null safety

app/src/main/java/me/lucky/wasted/AppNotificationManager.kt

@@ -10,11 +10,15 @@ class AppNotificationManager(private val ctx: Context) {
         const val CHANNEL_DEFAULT_ID = "default"
     }
 
+    private var manager: NotificationManager? = null
+
+    init {
+        manager = ctx.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager?
+    }
+
     fun createNotificationChannels() {
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) return
-        val notificationManager =
+        manager?.createNotificationChannel(
-            ctx.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
-        notificationManager.createNotificationChannel(
             NotificationChannel(
                 CHANNEL_DEFAULT_ID,
                 ctx.getString(R.string.notification_channel_default_name),

app/src/main/java/me/lucky/wasted/CodeReceiver.kt

@@ -9,7 +9,8 @@ class CodeReceiver : BroadcastReceiver() {
         const val KEY = "code"
         const val ACTION = "me.lucky.wasted.action.TRIGGER"
 
-        fun panic(context: Context, intent: Intent) {
+        fun panic(context: Context?, intent: Intent?) {
+            if (context == null || intent == null) return
             val prefs = Preferences(context)
             val code = prefs.code
             if (!prefs.isServiceEnabled ||
@@ -24,7 +25,7 @@ class CodeReceiver : BroadcastReceiver() {
         }
     }
 
-    override fun onReceive(context: Context, intent: Intent) {
+    override fun onReceive(context: Context?, intent: Intent?) {
         panic(context, intent)
     }
 }

app/src/main/java/me/lucky/wasted/DeviceAdminManager.kt

@@ -7,16 +7,18 @@ import android.content.Intent
 import android.os.Build
 
 class DeviceAdminManager(private val ctx: Context) {
-    private val dpm by lazy {
+    private var dpm: DevicePolicyManager? = null
-        ctx.getSystemService(Context.DEVICE_POLICY_SERVICE) as DevicePolicyManager
-    }
     private val deviceAdmin by lazy { ComponentName(ctx, DeviceAdminReceiver::class.java) }
     private val prefs by lazy { Preferences(ctx) }
 
-    fun remove() = dpm.removeActiveAdmin(deviceAdmin)
+    init {
-    fun isActive(): Boolean = dpm.isAdminActive(deviceAdmin)
+        dpm = ctx.getSystemService(Context.DEVICE_POLICY_SERVICE) as DevicePolicyManager?
-    fun getCurrentFailedPasswordAttempts(): Int = dpm.currentFailedPasswordAttempts
+    }
-    fun lockNow() = dpm.lockNow()
+
+    fun remove() = dpm?.removeActiveAdmin(deviceAdmin)
+    fun isActive(): Boolean = dpm?.isAdminActive(deviceAdmin) ?: false
+    fun getCurrentFailedPasswordAttempts(): Int = dpm?.currentFailedPasswordAttempts ?: 0
+    fun lockNow() = dpm?.lockNow()
 
     fun wipeData() {
         var flags = 0
@@ -24,7 +26,7 @@ class DeviceAdminManager(private val ctx: Context) {
             flags = flags.or(DevicePolicyManager.WIPE_SILENTLY)
         if (prefs.isWipeESIM && Build.VERSION.SDK_INT >= Build.VERSION_CODES.P)
             flags = flags.or(DevicePolicyManager.WIPE_EUICC)
-        dpm.wipeData(flags)
+        dpm?.wipeData(flags)
     }
 
     fun makeRequestIntent(): Intent {

app/src/main/java/me/lucky/wasted/MainActivity.kt

@@ -47,7 +47,7 @@ open class MainActivity : AppCompatActivity() {
     private fun update() {
         if (!admin.isActive() && prefs.isServiceEnabled)
             Snackbar.make(
-                findViewById(R.id.toggle),
+                binding.toggle,
                 R.string.service_unavailable_popup,
                 Snackbar.LENGTH_SHORT,
             ).show()
@@ -149,7 +149,7 @@ open class MainActivity : AppCompatActivity() {
 
     private fun showWipeJobServiceStartFailedPopup() {
         Snackbar.make(
-            findViewById(R.id.toggle),
+            binding.toggle,
             R.string.wipe_job_service_start_failed_popup,
             Snackbar.LENGTH_LONG,
         ).show()

app/src/main/java/me/lucky/wasted/Preferences.kt

@@ -38,8 +38,8 @@ class Preferences(ctx: Context) {
         get() = prefs.getBoolean(SERVICE_ENABLED, false)
         set(value) = prefs.edit { putBoolean(SERVICE_ENABLED, value) }
 
-    var code: String?
+    var code: String
-        get() = prefs.getString(CODE, "")
+        get() = prefs.getString(CODE, "") ?: ""
         set(value) = prefs.edit { putString(CODE, value) }
 
     var isCodeEnabled: Boolean

app/src/main/java/me/lucky/wasted/RestartReceiver.kt

@@ -6,7 +6,8 @@ import android.content.Intent
 import androidx.core.content.ContextCompat
 
 class RestartReceiver : BroadcastReceiver() {
-    override fun onReceive(context: Context, intent: Intent) {
+    override fun onReceive(context: Context?, intent: Intent?) {
+        if (context == null || intent == null) return
         if (intent.action != Intent.ACTION_BOOT_COMPLETED &&
             intent.action != Intent.ACTION_MY_PACKAGE_REPLACED) return
         val prefs = Preferences(context)

app/src/main/java/me/lucky/wasted/UnlockService.kt

@@ -19,13 +19,17 @@ class UnlockService : Service() {
     private lateinit var receiver: BroadcastReceiver
 
     private class UnlockReceiver : BroadcastReceiver() {
-        override fun onReceive(context: Context, intent: Intent) {
+        override fun onReceive(context: Context?, intent: Intent?) {
+            if (context == null) return
             val keyguardManager = context
-                .getSystemService(Context.KEYGUARD_SERVICE) as KeyguardManager
+                .getSystemService(Context.KEYGUARD_SERVICE) as KeyguardManager?
-            if (!keyguardManager.isDeviceSecure) return
+            if (keyguardManager?.isDeviceSecure != true) return
             val manager = WipeJobManager(context)
-            while (manager.schedule() != JobScheduler.RESULT_SUCCESS)
+            var delay = 1000L
-                SystemClock.sleep(1000)
+            while (manager.schedule() != JobScheduler.RESULT_SUCCESS) {
+                SystemClock.sleep(delay)
+                delay = delay.shl(1)
+            }
         }
     }
 

app/src/main/java/me/lucky/wasted/WipeJobManager.kt

@@ -11,24 +11,26 @@ class WipeJobManager(private val ctx: Context) {
         private const val JOB_ID = 1000
     }
     private val prefs by lazy { Preferences(ctx) }
-    private val jobScheduler by lazy {
+    private var scheduler: JobScheduler? = null
-        ctx.getSystemService(Context.JOB_SCHEDULER_SERVICE) as JobScheduler
+
+    init {
+        scheduler = ctx.getSystemService(Context.JOB_SCHEDULER_SERVICE) as JobScheduler?
     }
 
     fun schedule(): Int {
-        return jobScheduler.schedule(
+        return scheduler?.schedule(
             JobInfo.Builder(JOB_ID, ComponentName(ctx, WipeJobService::class.java))
                 .setMinimumLatency(TimeUnit.DAYS.toMillis(prefs.wipeOnInactivityDays.toLong()))
                 .setBackoffCriteria(0, JobInfo.BACKOFF_POLICY_LINEAR)
                 .setPersisted(true)
                 .build()
-        )
+        ) ?: JobScheduler.RESULT_FAILURE
     }
 
     fun setState(value: Boolean): Boolean {
         if (value) {
             if (schedule() == JobScheduler.RESULT_FAILURE) return false
-        } else { jobScheduler.cancel(JOB_ID) }
+        } else { scheduler?.cancel(JOB_ID) }
         return true
     }
 }