ContactsFragment now lists all visible devices.

Also added ChatService to handle discovery (only on service start
for now).

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

@@ -0,0 +1,72 @@
+package com.nutomic.ensichat.bluetooth
+
+import android.app.Service
+import android.bluetooth.{BluetoothDevice, BluetoothAdapter}
+import android.content.{Context, BroadcastReceiver, IntentFilter, Intent}
+import android.os.IBinder
+import android.util.Log
+import com.nutomic.ensichat.bluetooth.ChatService.DeviceListener
+
+object ChatService {
+  trait DeviceListener {
+    def onDeviceConnected(device: Device): Unit
+  }
+}
+
+class ChatService extends Service {
+
+  private val TAG = "ChatService"
+
+  private final val mBinder = new ChatServiceBinder(this)
+
+  private var mBluetoothAdapter: BluetoothAdapter = _
+
+  private var mDeviceListener: DeviceListener = _
+
+  override def onCreate(): Unit = {
+    super.onCreate()
+
+    mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter()
+
+    var filter: IntentFilter = new IntentFilter(BluetoothDevice.ACTION_FOUND)
+    registerReceiver(mReceiver, filter)
+    filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED)
+    registerReceiver(mReceiver, filter)
+    doDiscovery()
+  }
+
+  override def onBind(intent: Intent): IBinder = {
+    return mBinder
+  }
+
+  override def onDestroy(): Unit = {
+    super.onDestroy()
+    unregisterReceiver(mReceiver)
+  }
+
+  def doDiscovery() {
+    // If we're already discovering, stop it.
+    if (mBluetoothAdapter.isDiscovering()) {
+      mBluetoothAdapter.cancelDiscovery()
+    }
+
+    mBluetoothAdapter.startDiscovery()
+    Log.i(TAG, "Discovery started")
+  }
+
+  private final def mReceiver: BroadcastReceiver  = new BroadcastReceiver() {
+    override def onReceive(context: Context, intent: Intent) {
+      intent.getAction() match {
+        case BluetoothDevice.ACTION_FOUND =>
+          val btDevice: BluetoothDevice = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE)
+          mDeviceListener.onDeviceConnected(new Device(btDevice))
+        case _ =>
+      }
+    }
+  }
+
+  def registerDeviceListener(listener: DeviceListener): Unit = {
+    mDeviceListener = listener
+  }
+
+}

app/src/main/scala/com/nutomic/ensichat/bluetooth/ChatServiceBinder.scala

@@ -0,0 +1,11 @@
+package com.nutomic.ensichat.bluetooth
+
+import android.os.Binder
+
+class ChatServiceBinder (mService: ChatService) extends Binder {
+
+  def getService(): ChatService = {
+    return mService
+  }
+
+}

app/src/main/scala/com/nutomic/ensichat/bluetooth/Device.scala

@@ -0,0 +1,9 @@
+package com.nutomic.ensichat.bluetooth
+
+import android.bluetooth.BluetoothDevice
+
+class Device(mBluetoothDevice: BluetoothDevice) {
+
+  def name = mBluetoothDevice.getName()
+
+}

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

@@ -1,18 +1,61 @@
 package com.nutomic.ensichat.fragments
 
 import android.app.Fragment
-import android.os.Bundle
+import android.content.{Context, Intent, ComponentName, ServiceConnection}
+import android.os.{IBinder, Bundle}
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import android.widget.{ArrayAdapter, ListView}
 
 import com.nutomic.ensichat.R
+import com.nutomic.ensichat.bluetooth.ChatService.DeviceListener
+import com.nutomic.ensichat.bluetooth.{ChatServiceBinder, ChatService, Device}
+import com.nutomic.ensichat.util.DevicesAdapter
 
-class ContactsFragment extends Fragment {
+class ContactsFragment extends Fragment with DeviceListener {
+
+  private var mListView: ListView = _
+
+  private var mChatService: ChatService = _
+
+  private final val mChatServiceConnection: ServiceConnection = new ServiceConnection {
+    override def onServiceConnected(componentName: ComponentName, iBinder: IBinder): Unit = {
+      val binder: ChatServiceBinder = iBinder.asInstanceOf[ChatServiceBinder]
+      mChatService = binder.getService()
+      mChatService.registerDeviceListener(ContactsFragment.this)
+    }
+
+    override def onServiceDisconnected(componentName: ComponentName): Unit = {
+      mChatService = null
+    }
+  }
+
+  private var mAdapter: ArrayAdapter[Device] = _
 
   override def onCreateView(inflater: LayoutInflater, container: ViewGroup,
         savedInstanceState: Bundle): View = {
-    return inflater.inflate(R.layout.fragment_contacts, container, false)
+    val view: View =  inflater.inflate(R.layout.fragment_contacts, container, false)
+    mListView = view.findViewById(android.R.id.list).asInstanceOf[ListView]
+    mAdapter = new DevicesAdapter(getActivity)
+    mListView.setAdapter(mAdapter)
+    return view
+  }
+
+  override def onCreate(savedInstanceState: Bundle): Unit = {
+    super.onCreate(savedInstanceState)
+    getActivity.startService(new Intent(getActivity, classOf[ChatService]))
+    getActivity.bindService(new Intent(getActivity, classOf[ChatService]),
+      mChatServiceConnection, Context.BIND_AUTO_CREATE)
+  }
+
+  override def onDestroy(): Unit = {
+    super.onDestroy()
+    getActivity.unbindService(mChatServiceConnection)
+  }
+
+  override def onDeviceConnected(device: Device): Unit = {
+    mAdapter.add(device)
   }
 
 }

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

@@ -0,0 +1,17 @@
+package com.nutomic.ensichat.util
+
+import android.content.Context
+import android.view.{ViewGroup, View}
+import android.widget.{TextView, ArrayAdapter}
+import com.nutomic.ensichat.bluetooth.Device
+
+class DevicesAdapter(context: Context) extends ArrayAdapter[Device](context, android.R.layout.simple_list_item_1) {
+
+    override def getView(position: Int, convertView: View, parent: ViewGroup): View = {
+      val view = super.getView(position, convertView, parent)
+      val title: TextView = view.findViewById(android.R.id.text1).asInstanceOf[TextView]
+      title.setText(getItem(position).name)
+      return view
+    }
+
+}