Don't let the user manually stop the service

Closes #8

code/SensorLogger/res/layout/main.xml

@@ -25,7 +25,7 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_below="@id/entry"
-        android:text="Start/Stop service"/>
+        android:text="Start recording"/>
     <Button
         android:id="@+id/upload"
         android:layout_width="wrap_content"

code/SensorLogger/src/uk/co/md87/android/sensorlogger/MainActivity.java

@@ -55,7 +55,7 @@ public class MainActivity extends Activity implements OnClickListener {
         ACTIVITY = ((EditText) findViewById(R.id.entry)).getText().toString();
         
         if (view.getId() == R.id.start) {
-            if (!stopService(new Intent(this, SensorLoggerService.class))) {
+            if (!SensorLoggerService.STARTED) {
                 startService(new Intent(this, SensorLoggerService.class));
             }
         } else if (view.getId() == R.id.upload) {

code/SensorLogger/src/uk/co/md87/android/sensorlogger/SensorLoggerService.java

@@ -31,6 +31,8 @@ public class SensorLoggerService extends Service {
 
     private static final String TAG = "SensorLoggerService";
 
+    public static boolean STARTED = false;
+
     private SensorManager manager;
     private FileOutputStream stream;
     private OutputStreamWriter writer;
@@ -115,6 +117,8 @@ public class SensorLoggerService extends Service {
     public void onStart(final Intent intent, final int startId) {
         super.onStart(intent, startId);
 
+        STARTED = true;
+
         new Timer("Delay timer").schedule(new TimerTask() {
 
             @Override
@@ -155,6 +159,8 @@ public class SensorLoggerService extends Service {
     public void onDestroy() {
         manager.unregisterListener(accelListener);
 
+        STARTED = false;
+
         Toast.makeText(getApplicationContext(), "Sensor logger service stopped",
                 Toast.LENGTH_SHORT).show();
     }