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

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Here is the source code for com.google.gwt.maps.sample.hellomaps.client.DragMarkerDemo.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.InfoWindow;
import com.google.gwt.maps.client.InfoWindowContent;
import com.google.gwt.maps.client.MapWidget;
import com.google.gwt.maps.client.event.MarkerDragEndHandler;
import com.google.gwt.maps.client.event.MarkerDragStartHandler;
import com.google.gwt.maps.client.geom.LatLng;
import com.google.gwt.maps.client.overlay.Marker;
import com.google.gwt.maps.client.overlay.MarkerOptions;
import com.google.gwt.user.client.ui.HTML;

/**
 * Markers are interactive objects that can be clicked on and dragged to a new
 * location. In this example, we place a draggable marker on the map, and listen
 * to a few of its simpler events. Draggable markers support four kinds of
 * events -- click, dragstart, drag and dragend. By default, markers are
 * clickable but not draggable, so they need to be initialized with the
 * additional marker option draggable set to true. Draggable markers are also
 * bouncy by default. If you don't like this behavior, just set the bouncy
 * option to false and it will drop down gracefully.
 */
public class DragMarkerDemo 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.</p>"
            + "<p>Draws a marker at the center of the maps window.  The marker will move if you click and drag it.</p>\n"
            + "<p>Equivalent to the Maps JavaScript API Example: "
            + "<a href=\"http://code.google.com/apis/maps/documentation/examples/marker-drag.html\">"
            + "http://code.google.com/apis/maps/documentation/examples/marker-drag.html</a></p>\n";

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

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

            @Override
            public String getName() {
                return "Draggable Markers";
            }
        };
    }

    private MapWidget map;

    public DragMarkerDemo() {
        map = new MapWidget(LatLng.newInstance(37.4419, -122.1419), 13);
        map.setSize("500px", "300px");
        initWidget(map);
    }

    @Override
    public void onShow() {
        map.clearOverlays();

        MarkerOptions options = MarkerOptions.newInstance();
        options.setDraggable(true);
        final Marker marker = new Marker(map.getCenter(), options);
        final InfoWindow info = map.getInfoWindow();

        marker.addMarkerDragEndHandler(new MarkerDragEndHandler() {
            public void onDragEnd(MarkerDragEndEvent event) {
                info.open(marker, new InfoWindowContent("Just bouncing along..."));
            }

        });

        marker.addMarkerDragStartHandler(new MarkerDragStartHandler() {
            public void onDragStart(MarkerDragStartEvent event) {
                info.setVisible(false);
            }
        });

        map.addOverlay(marker);
    }
}