Introduce an interface to decouple platform specific API from the classes that require it. Also:

1) Put the service into foreground to prevent from being killed by the system
2) Fix a bug the prevented MyTracks from running on pre-Eclair devices

MyTracks/src/com/google/android/apps/mytracks/MyTracksMap.java

@@ -379,7 +379,8 @@ public class MyTracksMap extends MapActivity
   protected void onDestroy() {
     Log.d(MyTracksConstants.TAG, "MyTracksMap.onDestroy");
     if (updateTrackThread != null) {
-      updateTrackThread.quit();
+      ApiFeatures.getInstance().getApiPlatformAdapter().stopHandlerThread(
+          updateTrackThread);
     }
     
     super.onDestroy();

MyTracks/src/com/google/android/apps/mytracks/services/TrackRecordingService.java

@@ -28,6 +28,7 @@ import com.google.android.apps.mytracks.content.WaypointsColumns;
 import com.google.android.apps.mytracks.stats.TripStatistics;
 import com.google.android.apps.mytracks.stats.TripStatisticsBuilder;
 import com.google.android.apps.mytracks.util.ApiFeatures;
+import com.google.android.apps.mytracks.util.ApiPlatformAdapter;
 import com.google.android.apps.mytracks.util.MyTracksUtils;
 import com.google.android.apps.mytracks.util.StringUtils;
 import com.google.android.maps.mytracks.R;
@@ -329,6 +330,8 @@ public class TrackRecordingService extends Service implements LocationListener {
    * Shows the notification message and icon in the notification bar.
    */
   public void showNotification() {
+    final ApiPlatformAdapter apiPlatformAdapter =
+        ApiFeatures.getInstance().getApiPlatformAdapter();
     if (isRecording) {
       Notification notification = new Notification(
           R.drawable.arrow_320, null /* tickerText */,
@@ -339,9 +342,10 @@ public class TrackRecordingService extends Service implements LocationListener {
       notification.setLatestEventInfo(this, getString(R.string.app_name),
           getString(R.string.recording_your_track), contentIntent);
       notification.flags += Notification.FLAG_NO_CLEAR;
-      notificationManager.notify(1, notification);
+      apiPlatformAdapter.startForeground(this, notificationManager, 1,
+          notification);
     } else {
-      notificationManager.cancelAll();
+      apiPlatformAdapter.stopForeground(this, notificationManager, 1);
     }
   }
 

MyTracks/src/com/google/android/apps/mytracks/util/ApiFeatures.java

@@ -15,7 +15,10 @@
  */
 package com.google.android.apps.mytracks.util;
 
+import com.google.android.apps.mytracks.MyTracksConstants;
+
 import android.os.Build;
+import android.util.Log;
 
 /**
  * Utility class for determining if newer-API features are available on the
@@ -28,9 +31,15 @@ public class ApiFeatures {
   /**
    * The API level of the Android version we're being run under.
    */
-  public static final int ANDROID_API_LEVEL = Integer.parseInt(Build.VERSION.SDK);
-
+  public static final int ANDROID_API_LEVEL = Integer.parseInt(
+      Build.VERSION.SDK);
+  
   private static ApiFeatures instance;
+  
+  /**
+   * The API platform adapter supported by this system.
+   */
+  private ApiPlatformAdapter apiPlatformAdapter;
 
   /**
    * Returns the singleton instance of this class.
@@ -52,7 +61,28 @@ public class ApiFeatures {
   /**
    * Allow subclasses for mocking, but no direct instantiation.
    */
-  protected ApiFeatures() {}
+  protected ApiFeatures() {
+    if (getApiLevel() >= 5) {
+      try {
+        Class<?> clazz = Class.forName(
+            "com.google.android.apps.mytracks.util.EclairPlatformAdapter");
+        apiPlatformAdapter = (ApiPlatformAdapter) clazz.newInstance();
+      } catch (Exception e) {
+        Log.i(MyTracksConstants.TAG, "ApiFeatures: Unable to instantiate Eclair"
+            + " platform adapter", e);
+      }
+    }
+    if (apiPlatformAdapter == null) {
+      Log.i(MyTracksConstants.TAG,
+          "ApiFeatures: Using default platform adapter");
+      // Cupcake adapter is always supported, so it's safe to do static linkage.
+      apiPlatformAdapter = new CupcakePlatformAdapter();
+    }
+  }
+  
+  public ApiPlatformAdapter getApiPlatformAdapter() {
+    return apiPlatformAdapter;
+  }
 
   /**
    * Returns whether cloud backup (a.k.a. Froyo backup) is available.
@@ -81,7 +111,7 @@ public class ApiFeatures {
   public boolean hasModernSignalStrength() {
     return getApiLevel() >= 7;
   }
-
+  
   // Visible for testing.
   protected int getApiLevel() {
     return ANDROID_API_LEVEL;

MyTracks/src/com/google/android/apps/mytracks/util/ApiPlatformAdapter.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2010 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.google.android.apps.mytracks.util;
+
+import android.app.Notification;
+import android.app.NotificationManager;
+import android.app.Service;
+import android.os.HandlerThread;
+
+/**
+ * A set of methods that may be implemented in a platform specific way. 
+ *  
+ * @author Bartlomiej Niechwiej
+ */
+public interface ApiPlatformAdapter {
+  
+  /**
+   * Puts the specified service into foreground.
+   * 
+   * @param service the service to be put in foreground.
+   * @param notificationManager the notification manager used to post the given
+   *        notification.
+   * @param id the ID of the notification, unique within the application.
+   * @param notification the notification to post.
+   */
+  void startForeground(Service service, NotificationManager notificationManager,
+      int id, Notification notification);
+  
+  /**
+   * Puts the given service into background.
+   * @param service the service to put into background.
+   * @param notificationManager the notification manager to user when removing
+   *        notifications. 
+   * @param id the ID of the notification to be remove, or -1 if the
+   *        notification shouldn't be removed.
+   */
+  void stopForeground(Service service, NotificationManager notificationManager,
+      int id);
+
+  /**
+   * Terminates the given handler thread.
+   * 
+   * @param handlerThread the thread to be terminated.
+   * @return true whether the handler has been stopped or not.
+   */
+  boolean stopHandlerThread(HandlerThread handlerThread);
+}

MyTracks/src/com/google/android/apps/mytracks/util/CupcakePlatformAdapter.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2010 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.google.android.apps.mytracks.util;
+
+import android.app.Notification;
+import android.app.NotificationManager;
+import android.app.Service;
+import android.os.HandlerThread;
+
+/**
+ * The Cupcake (API level 3) specific implementation of the
+ * {@link ApiPlatformAdapter}.
+ * 
+ * @author Bartlomiej Niechwiej
+ */
+public class CupcakePlatformAdapter implements ApiPlatformAdapter {
+
+  @Override
+  public void startForeground(Service service,
+      NotificationManager notificationManager, int id,
+      Notification notification) {
+    service.setForeground(true);
+    notificationManager.notify(id, notification);
+  }
+
+  @Override
+  public void stopForeground(Service service,
+      NotificationManager notificationManager, int id) {
+    service.setForeground(false);
+    if (id != -1) {
+      notificationManager.cancel(id);
+    }
+  }
+
+  @Override
+  public boolean stopHandlerThread(HandlerThread handlerThread) {
+    // Do nothing, as Cupcake doesn't provide quit().
+    return false;
+  }
+}

MyTracks/src/com/google/android/apps/mytracks/util/EclairPlatformAdapter.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2010 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.google.android.apps.mytracks.util;
+
+import android.app.Notification;
+import android.app.NotificationManager;
+import android.app.Service;
+import android.os.HandlerThread;
+
+/**
+ * The Eclair (API level 5) specific implementation of the
+ * {@link ApiPlatformAdapter}.
+ * 
+ * @author Bartlomiej Niechwiej
+ */
+public class EclairPlatformAdapter implements ApiPlatformAdapter {
+
+  @Override
+  public void startForeground(Service service,
+      NotificationManager notificationManager, int id,
+      Notification notification) {
+    service.startForeground(id, notification);
+  }
+
+  @Override
+  public void stopForeground(Service service,
+      NotificationManager notificationManager, int id) {
+    service.stopForeground(id != -1);
+  }
+
+  @Override
+  public boolean stopHandlerThread(HandlerThread handlerThread) {
+    return handlerThread.quit();
+  }
+}

MyTracksTest/src/com/google/android/apps/mytracks/services/TrackRecordingServiceTest.java

@@ -23,6 +23,7 @@ import com.google.android.apps.mytracks.content.MyTracksProviderUtils;
 import com.google.android.apps.mytracks.content.Track;
 import com.google.android.apps.mytracks.content.Waypoint;
 import com.google.android.apps.mytracks.stats.TripStatistics;
+import com.google.android.apps.mytracks.util.ApiFeatures;
 import com.google.android.maps.mytracks.R;
 
 import android.content.ContentResolver;
@@ -57,6 +58,9 @@ public class TrackRecordingServiceTest
     super(TrackRecordingService.class);
   }
 
+  /**
+   * A context wrapper with the user provided {@link ContentResolver}.  
+   */
   private static class MockContext extends ContextWrapper {
     private final ContentResolver contentResolver;
     
@@ -70,11 +74,26 @@ public class TrackRecordingServiceTest
       return contentResolver;
     }
   }
+
+  /**
+   * A mock class that forces API level < 5 to make sure we can workaround a bug
+   * in ServiceTestCase (throwing a NPE).
+   * See http://code.google.com/p/android/issues/detail?id=12122 for more
+   * details.
+   */
+  private static class MockApiFeatures extends ApiFeatures {
+    @Override
+    protected int getApiLevel() {
+      return 4;
+    }
+  }
   
   @Override
   protected void setUp() throws Exception {
     super.setUp();
     
+    ApiFeatures.injectInstance(new MockApiFeatures());
+    
     MockContentResolver mockContentResolver = new MockContentResolver();
     RenamingDelegatingContext targetContext = new RenamingDelegatingContext(
         getContext(), getContext(), "test.");

MyTracksTest/src/com/google/android/apps/mytracks/util/ApiFeaturesTest.java

@@ -75,4 +75,8 @@ public class ApiFeaturesTest extends TestCase {
     features.setApiLevel(8);
     assertTrue(features.hasModernSignalStrength());
   }
+  
+  public void testGetApiPlatformAdapter() {
+    assertNotNull(features.getApiPlatformAdapter());
+  }
 }