added some Javadoc in the trackfiles import stuff

java/com.sap.sailing.server.trackfiles/src/com/sap/sailing/server/trackfiles/common/BaseGPSFixImporterImpl.java

@@ -7,9 +7,18 @@ import com.sap.sailing.domain.tracking.GPSFixMoving;
 import com.sap.sailing.domain.tracking.impl.GPSFixMovingImpl;
 
 /**
- * Provide inference functionality.
+ * When an importer only provides latitude/longitude positions but no course over ground (COG) and no speed over ground
+ * (SOG) values, this class infers the COG/SOG values from the positions and timestamps of the basic fixes. Objects of this
+ * class are stateful in the sense that each call to {@link #addFixAndInfer(com.sap.sailing.domain.trackimport.GPSFixImporter.Callback, boolean, GPSFix)}
+ * remembers the fix just handled. The {@link #addFixAndInfer(com.sap.sailing.domain.trackimport.GPSFixImporter.Callback, boolean, GPSFix)} method
+ * therefore needs to be invoked with the fixes in ascending time point order.<p>
+ * 
+ * If the fixes delivered to {@link #addFixAndInfer(com.sap.sailing.domain.trackimport.GPSFixImporter.Callback, boolean, GPSFix)} are
+ * already of type {@link GPSFixMoving}, they are used as-is. Otherwise, except for the first fix which is dropped, COG/SOG values
+ * will be inferred, a {@link GPSFixMoving} will be constructed and forwarded to the callback instance.
+ * 
  * @author Fredrik Teschke
- *
+ * 
  */
 public abstract class BaseGPSFixImporterImpl implements GPSFixImporter {
     private GPSFix previousFix;
@@ -23,7 +32,6 @@ public abstract class BaseGPSFixImporterImpl implements GPSFixImporter {
             SpeedWithBearing speedWithBearing = previousFix.getSpeedAndBearingRequiredToReach(fix);
             fix = new GPSFixMovingImpl(fix.getPosition(), fix.getTimePoint(), speedWithBearing);
         }
-        
         previousFix = fix;
         callback.addFix(fix);
     }

java/com.sap.sailing.server.trackfiles/src/com/sap/sailing/server/trackfiles/common/GPSFixImporterRegistration.java

@@ -19,6 +19,12 @@ public class GPSFixImporterRegistration {
         return properties;
     }
     
+    /**
+     * Registers the <code>importer</code> as an OSGi service for the {@link GPSFixImporter} interface, once for each
+     * {@link GPSFixImporter#getSupportedFileExtensions() supported file extension} , using its
+     * {@link GPSFixImporter#getType() type} as the {@link TypeBasedServiceFinder#TYPE} property and the
+     * file extension as the {@link GPSFixImporter#FILE_EXTENSION_PROPERTY} property.
+     */
     public static Collection<ServiceRegistration<GPSFixImporter>>
         register(GPSFixImporter importer, BundleContext context) {
         List<ServiceRegistration<GPSFixImporter>> registrations = new ArrayList<>();