Use LocalBroadcastManager instead of ContactsUpdatedListener.

app/src/androidTest/scala/com/nutomic/ensichat/util/DatabaseTest.scala

@@ -2,9 +2,10 @@ package com.nutomic.ensichat.util
 
 import java.util.concurrent.CountDownLatch
 
-import android.content.Context
+import android.content.{IntentFilter, Intent, BroadcastReceiver, Context}
 import android.database.DatabaseErrorHandler
 import android.database.sqlite.SQLiteDatabase
+import android.support.v4.content.LocalBroadcastManager
 import android.test.{AndroidTestCase, mock}
 import com.nutomic.ensichat.protocol.{MessageTest, UserTest}
 import com.nutomic.ensichat.protocol.body.CryptoData
@@ -12,7 +13,6 @@ import com.nutomic.ensichat.protocol.header.ContentHeaderTest
 import com.nutomic.ensichat.protocol.header.ContentHeader
 import ContentHeaderTest._
 import MessageTest._
-import com.nutomic.ensichat.util.Database.OnContactsUpdatedListener
 import junit.framework.Assert._
 
 object DatabaseTest {
@@ -29,6 +29,7 @@ object DatabaseTest {
       dbFile = file + "-test"
       context.openOrCreateDatabase(dbFile, mode, factory, errorHandler)
     }
+    override def getApplicationContext = context
     def deleteDbFile() = context.deleteDatabase(dbFile)
   }
 
@@ -94,11 +95,14 @@ class DatabaseTest extends AndroidTestCase {
 
   def testAddContactCallback(): Unit = {
     val latch = new CountDownLatch(1)
-    database.runOnContactsUpdated(new OnContactsUpdatedListener {
-      override def onContactsUpdated() = latch.countDown()
-    })
+    val lbm = LocalBroadcastManager.getInstance(context)
+    val receiver = new BroadcastReceiver {
+      override def onReceive(context: Context, intent: Intent): Unit = latch.countDown()
+    }
+    lbm.registerReceiver(receiver, new IntentFilter(Database.ActionContactsUpdated))
     database.addContact(UserTest.u1)
     latch.await()
+    lbm.unregisterReceiver(receiver)
   }
   
   def testGetContact(): Unit = {

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

@@ -1,22 +1,22 @@
 package com.nutomic.ensichat.activities
 
-import android.content.Intent
+import android.content.{IntentFilter, Intent, Context, BroadcastReceiver}
 import android.os.Bundle
 import android.support.v4.app.NavUtils
+import android.support.v4.content.LocalBroadcastManager
 import android.view._
 import android.widget.AdapterView.OnItemClickListener
 import android.widget._
 import com.nutomic.ensichat.R
 import com.nutomic.ensichat.protocol.ChatService
 import com.nutomic.ensichat.protocol.body.RequestAddContact
-import com.nutomic.ensichat.util.Database.OnContactsUpdatedListener
 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 with OnContactsUpdatedListener {
+  with OnItemClickListener {
 
   private val Tag = "AddContactsActivity"
 
@@ -39,11 +39,17 @@ class AddContactsActivity extends EnsichatActivity with ChatService.OnConnection
 
     runOnServiceConnected(() => {
       service.registerConnectionListener(AddContactsActivity.this)
-      database.runOnContactsUpdated(this)
     })
+    LocalBroadcastManager.getInstance(this)
+      .registerReceiver(onContactsUpdatedListener, new IntentFilter(Database.ActionContactsUpdated))
   }
 
-  override def onConnectionsChanged() = onContactsUpdated()
+  override def onDestroy(): Unit = {
+    super.onDestroy()
+    LocalBroadcastManager.getInstance(this).unregisterReceiver(onContactsUpdatedListener)
+  }
+
+  override def onConnectionsChanged() = onContactsUpdatedListener.onReceive(null, null)
 
   /**
    * Initiates adding the device as contact if it hasn't been added yet.
@@ -67,14 +73,16 @@ class AddContactsActivity extends EnsichatActivity with ChatService.OnConnection
   /**
    * Fetches connections and displays them (excluding contacts).
    */
-  override def onContactsUpdated(): Unit ={
-    runOnUiThread(new Runnable {
-      override def run(): Unit  = {
-        adapter.clear()
-        (service.connections().map(a => service.getUser(a)) -- database.getContacts)
-          .foreach(adapter.add)
-      }
-    })
+  private val onContactsUpdatedListener = new BroadcastReceiver() {
+    override def onReceive(context: Context, intent: Intent): Unit = {
+      runOnUiThread(new Runnable {
+        override def run(): Unit  = {
+          adapter.clear()
+          (service.connections().map(a => service.getUser(a)) -- database.getContacts)
+            .foreach(adapter.add)
+        }
+      })
+    }
   }
 
 }

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

@@ -3,22 +3,22 @@ package com.nutomic.ensichat.fragments
 import java.io.File
 
 import android.app.ListFragment
-import android.content.Intent
+import android.content.{IntentFilter, Context, BroadcastReceiver, Intent}
 import android.net.Uri
 import android.os.Bundle
+import android.support.v4.content.LocalBroadcastManager
 import android.view._
 import android.widget.ListView
 import com.nutomic.ensichat.R
 import com.nutomic.ensichat.activities.{AddContactsActivity, EnsichatActivity, MainActivity, SettingsActivity}
 import com.nutomic.ensichat.protocol.ChatService
-import com.nutomic.ensichat.util.Database.OnContactsUpdatedListener
 import com.nutomic.ensichat.util.{Database, UsersAdapter}
 import scala.collection.JavaConversions._
 
 /**
  * Lists all nearby, connected devices.
  */
-class ContactsFragment extends ListFragment with OnContactsUpdatedListener {
+class ContactsFragment extends ListFragment {
 
   private lazy val adapter = new UsersAdapter(getActivity)
 
@@ -32,8 +32,14 @@ class ContactsFragment extends ListFragment with OnContactsUpdatedListener {
 
     getActivity.asInstanceOf[EnsichatActivity].runOnServiceConnected(() => {
       database.getContacts.foreach(adapter.add)
-      database.runOnContactsUpdated(this)
     })
+    LocalBroadcastManager.getInstance(getActivity)
+      .registerReceiver(onContactsUpdatedListener, new IntentFilter(Database.ActionContactsUpdated))
+  }
+
+  override def onDestroy(): Unit = {
+    super.onDestroy()
+    LocalBroadcastManager.getInstance(getActivity).unregisterReceiver(onContactsUpdatedListener)
   }
 
   override def onCreateView(inflater: LayoutInflater, container: ViewGroup,
@@ -75,13 +81,15 @@ class ContactsFragment extends ListFragment with OnContactsUpdatedListener {
   override def onListItemClick(l: ListView, v: View, position: Int, id: Long): Unit =
     getActivity.asInstanceOf[MainActivity].openChat(adapter.getItem(position).address)
 
-  override def onContactsUpdated(): Unit = {
-    getActivity.runOnUiThread(new Runnable {
-      override def run(): Unit = {
-        adapter.clear()
-        database.getContacts.foreach(adapter.add)
-      }
-    })
+  private val onContactsUpdatedListener = new BroadcastReceiver() {
+    override def onReceive(context: Context, intent: Intent): Unit = {
+      getActivity.runOnUiThread(new Runnable {
+        override def run(): Unit = {
+          adapter.clear()
+          database.getContacts.foreach(adapter.add)
+        }
+      })
+    }
   }
 
 }

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

@@ -2,19 +2,21 @@ package com.nutomic.ensichat.util
 
 import java.util.Date
 
-import android.content.{ContentValues, Context}
+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
-import com.nutomic.ensichat.util.Database.OnContactsUpdatedListener
 
 import scala.collection.immutable.TreeSet
 import scala.collection.{SortedSet, mutable}
 
 object Database {
 
+  val ActionContactsUpdated = "Contacts_Updated"
+
   private val DatabaseName = "message_store.db"
 
   private val DatabaseVersion = 1
@@ -35,13 +37,6 @@ object Database {
     "address TEXT NOT NULL," +
     "name TEXT NOT NULL)"
 
-  trait OnContactsUpdatedListener {
-    def onContactsUpdated()
-  }
-
-  private var contactsUpdatedListeners =
-    new mutable.WeakHashMap[OnContactsUpdatedListener, Unit].keySet
-
 }
 
 /**
@@ -139,21 +134,20 @@ class Database(context: Context)
     cv.put("address", contact.address.toString)
     cv.put("name", contact.name.toString)
     getWritableDatabase.insert("contacts", null, cv)
-    Database.contactsUpdatedListeners.foreach(_.onContactsUpdated()    )
+    contactsUpdated()
   }
   
   def changeContactName(contact: User): Unit = {
     val cv = new ContentValues()
     cv.put("name", contact.name.toString)
     getWritableDatabase.update("contacts", cv, "address = ?", Array(contact.address.toString))
-    Database.contactsUpdatedListeners.foreach(_.onContactsUpdated())
+    contactsUpdated()
   }
 
-  /**
-   * Pass a callback that is called whenever a new contact is added.
-   */
-  def runOnContactsUpdated(listener: OnContactsUpdatedListener) =
-    Database.contactsUpdatedListeners += listener
+  private def contactsUpdated(): Unit = {
+    LocalBroadcastManager.getInstance(context)
+      .sendBroadcast(new Intent(Database.ActionContactsUpdated))
+  }
 
   override def onUpgrade(db: SQLiteDatabase, oldVersion: Int, newVersion: Int): Unit = {
   }