Added preferences with setting for scan interval.

app/proguard-rules.pro

@@ -19,6 +19,10 @@
 -dontwarn scala.**
 -keep class !scala*.** { *; }
 -ignorewarnings
+# Avoid crash when invoking String.toInt (see https://issues.scala-lang.org/browse/SI-5397).
+-keep class scala.collection.SeqLike {
+    public protected *;
+}
 
 # Suppress warnings caused by msgpack (code works fine anyway).
 -dontwarn

app/src/main/AndroidManifest.xml

@@ -12,6 +12,7 @@
         android:icon="@drawable/ic_launcher"
         android:label="@string/app_name"
         android:theme="@style/AppTheme" >
+
         <activity
             android:name=".activities.MainActivity"
             android:label="@string/app_name" >
@@ -21,7 +22,14 @@
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+
+        <activity
+            android:name=".activities.SettingsActivity"
+            android:label="@string/settings"
+            android:parentActivityName=".activities.MainActivity" />
+
         <service android:name=".bluetooth.ChatService" />
+
     </application>
 
 </manifest>

app/src/main/res/menu/main.xml

@@ -2,7 +2,14 @@
 
 <menu xmlns:android="http://schemas.android.com/apk/res/android">
 
+    <item
+        android:id="@+id/settings"
+        android:icon="@drawable/ic_action_settings"
+        android:title="@string/settings"
+        android:showAsAction="ifRoom" />
+
     <item
         android:id="@+id/exit"
         android:title="Exit" />
+
 </menu>

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

@@ -5,8 +5,8 @@
 
     <string name="app_name">EnsiChat</string>
 
-    <!-- MainActivity -->
 
+    <!-- MainActivity -->
 
     <!-- Toast shown if user denies request to enable bluetooth -->
     <string name="bluetooth_required">Bluetooth is required for this app.</string>
@@ -14,10 +14,19 @@
     <!-- Menu item to close app and stop service -->
     <string name="exit">Exit</string>
 
-    <!-- ContactsFragment -->
 
+    <!-- ContactsFragment -->
 
     <!-- Empty text for contacts list -->
     <string name="no_contacts_found">No contacts found :(</string>
 
+
+    <!-- SettingsActivity -->
+
+    <!-- Activity title -->
+    <string name="settings">Settings</string>
+
+    <!-- Preference title -->
+    <string name="scan_interval_seconds">Scan Interval (seconds)</string>
+
 </resources>

app/src/main/res/xml/settings.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <EditTextPreference
+        android:title="@string/scan_interval_seconds"
+        android:key="scan_interval_seconds"
+        android:defaultValue="5"
+        android:inputType="number"
+        android:numeric="integer" />
+
+</PreferenceScreen>

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

@@ -0,0 +1,36 @@
+package com.nutomic.ensichat.activities
+
+import android.app.Fragment
+import android.os.Bundle
+import com.nutomic.ensichat.fragments.SettingsFragment
+
+/**
+ * Holder for [[SettingsFragment]].
+ */
+class SettingsActivity extends EnsiChatActivity {
+
+  private var fragment: Fragment = _
+
+  override def onCreate(savedInstanceState: Bundle): Unit = {
+    super.onCreate(savedInstanceState)
+    getActionBar.setDisplayHomeAsUpEnabled(true)
+
+    val fm = getFragmentManager
+    fragment =
+      if (savedInstanceState != null) {
+        fm.getFragment(savedInstanceState, "settings_fragment")
+      } else {
+        new SettingsFragment()
+      }
+    fm.beginTransaction()
+      .replace(android.R.id.content, fragment)
+      .commit()
+  }
+
+  override def onSaveInstanceState(outState: Bundle): Unit = {
+    super.onSaveInstanceState(outState)
+
+    getFragmentManager.putFragment(outState, "settings_fragment", fragment)
+  }
+
+}

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

@@ -6,6 +6,7 @@ import android.app.Service
 import android.bluetooth.{BluetoothAdapter, BluetoothDevice, BluetoothSocket}
 import android.content.{BroadcastReceiver, Context, Intent, IntentFilter}
 import android.os.Handler
+import android.preference.PreferenceManager
 import android.util.Log
 import com.nutomic.ensichat.R
 import com.nutomic.ensichat.bluetooth.ChatService.{OnConnectionChangedListener, OnMessageReceivedListener}
@@ -41,8 +42,6 @@ class ChatService extends Service {
 
   private val Tag = "ChatService"
 
-  private val ScanInterval = 5000
-
   private val Binder = new ChatServiceBinder(this)
 
   private var bluetoothAdapter: BluetoothAdapter = _
@@ -124,9 +123,11 @@ class ChatService extends Service {
       bluetoothAdapter.startDiscovery()
     }
 
+    val scanInterval = PreferenceManager.getDefaultSharedPreferences(this)
+      .getString("scan_interval_seconds", "5").toInt * 1000
     MainHandler.postDelayed(new Runnable {
       override def run(): Unit = discover()
-    }, ScanInterval)
+    }, scanInterval)
   }
 
   /**

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

@@ -6,7 +6,7 @@ import android.os.{Bundle, IBinder}
 import android.view._
 import android.widget.{ArrayAdapter, ListView}
 import com.nutomic.ensichat.R
-import com.nutomic.ensichat.activities.{EnsiChatActivity, MainActivity}
+import com.nutomic.ensichat.activities.{SettingsActivity, EnsiChatActivity, MainActivity}
 import com.nutomic.ensichat.bluetooth.{ChatService, ChatServiceBinder, Device}
 import com.nutomic.ensichat.util.{MessagesAdapter, DevicesAdapter}
 
@@ -44,6 +44,9 @@ class ContactsFragment extends ListFragment with ChatService.OnConnectionChanged
 
   override def onOptionsItemSelected(item: MenuItem): Boolean = {
     item.getItemId match {
+      case R.id.settings =>
+        startActivity(new Intent(getActivity, classOf[SettingsActivity]))
+        true
       case R.id.exit =>
         getActivity.stopService(new Intent(getActivity, classOf[ChatService]))
         getActivity.finish()

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

@@ -0,0 +1,16 @@
+package com.nutomic.ensichat.fragments
+
+import android.os.Bundle
+import android.preference.PreferenceFragment
+
+import com.nutomic.ensichat.R
+
+class SettingsFragment extends PreferenceFragment {
+
+  override def onCreate(savedInstanceState: Bundle): Unit =  {
+    super.onCreate(savedInstanceState)
+
+    addPreferencesFromResource(R.xml.settings)
+  }
+
+}