Generate offline map

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/*
 * Copyright 2018 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.generate_offline_map;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;

import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.Point2D;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Alert;
import javafx.scene.control.Button;
import javafx.scene.control.ProgressBar;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

import com.esri.arcgisruntime.ArcGISRuntimeEnvironment;
import com.esri.arcgisruntime.concurrent.Job;
import com.esri.arcgisruntime.geometry.Envelope;
import com.esri.arcgisruntime.geometry.Point;
import com.esri.arcgisruntime.loadable.LoadStatus;
import com.esri.arcgisruntime.mapping.ArcGISMap;
import com.esri.arcgisruntime.mapping.view.Graphic;
import com.esri.arcgisruntime.mapping.view.GraphicsOverlay;
import com.esri.arcgisruntime.mapping.view.MapView;
import com.esri.arcgisruntime.portal.Portal;
import com.esri.arcgisruntime.portal.PortalItem;
import com.esri.arcgisruntime.symbology.SimpleLineSymbol;
import com.esri.arcgisruntime.tasks.offlinemap.GenerateOfflineMapJob;
import com.esri.arcgisruntime.tasks.offlinemap.GenerateOfflineMapParameters;
import com.esri.arcgisruntime.tasks.offlinemap.GenerateOfflineMapResult;
import com.esri.arcgisruntime.tasks.offlinemap.OfflineMapTask;

public class GenerateOfflineMapSample extends Application {

  private ArcGISMap map; // keep loadable in scope to avoid garbage collection
  private MapView mapView;

  @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("Generate Offline Map 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 button to take the map offline
      Button offlineMapButton = new Button("Take Map Offline");
      offlineMapButton.setDisable(true);

      // create a portal item with the itemId of the web map
      var portal = new Portal("https://www.arcgis.com");
      var portalItem = new PortalItem(portal, "acc027394bc84c2fb04d1ed317aac674");

      // create a map with the portal item
      map = new ArcGISMap(portalItem);
      map.addDoneLoadingListener(() -> {
        // enable the button when the map is loaded
        if (map.getLoadStatus() == LoadStatus.LOADED) {
          offlineMapButton.setDisable(false);
        }
      });

      // set the map to the map view
      mapView = new MapView();
      mapView.setMap(map);

      // create a graphics overlay for the map view
      var graphicsOverlay = new GraphicsOverlay();
      mapView.getGraphicsOverlays().add(graphicsOverlay);

      // create a graphic to show a box around the extent we want to download
      Graphic downloadArea = new Graphic();
      graphicsOverlay.getGraphics().add(downloadArea);
      SimpleLineSymbol simpleLineSymbol = new SimpleLineSymbol(SimpleLineSymbol.Style.SOLID, 0xFFFF0000, 2);
      downloadArea.setSymbol(simpleLineSymbol);

      // update the box whenever the viewpoint changes
      mapView.addViewpointChangedListener(viewpointChangedEvent -> {
        if (map.getLoadStatus() == LoadStatus.LOADED) {
          // upper left corner of the area to take offline
          Point2D minScreenPoint = new Point2D(50, 50);
          // lower right corner of the downloaded area
          Point2D maxScreenPoint = new Point2D(mapView.getWidth() - 50, mapView.getHeight() - 50);
          // convert screen points to map points
          Point minPoint = mapView.screenToLocation(minScreenPoint);
          Point maxPoint = mapView.screenToLocation(maxScreenPoint);
          // use the points to define and return an envelope
          if (minPoint != null && maxPoint != null) {
            Envelope envelope = new Envelope(minPoint, maxPoint);
            downloadArea.setGeometry(envelope);
          }
        }
      });

      // create progress bar to show download progress
      var progressBar = new ProgressBar(0.0);
      progressBar.setVisible(false);

      // when the button is clicked, start the offline map task job
      offlineMapButton.setOnAction(e -> {
        try {
          // show the progress bar
          progressBar.setVisible(true);

          // specify the extent, min scale, and max scale as parameters
          double minScale = mapView.getMapScale();
          double maxScale = map.getMaxScale();
          // minScale must always be larger than maxScale
          if (minScale <= maxScale) {
            minScale = maxScale + 1;
          }
          GenerateOfflineMapParameters params = new GenerateOfflineMapParameters(downloadArea.getGeometry(), minScale, maxScale);

          // create an offline map task with the map
          OfflineMapTask task = new OfflineMapTask(map);

          // create an offline map job with the download directory path and parameters and start the job
          Path tempDirectory = Files.createTempDirectory("offline_map");
          GenerateOfflineMapJob job = task.generateOfflineMap(params, tempDirectory.toAbsolutePath().toString());
          job.start();
          job.addJobDoneListener(() -> {
            if (job.getStatus() == Job.Status.SUCCEEDED) {
              // replace the current map with the result offline map when the job finishes
              GenerateOfflineMapResult result = job.getResult();
              mapView.setMap(result.getOfflineMap());
              graphicsOverlay.getGraphics().clear();
              offlineMapButton.setDisable(true);
            } else {
              new Alert(Alert.AlertType.ERROR, job.getError().getAdditionalMessage()).show();
            }
            Platform.runLater(() -> progressBar.setVisible(false));
          });
          // show the job's progress with the progress bar
          job.addProgressChangedListener(() -> progressBar.setProgress(job.getProgress() / 100.0));
        } catch (IOException ex) {
          new Alert(Alert.AlertType.ERROR, "Failed to create temporary directory").show();
        }
      });

      // add the map view, button, and progress bar to stack pane
      stackPane.getChildren().addAll(mapView, offlineMapButton, progressBar);
      StackPane.setAlignment(offlineMapButton, Pos.TOP_LEFT);
      StackPane.setAlignment(progressBar, Pos.TOP_RIGHT);
    } catch (Exception e) {
      // on any error, display the stack trace.
      e.printStackTrace();
    }
  }

  /**
   * Stops and releases all resources used in the 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);
  }

}