Replaced weak listeners with local broadcasts.

app/src/main/scala/com/nutomic/ensichat/activities/AddContactsActivity.scala

@@ -15,8 +15,7 @@ import com.nutomic.ensichat.util.{Database, UsersAdapter}
 /**
  * Lists all nearby, connected devices and allows adding them to be added as contacts.
  */
-class AddContactsActivity extends EnsichatActivity with ChatService.OnConnectionsChangedListener
-  with OnItemClickListener {
+class AddContactsActivity extends EnsichatActivity with OnItemClickListener {
 
   private val Tag = "AddContactsActivity"
 
@@ -37,20 +36,18 @@ class AddContactsActivity extends EnsichatActivity with ChatService.OnConnection
     list.setOnItemClickListener(this)
     list.setEmptyView(findViewById(android.R.id.empty))
 
-    runOnServiceConnected(() => {
-      service.registerConnectionListener(AddContactsActivity.this)
-    })
+    val filter = new IntentFilter()
+    filter.addAction(ChatService.ActionConnectionsChanged)
+    filter.addAction(Database.ActionContactsUpdated)
     LocalBroadcastManager.getInstance(this)
-      .registerReceiver(onContactsUpdatedListener, new IntentFilter(Database.ActionContactsUpdated))
+      .registerReceiver(onContactsUpdatedReceiver, filter)
   }
 
   override def onDestroy(): Unit = {
     super.onDestroy()
-    LocalBroadcastManager.getInstance(this).unregisterReceiver(onContactsUpdatedListener)
+    LocalBroadcastManager.getInstance(this).unregisterReceiver(onContactsUpdatedReceiver)
   }
 
-  override def onConnectionsChanged() = onContactsUpdatedListener.onReceive(null, null)
-
   /**
    * Initiates adding the device as contact if it hasn't been added yet.
    */
@@ -73,7 +70,7 @@ class AddContactsActivity extends EnsichatActivity with ChatService.OnConnection
   /**
    * Fetches connections and displays them (excluding contacts).
    */
-  private val onContactsUpdatedListener = new BroadcastReceiver() {
+  private val onContactsUpdatedReceiver = new BroadcastReceiver() {
     override def onReceive(context: Context, intent: Intent): Unit = {
       runOnUiThread(new Runnable {
         override def run(): Unit  = {

app/src/main/scala/com/nutomic/ensichat/fragments/ChatFragment.scala

@@ -1,7 +1,9 @@
 package com.nutomic.ensichat.fragments
 
 import android.app.ListFragment
+import android.content.{IntentFilter, Intent, Context, BroadcastReceiver}
 import android.os.Bundle
+import android.support.v4.content.LocalBroadcastManager
 import android.view.View.OnClickListener
 import android.view.inputmethod.EditorInfo
 import android.view.{KeyEvent, LayoutInflater, View, ViewGroup}
@@ -9,7 +11,6 @@ import android.widget.TextView.OnEditorActionListener
 import android.widget._
 import com.nutomic.ensichat.R
 import com.nutomic.ensichat.activities.EnsichatActivity
-import com.nutomic.ensichat.protocol.ChatService.OnMessageReceivedListener
 import com.nutomic.ensichat.protocol.body.Text
 import com.nutomic.ensichat.protocol.{Message, Address, ChatService}
 import com.nutomic.ensichat.util.{Database, MessagesAdapter}
@@ -17,8 +18,7 @@ import com.nutomic.ensichat.util.{Database, MessagesAdapter}
 /**
  * Represents a single chat with another specific device.
  */
-class ChatFragment extends ListFragment with OnClickListener
-    with OnMessageReceivedListener {
+class ChatFragment extends ListFragment with OnClickListener {
 
   /**
    * Fragments need to have a default constructor, so this is optional.
@@ -40,7 +40,7 @@ class ChatFragment extends ListFragment with OnClickListener
 
   private var listView: ListView = _
 
-  private var adapter: ArrayAdapter[Message] = _
+  private var adapter: MessagesAdapter = _
 
   override def onActivityCreated(savedInstanceState: Bundle): Unit = {
     super.onActivityCreated(savedInstanceState)
@@ -53,7 +53,6 @@ class ChatFragment extends ListFragment with OnClickListener
 
       // Read local device ID from service,
       adapter = new MessagesAdapter(getActivity, address)
-      chatService.registerMessageListener(ChatFragment.this)
       database.getMessages(address, 15).foreach(adapter.add)
 
       if (listView != null) {
@@ -87,6 +86,9 @@ class ChatFragment extends ListFragment with OnClickListener
 
     if (savedInstanceState != null)
       address = new Address(savedInstanceState.getByteArray("address"))
+
+    LocalBroadcastManager.getInstance(getActivity)
+      .registerReceiver(onMessageReceivedReceiver, new IntentFilter(ChatService.ActionMessageReceived))
   }
 
   override def onSaveInstanceState(outState: Bundle): Unit = {
@@ -94,6 +96,11 @@ class ChatFragment extends ListFragment with OnClickListener
     outState.putByteArray("address", address.bytes)
   }
 
+  override def onDestroy(): Unit = {
+    super.onDestroy()
+    LocalBroadcastManager.getInstance(getActivity).unregisterReceiver(onMessageReceivedReceiver)
+  }
+
   /**
    * Send message if send button was clicked.
    */
@@ -110,13 +117,16 @@ class ChatFragment extends ListFragment with OnClickListener
   /**
    * Displays new messages in UI.
    */
-  override def onMessageReceived(msg: Message): Unit = {
-    if (!Set(msg.header.origin, msg.header.target).contains(address))
-      return
+  private val onMessageReceivedReceiver = new BroadcastReceiver {
+    override def onReceive(context: Context, intent: Intent): Unit = {
+      val msg = intent.getSerializableExtra(ChatService.ExtraMessage).asInstanceOf[Message]
+      if (!Set(msg.header.origin, msg.header.target).contains(address))
+        return
 
-    msg.body match {
-      case _: Text => adapter.add(msg)
-      case _ =>
+      msg.body match {
+        case _: Text => adapter.add(msg)
+        case _ =>
+      }
     }
   }
 

app/src/main/scala/com/nutomic/ensichat/protocol/ChatService.scala

@@ -7,23 +7,26 @@ import android.app.{Notification, NotificationManager, PendingIntent, Service}
 import android.content.{Context, Intent}
 import android.os.Handler
 import android.preference.PreferenceManager
+import android.support.v4.content.LocalBroadcastManager
 import android.util.Log
 import com.nutomic.ensichat.R
 import com.nutomic.ensichat.activities.MainActivity
 import com.nutomic.ensichat.bluetooth.BluetoothInterface
 import com.nutomic.ensichat.fragments.SettingsFragment
-import com.nutomic.ensichat.protocol.ChatService.{OnConnectionsChangedListener, OnMessageReceivedListener}
 import com.nutomic.ensichat.protocol.body.{ConnectionInfo, MessageBody, UserInfo}
 import com.nutomic.ensichat.protocol.header.ContentHeader
 import com.nutomic.ensichat.util.{AddContactsHandler, Database, NotificationHandler}
 
-import scala.collection.mutable
 import scala.concurrent.ExecutionContext.Implicits.global
 import scala.concurrent.Future
 
 object ChatService {
 
-  val ActionStopService = "stop_service"
+  val ActionStopService        = "stop_service"
+  val ActionMessageReceived    = "message_received"
+  val ActionConnectionsChanged = "connections_changed"
+
+  val ExtraMessage             = "extra_message"
 
   abstract class InterfaceHandler {
 
@@ -35,18 +38,6 @@ object ChatService {
 
   }
 
-  trait OnMessageReceivedListener {
-    def onMessageReceived(messages: Message): Unit
-  }
-
-  /**
-   * Used with [[ChatService.registerConnectionListener]], called when a Bluetooth device
-   * connects or disconnects
-   */
-  trait OnConnectionsChangedListener {
-    def onConnectionsChanged(): Unit
-  }
-
 }
 
 /**
@@ -77,15 +68,6 @@ class ChatService extends Service {
 
   private lazy val seqNumGenerator = new SeqNumGenerator(this)
 
-  /**
-   * For this (and [[messageListeners]], functions would be useful instead of instances,
-   * but on a Nexus S (Android 4.1.2), these functions are garbage collected even when
-   * referenced.
-   */
-  private var connectionListeners = new mutable.WeakHashMap[OnConnectionsChangedListener, Unit].keySet
-
-  private var messageListeners = new mutable.WeakHashMap[OnMessageReceivedListener, Unit].keySet
-
   private lazy val notificationManager =
     getSystemService(Context.NOTIFICATION_SERVICE).asInstanceOf[NotificationManager]
 
@@ -106,9 +88,6 @@ class ChatService extends Service {
 
     Future {
       crypto.generateLocalKeys()
-      registerMessageListener(database)
-      registerMessageListener(notificationHandler)
-      registerMessageListener(addContactsHandler)
 
       btInterface.create()
       Log.i(Tag, "Service started, address is " + crypto.localAddress)
@@ -136,21 +115,6 @@ class ChatService extends Service {
 
   override def onBind(intent: Intent) =  binder
 
-  /**
-   * Registers a listener that is called whenever a new message is sent or received.
-   */
-  def registerMessageListener(listener: OnMessageReceivedListener): Unit = {
-    messageListeners += listener
-  }
-
-  /**
-   * Registers a listener that is called whenever a new device is connected.
-   */
-  def registerConnectionListener(listener: OnConnectionsChangedListener): Unit = {
-    connectionListeners += listener
-    listener.onConnectionsChanged()
-  }
-
   /**
    * Sends a new message to the given target address.
    */
@@ -200,10 +164,13 @@ class ChatService extends Service {
 
       callConnectionListeners()
     case _ =>
-      mainHandler.post(new Runnable {
-        override def run(): Unit =
-          messageListeners.foreach(_.onMessageReceived(msg))
-    })
+      database.onMessageReceived(msg)
+      notificationHandler.onMessageReceived(msg)
+      addContactsHandler.onMessageReceived(msg)
+      val i = new Intent(ChatService.ActionMessageReceived)
+      i.putExtra(ChatService.ExtraMessage, msg)
+      LocalBroadcastManager.getInstance(this)
+        .sendBroadcast(i)
   }
 
   /**
@@ -249,14 +216,9 @@ class ChatService extends Service {
     true
   }
 
-  /**
-   * Calls all [[connectionListeners]] with the currently active connections.
-   *
-   * Should be called whenever a neighbor connects or disconnects.
-   */
   def callConnectionListeners(): Unit = {
-    connectionListeners
-      .foreach(_.onConnectionsChanged())
+    LocalBroadcastManager.getInstance(this)
+      .sendBroadcast(new Intent(ChatService.ActionConnectionsChanged))
   }
 
   def connections() =

app/src/main/scala/com/nutomic/ensichat/util/AddContactsHandler.scala

@@ -2,12 +2,13 @@ package com.nutomic.ensichat.util
 
 import android.app.{NotificationManager, PendingIntent}
 import android.content.{Context, Intent}
+import android.os
+import android.os.{Handler, Looper}
 import android.support.v4.app.NotificationCompat
 import android.util.Log
 import android.widget.Toast
 import com.nutomic.ensichat.R
 import com.nutomic.ensichat.activities.ConfirmAddContactActivity
-import com.nutomic.ensichat.protocol.ChatService.OnMessageReceivedListener
 import com.nutomic.ensichat.protocol.body.{RequestAddContact, ResultAddContact}
 import com.nutomic.ensichat.protocol.{Address, Message, User}
 
@@ -17,8 +18,7 @@ import com.nutomic.ensichat.protocol.{Address, Message, User}
  * @param getUser Returns info about a given address.
  * @param localAddress Address of the local device.
  */
-class AddContactsHandler(context: Context, getUser: (Address) => User, localAddress: Address)
-  extends OnMessageReceivedListener {
+class AddContactsHandler(context: Context, getUser: (Address) => User, localAddress: Address) {
 
   private val Tag = "AddContactsHandler"
 
@@ -93,9 +93,14 @@ class AddContactsHandler(context: Context, getUser: (Address) => User, localAddr
     if (info.localConfirmed && info.remoteConfirmed) {
       Log.i(Tag, "Adding new contact " + user.toString)
       database.addContact(user)
-      Toast
-        .makeText(context, context.getString(R.string.contact_added, user.name), Toast.LENGTH_SHORT)
-        .show()
+      new Handler(Looper.getMainLooper).post(new Runnable {
+        override def run(): Unit = {
+          Toast
+            .makeText(context,
+              context.getString(R.string.contact_added, user.name), Toast.LENGTH_SHORT)
+            .show()
+        }
+      })
       currentlyAdding -= address
     }
   }

app/src/main/scala/com/nutomic/ensichat/util/Database.scala

@@ -5,7 +5,6 @@ import java.util.Date
 import android.content.{Intent, ContentValues, Context}
 import android.database.sqlite.{SQLiteDatabase, SQLiteOpenHelper}
 import android.support.v4.content.LocalBroadcastManager
-import com.nutomic.ensichat.protocol.ChatService.OnMessageReceivedListener
 import com.nutomic.ensichat.protocol._
 import com.nutomic.ensichat.protocol.body.{Text, ResultAddContact, RequestAddContact}
 import com.nutomic.ensichat.protocol.header.ContentHeader
@@ -15,7 +14,7 @@ import scala.collection.{SortedSet, mutable}
 
 object Database {
 
-  val ActionContactsUpdated = "Contacts_Updated"
+  val ActionContactsUpdated = "contacts_updated"
 
   private val DatabaseName = "message_store.db"
 
@@ -44,8 +43,7 @@ object Database {
  * Stores all messages and contacts in SQL database.
  */
 class Database(context: Context)
-  extends SQLiteOpenHelper(context, Database.DatabaseName, null, Database.DatabaseVersion)
-  with OnMessageReceivedListener {
+  extends SQLiteOpenHelper(context, Database.DatabaseName, null, Database.DatabaseVersion) {
 
   override def onCreate(db: SQLiteDatabase): Unit = {
     db.execSQL(Database.CreateContactsTable)
@@ -79,7 +77,7 @@ class Database(context: Context)
   /**
    * Inserts the given new message into the database.
    */
-  override def onMessageReceived(msg: Message): Unit = msg.body match {
+  def onMessageReceived(msg: Message): Unit = msg.body match {
     case text: Text =>
       val cv =  new ContentValues()
       val ch = msg.header.asInstanceOf[ContentHeader]

app/src/main/scala/com/nutomic/ensichat/util/NotificationHandler.scala

@@ -6,7 +6,6 @@ import android.preference.PreferenceManager
 import android.support.v4.app.NotificationCompat
 import com.nutomic.ensichat.R
 import com.nutomic.ensichat.activities.MainActivity
-import com.nutomic.ensichat.protocol.ChatService.OnMessageReceivedListener
 import com.nutomic.ensichat.protocol.body.Text
 import com.nutomic.ensichat.protocol.{Crypto, Message}
 
@@ -21,7 +20,7 @@ object NotificationHandler {
 /**
  * Displays notifications for new messages.
  */
-class NotificationHandler(context: Context) extends OnMessageReceivedListener {
+class NotificationHandler(context: Context) {
 
   def onMessageReceived(msg: Message): Unit = msg.body match {
     case text: Text =>