Fixed Javascript race condition.

website/script/simstadt_openlayers.js

@@ -117,8 +117,11 @@ var map = new ol.Map({
 
 var geoJSONformat = new ol.format.GeoJSON();
 kml_layer.addEventListener("change", function(event) {
-	var fromJavaFX = (typeof fxapp !== 'undefined');
 	map.getView().fitExtent(kml_source.getExtent(), (map.getSize()));
+});
+
+function updateGMLPolygons(){
+	var fromJavaFX = (typeof fxapp !== 'undefined');
 	kml_source.forEachFeature(function(feature) {
 		feature["geoJSON"] = geoJSONformat.writeFeatureObject(feature);
 		feature["area"] = feature.getGeometry().getArea();
@@ -131,7 +134,7 @@ kml_layer.addEventListener("change", function(event) {
 		}
 		feature["available"] = citygmlHere;
 	});
-});
+}
 
 // The features are not added to a regular vector layer/source,
 // but to a feature overlay which holds a collection of features.
@@ -185,6 +188,7 @@ var sketch;
 draw.on('drawstart', function(evt) {
 	sketch = evt.feature;
 	reset_btn.disabled = false;
+	updateGMLPolygons();
 });
 var sourceProj = map.getView().getProjection();