Fix empty point, holepoints after polygon drag (#1898)

Change-Id: Ic56b10d6ca1df949a2bbf342b4bc7d3d473a6342

appinventor/components/src/com/google/appinventor/components/runtime/util/NativeOpenStreetMapController.java

@@ -694,10 +694,8 @@ class NativeOpenStreetMapController implements MapController, MapListener {
           }
           ((MapRectangle) component).updateBounds(north, west, south, east);
         } else {
-          ((MapPolygon) component).updatePoints(Collections.singletonList(polygon.getPoints()));
-          List<List<GeoPoint>> holes = new ArrayList<List<GeoPoint>>();
-          holes.addAll(polygon.getHoles());
-          ((MapPolygon) component).updateHolePoints(Collections.singletonList(holes));
+          ((MapPolygon) component).updatePoints(((MultiPolygon) polygon).getMultiPoints());
+          ((MapPolygon) component).updateHolePoints(((MultiPolygon) polygon).getMultiHoles());
         }
         for (MapEventListener listener : eventListeners) {
           listener.onFeatureStopDrag(component);
@@ -1343,6 +1341,14 @@ class NativeOpenStreetMapController implements MapController, MapListener {
       }
     }
 
+    public List<List<GeoPoint>> getMultiPoints() {
+      List<List<GeoPoint>> result = new ArrayList<>();
+      for (Polygon p : children) {
+        result.add(p.getPoints());
+      }
+      return result;
+    }
+
     public void setMultiPoints(List<List<GeoPoint>> points) {
       Iterator<Polygon> polygonIterator = children.iterator();
       Iterator<List<GeoPoint>> pointIterator = points.iterator();
@@ -1367,6 +1373,15 @@ class NativeOpenStreetMapController implements MapController, MapListener {
       }
     }
 
+    @SuppressWarnings("unchecked")  // upcasting nested ArrayList to List
+    public List<List<List<GeoPoint>>> getMultiHoles() {
+      List<List<List<GeoPoint>>> result = new ArrayList<>();
+      for (Polygon p : children) {
+        result.add((List) p.getHoles());
+      }
+      return result;
+    }
+
     public void setMultiHoles(List<List<List<GeoPoint>>> holes) {
       if (holes == null || holes.isEmpty()) {
         for (Polygon child : children) {