Clean up SensorManagerFactory.

- not using reference count.
- make sure SensorStateActivity will not
  disconnect a connection used by TrackRecordingService

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

@@ -126,7 +126,7 @@ public class SensorStateActivity extends AbstractMyTracksActivity {
    */
   private void stopTempSensorManager() {
     if (tempSensorManager != null) {
-      SensorManagerFactory.getInstance().releaseSensorManager(tempSensorManager);
+      SensorManagerFactory.releaseTempSensorManager();
       tempSensorManager = null;
     }
   }
@@ -139,7 +139,7 @@ public class SensorStateActivity extends AbstractMyTracksActivity {
     Sensor.SensorDataSet sensorDataSet = null;
 
     if (tempSensorManager == null) {
-      tempSensorManager = SensorManagerFactory.getInstance().getSensorManager(this);
+      tempSensorManager = SensorManagerFactory.getTempSensorManager(this);
     }
 
     if (tempSensorManager != null) {

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

@@ -359,7 +359,7 @@ public class TrackRecordingService extends Service {
     unregisterLocationListener();
     shutdownTaskExecutors();
     if (sensorManager != null) {
-      SensorManagerFactory.getInstance().releaseSensorManager(sensorManager);
+      SensorManagerFactory.releaseSystemSensorManager();
       sensorManager = null;
     }
 
@@ -595,7 +595,7 @@ public class TrackRecordingService extends Service {
     length = 0;
     showNotification();
     registerLocationListener();
-    sensorManager = SensorManagerFactory.getInstance().getSensorManager(this);
+    sensorManager = SensorManagerFactory.getSystemSensorManager(this);
 
     // Reset the number of auto-resume retries.
     setAutoResumeTrackRetries(0);
@@ -1042,7 +1042,7 @@ public class TrackRecordingService extends Service {
     PreferencesUtils.setLong(this, R.string.recording_track_id_key, recordingTrackId);
 
     if (sensorManager != null) {
-      SensorManagerFactory.getInstance().releaseSensorManager(sensorManager);
+      SensorManagerFactory.releaseSystemSensorManager();
       sensorManager = null;
     }
 

MyTracks/src/com/google/android/apps/mytracks/services/sensors/SensorManagerFactory.java

@@ -13,101 +13,99 @@
  * License for the specific language governing permissions and limitations under
  * the License.
  */
+
 package com.google.android.apps.mytracks.services.sensors;
 
-import com.google.android.apps.mytracks.Constants;
 import com.google.android.apps.mytracks.services.sensors.ant.AntDirectSensorManager;
 import com.google.android.apps.mytracks.services.sensors.ant.AntSrmBridgeSensorManager;
 import com.google.android.apps.mytracks.util.PreferencesUtils;
 import com.google.android.maps.mytracks.R;
 
 import android.content.Context;
-import android.util.Log;
 
 /**
- * A factory of SensorManagers.
+ * A factory of {@link SensorManager}.
  *
  * @author Sandor Dornbush
  */
 public class SensorManagerFactory {
 
-  private String activeSensorType = null;
-  private SensorManager activeSensorManager = null;
-  private int refCount = 0;
+  private static SensorManager systemSensorManager = null;
+  private static SensorManager tempSensorManager = null;
 
-  private static SensorManagerFactory instance = new SensorManagerFactory();
+  private SensorManagerFactory() {}
 
-  private SensorManagerFactory() {
+  /**
+   * Gets the system sensor manager.
+   *
+   * @param context the context
+   */
+  public static SensorManager getSystemSensorManager(Context context) {
+    releaseTempSensorManager();
+    releaseSystemSensorManager();
+    systemSensorManager = getSensorManager(context);
+    if (systemSensorManager != null) {
+      systemSensorManager.startSensor();
+    }
+    return systemSensorManager;
   }
 
   /**
-   * Get the factory instance. 
+   * Releases the system sensor manager.
    */
-  public static SensorManagerFactory getInstance() {
-    return instance;
+  public static void releaseSystemSensorManager() {
+    if (systemSensorManager != null) {
+      systemSensorManager.stopSensor();
+    }
+    systemSensorManager = null;
   }
 
   /**
-   * Get and start a new sensor manager.
-   * @param context Context to fetch system preferences.
-   * @return The sensor manager that corresponds to the sensor type setting.
+   * Gets the temp sensor manager.
+   *
+   * @param context
    */
-  public SensorManager getSensorManager(Context context) {
-    context = context.getApplicationContext();
+  public static SensorManager getTempSensorManager(Context context) {
+    releaseTempSensorManager();
+    if (systemSensorManager != null) {
+      return null;
+    }
+    tempSensorManager = getSensorManager(context);
+    if (tempSensorManager != null) {
+      tempSensorManager.startSensor();
+    }
+    return tempSensorManager;
+  }
+
+  /**
+   * Releases the temp sensor manager.
+   */
+  public static void releaseTempSensorManager() {
+    if (tempSensorManager != null) {
+      tempSensorManager.stopSensor();
+    }
+    tempSensorManager = null;
+  }
+
+  /**
+   * Gets the sensor manager.
+   *
+   * @param context the context
+   */
+  private static SensorManager getSensorManager(Context context) {
     String sensorTypeValueNone = context.getString(R.string.sensor_type_value_none);
     String sensorType = PreferencesUtils.getString(
         context, R.string.sensor_type_key, sensorTypeValueNone);
-    Log.i(Constants.TAG, "Creating sensor of type: " + sensorType);
-
-    if (sensorTypeValueNone.equals(sensorType)) {
-      reset();
-      return null;
-    }
-    if (sensorType.equals(activeSensorType)) {
-      Log.i(Constants.TAG, "Returning existing sensor manager.");
-      refCount++;
-      return activeSensorManager;
-    }
-    reset();
 
     if (sensorType.equals(context.getString(R.string.sensor_type_value_ant))) {
-      activeSensorManager = new AntDirectSensorManager(context);
+      return new AntDirectSensorManager(context);
     } else if (sensorType.equals(context.getString(R.string.sensor_type_value_srm_ant_bridge))) {
-      activeSensorManager = new AntSrmBridgeSensorManager(context);
+      return new AntSrmBridgeSensorManager(context);
     } else if (sensorType.equals(context.getString(R.string.sensor_type_value_zephyr))) {
-      activeSensorManager = new ZephyrSensorManager(context);
+      return new ZephyrSensorManager(context);
     } else if (sensorType.equals(context.getString(R.string.sensor_type_value_polar))) {
-      activeSensorManager = new PolarSensorManager(context);
-    } else  {
-      Log.w(Constants.TAG, "Unable to find sensor type: " + sensorType);
-      return null;
+      return new PolarSensorManager(context);
     }
-    activeSensorType = sensorType;
-    refCount = 1;
-    activeSensorManager.startSensor();
-    return activeSensorManager;
-  }
-
-  /**
-   * Finish using a sensor manager.
-   */
-  public void releaseSensorManager(SensorManager sensorManager) {
-    Log.i(Constants.TAG, "releaseSensorManager: " + activeSensorType + " " + refCount);
-    if (sensorManager != activeSensorManager) {
-      Log.e(Constants.TAG, "invalid parameter to releaseSensorManager");
-    }
-    if (--refCount > 0) {
-      return;
-    }
-    reset();
-  }
-
-  private void reset() {
-    activeSensorType = null;
-    if (activeSensorManager != null) {
-      activeSensorManager.stopSensor();
-    }
-    activeSensorManager = null;
-    refCount = 0;
+    return null;
   }
 }

MyTracksTest/src/com/google/android/apps/mytracks/services/sensors/SensorManagerFactoryTest.java

@@ -23,7 +23,7 @@ public class SensorManagerFactoryTest extends AndroidTestCase {
 
   @SmallTest
   public void testDefaultSettings() throws Exception {
-    assertNull(SensorManagerFactory.getInstance().getSensorManager(getContext()));
+    assertNull(SensorManagerFactory.getSystemSensorManager(getContext()));
   }
 
   @SmallTest
@@ -38,9 +38,9 @@ public class SensorManagerFactoryTest extends AndroidTestCase {
 
   private void assertClassForName(Class<?> c, int i) {
     PreferencesUtils.setString(getContext(), R.string.sensor_type_key, getContext().getString(i));
-    SensorManager sm = SensorManagerFactory.getInstance().getSensorManager(getContext());
+    SensorManager sm = SensorManagerFactory.getSystemSensorManager(getContext());
     assertNotNull(sm);
     assertTrue(c.isInstance(sm));
-    SensorManagerFactory.getInstance().releaseSensorManager(sm);
+    SensorManagerFactory.releaseSystemSensorManager();
   }
 }