Identify Raster Cell

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/*
 * Copyright 2020 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.identify_raster_cell;

import java.io.File;
import java.util.List;
import java.util.concurrent.ExecutionException;

import javafx.application.Application;
import javafx.geometry.Point2D;
import javafx.scene.Scene;
import javafx.scene.control.Alert;
import javafx.scene.input.MouseButton;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

import com.esri.arcgisruntime.ArcGISRuntimeEnvironment;
import com.esri.arcgisruntime.concurrent.ListenableFuture;
import com.esri.arcgisruntime.geometry.Point;
import com.esri.arcgisruntime.layers.RasterLayer;
import com.esri.arcgisruntime.loadable.LoadStatus;
import com.esri.arcgisruntime.mapping.ArcGISMap;
import com.esri.arcgisruntime.mapping.BasemapStyle;
import com.esri.arcgisruntime.mapping.GeoElement;
import com.esri.arcgisruntime.mapping.view.Callout;
import com.esri.arcgisruntime.mapping.view.IdentifyLayerResult;
import com.esri.arcgisruntime.mapping.view.MapView;
import com.esri.arcgisruntime.raster.Raster;
import com.esri.arcgisruntime.raster.RasterCell;

public class IdentifyRasterCellSample extends Application {

  private boolean calloutLocked = false;
  private Callout callout;
  private MapView mapView;
  private RasterLayer rasterLayer;

  @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("Identify Raster Cell 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 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);

      // create a raster from a local raster file
      Raster raster = new Raster(new File(System.getProperty("data.dir"), "./samples-data/SA_EVI_8Day_03May20/SA_EVI_8Day_03May20.tif").getAbsolutePath());

      // create a raster layer
      rasterLayer = new RasterLayer(raster);

      // add the raster layer to the map's operational layers
      map.getOperationalLayers().add(rasterLayer);

      // set viewpoint on the raster
      rasterLayer.addDoneLoadingListener(() -> {
        if (map.getLoadStatus() == LoadStatus.LOADED) {
          mapView.setViewpointGeometryAsync(rasterLayer.getFullExtent(), 50);
        } else {
          Alert alert = new Alert(Alert.AlertType.ERROR, "Raster Layer Failed to Load!");
          alert.show();
        }
      });

      // get a handle on the callout
      callout = mapView.getCallout();
      callout.setTitle("Raster cell attributes:");
      // make the callout transparent to mouse interactions, so that we keep identifying raster cells behind it
      callout.setMouseTransparent(true);

      // start identifying on-the-fly if the mouse enters the map view, and the callout is not locked
      mapView.setOnMouseEntered(mouseEvent -> {
        if (!calloutLocked) {
          mapView.setOnMouseMoved(this::identifyRasterCell);
        }
      });

      // stop identifying on-the-fly when the mouse leaves the map view
      mapView.setOnMouseExited(null);

      // on click, either lock the callout in place if raster cells are identified on-the-fly,
      // or release the callout again and start identifying on-the-fly
      mapView.setOnMouseClicked(mouseEvent -> {
        if (mouseEvent.getButton() == MouseButton.PRIMARY && mouseEvent.isStillSincePress()) {

          if (!calloutLocked) {
            // stop identifying on the fly
            mapView.setOnMouseMoved(null);
            // lock the callout in place
            calloutLocked = true;

          } else {
            // dismiss the callout
            callout.dismiss();
            // unlock the callout
            calloutLocked = false;
            // show a new callout at the clicked location
            identifyRasterCell(mouseEvent);
            // start identifying on-the-fly
            mapView.setOnMouseMoved(this::identifyRasterCell);
          }
        }
      });

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

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

  /**
   * Identifies the raster cell at the mouse event's location and displays a callout at that location.
   *
   * @param mouseEvent the mouse event used to identify the raster cell and show the callout
   */
  private void identifyRasterCell(MouseEvent mouseEvent) {

    // get the map point where the user clicked
    Point2D point = new Point2D(mouseEvent.getX(), mouseEvent.getY());
    Point mapPoint = mapView.screenToLocation(point);

    // identify the layers at the clicked location
    ListenableFuture<IdentifyLayerResult> identifyLayerResultFuture
      = mapView.identifyLayerAsync(rasterLayer, point, 10, false, 1);

    identifyLayerResultFuture.addDoneListener(() -> {
      try {
        // get the result of the query
        IdentifyLayerResult identifyLayerResult = identifyLayerResultFuture.get();

        // get the read only list of geo-elements (they contain RasterCells)
        List<GeoElement> geoElements = identifyLayerResult.getElements();

        // create a StringBuilder to display information to the user
        StringBuilder stringBuilder = new StringBuilder();

        // loop through each RasterCell
        for (GeoElement geoElement : geoElements) {

          if (geoElement instanceof RasterCell) {
            RasterCell rasterCell = (RasterCell) geoElement;

            // loop through the attributes (key/value pairs)
            rasterCell.getAttributes().forEach((key, value) ->
              // add the key-value pair to the string builder
              stringBuilder.append(key).append(": ").append(value).append("\n")
            );

            // get and format the X and Y values for the cell
            double x = rasterCell.getGeometry().getExtent().getXMin();
            double y = rasterCell.getGeometry().getExtent().getYMin();
            String string = "X: " + Math.round(x) + " Y: " + Math.round(y);

            // add the X & Y coordinates where the user clicked raster cell to the string builder
            stringBuilder.append(string);

            // define a callout based on the string builder
            callout.setDetail(stringBuilder.toString());
            callout.showCalloutAt(mapPoint);
          }
        }
      } catch (InterruptedException | ExecutionException e) {
        new Alert(Alert.AlertType.ERROR, "Error identifying layer").show();
      }
    });

  }

  /**
   * 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);
  }

}