Add custom dynamic entity data source

/*
 * Copyright 2023 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.
 */
module com.esri.samples.add_custom_dynamic_entity_data_source {
  // require ArcGIS Maps SDK for Java module
  requires com.esri.arcgisruntime;

  // handle SLF4J http://www.slf4j.org/codes.html#StaticLoggerBinder
  requires org.slf4j.nop;

  // require JavaFX modules that the application uses
  requires javafx.graphics;
  requires javafx.controls;

  // require Gson for parsing json data
  requires com.google.gson;

  exports com.esri.samples.add_custom_dynamic_entity_data_source;
}

/*
 * Copyright 2023 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.add_custom_dynamic_entity_data_source;

import java.io.File;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

import com.esri.arcgisruntime.ArcGISRuntimeEnvironment;
import com.esri.arcgisruntime.arcgisservices.LabelDefinition;
import com.esri.arcgisruntime.geometry.Point;
import com.esri.arcgisruntime.geometry.SpatialReferences;
import com.esri.arcgisruntime.layers.DynamicEntityLayer;
import com.esri.arcgisruntime.mapping.ArcGISMap;
import com.esri.arcgisruntime.mapping.BasemapStyle;
import com.esri.arcgisruntime.mapping.Viewpoint;
import com.esri.arcgisruntime.mapping.labeling.SimpleLabelExpression;
import com.esri.arcgisruntime.mapping.view.MapView;
import com.esri.arcgisruntime.realtime.ConnectionStatus;
import com.esri.arcgisruntime.symbology.TextSymbol;

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.StackPane;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

public class AddCustomDynamicEntityDataSourceSample extends Application {

  private MapView mapView;

  private SimulatedDataSource dynamicEntityDataSource;

  @Override
  public void start(Stage stage) {
    StackPane stackPane = new StackPane();
    Scene scene = new Scene(stackPane);

    // set title, size, and add scene to stage
    stage.setTitle("Add custom dynamic entity data source");
    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 new map with the oceans basemap style
    ArcGISMap map = new ArcGISMap(BasemapStyle.ARCGIS_OCEANS);

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

    // set the initial viewpoint
    mapView.setViewpoint(new Viewpoint(new Point(-123.657, 47.984, SpatialReferences.getWgs84()), 3e6));

    // a JSON file with observations for use as the custom data source
    var resource = new File(System.getProperty("data.dir"), "./samples-data/real_time/AIS_MarineCadastre_SelectedVessels_CustomDataSource.json").getPath();

    // create a custom data source implementation of a DynamicEntityDataSource with a data source,
    // an entity id field name (a unique identifier for each entity), and an update delay
    dynamicEntityDataSource = new SimulatedDataSource(resource, "MMSI", 10);

    dynamicEntityDataSource.connectionStatusProperty().addListener((property, oldValue, newValue) -> {
      if (newValue == ConnectionStatus.FAILED) {
        System.err.println("The connection failed");
      }
    });

    dynamicEntityDataSource.connectionErrorProperty().addListener((property, oldValue, newValue) -> {
      if (newValue != null) {
        System.err.println("The connection failed: " + newValue.getMessage());
      }
    });

    // create the dynamic entity layer using the custom data source
    var dynamicEntityLayer = new DynamicEntityLayer(dynamicEntityDataSource);

    // set up the track display properties
    setupTrackDisplayProperties(dynamicEntityLayer);

    // set up the dynamic entity labeling
    setupLabeling(dynamicEntityLayer);

    // add the dynamic entity layer to the map
    map.getOperationalLayers().add(dynamicEntityLayer);

    // add the map view to the stack pane
    stackPane.getChildren().addAll(mapView);
  }

  /**
   * Set up the track display properties, these properties will be used to configure the appearance of the track line
   * and previous observations.
   *
   * @param layer the DynamicEntityLayer to be configured
   */
  private void setupTrackDisplayProperties(DynamicEntityLayer layer) {
    var trackDisplayProperties = layer.getTrackDisplayProperties();
    trackDisplayProperties.setShowPreviousObservations(true);
    trackDisplayProperties.setShowTrackLine(true);
    trackDisplayProperties.setMaximumDuration(200);
  }

  /**
   * Configure labeling on the layer to use a red label using the VesselName attribute.
   *
   * @param layer the DynamicEntityLayer for the labels
   */
  private void setupLabeling(DynamicEntityLayer layer) {
    // define the label expression to be used, in this case we will use the "VesselName" for each of the dynamic entities
    var simpleLabelExpression = new SimpleLabelExpression("[VesselName]");

    // set the text symbol color and size for the labels
    var labelSymbol = new TextSymbol(12, "", Color.RED, TextSymbol.HorizontalAlignment.CENTER, TextSymbol.VerticalAlignment.BOTTOM);

    // set the label position
    var labelDef = new LabelDefinition(simpleLabelExpression, labelSymbol);

    // add the label definition to the dynamic entity layer and enable labels
    layer.getLabelDefinitions().add(labelDef);
    layer.labelsEnabledProperty().set(true);
  }

  /**
   * Stops and releases all resources used in application.
   */
  @Override
  public void stop() {
    // notify the observations processing to stop
    if (dynamicEntityDataSource != null) {
      try {
        dynamicEntityDataSource.disconnectAsync().get(2, TimeUnit.SECONDS);
      } catch (InterruptedException | TimeoutException | ExecutionException e) {
        System.err.println("Exception when disconnecting from data source: " + e);
      }
    }

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

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

/*
 * Copyright 2023 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.add_custom_dynamic_entity_data_source;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Objects;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CompletionException;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

import com.google.gson.Gson;

import com.esri.arcgisruntime.data.Field;
import com.esri.arcgisruntime.geometry.Point;
import com.esri.arcgisruntime.geometry.SpatialReferences;
import com.esri.arcgisruntime.realtime.DynamicEntityDataSource;
import com.esri.arcgisruntime.realtime.DynamicEntityDataSourceInfo;

/**
 * A custom DynamicEntityDataSource for processing observations read from a given JSON file.
 */
class SimulatedDataSource extends DynamicEntityDataSource {

  private final String fileName;
  private final String entityIdFieldName;
  private final long delay;
  private final ScheduledExecutorService executorService = Executors.newSingleThreadScheduledExecutor();
  private ScheduledFuture<?> observationProcessing;
  private final AtomicInteger currentLineNumber = new AtomicInteger();
  private final List<String> allJsonLines = new ArrayList<>();
  private final Gson gson = new Gson();

  /**
   * Construct a custom DynamicEntityDataSource.
   *
   * @param fileName name of a file with JSON observation data
   * @param entityIdFieldName the name of the field containing values that uniquely identifies each entity
   * @param delay millisecond delay between observations being added to the data source
   */
  SimulatedDataSource(String fileName, String entityIdFieldName, long delay) {
    this.fileName = fileName;
    this.entityIdFieldName = entityIdFieldName;
    this.delay = delay;
  }

  @Override
  protected CompletableFuture<Void> onConnectAsync() {
    return new CompletableFuture<Void>().completeAsync(() -> {
      try {
        startProcessingObservations();
        return null;
      } catch (IOException e) {
        throw new CompletionException(e);
      }
    });
  }

  /**
   * Read a file of observation data and start processing.
   */
  private void startProcessingObservations() throws IOException {
    // store all lines from file in a list
    try (BufferedReader bufferedReader = new BufferedReader(new FileReader(fileName))) {
      allJsonLines.addAll(bufferedReader.lines().filter(Objects::nonNull).toList());
    } catch (IOException e) {
      System.err.println("Failed to start processing observations: " + e.getMessage());
      throw e;
    }
    // process file data a line at a time
    observationProcessing = executorService.scheduleAtFixedRate(this::processNextObservation, 0L, delay, TimeUnit.MILLISECONDS);
  }

  /**
   * Process the next observation, canceling the task when all lines have been processed.
   */
  private void processNextObservation() {
    int lineNumber = currentLineNumber.getAndAdd(1);
    if (lineNumber >= allJsonLines.size()) {
      // finished all the lines
      observationProcessing.cancel(false);
    } else {
      // process the line by parsing the JSON, and creating the observation, and adding to the data source
      var observation = gson.fromJson(allJsonLines.get(lineNumber), Observation.class);
      var point = new Point(observation.geometry.x, observation.geometry.y, SpatialReferences.getWgs84());
      addObservation(point, observation.attributes);
    }
  }

  @Override
  protected CompletableFuture<Void> onDisconnectAsync() {
    if (observationProcessing != null) {
      observationProcessing.cancel(true);
    }
    executorService.shutdown();
    return CompletableFuture.completedFuture(null);
  }

  @Override
  protected CompletableFuture<DynamicEntityDataSourceInfo> onLoadAsync() {
    var dynamicEntityDataSourceInfo = new DynamicEntityDataSourceInfo(entityIdFieldName,
      List.of(
        Field.createString("MMSI", null, 256),
        Field.createDouble("BaseDateTime", null),
        Field.createDouble("LAT", null),
        Field.createDouble("LONG", null),
        Field.createDouble("SOG", null),
        Field.createDouble("COG", null),
        Field.createDouble("Heading", null),
        Field.createString("VesselName", null, 256),
        Field.createString("IMO", null, 256),
        Field.createString("CallSign", null, 256),
        Field.createString("VesselType", null, 256),
        Field.createString("Status", null, 256),
        Field.createDouble("Length", null),
        Field.createDouble("Width", null),
        Field.createString("Cargo", null, 256),
        Field.createString("globalid", null, 256)
      ));
    dynamicEntityDataSourceInfo.setSpatialReference(SpatialReferences.getWgs84());
    return CompletableFuture.completedFuture(dynamicEntityDataSourceInfo);
  }

  @Override
  public String getUri() {
    return null;
  }

  /**
   * Used by Gson for parsing the data.
   */
  public static class ObservationSpatialReference {
    public int wkid;
  }

  /**
   * Used by Gson for parsing the data.
   */
  public static class ObservationGeometry {
    public double x;
    public double y;
    public ObservationSpatialReference spatialReference;
  }

  /**
   * Used by Gson for parsing the data.
   */
  public static class Observation {
    public ObservationGeometry geometry;
    public HashMap<String, Object> attributes;
  }
}