ConfigurationAccessService: prevent service from being stopped when app loses focus

This makes the ConfigurationAccessService (formerly ConfigurationFtpService) start in foreground
through the use of a persistent notification so that it isn't stopped by the system after the app
loses the focus on the user's screen, which happens when the user switches to an FTP client
application on the same device.

3 files changed, 65 insertions, 24 deletions

diff --git a/app/src/main/java/org/pacien/tincapp/activities/configure/ConfigurationFtpServerFragment.kt b/app/src/main/java/org/pacien/tincapp/activities/configure/ConfigurationAccessServerFragment.kt
index b97a15e..9fee749 100644
--- a/app/src/main/java/org/pacien/tincapp/activities/configure/ConfigurationFtpServerFragment.kt
+++ b/app/src/main/java/org/pacien/tincapp/activities/configure/ConfigurationAccessServerFragment.kt
@@ -26,43 +26,43 @@ import android.view.ViewGroup
 import androidx.databinding.Observable
 import androidx.databinding.ObservableBoolean
 import org.pacien.tincapp.activities.BaseFragment
-import org.pacien.tincapp.databinding.ConfigureToolsConfigurationFtpServerFragmentBinding
-import org.pacien.tincapp.service.ConfigurationFtpService
+import org.pacien.tincapp.databinding.ConfigureToolsConfigurationAccessFragmentBinding
+import org.pacien.tincapp.service.ConfigurationAccessService
 
 /**
  * @author pacien
  */
-class ConfigurationFtpServerFragment : BaseFragment() {
+class ConfigurationAccessServerFragment : BaseFragment() {
   private val ftpServerStartListener = object : Observable.OnPropertyChangedCallback() {
     override fun onPropertyChanged(sender: Observable, propertyId: Int) {
       binding.ftpEnabled = (sender as ObservableBoolean).get()
     }
   }
 
-  private lateinit var binding: ConfigureToolsConfigurationFtpServerFragmentBinding
+  private lateinit var binding: ConfigureToolsConfigurationAccessFragmentBinding
 
   override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
-    binding = ConfigureToolsConfigurationFtpServerFragmentBinding.inflate(inflater, container, false)
-    binding.ftpUsername = ConfigurationFtpService.FTP_USERNAME
-    binding.ftpPassword = ConfigurationFtpService.FTP_PASSWORD
-    binding.ftpPort = ConfigurationFtpService.FTP_PORT
+    binding = ConfigureToolsConfigurationAccessFragmentBinding.inflate(inflater, container, false)
+    binding.ftpUsername = ConfigurationAccessService.FTP_USERNAME
+    binding.ftpPassword = ConfigurationAccessService.FTP_PASSWORD
+    binding.ftpPort = ConfigurationAccessService.FTP_PORT
     binding.toggleFtpState = { toggleServer() }
     return binding.root
   }
 
   override fun onResume() {
     super.onResume()
-    ConfigurationFtpService.runningState.addOnPropertyChangedCallback(ftpServerStartListener)
-    binding.ftpEnabled = ConfigurationFtpService.runningState.get()
+    ConfigurationAccessService.runningState.addOnPropertyChangedCallback(ftpServerStartListener)
+    binding.ftpEnabled = ConfigurationAccessService.runningState.get()
   }
 
   override fun onPause() {
-    ConfigurationFtpService.runningState.removeOnPropertyChangedCallback(ftpServerStartListener)
+    ConfigurationAccessService.runningState.removeOnPropertyChangedCallback(ftpServerStartListener)
     super.onPause()
   }
 
   private fun toggleServer() {
-    val targetServiceIntent = Intent(requireContext(), ConfigurationFtpService::class.java)
+    val targetServiceIntent = Intent(requireContext(), ConfigurationAccessService::class.java)
 
     if (binding.ftpEnabled)
       requireContext().stopService(targetServiceIntent)
diff --git a/app/src/main/java/org/pacien/tincapp/context/AppNotificationManager.kt b/app/src/main/java/org/pacien/tincapp/context/AppNotificationManager.kt
index 38bf6e4..9d731a5 100644
--- a/app/src/main/java/org/pacien/tincapp/context/AppNotificationManager.kt
+++ b/app/src/main/java/org/pacien/tincapp/context/AppNotificationManager.kt
@@ -1,6 +1,6 @@
 /*
  * Tinc App, an Android binding and user interface for the tinc mesh VPN daemon
- * Copyright (C) 2017-2019 Pacien TRAN-GIRARD
+ * Copyright (C) 2017-2020 Pacien TRAN-GIRARD
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -18,6 +18,7 @@
 
 package org.pacien.tincapp.context
 
+import android.app.Notification
 import android.app.NotificationChannel
 import android.app.NotificationManager
 import android.app.PendingIntent
@@ -35,16 +36,19 @@ import org.pacien.tincapp.R
  */
 class AppNotificationManager(private val context: Context) {
   companion object {
-    private const val CHANNEL_ID = "org.pacien.tincapp.notification.channels.error"
-    private const val ERROR_NOTIFICATION_ID = 0
+    private const val ERROR_CHANNEL_ID = "org.pacien.tincapp.notification.channels.error"
+    private const val CONFIG_ACCESS_CHANNEL_ID = "org.pacien.tincapp.notification.channels.configuration"
+
+    const val ERROR_NOTIFICATION_ID = 0
+    const val CONFIG_ACCESS_NOTIFICATION_ID = 1
   }
 
   init {
-    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) registerChannel()
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) registerChannels()
   }
 
   fun notifyError(title: String, message: String, manualLink: String? = null) {
-    val notification = NotificationCompat.Builder(context, CHANNEL_ID)
+    val notification = NotificationCompat.Builder(context, ERROR_CHANNEL_ID)
       .setSmallIcon(R.drawable.ic_warning_primary_24dp)
       .setContentTitle(title)
       .setContentText(message)
@@ -62,13 +66,26 @@ class AppNotificationManager(private val context: Context) {
     NotificationManagerCompat.from(context).cancelAll()
   }
 
+  fun newConfigurationAccessNotificationBuilder() =
+    NotificationCompat.Builder(context, CONFIG_ACCESS_CHANNEL_ID)
+
   @RequiresApi(Build.VERSION_CODES.O)
-  private fun registerChannel() {
-    val name = context.getString(R.string.notification_error_channel_name)
-    val importance = NotificationManager.IMPORTANCE_HIGH
-    val channel = NotificationChannel(CHANNEL_ID, name, importance)
-    val notificationManager = context.getSystemService(NotificationManager::class.java)
-    notificationManager.createNotificationChannel(channel)
+  private fun registerChannels() {
+    context.getSystemService(NotificationManager::class.java)
+      .apply {
+        createNotificationChannel(NotificationChannel(
+          ERROR_CHANNEL_ID,
+          context.getString(R.string.notification_error_channel_name),
+          NotificationManager.IMPORTANCE_HIGH
+        ))
+      }
+      .apply {
+        createNotificationChannel(NotificationChannel(
+          CONFIG_ACCESS_CHANNEL_ID,
+          context.getString(R.string.notification_config_access_channel_name),
+          NotificationManager.IMPORTANCE_MIN
+        ))
+      }
   }
 
   private fun NotificationCompat.Builder.setHighPriority() = apply {
diff --git a/app/src/main/java/org/pacien/tincapp/service/ConfigurationFtpService.kt b/app/src/main/java/org/pacien/tincapp/service/ConfigurationAccessService.kt
index 2ea4a16..b083a83 100644
--- a/app/src/main/java/org/pacien/tincapp/service/ConfigurationFtpService.kt
+++ b/app/src/main/java/org/pacien/tincapp/service/ConfigurationAccessService.kt
@@ -18,6 +18,7 @@
 
 package org.pacien.tincapp.service
 
+import android.app.PendingIntent
 import android.app.Service
 import android.content.Intent
 import android.os.IBinder
@@ -31,7 +32,9 @@ import org.apache.ftpserver.listener.ListenerFactory
 import org.apache.ftpserver.usermanager.UsernamePasswordAuthentication
 import org.apache.ftpserver.usermanager.impl.WritePermission
 import org.pacien.tincapp.R
+import org.pacien.tincapp.activities.configure.ConfigureActivity
 import org.pacien.tincapp.context.App
+import org.pacien.tincapp.context.AppNotificationManager
 import org.pacien.tincapp.extensions.Java.defaultMessage