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

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Here is the source code for com.google.gwt.maps.sample.hellomaps.client.EventDemo.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.maps.client.MapWidget;
import com.google.gwt.maps.client.control.SmallMapControl;
import com.google.gwt.maps.client.event.MapMoveEndHandler;
import com.google.gwt.maps.client.geom.LatLng;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.Panel;

/**
 * To register an event listener, call the GEvent.addListener method. Pass it a
 * map, an event to listen for, and a function to call when the specified event
 * occurs. In the following example code, we display the latitude and longitude
 * of the center of the map after the user drags the map.
 */
public class EventDemo extends MapsDemo {

    private static HTML descHTML = null;
    private static final String descString = "<p>Creates a 500 x 300 pixel map viewport centered on Palo Alto, CA USA. "
            + "You should be able to scroll the viewport by clicking and dragging " + "with the mouse.</p>\n"
            + "<p>Dragging the map fires a MapMoveListener that reports the "
            + "Lat/Lng coordinates below the map.</p>" + "<p>Equivalent to the Maps JavaScript API Example: "
            + "<a href=\"http://code.google.com/apis/maps/documentation/examples/event-context.html\">"
            + "http://code.google.com/apis/maps/documentation/examples/event-context.html</a></p>\n";

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

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

            @Override
            public String getName() {
                return "Simple Event Handler Demo";
            }
        };
    }

    private MapWidget map;

    public EventDemo() {
        Panel panel = new FlowPanel();
        map = new MapWidget(LatLng.newInstance(37.4419, -122.1419), 13);
        map.setSize("500px", "300px");
        map.addControl(new SmallMapControl());
        panel.add(map);
        final Label message = new Label();
        panel.add(message);
        initWidget(panel);

        map.addMapMoveEndHandler(new MapMoveEndHandler() {
            public void onMoveEnd(MapMoveEndEvent event) {
                message.setText(map.getCenter().toString());
            }
        });
    }
}