Java tutorial
/* * 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.InfoWindow; import com.google.gwt.maps.client.InfoWindowContent; import com.google.gwt.maps.client.MapWidget; 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.geom.LatLng; import com.google.gwt.maps.client.overlay.Marker; import com.google.gwt.user.client.Window; import com.google.gwt.user.client.ui.Button; import com.google.gwt.user.client.ui.ClickListener; import com.google.gwt.user.client.ui.FlowPanel; import com.google.gwt.user.client.ui.FormHandler; import com.google.gwt.user.client.ui.FormPanel; import com.google.gwt.user.client.ui.FormSubmitCompleteEvent; import com.google.gwt.user.client.ui.FormSubmitEvent; import com.google.gwt.user.client.ui.Grid; import com.google.gwt.user.client.ui.HTML; import com.google.gwt.user.client.ui.Label; import com.google.gwt.user.client.ui.Panel; import com.google.gwt.user.client.ui.TextBox; import com.google.gwt.user.client.ui.Widget; /** * You can access the Google Maps API geocoder via the GClientGeocoder object. * Use the GClientGeocoder.getLatLng() method to convert a string address into a * GLatLng. Because geocoding involves sending a request to Google's servers, it * can take some time. To avoid making your script wait, you should pass in a * callback function to execute after the response returns. * * In this example, we geocode an address, add a marker at that point, and open * an info window displaying the address. */ public class Geocoder2Demo extends MapsDemo { private static HTML descHTML = null; private static final String descString = "<p> Creates a zoomed out map.</p>" + "<p>Clicking on one of the buttons below the map submits the address to " + "the Google Geocoding service. When the query returns successfully" + "the map will display a marker on the coordinates and display the " + "country code returned from the query in an InfoWindow.</p>" + "<p>Equivalent to the Maps JavaScript API Example: " + "<a href=\"http://code.google.com/apis/maps/documentation/examples/geocoding-extraction.html\">" + "http://code.google.com/apis/maps/documentation/examples/geocoding-extraction.html</a></p>\n"; private static final String[] sampleAddresses = { "1600 amphitheatre mtn view ca", "1 Telegraph Hill Blvd, San Francisco, CA, USA", "4141 Avenue Pierre-De-Coubertin, Montral, QC, Canada", "Champ de Mars 75007 Paris, France", "Piazza del Colosseo, Roma, Italia", "Domkloster 3, 50667 Kln, Deutschland", "Plaza de la Virgen de los Reyes, 41920, Sevilla, Espaa", "123 Main St, Googleville" }; /** * Constant used to layout the preconfigured addresses into a grid using this * number of columns. */ private static final int NUM_ADDRESS_COLUMNS = 2; public static MapsDemoInfo init() { return new MapsDemoInfo() { @Override public MapsDemo createInstance() { return new Geocoder2Demo(); } @Override public HTML getDescriptionHTML() { if (descHTML == null) { descHTML = new HTML(descString); } return descHTML; } @Override public String getName() { return "Geocoding: Extracting Address Information"; } }; } private final Geocoder geocoder; private final MapWidget map; public Geocoder2Demo() { Panel panel = new FlowPanel(); final FormPanel form = new FormPanel(); form.setAction("#"); Panel formElements = new FlowPanel(); Label label = new Label("Search for an address:"); formElements.add(label); final TextBox addressBox = new TextBox(); addressBox.setVisibleLength(40); formElements.add(addressBox); Button submit = new Button("Search"); submit.addClickListener(new ClickListener() { public void onClick(Widget sender) { form.submit(); } }); formElements.add(submit); form.add(formElements); form.addFormHandler(new FormHandler() { public void onSubmit(FormSubmitEvent event) { showAddress(addressBox.getText()); event.setCancelled(true); } public void onSubmitComplete(FormSubmitCompleteEvent event) { } }); panel.add(form); map = new MapWidget(LatLng.newInstance(34, 0), 1); map.setSize("100%", "480px"); panel.add(map); Grid grid = new Grid((sampleAddresses.length / NUM_ADDRESS_COLUMNS) + 1, NUM_ADDRESS_COLUMNS); for (int i = 0; i < sampleAddresses.length; i++) { final String address = sampleAddresses[i]; Button link = new Button(address); // Hyperlink link = new Hyperlink(address, true, // "Extracting Structured Address Information"); link.addClickListener(new ClickListener() { public void onClick(Widget sender) { addressBox.setText(address); form.submit(); } }); grid.setWidget(i / NUM_ADDRESS_COLUMNS, i % NUM_ADDRESS_COLUMNS, link); } panel.add(grid); initWidget(panel); geocoder = new Geocoder(); } private void showAddress(final String address) { final InfoWindow info = map.getInfoWindow(); geocoder.getLocations(address, new LocationCallback() { public void onFailure(int statusCode) { Window.alert("Sorry, we were unable to geocode that address"); } public void onSuccess(JsArray<Placemark> locations) { Placemark place = locations.get(0); Marker marker = new Marker(place.getPoint()); map.addOverlay(marker); String message = place.getAddress() + "<br>" + "<b>Country code:</b> " + place.getCountry(); info.open(marker, new InfoWindowContent(message)); } }); } }