!BoostService.isRunning) {
+            audioController.release()
+        }
         handler.removeCallbacks(updateRunnable)
         handler.removeCallbacksAndMessages(null)
     }

app/src/main/java/com/example/boostx/AudioController.kt

@@ -12,7 +12,7 @@ import android.os.Handler
 import android.os.Looper
 import android.view.KeyEvent
 
-class AudioController(private val context: Context) {
+class AudioController private constructor(private val context: Context) {
     private val audioManager: AudioManager = context.getSystemService(Context.AUDIO_SERVICE) as AudioManager
     private var loudnessEnhancer: LoudnessEnhancer? = null
     private var dynamicsProcessing: DynamicsProcessing? = null
@@ -27,6 +27,17 @@ class AudioController(private val context: Context) {
 
     private var currentBoostLevel: Int = 0
 
+    companion object {
+        @Volatile
+        private var instance: AudioController? = null
+
+        fun getInstance(context: Context): AudioController {
+            return instance ?: synchronized(this) {
+                instance ?: AudioController(context.applicationContext).also { instance = it }
+            }
+        }
+    }
+
     init {
         setupEffects()
         audioSessionID = audioManager.generateAudioSessionId()
@@ -235,5 +246,9 @@ class AudioController(private val context: Context) {
         loudnessEnhancer?.release()
         dynamicsProcessing?.release()
         visualizer?.release()
+        loudnessEnhancer = null
+        dynamicsProcessing = null
+        visualizer = null
+        instance = null
     }
 }

app/src/main/java/com/example/boostx/BoostService.kt

@@ -0,0 +1,97 @@
+package com.example.boostx
+
+import android.app.Notification
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.PendingIntent
+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 androidx.core.app.NotificationCompat
+import androidx.core.app.ServiceCompat
+import androidx.core.content.ContextCompat
+
+class BoostService : Service() {
+
+    companion object {
+        private const val CHANNEL_ID = "boostx_service"
+        private const val NOTIFICATION_ID = 1
+
+        @Volatile
+        var isRunning = false
+            private set
+
+        fun start(context: Context) {
+            ContextCompat.startForegroundService(context, Intent(context, BoostService::class.java))
+        }
+
+        fun stop(context: Context) {
+            context.stopService(Intent(context, BoostService::class.java))
+        }
+    }
+
+    override fun onCreate() {
+        super.onCreate()
+        isRunning = true
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            val channel = NotificationChannel(
+                CHANNEL_ID,
+                getString(R.string.boost_service_channel_name),
+                NotificationManager.IMPORTANCE_LOW
+            )
+            val notificationManager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
+            notificationManager.createNotificationChannel(channel)
+        }
+    }
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        val prefs = getSharedPreferences("BoostXPrefs", Context.MODE_PRIVATE)
+        val boostLevel = prefs.getFloat("boost_value", 0f).toInt()
+        val volumeLevel = prefs.getFloat("volume_value", 100f).toInt()
+
+        val contentIntent = PendingIntent.getActivity(
+            this,
+            0,
+            Intent(this, MainActivity::class.java),
+            PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
+        )
+
+        val notification = NotificationCompat.Builder(this, CHANNEL_ID)
+            .setContentTitle(getString(R.string.boost_notification_title))
+            .setContentText(getString(R.string.boost_notification_text, boostLevel))
+            .setSmallIcon(R.drawable.ic_launcher_foreground)
+            .setOngoing(true)
+            .setOnlyAlertOnce(true)
+            .setPriority(NotificationCompat.PRIORITY_LOW)
+            .setContentIntent(contentIntent)
+            .build()
+
+        val type = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.UPSIDE_DOWN_CAKE) {
+            ServiceInfo.FOREGROUND_SERVICE_TYPE_SPECIAL_USE
+        } else {
+            0
+        }
+
+        ServiceCompat.startForeground(this, NOTIFICATION_ID, notification, type)
+
+        try {
+            val controller = AudioController.getInstance(this)
+            controller.applyBoost(boostLevel)
+            controller.applyVolume(volumeLevel)
+        } catch (e: Exception) {
+            e.printStackTrace()
+        }
+
+        return START_STICKY
+    }
+
+    override fun onDestroy() {
+        isRunning = false
+        super.onDestroy()
+    }
+
+    override fun onBind(intent: Intent?): IBinder? = null
+}

app/src/main/java/com/example/boostx/BootReceiver.kt

@@ -7,15 +7,14 @@ import android.content.Intent
 class BootReceiver : BroadcastReceiver() {
     override fun onReceive(context: Context, intent: Intent) {
         if (intent.action == Intent.ACTION_BOOT_COMPLETED || 
-            intent.action == "android.intent.action.QUICKBOOT_POWERON") {
+            intent.action == "android.intent.action.QUICKBOOT_POWERON" ||
+            intent.action == "com.htc.intent.action.QUICKBOOT_POWERON") {
 
             val prefs = context.getSharedPreferences("BoostXPrefs", Context.MODE_PRIVATE)
             val bootStart = prefs.getBoolean("boot_start", false)
 
             if (bootStart) {
-                val i = Intent(context, MainActivity::class.java)
-                i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
-                context.startActivity(i)
+                BoostService.start(context)
             }
         }
     }

app/src/main/res/values-nl/strings.xml

@@ -33,4 +33,7 @@
     <string name="device_earpiece">Oortje</string>
     <string name="device_unknown">Onbekend apparaat</string>
     <string name="format_unknown">Onbekend formaat</string>
+    <string name="boost_service_channel_name">Achtergrond-boostservice</string>
+    <string name="boost_notification_title">BoostX actief</string>
+    <string name="boost_notification_text">Volumeboost actief op %1$d%%</string>
 </resources>

app/src/main/res/values/strings.xml

@@ -33,4 +33,7 @@
     <string name="device_earpiece">Earpiece</string>
     <string name="device_unknown">Unknown Device</string>
     <string name="format_unknown">Unknown Format</string>
+    <string name="boost_service_channel_name">Background boost service</string>
+    <string name="boost_notification_title">BoostX active</string>
+    <string name="boost_notification_text">Keeping volume boost at %1$d%%</string>
 </resources>