Example 11 - More Events

This little example just lets the user click around the map, generating a polyline from point to point.

Here's the code we used:

First the <googlemaps:map> tag with the event tag added:

<googlemaps:map id="map3" width="250" height="300" version="2" type="STREET" 
		scope="site">
  	<googlemaps:key domain="localhost" key="xxxx"/>
  	<googlemaps:point id="point1" address="74 Connors Lane" city="Elkton" 
  			state="MD" zipcode="21921" country="US"/>
	<googlemaps:event action="click" url="/GoogleMaps/example_11.jsp"/>
	<googlemaps:message>
		<img src="/GoogleMaps/images/loading.gif"/> Please wait...
	</googlemaps:message>
</googlemaps:map>
  

Here's the bean mapping:

  <jsp:useBean id="processor2" class="com.lamatek.beans.PolyLineBean">
	<jsp:setProperty name="processor2" property="pageContext" 
			value="<%=pageContext%>"/>
  </jsp:useBean> 
  

And last is the actual code for the bean:

package com.lamatek.beans;

import java.util.Date;

import javax.servlet.ServletRequest;

import com.lamatek.beans.google.DefaultEventListenerBean;
import com.lamatek.tags.google.GoogleMapPointTag;
import com.lamatek.tags.google.GoogleMapPolylineTag;
import com.lamatek.tags.google.GoogleMapTag;


public class PolyLineBean extends DefaultEventListenerBean {

    String lineId = "line_" + (new Date()).getTime();
    
    public void processClickEvent(GoogleMapTag map, double longitude,
            double latitude) {
        super.processClickEvent(map, longitude, latitude);
        try {
	        if (getPageContext().getSession().getAttribute("lineId") == null)
	            getPageContext().getSession().setAttribute("lineId", lineId);
	        else 
	            lineId = (String) getPageContext().getSession().getAttribute("lineId");
	        GoogleMapPointTag point = new GoogleMapPointTag();
	        point.setLatitude(latitude);
	        point.setLongitude(longitude);
	        String pointID = "point_" + (new Date()).getTime();
	        point.setId(pointID);
	        map.addPoint(point);
	        GoogleMapPolylineTag line = map.getPolyline(lineId);
	        if (line == null) {
	            line = new GoogleMapPolylineTag();
	            line.setId(lineId);
	            line.setPointlist(pointID);
	            map.addPolyline(line);
	        }
	        else {
	            line.setPointlist(line.getPointlist() + "," + pointID);
	        }
        }
        catch(Exception ex) {
            ex.printStackTrace(System.out);
        }
    }
}
  

To see the test in action, start clicking on the map. Starting with your second click, you'll see a polyline follow you around.

In Example 12 we'll experiment with asynchronous events.