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.GWT; import com.google.gwt.maps.client.MapWidget; import com.google.gwt.maps.client.geocode.DirectionQueryOptions; import com.google.gwt.maps.client.geocode.DirectionResults; import com.google.gwt.maps.client.geocode.Directions; import com.google.gwt.maps.client.geocode.DirectionsCallback; import com.google.gwt.maps.client.geocode.DirectionsPanel; import com.google.gwt.maps.client.geocode.StatusCodes; import com.google.gwt.maps.client.geom.LatLng; import com.google.gwt.user.client.Window; import com.google.gwt.user.client.ui.Grid; import com.google.gwt.user.client.ui.HTML; import com.google.gwt.user.client.ui.HasVerticalAlignment; /** * You can add driving directions using the Google Maps API by using the new * GDirections object. The GDirections objects requests and receives direction * results using either query strings (e.g. "New York, NY to Chicago, IL") or * provided textual lat/lons (e.g. "40.712882, -73.967257 to * 41.943181,-87.770677"). The GDirections object also supports multi-part * driving directions using a series of points. Directions may be displayed as * either a polyline drawing the route on a map, as a series of textual * description within a DIV element (e.g. "Turn right onto the Williamsburg * Bridge ramp") or both. * * To use directions in the Google Maps API, create an object of type * GDirections and designate a Map object and/or DIV to receive and display * results. By default, the map is centered and bounded by the returned route(s) * (though you can change this with parameters within a GDirectionOptions * object). * * Driving directions are requested using the GDirections.load() method. This * method takes a query string and a set of optional GDirectionsOptions * parameters. If the GDirections object was constructed with a supplied Map * object, then the returned directions will contain a polyline overlay. If the * GDirections object was constructed with a supplied DIV element, then the * returned directions will contain a GRoute object, containing a set of GStep * objects. (If the directions consist of multi-point directions, the returned * directions will contain multiple GRoute objects, each consisting of a series * of GStep objects.) * * Note that the directions object is not populated with this return information * immediately. For this reason, the GDirections object defines a "load" event * which you can intercept to determine this state. * * Once directions are returned, the GDirections object will internally store * results which you can retrieve using GDirections.getPolyline() and/or * GDirections.getRoute(i:Number) methods. Steps within a route can be retrieved * using the GRoute.getStep(i:Number) method and the HTML summary of that step * can be retrieved using GStep.getDescriptionHtml(). * * The GDirections object also supports multi-point directions, which can be * constructed using the GDirections.loadFromWaypoints() method. This method * takes an array of textual input addresses or textual lat/lon points. Each * separate waypoint is computed as a separate route and returned in a separate * GRoute object, each of which contains a series of GStep objects. * * GRoute objects store the number of steps (of type GStep for that route, the * starting and ending geocode for that route, and other computed information * such as distance, duration, and exact lat/lon of the endpoint (which may be * different than the ending geocode if the geocode does not lie on a road * segment). Each GStep object as well contains the description for that text * (e.g. "Merge onto US-101 S via the ramp to San Jose") plus computed * information including the distance, duration, and exact lat/lon as well. * * The GDirections object fires three events which you can intercept: * * "load": This event is triggered when a directions result successfully * returns, but before any overlay elements are added to the map/panel. * "addoverlay": This event is triggered after the polyline and/or textual * directions components are added to the map and/or DIV elements. "error": This * event is triggered if a directions request results in an error. Callers can * use GDirections.getStatus() to get more information about the error. * * For full documentation of the various objects, methods and events in the * Directions API package, consult the API Reference */ public class SimpleDirectionsDemo extends MapsDemo { private static HTML descHTML = null; private static final String descString = "<p>Displays a map centered on " + "Cambridge, MA USA</p>" + "<p>Queries the Google Directions service and displays a polyline, " + "markers on the map, and textual directions on the right. The " + "directions are from the MIT dorms to Fenway Park.</p>\n" + "<p>Equivalent to the Maps JavaScript API Example: " + "<a href=\"http://code.google.com/apis/maps/documentation/examples/directions-simple.html\">" + "http://code.google.com/apis/maps/documentation/examples/directions-simple.html</a></p>\n"; public static MapsDemoInfo init() { return new MapsDemoInfo() { @Override public MapsDemo createInstance() { return new SimpleDirectionsDemo(); } @Override public HTML getDescriptionHTML() { if (descHTML == null) { descHTML = new HTML(descString); } return descHTML; } @Override public String getName() { return "Simple Directions"; } }; } private MapWidget map; public SimpleDirectionsDemo() { final Grid grid = new Grid(1, 2); grid.setWidth("100%"); grid.getCellFormatter().setWidth(0, 0, "74%"); grid.getCellFormatter().setVerticalAlignment(0, 0, HasVerticalAlignment.ALIGN_TOP); grid.getCellFormatter().setWidth(0, 1, "24%"); grid.getCellFormatter().setVerticalAlignment(0, 1, HasVerticalAlignment.ALIGN_TOP); map = new MapWidget(LatLng.newInstance(42.351505, -71.094455), 15); map.setHeight("480px"); grid.setWidget(0, 0, map); DirectionsPanel directionsPanel = new DirectionsPanel(); grid.setWidget(0, 1, directionsPanel); directionsPanel.setSize("100%", "100%"); initWidget(grid); DirectionQueryOptions opts = new DirectionQueryOptions(map, directionsPanel); String query = "from: 500 Memorial Dr, Cambridge, MA to: 4 Yawkey Way, Boston, MA"; Directions.load(query, opts, new DirectionsCallback() { public void onFailure(int statusCode) { Window.alert( "Failed to load directions: Status " + StatusCodes.getName(statusCode) + " " + statusCode); } public void onSuccess(DirectionResults result) { GWT.log("Successfully loaded directions.", null); } }); } }