Display KML

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Display KML from a URL, portal item, or local KML file.

Image of display KML

Use case

Keyhole Markup Language (KML) is a data format used by Google Earth. KML is popular as a transmission format for consumer use and for sharing geographic data between apps. You can use Runtime to display KML files, with full support for a variety of features, including network links, 3D models, screen overlays, and tours.

How to use the sample

Use the overflow menu to select a source. A KML file from that source will be loaded and displayed in the map.

How it works

  1. To create a KML layer from a URL, create a KmlDataset using the URL to the KML file. Then pass the dataset to the KmlLayer constructor.
  2. To create a KML layer from a portal item, construct a PortalItem with a Portal and the KML portal item ID. Pass the portal item to the KmlLayer constructor.
  3. To create a KML layer from a local file, create a KmlDataset using the absolute file path to the local KML file. Then pass the dataset to the KmlLayer constructor.
  4. Add the layer as an operational layer to the map with map.getOperationalLayers().add(kmlLayer).

Relevant API

  • KmlDataset
  • KmlLayer

Offline Data

  1. Download the data from ArcGIS Online.
  2. Open your command prompt and navigate to the folder where you extracted the contents of the data from step 1.
  3. Push the data into the scoped storage of the sample app: adb push US_State_Capitals.kml /Android/data/com.esri.arcgisruntime.sample.displaykml/files/US_State_Capitals.kml

About the data

This sample displays three different KML files:

  • From URL - this is a map of the significant weather outlook produced by NOAA/NWS. It uses KML network links to always show the latest data.
  • From local file - this is a map of U.S. state capitals. It doesn't define an icon, so the default pushpin is used for the points.
  • From portal item - this is a map of U.S. states.

Tags

keyhole, KML, KMZ, OGC

Sample Code

MainActivity.java
                                                                                                                                                                                        
/* 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.arcgisruntime.sample.displaykml;

import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;
import com.esri.arcgisruntime.ArcGISRuntimeEnvironment;
import com.esri.arcgisruntime.layers.KmlLayer;
import com.esri.arcgisruntime.loadable.LoadStatus;
import com.esri.arcgisruntime.mapping.ArcGISMap;
import com.esri.arcgisruntime.mapping.BasemapStyle;
import com.esri.arcgisruntime.mapping.Viewpoint;
import com.esri.arcgisruntime.mapping.view.MapView;
import com.esri.arcgisruntime.ogc.kml.KmlDataset;
import com.esri.arcgisruntime.portal.Portal;
import com.esri.arcgisruntime.portal.PortalItem;

public class MainActivity extends AppCompatActivity {

  private static final String TAG = MainActivity.class.getSimpleName();

  private MapView mMapView;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // authentication with an API key or named user is required to access basemaps and other
    // location services
    ArcGISRuntimeEnvironment.setApiKey(BuildConfig.API_KEY);

    // get the reference to the map view
    mMapView = findViewById(R.id.mapView);

    // create a map with the dark gray canvas basemap
    ArcGISMap map = new ArcGISMap(BasemapStyle.ARCGIS_DARK_GRAY);

    // set the map to the map view
    mMapView.setMap(map);
    mMapView.setViewpoint(new Viewpoint(39, -98, 100000000));

    // set the initial source to a KML layer from a URL
    changeSourceToURL();
  }

  /**
   * Clear all operational layers and add the kml layer to the map as an operational layer.
   *
   * @param kmlLayer to add to the map
   */
  private void display(KmlLayer kmlLayer) {
    // clear the existing layers from the map
    mMapView.getMap().getOperationalLayers().clear();

    // add the KML layer to the map
    mMapView.getMap().getOperationalLayers().add(kmlLayer);
  }

  /**
   * Display a kml layer from a URL.
   */
  private void changeSourceToURL() {
    // create a kml data set from a URL
    KmlDataset kmlDataset = new KmlDataset(getString(R.string.noaa_weather_kml_url));

    // a KML layer created from a remote KML file
    KmlLayer kmlLayer = new KmlLayer(kmlDataset);
    display(kmlLayer);

    // report errors if failed to load
    kmlDataset.addDoneLoadingListener(() -> {
      if (kmlDataset.getLoadStatus() != LoadStatus.LOADED) {
        String error = "Failed to load kml layer from URL: " + kmlDataset.getLoadError().getMessage();
        Toast.makeText(this, error, Toast.LENGTH_LONG).show();
        Log.e(TAG, error);
      }
    });
  }

  /**
   * Display a kml layer from a portal item.
   */
  private void changeSourceToPortalItem() {
    // create a portal to ArcGIS Online
    Portal portal = new Portal(getString(R.string.arcgis_online_url));

    // create a portal item from a kml item id
    PortalItem portalItem = new PortalItem(portal, getString(R.string.kml_item_id));

    // a KML layer created from an ArcGIS Online portal item
    KmlLayer kmlLayer = new KmlLayer(portalItem);
    display(kmlLayer);

    // report errors if failed to load
    kmlLayer.addDoneLoadingListener(() -> {
      if (kmlLayer.getLoadStatus() != LoadStatus.LOADED) {
        String error = "Failed to load kml layer from portal item: " + kmlLayer.getLoadError().getCause().getMessage();
        Toast.makeText(this, error, Toast.LENGTH_LONG).show();
        Log.e(TAG, error);
      }
    });
  }

  /**
   * Display a kml layer from external storage.
   */
  private void changeSourceToFileExternalStorage() {
    // a data set made from data in external storage
    KmlDataset kmlDataset = new KmlDataset(getExternalFilesDir(null) + getString(R.string.kml_path));

    // a KML layer created from a local KML file
    KmlLayer kmlLayer = new KmlLayer(kmlDataset);
    display(kmlLayer);

    // report errors if failed to load
    kmlDataset.addDoneLoadingListener(() -> {
      if (kmlDataset.getLoadStatus() != LoadStatus.LOADED) {
        String error =
            "Failed to load kml data set from external storage: " + kmlDataset.getLoadError().getCause().getMessage();
        Toast.makeText(this, error, Toast.LENGTH_LONG).show();
        Log.e(TAG, error);
      }
    });
  }

  @Override public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.kml_sources, menu);
    return super.onCreateOptionsMenu(menu);
  }

  @Override public boolean onOptionsItemSelected(MenuItem item) {
    int i = item.getItemId();
    if (i == R.id.kmlFromUrl) {
      changeSourceToURL();
    } else if (i == R.id.kmlFromPortal) {
      changeSourceToPortalItem();
    } else if (i == R.id.kmlFromExternalStorage) {
      changeSourceToFileExternalStorage();
    } else {
      Log.e(TAG, "Menu option not implemented");
    }
    return super.onOptionsItemSelected(item);
  }

  @Override
  protected void onPause() {
    mMapView.pause();
    super.onPause();
  }

  @Override
  protected void onResume() {
    super.onResume();
    mMapView.resume();
  }

  @Override
  protected void onDestroy() {
    mMapView.dispose();
    super.onDestroy();
  }
}