Delete features

/*
 * Copyright 2017 Esri.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package com.esri.samples.delete_features;

import java.util.List;
import java.util.concurrent.ExecutionException;
import java.util.stream.Collectors;

import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.Insets;
import javafx.geometry.Point2D;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Alert;
import javafx.scene.control.Alert.AlertType;
import javafx.scene.control.Button;
import javafx.scene.input.MouseButton;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

import com.esri.arcgisruntime.ArcGISRuntimeEnvironment;
import com.esri.arcgisruntime.concurrent.ListenableFuture;
import com.esri.arcgisruntime.data.Feature;
import com.esri.arcgisruntime.data.FeatureTableEditResult;
import com.esri.arcgisruntime.data.FeatureQueryResult;
import com.esri.arcgisruntime.data.ServiceFeatureTable;
import com.esri.arcgisruntime.data.ServiceGeodatabase;
import com.esri.arcgisruntime.layers.FeatureLayer;
import com.esri.arcgisruntime.mapping.ArcGISMap;
import com.esri.arcgisruntime.mapping.BasemapStyle;
import com.esri.arcgisruntime.mapping.Viewpoint;
import com.esri.arcgisruntime.mapping.view.IdentifyLayerResult;
import com.esri.arcgisruntime.mapping.view.MapView;

public class DeleteFeaturesSample extends Application {

  private MapView mapView;
  private FeatureLayer featureLayer;
  private ServiceFeatureTable featureTable;
  private Button deleteButton;
  private ListenableFuture<FeatureQueryResult> selectionResult;

  private static final String FEATURE_LAYER_URL =
      "https://sampleserver6.arcgisonline.com/arcgis/rest/services/DamageAssessment/FeatureServer";

  @Override
  public void start(Stage stage) {

    try {
      // create stack pane and application scene
      StackPane stackPane = new StackPane();
      Scene scene = new Scene(stackPane);

      // set title, size, and add scene to stage
      stage.setTitle("Delete Features Sample");
      stage.setWidth(800);
      stage.setHeight(700);
      stage.setScene(scene);
      stage.show();

      // authentication with an API key or named user is required to access basemaps and other location services
      String yourAPIKey = System.getProperty("apiKey");
      ArcGISRuntimeEnvironment.setApiKey(yourAPIKey);

      // create a delete button and fill the width of the screen
      deleteButton = new Button("Delete");
      deleteButton.setMaxWidth(130);
      deleteButton.setDisable(true);

      // create event to delete the selected features on click
      deleteButton.setOnAction(event -> {
        // get selected features
        selectionResult = featureLayer.getSelectedFeaturesAsync();
        selectionResult.addDoneListener(() -> {
          try {
            FeatureQueryResult selected = selectionResult.get();
            // delete selected features
            deleteFeatures(selected, featureTable);
          } catch (InterruptedException | ExecutionException e) {
            displayMessage("Cannot delete features", e.getCause().getMessage());
          }
        });
      });

      // create a map with the streets basemap style
      ArcGISMap map = new ArcGISMap(BasemapStyle.ARCGIS_STREETS);

      // create a map view and set the map to it
      mapView = new MapView();
      mapView.setMap(map);

      // set a viewpoint on the map view
      mapView.setViewpoint(new Viewpoint(40, -95, 36978595));

      // create a service geodatabase from the service layer url and load it
      var serviceGeodatabase = new ServiceGeodatabase(FEATURE_LAYER_URL);
      serviceGeodatabase.addDoneLoadingListener(() -> {

        // create a service feature table from the first layer on the service geodatabase's table
        featureTable = serviceGeodatabase.getTable(0);

        // create a feature layer from the feature table
        featureLayer = new FeatureLayer(featureTable);

        // add the layer to the ArcGISMap
        map.getOperationalLayers().add(featureLayer);
      });
      serviceGeodatabase.loadAsync();

      mapView.setOnMouseClicked(event -> {
        // check for primary or secondary mouse click
        if (event.isStillSincePress() && event.getButton() == MouseButton.PRIMARY) {
          // create a point from where the user clicked
          Point2D point = new Point2D(event.getX(), event.getY());

          // clear any previous selection
          featureLayer.clearSelection();
          deleteButton.setDisable(true);

          // identify the clicked feature
          ListenableFuture<IdentifyLayerResult> results = mapView.identifyLayerAsync(featureLayer, point, 1, false);
          results.addDoneListener(() -> {
            try {
              IdentifyLayerResult layer = results.get();
              if (!layer.getElements().isEmpty()) {
                // search the layers for identified features
                List<Feature> features = layer.getElements()
                  .stream()
                  .filter(g -> g instanceof Feature)
                  .map(g -> (Feature) g)
                  .collect(Collectors.toList());
                // add the clicked feature to the selection
                if (features.size() > 0) {
                  featureLayer.selectFeatures(features);
                  deleteButton.setDisable(false);
                }
              }
            } catch (InterruptedException | ExecutionException e) {
              displayMessage("Exception getting identify result", e.getCause().getMessage());
            }
          });
        }
      });

      // add the map view and control box to stack pane
      stackPane.getChildren().addAll(mapView, deleteButton);
      StackPane.setAlignment(deleteButton, Pos.TOP_LEFT);
      StackPane.setMargin(deleteButton, new Insets(10, 0, 0, 10));

    } catch (Exception e) {
      // on any error, display the stack trace
      e.printStackTrace();
    }
  }

  /**
   * Deletes features from a ServiceFeatureTable and applies the changes to the
   * server.
   */
  private void deleteFeatures(FeatureQueryResult features, ServiceFeatureTable featureTable) {

    // delete feature from the feature table and apply edit to server
    featureTable.deleteFeaturesAsync(features).addDoneListener(() -> applyEdits(featureTable));
  }

  /**
   * Sends any edits on the ServiceFeatureTable to the server.
   *
   * @param featureTable service feature table
   */
  private void applyEdits(ServiceFeatureTable featureTable) {

    // apply the changes to the server
    ListenableFuture<List<FeatureTableEditResult>> editResult = featureTable.getServiceGeodatabase().applyEditsAsync();
    editResult.addDoneListener(() -> {
      try {
        List<FeatureTableEditResult> edits = editResult.get();
        // check if the server edit was successful
        if (edits != null && edits.size() > 0) {
          var featureEditResult = edits.get(0).getEditResult().get(0);
          if (!featureEditResult.hasCompletedWithErrors()) {
            displayMessage(null, "Feature successfully deleted");
            deleteButton.setDisable(true);
          } else {
            throw featureEditResult.getError();
          }
        }
      } catch (InterruptedException | ExecutionException e) {
        displayMessage("Exception applying edits on server", e.getCause().getMessage());
      }
    });
  }

  /**
   * Shows a message in an alert dialog.
   *
   * @param title title of alert
   * @param message message to display
   */
  private void displayMessage(String title, String message) {

    Platform.runLater(() -> {
      Alert dialog = new Alert(AlertType.INFORMATION);
      dialog.initOwner(mapView.getScene().getWindow());
      dialog.setHeaderText(title);
      dialog.setContentText(message);
      dialog.showAndWait();
    });
  }

  /**
   * Stops and releases all resources used in application.
   */
  @Override
  public void stop() {

    if (mapView != null) {
      mapView.dispose();
    }
  }

  /**
   * Opens and runs application.
   *
   * @param args arguments passed to this application
   */
  public static void main(String[] args) {

    Application.launch(args);
  }

}