Project

View on GitHub
Sample viewer app

Project a point from one spatial reference to another.

Image of project

Use case

Being able to project between spatial references is fundamental to a GIS. An example of when you would need to re-project data is if you had data in two different spatial references, but wanted to perform an intersect analysis with the GeometryEngine.intersect function. This function takes two geometries as parameters, and both geometries must be in the same spatial reference. If they are not, you could first use GeometryEngine.project to convert the geometries so they match.

How to use the sample

Click anywhere on the map. A callout will display the clicked location's coordinate in the original (basemap's) spatial reference and in the projected spatial reference.

How it works

  1. Call the static method, GeometryEngine.project, passing in the original Geometry and a SpatialReference to which it should be projected.

Relevant API

  • GeometryEngine
  • Point
  • SpatialReference

Additional information

In cases where the the output spatial reference uses a different geographic coordinate system than that of the input spatial reference, see the GeometryEngine.project method that additionally takes in a DatumTransformation parameter.

Tags

coordinate system, coordinates, latitude, longitude, projected, projection, spatial reference, Web Mercator, WGS 84

Sample Code

ProjectSample.java
                                                                                                                                            
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
/*
 * 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.project;

import java.text.DecimalFormat;

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

import com.esri.arcgisruntime.ArcGISRuntimeEnvironment;
import com.esri.arcgisruntime.geometry.Envelope;
import com.esri.arcgisruntime.geometry.Geometry;
import com.esri.arcgisruntime.geometry.GeometryEngine;
import com.esri.arcgisruntime.geometry.Point;
import com.esri.arcgisruntime.geometry.SpatialReference;
import com.esri.arcgisruntime.geometry.SpatialReferences;
import com.esri.arcgisruntime.mapping.ArcGISMap;
import com.esri.arcgisruntime.mapping.BasemapStyle;
import com.esri.arcgisruntime.mapping.view.Callout;
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.symbology.SimpleMarkerSymbol;

public class ProjectSample extends Application {

  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("Project 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 navigation basemap style
      ArcGISMap map = new ArcGISMap(BasemapStyle.ARCGIS_NAVIGATION);

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

      // zoom to Minneapolis
      Geometry startingEnvelope = new Envelope(-10995912.335747, 5267868.874421, -9880363.974046, 5960699.183877,
          SpatialReferences.getWebMercator());
      mapView.setViewpointGeometryAsync(startingEnvelope);

      // create a graphics to show the input location
      GraphicsOverlay graphicsOverlay = new GraphicsOverlay();
      mapView.getGraphicsOverlays().add(graphicsOverlay);

      // create a red marker symbol for the input point
      final SimpleMarkerSymbol markerSymbol = new SimpleMarkerSymbol(SimpleMarkerSymbol.Style.CIRCLE, 0xFFFF0000, 5);
      Graphic inputPointGraphic = new Graphic();
      inputPointGraphic.setSymbol(markerSymbol);
      graphicsOverlay.getGraphics().add(inputPointGraphic);

      DecimalFormat decimalFormat = new DecimalFormat("#.00000");

      // show the input location where the user clicks on the map
      mapView.setOnMouseClicked(e -> {
        if (e.isStillSincePress() && e.getButton() == MouseButton.PRIMARY) {
          Point2D point2D = new Point2D(e.getX(), e.getY());
          // show the clicked location on the map with a graphic
          Point originalPoint = mapView.screenToLocation(point2D);
          inputPointGraphic.setGeometry(originalPoint);
          // project the web mercator point to WGS84 (WKID 4326)
          Point projectedPoint = (Point) GeometryEngine.project(originalPoint, SpatialReference.create(4236));
          // show the original and projected point coordinates in a callout from the graphic
          Callout callout = mapView.getCallout();
          callout.setTitle("Coordinates");
          String ox = decimalFormat.format(originalPoint.getX());
          String oy = decimalFormat.format(originalPoint.getY());
          String px = decimalFormat.format(projectedPoint.getX());
          String py = decimalFormat.format(projectedPoint.getY());
          callout.setDetail("Original: " + ox + ", " + oy + "\n" + "Projected: " + px + ", " + py);
          callout.showCalloutAt(inputPointGraphic, originalPoint);
        }
      });

      // add the map view to the stack pane
      stackPane.getChildren().add(mapView);
    } catch (Exception e) {
      // on any error, display the stack trace.
      e.printStackTrace();
    }
  }

  /**
   * 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);
  }

}

Your browser is no longer supported. Please upgrade your browser for the best experience. See our browser deprecation post for more details.