[Sample Update] Feature Layer Dictionary Renderer sample (#702)

* Update FeatureLayerDictionaryRendererSample.java

* Update feature_layers/feature-layer-dictionary-renderer/src/main/java/com/esri/samples/feature_layer_dictionary_renderer/FeatureLayerDictionaryRendererSample.java

Co-authored-by: Jen Merritt <[email protected]>

* Update feature_layers/feature-layer-dictionary-renderer/src/main/java/com/esri/samples/feature_layer_dictionary_renderer/FeatureLayerDictionaryRendererSample.java

Co-authored-by: Jen Merritt <[email protected]>

* Update feature_layers/feature-layer-dictionary-renderer/src/main/java/com/esri/samples/feature_layer_dictionary_renderer/FeatureLayerDictionaryRendererSample.java

Co-authored-by: Jen Merritt <[email protected]>

* Update feature_layers/feature-layer-dictionary-renderer/src/main/java/com/esri/samples/feature_layer_dictionary_renderer/FeatureLayerDictionaryRendererSample.java

Co-authored-by: Jen Merritt <[email protected]>

* Update feature_layers/feature-layer-dictionary-renderer/src/main/java/com/esri/samples/feature_layer_dictionary_renderer/FeatureLayerDictionaryRendererSample.java

Co-authored-by: Jen Merritt <[email protected]>

Co-authored-by: Jen Merritt <[email protected]>

Author: Rachael-E

feature_layers/feature-layer-dictionary-renderer/src/main/java/com/esri/samples/feature_layer_dictionary_renderer/FeatureLayerDictionaryRendererSample.java

@@ -37,9 +37,7 @@
 public class FeatureLayerDictionaryRendererSample extends Application {
 
   private MapView mapView;
-  // keep loadables in scope to avoid garbage collection
-  private Geodatabase geodatabase;
-  private FeatureLayer featureLayer;
+  private Geodatabase geodatabase;   // keep loadable in scope to avoid garbage collection
 
   @Override
   public void start(Stage stage) {
@@ -63,46 +61,63 @@ public void start(Stage stage) {
     ArcGISMap map = new ArcGISMap(BasemapStyle.ARCGIS_TOPOGRAPHIC);
     mapView.setMap(map);
 
-    // load geo-database from local location
+    // define and load a dictionary symbol style from a local style file
+    File stylxFile = new File(System.getProperty("data.dir"), "./samples-data/stylx/mil2525d.stylx");
+    var dictionarySymbolStyle = DictionarySymbolStyle.createFromFile(stylxFile.getAbsolutePath());
+    dictionarySymbolStyle.loadAsync();
+
+    // create a new geodatabase instance from the geodatabase stored at the local location
     File geodatabaseFile = new File(System.getProperty("data.dir"), "./samples-data/dictionary/militaryoverlay" +
-            ".geodatabase");
+      ".geodatabase");
     geodatabase = new Geodatabase(geodatabaseFile.getAbsolutePath());
-    geodatabase.loadAsync();
-
-    // render tells layer what symbols to apply to what features
-    File stylxFile = new File(System.getProperty("data.dir"), "./samples-data/stylx/mil2525d.stylx");
-    DictionarySymbolStyle symbolDictionary = DictionarySymbolStyle.createFromFile(stylxFile.getAbsolutePath());
-    symbolDictionary.loadAsync();
 
     geodatabase.addDoneLoadingListener(() -> {
+    // check if the geodatabase has loaded successfully
       if (geodatabase.getLoadStatus() == LoadStatus.LOADED) {
-        geodatabase.getGeodatabaseFeatureTables().forEach(table -> {
-          // add each layer to map
-          featureLayer = new FeatureLayer(table);
-          featureLayer.loadAsync();
-          // Features no longer show after this scale
-          featureLayer.setMinScale(1000000);
-          map.getOperationalLayers().add(featureLayer);
-
-          // displays features from layer using mil2525d symbols
-          DictionaryRenderer dictionaryRenderer = new DictionaryRenderer(symbolDictionary);
-          featureLayer.setRenderer(dictionaryRenderer);
-
-          featureLayer.addDoneLoadingListener(() -> {
-            if (featureLayer.getLoadStatus() == LoadStatus.LOADED) {
-              // initial viewpoint to encompass all graphics displayed on the map view 
-              mapView.setViewpointGeometryAsync(featureLayer.getFullExtent());
-            } else {
-              Alert alert = new Alert(Alert.AlertType.ERROR, "Feature Layer Failed to Load!");
-              alert.show();
-            }
-          });
+        var mapOperationalLayersList = map.getOperationalLayers();
+        var geodatabaseFeatureTablesList = geodatabase.getGeodatabaseFeatureTables();
+
+        geodatabaseFeatureTablesList.forEach(table -> {
+          // create a new feature layer from each geodatabase feature table and
+          // add it to the map's list of operational layers
+          mapOperationalLayersList.add(new FeatureLayer(table));
         });
+
+        // check the map operational layers size matches that of the geodatabase's feature tables size
+        if (!mapOperationalLayersList.isEmpty() && mapOperationalLayersList.size() == geodatabaseFeatureTablesList.size()) {
+
+          // check that each layer has loaded correctly and if not display an error message
+          mapOperationalLayersList.forEach(layer ->
+            layer.addDoneLoadingListener(() -> {
+              if (layer.getLoadStatus() == LoadStatus.LOADED) {
+                
+                // set the feature layer's minimum scale so that features no longer show after this scale
+                layer.setMinScale(1000000);
+                
+                // set the dictionary renderer as the feature layer's renderer
+                if (layer instanceof FeatureLayer) {
+                  ((FeatureLayer) layer).setRenderer(new DictionaryRenderer(dictionarySymbolStyle));
+                }
+                
+                // set the map view viewpoint
+                mapView.setViewpointGeometryAsync(layer.getFullExtent());
+
+              } else {
+                new Alert(Alert.AlertType.ERROR,
+                  "Feature layer failed to load: " + layer.getLoadError().getCause().getMessage()).show();
+              }
+            })
+          );
+        } else {
+          new Alert(Alert.AlertType.ERROR, "Error: Map operational list size does not match geodatabase feature table list size").show();
+        }
       } else {
-        Alert alert = new Alert(Alert.AlertType.ERROR, "Geodatabase Failed to Load!");
-        alert.show();
+        new Alert(Alert.AlertType.ERROR, "Geodatabase Failed to Load!").show();
       }
     });
+    
+    // load the geodatabase
+    geodatabase.loadAsync();
   }
 
   /**