Use listener instead of anonymous function for database contacts update.

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

@@ -9,6 +9,7 @@ import android.test.AndroidTestCase
 import android.test.mock.MockContext
 import com.nutomic.ensichat.protocol.UserTest
 import com.nutomic.ensichat.protocol.messages.MessageTest._
+import com.nutomic.ensichat.util.Database.OnContactsUpdatedListener
 import junit.framework.Assert._
 
 class DatabaseTest extends AndroidTestCase {
@@ -66,8 +67,8 @@ class DatabaseTest extends AndroidTestCase {
 
   def testAddContactCallback(): Unit = {
     val latch = new CountDownLatch(1)
-    database.runOnContactsUpdated(() => {
-      latch.countDown()
+    database.runOnContactsUpdated(new OnContactsUpdatedListener {
+      override def onContactsUpdated() = latch.countDown()
     })
     database.addContact(UserTest.u1)
     latch.await()

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

@@ -9,13 +9,14 @@ import android.widget._
 import com.nutomic.ensichat.R
 import com.nutomic.ensichat.protocol.ChatService
 import com.nutomic.ensichat.protocol.messages.RequestAddContact
+import com.nutomic.ensichat.util.Database.OnContactsUpdatedListener
 import com.nutomic.ensichat.util.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 OnItemClickListener with OnContactsUpdatedListener {
 
   private val Tag = "AddContactsActivity"
 
@@ -36,11 +37,11 @@ class AddContactsActivity extends EnsiChatActivity with ChatService.OnConnection
 
     runOnServiceConnected(() => {
       service.registerConnectionListener(AddContactsActivity.this)
-      service.database.runOnContactsUpdated(updateList)
+      service.database.runOnContactsUpdated(this)
     })
   }
 
-  override def onConnectionsChanged() = updateList()
+  override def onConnectionsChanged() = onContactsUpdated()
 
   /**
    * Initiates adding the device as contact if it hasn't been added yet.
@@ -64,7 +65,7 @@ class AddContactsActivity extends EnsiChatActivity with ChatService.OnConnection
   /**
    * Fetches connections and displays them (excluding contacts).
    */
-  private def updateList(): Unit ={
+  override def onContactsUpdated(): Unit ={
     runOnUiThread(new Runnable {
       override def run(): Unit  = {
         adapter.clear()

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

@@ -8,12 +8,13 @@ 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.UsersAdapter
 
 /**
  * Lists all nearby, connected devices.
  */
-class ContactsFragment extends ListFragment {
+class ContactsFragment extends ListFragment with OnContactsUpdatedListener {
 
   private lazy val adapter = new UsersAdapter(getActivity)
 
@@ -27,14 +28,7 @@ class ContactsFragment extends ListFragment {
 
     getActivity.asInstanceOf[EnsiChatActivity].runOnServiceConnected(() => {
       database.getContacts.foreach(adapter.add)
-      database.runOnContactsUpdated(() => {
-        getActivity.runOnUiThread(new Runnable {
-          override def run(): Unit = {
-            adapter.clear()
-            database.getContacts.foreach(adapter.add)
-          }
-        })
-      })
+      database.runOnContactsUpdated(this)
     })
   }
 
@@ -68,4 +62,12 @@ class ContactsFragment extends ListFragment {
   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)
+      }
+    })
+  }
 }

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

@@ -7,8 +7,9 @@ import android.database.sqlite.{SQLiteDatabase, SQLiteOpenHelper}
 import com.nutomic.ensichat.protocol.ChatService.OnMessageReceivedListener
 import com.nutomic.ensichat.protocol._
 import com.nutomic.ensichat.protocol.messages._
+import com.nutomic.ensichat.util.Database.OnContactsUpdatedListener
 
-import scala.collection.SortedSet
+import scala.collection.{mutable, SortedSet}
 import scala.collection.immutable.TreeSet
 
 object Database {
@@ -29,6 +30,10 @@ object Database {
     "address text not null," +
     "name text not null)"
 
+  trait OnContactsUpdatedListener {
+    def onContactsUpdated()
+  }
+
 }
 
 /**
@@ -38,7 +43,8 @@ class Database(context: Context)
   extends SQLiteOpenHelper(context, Database.DatabaseName, null, Database.DatabaseVersion)
   with OnMessageReceivedListener {
 
-  private var contactsUpdatedListeners = Set[() => Unit]()
+  private var contactsUpdatedListeners =
+    new mutable.WeakHashMap[OnContactsUpdatedListener, Unit].keySet
 
   override def onCreate(db: SQLiteDatabase): Unit = {
     db.execSQL(Database.CreateContactsTable)
@@ -127,20 +133,21 @@ class Database(context: Context)
     cv.put("address", contact.Address.toString)
     cv.put("name", contact.Name.toString)
     getWritableDatabase.insert("contacts", null, cv)
-    contactsUpdatedListeners.foreach(_())
+    contactsUpdatedListeners.foreach(_.onContactsUpdated()    )
   }
   
   def changeContactName(contact: User): Unit = {
     val cv = new ContentValues()
     cv.put("name", contact.Name.toString)
     getWritableDatabase.update("contacts", cv, "address = ?", Array(contact.Address.toString))
-    contactsUpdatedListeners.foreach(_())
+    contactsUpdatedListeners.foreach(_.onContactsUpdated())
   }
 
   /**
    * Pass a callback that is called whenever a new contact is added.
    */
-  def runOnContactsUpdated(l: () => Unit): Unit = contactsUpdatedListeners += l
+  def runOnContactsUpdated(listener: OnContactsUpdatedListener) =
+    contactsUpdatedListeners += listener
 
   override def onUpgrade(db: SQLiteDatabase, oldVersion: Int, newVersion: Int): Unit = {
   }