feat(demo): add new marker clustering demo

Author: paodb

src/test/java/com/flowingcode/vaadin/addons/googlemaps/GooglemapsDemoView.java

@@ -39,6 +39,7 @@ public GooglemapsDemoView() {
     addDemo(new CloudBasedMapStylingDemo());
     addDemo(new ControlSizeDemo());
     addDemo(new KMLLayerDemo());
+    addDemo(new MarkerClusteringDemo());
     setSizeFull();
   }
 }

src/test/java/com/flowingcode/vaadin/addons/googlemaps/MarkerClusteringDemo.java

@@ -0,0 +1,39 @@
+package com.flowingcode.vaadin.addons.googlemaps;
+
+import com.flowingcode.vaadin.addons.demo.DemoSource;
+import com.flowingcode.vaadin.addons.googlemaps.GoogleMap.MapType;
+import com.vaadin.flow.router.PageTitle;
+
+@PageTitle("Marker Clustering Demo")
+@DemoSource(
+    "https://github.com/FlowingCode/GoogleMapsAddon/blob/master/src/test/java/com/flowingcode/vaadin/addons/googlemaps/MarkerClusteringDemo.java")
+@SuppressWarnings("serial")
+public class MarkerClusteringDemo extends AbstractGoogleMapsDemo {
+
+  @Override
+  protected void createGoogleMapsDemo(String apiKey) {
+    GoogleMap gmaps = new GoogleMap(apiKey, null, null);
+    gmaps.setMapType(MapType.ROADMAP);
+    gmaps.setSizeFull();
+    gmaps.setZoom(5);
+    gmaps.setCenter(new LatLon(-31.636036, -60.7055271));
+    
+    gmaps.addMarker("Marker 1", new LatLon(-31.646036, -60.7055290), true, Markers.PINK);    
+    gmaps.addMarker("Marker 2", new LatLon(-31.562346, -60.6176364), true, Markers.PINK);    
+    gmaps.addMarker("Marker 3", new LatLon(-31.531917, -60.8456027), true, Markers.PINK);
+    gmaps.addMarker("Marker 4", new LatLon(-31.651667, -60.9555557), true, Markers.PINK);
+    
+    gmaps.addMarker("Marker 5", new LatLon(-30.997815, -65.60542944), false, Markers.BLUE);
+    gmaps.addMarker("Marker 6", new LatLon(-31.298693, -66.50630836), false, Markers.BLUE);
+    gmaps.addMarker("Marker 7", new LatLon(-31.878914, -66.28658178), false, Markers.BLUE);
+    
+    gmaps.addMarker("Marker 8", new LatLon(-33.138889, -65.95699194), false, Markers.GREEN);
+    gmaps.addMarker("Marker 9", new LatLon(-33.322683, -65.12203100), false, Markers.GREEN);
+    gmaps.addMarker("Marker 10", new LatLon(-33.652538, -65.737265381), false, Markers.GREEN);
+    
+    gmaps.enableMarkersClustering();
+    
+    add(gmaps);    
+  }
+
+}