Implement background notifications

app/src/main/java/de/kuschku/quasseldroid_ng/service/QuasselService.kt

@@ -4,13 +4,17 @@ import android.annotation.SuppressLint
 import android.arch.lifecycle.LifecycleService
 import android.arch.lifecycle.Observer
 import android.content.Intent
+import android.content.SharedPreferences
 import android.os.Binder
+import android.support.v7.preference.PreferenceManager
 import de.kuschku.libquassel.protocol.*
 import de.kuschku.libquassel.session.*
 import de.kuschku.quasseldroid_ng.BuildConfig
 import de.kuschku.quasseldroid_ng.R
 import de.kuschku.quasseldroid_ng.persistence.QuasselBacklogStorage
 import de.kuschku.quasseldroid_ng.persistence.QuasselDatabase
+import de.kuschku.quasseldroid_ng.ui.settings.data.ConnectionSettings
+import de.kuschku.quasseldroid_ng.ui.settings.data.Settings
 import de.kuschku.quasseldroid_ng.util.AndroidHandlerThread
 import de.kuschku.quasseldroid_ng.util.compatibility.AndroidHandlerService
 import de.kuschku.quasseldroid_ng.util.helper.toLiveData
@@ -19,11 +23,33 @@ import java.security.cert.X509Certificate
 import java.util.concurrent.TimeUnit
 import javax.net.ssl.X509TrustManager
 
-class QuasselService : LifecycleService() {
+class QuasselService : LifecycleService(), SharedPreferences.OnSharedPreferenceChangeListener {
+  override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
+    val connectionSettings = Settings.connection(this)
+    if (this.connectionSettings.showNotification != connectionSettings.showNotification) {
+      this.connectionSettings = connectionSettings
+
+      updateNotification(connectionSettings.showNotification)
+    }
+  }
+
+  private lateinit var notificationManager: de.kuschku.quasseldroid_ng.util.NotificationManager
+
+  private fun updateNotification(showNotification: Boolean) {
+    if (showNotification) {
+      val (id, notification) = notificationManager.notificationBackground()
+      startForeground(id, notification)
+    } else {
+      stopForeground(true)
+    }
+  }
+
   private lateinit var sessionManager: SessionManager
 
   private lateinit var clientData: ClientData
 
+  private lateinit var connectionSettings: ConnectionSettings
+
   private val trustManager = object : X509TrustManager {
     @SuppressLint("TrustAllX509TrustManager")
     override fun checkClientTrusted(p0: Array<out X509Certificate>?, p1: String?) = Unit
@@ -126,6 +152,15 @@ class QuasselService : LifecycleService() {
         sessionManager.reconnect()
       }
       )
+
+    connectionSettings = Settings.connection(this)
+
+    PreferenceManager.getDefaultSharedPreferences(this)
+      .registerOnSharedPreferenceChangeListener(this)
+
+    notificationManager = de.kuschku.quasseldroid_ng.util.NotificationManager(this)
+    notificationManager.init()
+    updateNotification(connectionSettings.showNotification)
   }
 
   override fun onBind(intent: Intent?): QuasselBinder {

app/src/main/java/de/kuschku/quasseldroid_ng/ui/settings/data/ConnectionSettings.kt

+package de.kuschku.quasseldroid_ng.ui.settings.data
+
+data class ConnectionSettings(
+  val showNotification: Boolean = true
+) {
+  companion object {
+    val DEFAULT = ConnectionSettings()
+  }
+}
\ No newline at end of file

app/src/main/java/de/kuschku/quasseldroid_ng/ui/settings/data/Settings.kt

 package de.kuschku.quasseldroid_ng.ui.settings.data
 
 import android.content.Context
-import android.content.SharedPreferences
-import android.preference.PreferenceManager
 import de.kuschku.quasseldroid_ng.R
 import de.kuschku.quasseldroid_ng.ui.settings.data.AppearanceSettings.*
+import de.kuschku.quasseldroid_ng.util.helper.sharedPreferences
 
 object Settings {
-  private fun <T> settings(context: Context,
-                           f: SharedPreferences.() -> T) = PreferenceManager.getDefaultSharedPreferences(
-    context
-  ).f()
-
-  fun appearance(context: Context) = settings(
-    context
-  ) {
+  fun appearance(context: Context) = context.sharedPreferences {
     AppearanceSettings(
       theme = Theme.valueOf(
         getString(
@@ -57,9 +49,7 @@ object Settings {
     )
   }
 
-  fun backlog(context: Context) = settings(
-    context
-  ) {
+  fun backlog(context: Context) = context.sharedPreferences {
     BacklogSettings(
       dynamicAmount = getString(
         context.getString(R.string.preference_dynamic_fetch_key),
@@ -67,4 +57,13 @@ object Settings {
       ).toIntOrNull() ?: BacklogSettings.DEFAULT.dynamicAmount
     )
   }
+
+  fun connection(context: Context) = context.sharedPreferences {
+    ConnectionSettings(
+      showNotification = getBoolean(
+        context.getString(R.string.preference_show_notification_key),
+        ConnectionSettings.DEFAULT.showNotification
+      )
+    )
+  }
 }
\ No newline at end of file

app/src/main/java/de/kuschku/quasseldroid_ng/util/NotificationManager.kt

+package de.kuschku.quasseldroid_ng.util
+
+import android.annotation.TargetApi
+import android.app.Notification
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.PendingIntent
+import android.content.Context
+import android.content.Intent
+import android.os.Build
+import android.support.v4.app.NotificationCompat
+import de.kuschku.quasseldroid_ng.R
+import de.kuschku.quasseldroid_ng.ui.setup.accounts.AccountSelectionActivity
+import de.kuschku.quasseldroid_ng.util.helper.editApply
+import de.kuschku.quasseldroid_ng.util.helper.sharedPreferences
+import de.kuschku.quasseldroid_ng.util.helper.systemService
+
+class NotificationManager(private val context: Context) {
+  fun init() {
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
+      prepareChannels()
+  }
+
+  @TargetApi(Build.VERSION_CODES.O)
+  private fun prepareChannels() {
+    val notificationManager = context.systemService<NotificationManager>()
+    notificationManager.createNotificationChannels(
+      listOf(
+        NotificationChannel(
+          context.getString(R.string.notification_channel_background),
+          context.getString(R.string.notification_channel_background_title),
+          NotificationManager.IMPORTANCE_MIN
+        ),
+        NotificationChannel(
+          context.getString(R.string.notification_channel_highlight),
+          context.getString(R.string.notification_channel_highlight_title),
+          NotificationManager.IMPORTANCE_HIGH
+        )
+      )
+    )
+  }
+
+  private fun id(): Int = context.sharedPreferences {
+    val key = context.getString(R.string.preference_notification_id_key)
+    val id = getInt(key, 1) + 1
+    editApply {
+      putInt(key, id)
+    }
+    id
+  }
+
+  fun notificationBackground(): Pair<Int, Notification> {
+    val notification = NotificationCompat.Builder(
+      context.applicationContext,
+      context.getString(R.string.notification_channel_background)
+    )
+      .setContentIntent(
+        PendingIntent.getActivity(
+          context.applicationContext, 0,
+          Intent(context.applicationContext, AccountSelectionActivity::class.java), 0
+        )
+      )
+      .setContentText(context.getString(R.string.label_running_in_background))
+      .setSmallIcon(R.mipmap.ic_launcher_recents)
+      .setPriority(NotificationCompat.PRIORITY_MIN)
+      .build()
+
+    return BACKGROUND_NOTIFICATION_ID to notification
+  }
+
+  companion object {
+    val BACKGROUND_NOTIFICATION_ID = Int.MAX_VALUE
+  }
+}
\ No newline at end of file

app/src/main/java/de/kuschku/quasseldroid_ng/util/helper/ContextHelper.kt

 package de.kuschku.quasseldroid_ng.util.helper
 
 import android.content.Context
+import android.content.SharedPreferences
 import android.graphics.drawable.Drawable
 import android.os.Build
+import android.preference.PreferenceManager
 import android.support.annotation.ColorInt
 import android.support.annotation.ColorRes
 import android.support.annotation.DrawableRes
@@ -38,3 +40,7 @@ fun Context.getCompatColor(@ColorRes id: Int): Int {
     this.resources.getColor(id)
   }
 }
+
+
+fun <T> Context.sharedPreferences(f: SharedPreferences.() -> T) =
+  PreferenceManager.getDefaultSharedPreferences(this).f()
\ No newline at end of file

app/src/main/java/de/kuschku/quasseldroid_ng/util/service/ServiceBoundActivity.kt

@@ -10,6 +10,7 @@ import de.kuschku.libquassel.session.Backend
 import de.kuschku.quasseldroid_ng.Keys
 import de.kuschku.quasseldroid_ng.R
 import de.kuschku.quasseldroid_ng.ui.settings.data.AppearanceSettings
+import de.kuschku.quasseldroid_ng.ui.settings.data.ConnectionSettings
 import de.kuschku.quasseldroid_ng.ui.settings.data.Settings
 import de.kuschku.quasseldroid_ng.util.helper.updateRecentsHeaderIfExisting
 
@@ -24,12 +25,14 @@ abstract class ServiceBoundActivity : AppCompatActivity() {
     get() = connection.backend
 
   protected lateinit var appearanceSettings: AppearanceSettings
+  protected lateinit var connectionSettings: ConnectionSettings
   protected var accountId: Long = -1
 
   override fun onCreate(savedInstanceState: Bundle?) {
     connection.context = this
 
     appearanceSettings = Settings.appearance(this)
+    connectionSettings = Settings.connection(this)
     accountId = getSharedPreferences(Keys.Status.NAME, Context.MODE_PRIVATE)
       ?.getLong(Keys.Status.selectedAccount, -1) ?: -1
 

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

@@ -13,7 +13,13 @@
   <string name="label_filter_messages">Filter Messages</string>
   <string name="label_input_history">Input History</string>
   <string name="label_placeholder">Write a message…</string>
+  <string name="label_running_in_background">Running in background</string>
   <string name="label_save">Save</string>
   <string name="label_select_multiple">Select</string>
   <string name="label_settings">Settings</string>
+
+  <string name="notification_channel_background" translatable="false">background</string>
+  <string name="notification_channel_background_title">Background</string>
+  <string name="notification_channel_highlight" translatable="false">highlight</string>
+  <string name="notification_channel_highlight_title">Highlight</string>
 </resources>

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

@@ -86,4 +86,13 @@
   <string name="preference_dynamic_fetch_key" translatable="false">dynamic_fetch</string>
   <string name="preference_dynamic_fetch_title">Dynamic Fetch Amount</string>
   <string name="preference_dynamic_fetch_summary">The number of backlog messages to fetch each time</string>
+
+
+  <string name="preference_connection_title">Connection</string>
+
+  <string name="preference_show_notification_key" translatable="false">show_notification</string>
+  <string name="preference_show_notification_title">Show notification</string>
+  <string name="preference_show_notification_summary">Keeps QuasselDroid always connected by showing a persistent notification</string>
+
+  <string name="preference_notification_id_key" translatable="false">notification_id</string>
 </resources>
\ No newline at end of file

app/src/main/res/xml/preferences.xml

@@ -59,4 +59,12 @@
       android:summary="@string/preference_dynamic_fetch_summary"
       android:title="@string/preference_dynamic_fetch_title" />
   </PreferenceCategory>
+
+  <PreferenceCategory android:title="@string/preference_connection_title">
+    <SwitchPreference
+      android:defaultValue="true"
+      android:key="@string/preference_show_notification_key"
+      android:summary="@string/preference_show_notification_summary"
+      android:title="@string/preference_show_notification_title" />
+  </PreferenceCategory>
 </PreferenceScreen>
\ No newline at end of file