3 files changed, 16 insertions, 8 deletions
diff --git a/main/src/cgeo/geocaching/maps/google/GoogleMapActivity.java b/main/src/cgeo/geocaching/maps/google/GoogleMapActivity.java
index 0377fe9..5649d19 100644
--- a/main/src/cgeo/geocaching/maps/google/GoogleMapActivity.java
+++ b/main/src/cgeo/geocaching/maps/google/GoogleMapActivity.java
@@ -1,5 +1,6 @@
 package cgeo.geocaching.maps.google;
 
+import cgeo.geocaching.activity.FilteredActivity;
 import cgeo.geocaching.maps.AbstractMap;
 import cgeo.geocaching.maps.CGeoMap;
 import cgeo.geocaching.maps.interfaces.MapActivityImpl;
@@ -12,7 +13,7 @@ import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 
-public class GoogleMapActivity extends MapActivity implements MapActivityImpl {
+public class GoogleMapActivity extends MapActivity implements MapActivityImpl, FilteredActivity {
 
     private AbstractMap mapBase;
 
@@ -127,4 +128,8 @@ public class GoogleMapActivity extends MapActivity implements MapActivityImpl {
         mapBase.goManual(view);
     }
 
+    @Override
+    public void showFilterMenu(View view) {
+        // do nothing, the filter bar only shows the global filter
+    }
 }
diff --git a/main/src/cgeo/geocaching/maps/google/GoogleMapProvider.java b/main/src/cgeo/geocaching/maps/google/GoogleMapProvider.java
index 6973338..1fa38ad 100644
--- a/main/src/cgeo/geocaching/maps/google/GoogleMapProvider.java
+++ b/main/src/cgeo/geocaching/maps/google/GoogleMapProvider.java
@@ -16,7 +16,6 @@ public final class GoogleMapProvider extends AbstractMapProvider {
 
     public static final String GOOGLE_MAP_ID = "GOOGLE_MAP";
     public static final String GOOGLE_SATELLITE_ID = "GOOGLE_SATELLITE";
-    private static GoogleMapProvider instance;
 
     private final MapItemFactory mapItemFactory;
 
@@ -29,15 +28,16 @@ public final class GoogleMapProvider extends AbstractMapProvider {
         mapItemFactory = new GoogleMapItemFactory();
     }
 
+    private static class Holder {
+        private static final GoogleMapProvider INSTANCE = new GoogleMapProvider();
+    }
+
     public static GoogleMapProvider getInstance() {
-        if (instance == null) {
-            instance = new GoogleMapProvider();
-        }
-        return instance;
+        return Holder.INSTANCE;
     }
 
     public static boolean isSatelliteSource(final MapSource mapSource) {
-        return mapSource != null && mapSource instanceof GoogleSatelliteSource;
+        return mapSource instanceof GoogleSatelliteSource;
     }
 
     @Override
@@ -67,7 +67,7 @@ public final class GoogleMapProvider extends AbstractMapProvider {
 
     private static abstract class AbstractGoogleMapSource extends AbstractMapSource {
 
-        public AbstractGoogleMapSource(final String id, final MapProvider mapProvider, final String name) {
+        protected AbstractGoogleMapSource(final String id, final MapProvider mapProvider, final String name) {
             super(id, mapProvider, name);
         }
 
diff --git a/main/src/cgeo/geocaching/maps/google/GoogleOverlay.java b/main/src/cgeo/geocaching/maps/google/GoogleOverlay.java
index d86eafe..773f9ff 100644
--- a/main/src/cgeo/geocaching/maps/google/GoogleOverlay.java
+++ b/main/src/cgeo/geocaching/maps/google/GoogleOverlay.java
@@ -27,6 +27,9 @@ public class GoogleOverlay extends Overlay implements OverlayImpl {
                 break;
             case ScaleOverlay:
                 overlayBase = new ScaleOverlay(activityIn, this);
+                break;
+            default:
+                throw new IllegalArgumentException();
         }
     }