support for multiple legs (#496)

* support for multiple legs

* support for multiple legs added

* nit empty line

* added comment explaining the list adding

Author: Cameron Mace

mapbox/libandroid-services/src/main/java/com/mapbox/services/android/location/MockLocationEngine.java

@@ -301,21 +301,25 @@ public void setRoute(DirectionsRoute route) {
    */
   private void calculateStepPoints() {
     LineString line = LineString.fromPolyline(
-      route.getLegs().get(currentLeg)
-        .getSteps().get(currentStep).getGeometry(), Constants.PRECISION_6);
+      route.getLegs().get(currentLeg).getSteps().get(currentStep).getGeometry(), Constants.PRECISION_6);
 
-    if (currentStep < route.getLegs().get(currentLeg).getSteps().size() - 1) {
-      currentStep++;
-    } else if (currentLeg < route.getLegs().size() - 1) {
-      currentLeg++;
-    }
+    increaseIndex();
 
     sliceRoute(line, distance);
     if (noisyGps) {
       addNoiseToRoute(distance);
     }
   }
 
+  private void increaseIndex() {
+    if (currentStep < route.getLegs().get(currentLeg).getSteps().size() - 1) {
+      currentStep++;
+    } else if (currentLeg < route.getLegs().size() - 1) {
+      currentLeg++;
+      currentStep = 0;
+    }
+  }
+
   /**
    * Here we build the new mock {@link Location} object and fill in as much information we can calculate.
    *
@@ -353,7 +357,9 @@ private Location mockLocation(Position position) {
   private class LocationUpdateRunnable implements Runnable {
     @Override
     public void run() {
-      if (positions.size() <= 5) {
+      // Calculate the next steps points if the list becomes empty
+      // so that the mock location continues along the route
+      if (positions.size() <= 0) {
         calculateStepPoints();
       }