com.google.gwt.maps.sample.hellomaps.client.ReverseGeocoderDemo.java Source code

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Here is the source code for com.google.gwt.maps.sample.hellomaps.client.ReverseGeocoderDemo.java

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/*
 * Copyright 2008 Google Inc.
 * 
 * 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.google.gwt.maps.sample.hellomaps.client;

import com.google.gwt.core.client.JsArray;
import com.google.gwt.maps.client.InfoWindowContent;
import com.google.gwt.maps.client.MapUIOptions;
import com.google.gwt.maps.client.MapWidget;
import com.google.gwt.maps.client.event.MapClickHandler;
import com.google.gwt.maps.client.event.MarkerClickHandler;
import com.google.gwt.maps.client.geocode.Geocoder;
import com.google.gwt.maps.client.geocode.LocationCallback;
import com.google.gwt.maps.client.geocode.Placemark;
import com.google.gwt.maps.client.geocode.StatusCodes;
import com.google.gwt.maps.client.geom.LatLng;
import com.google.gwt.maps.client.overlay.Marker;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.VerticalPanel;

/**
 * An example of how to reverse geocode. Select a point on the map and a marker
 * will be added with the list of placemarks returned.
 */
public class ReverseGeocoderDemo extends MapsDemo {

    private static HTML descHTML = null;
    private static final String descString = "<p>Creates a 500 x 300 pixel map "
            + "viewport zoomed out to show the entire world.</p>"
            + "<p>Click on the map to show the closest municipalities.</p>\n";

    public static MapsDemoInfo init() {
        return new MapsDemoInfo() {
            @Override
            public MapsDemo createInstance() {
                return new ReverseGeocoderDemo();
            }

            @Override
            public HTML getDescriptionHTML() {
                if (descHTML == null) {
                    descHTML = new HTML(descString);
                }
                return descHTML;
            }

            @Override
            public String getName() {
                return "Geocoding: Reverse";
            }
        };
    }

    private Geocoder geocoder;

    private MapWidget map;

    public ReverseGeocoderDemo() {
        VerticalPanel outer = new VerticalPanel();
        map = new MapWidget(LatLng.newInstance(0, 0), 1);
        outer.add(map);
        map.setSize("500px", "300px");
        initWidget(outer);
        // Workaround for bug with click handler & setUItoDefaults() - see issue 260
        MapUIOptions opts = map.getDefaultUI();
        opts.setDoubleClick(false);
        map.setUI(opts);

        map.addMapClickHandler(new MapClickHandler() {

            public void onClick(final MapClickEvent event) {
                // Do not mis-interpret clicks on the info window and marker as
                // map click events to be reverse geocoded.
                if (event.getOverlay() != null) {
                    return;
                }
                final Marker marker = new Marker(event.getLatLng());
                final VerticalPanel panel = new VerticalPanel();
                final InfoWindowContent content = new InfoWindowContent(panel);
                panel.add(new Label("LatLng: " + event.getLatLng().toString()));

                // Do a reverse geocode of this position
                geocoder.getLocations(event.getLatLng(), new LocationCallback() {

                    public void onFailure(int statusCode) {
                        Window.alert("Failed to geocode position " + event.getLatLng() + ". Status: " + statusCode
                                + " " + StatusCodes.getName(statusCode));
                    }

                    public void onSuccess(JsArray<Placemark> locations) {
                        for (int i = 0; i < locations.length(); ++i) {
                            Placemark location = locations.get(i);
                            StringBuilder value = new StringBuilder();
                            if (location.getAddress() != null) {
                                value.append(location.getAddress());
                            } else {
                                if (location.getCity() != null) {
                                    value.append(location.getCity());
                                }
                                if (location.getAdministrativeArea() != null) {
                                    value.append(location.getAdministrativeArea() + ", ");
                                }
                                if (location.getCountry() != null) {
                                    value.append(location.getCountry());
                                }
                            }
                            int ordinal = (i + 1);
                            panel.add(new Label("  " + ordinal + ") " + value.toString()));
                        }
                        map.addOverlay(marker);
                        map.getInfoWindow().open(marker, content);
                    }
                });
                marker.addMarkerClickHandler(new MarkerClickHandler() {

                    public void onClick(MarkerClickEvent markerClickEvent) {
                        if (!map.getInfoWindow().isVisible()) {
                            map.getInfoWindow().open(marker, content);
                        }
                    }
                });
            }

        });
        geocoder = new Geocoder();
    }

}