[OpenLayers-Users] DrawFeature with callback?

Fri Dec 5 06:59:09 EST 2008

Hi Guys

Im doing a integration for the Apache Wicket framework( 
http://wicketstuff.org/confluence/display/STUFFWIKI/wicket-contrib-openlayers 
), and want to add some more features. Im looking into adding the 
possibility to draw polygons, however I cant find a example where theres 
a simple callback involved once the polygon are drawn, however the api 
mentions it's possible.

As you can see from the below code the only thing I need for this little 
thing to work are the function that calls the alert to be picked up. 
Please say if you want me to elaborate further.

<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <title>OpenLayers Regular Polygon Example</title>
    <script src="http://openlayers.org/api/OpenLayers.js"></script>
    <script type="text/javascript">
        var map, polygonControl;
        OpenLayers.Util.onImageLoadErrorColor = "transparent";
        function init(){
            map = new OpenLayers.Map('map');

            var wmsLayer = new OpenLayers.Layer.WMS( "OpenLayers WMS",
                "http://labs.metacarta.com/wms/vmap0?", {layers: 'basic'});

            var polygonLayer = new OpenLayers.Layer.Vector("Polygon Layer");

            map.addLayers([wmsLayer, polygonLayer]);
            map.addControl(new OpenLayers.Control.LayerSwitcher());
            map.addControl(new OpenLayers.Control.MousePosition());

            polyOptions = {sides: 4, callbacks: 
{function(value){alert('yeeeha');}}  };
            polygonControl = new 
OpenLayers.Control.DrawFeature(polygonLayer,

OpenLayers.Handler.RegularPolygon,
                                            {handlerOptions: polyOptions
                                                });

            map.addControl(polygonControl);

            map.setCenter(new OpenLayers.LonLat(0, 0), 3);

            document.getElementById('noneToggle').checked = true;
             document.getElementById('irregularToggle').checked = false;
        }
        function setOptions(options) {
            polygonControl.handler.setOptions(options);
        }
        function setSize(fraction) {
            var radius = fraction * map.getExtent().getHeight();
            polygonControl.handler.setOptions({radius: radius,
                                               angle: 0});
        }
    </script>

  </head>
  <body onload="init()">
    <h2 id="title">OpenLayers Regular Polygon Example</h2>
    <p id="shortdesc">
      Shows how to use the RegularPolygon handler to draw features with
      different numbers of sides.
    </p>
    <div id="map" class="smallmap"></div>
    <div id="config">

        <ul id="controls"><b>Map Controls</b>

            <li>
                <input type="radio" name="type"
                       value="none" id="noneToggle"
                       onclick="polygonControl.deactivate()"
                       checked="checked" />
                <label for="noneToggle">navigate</label>
            </li>
            <li>
                <input type="radio" name="type"
                       value="polygon" id="polygonToggle"
                       onclick="polygonControl.activate()" />
                <label for="polygonToggle">draw polygon</label>
            </li>

        </ul>

    </div>
  </body>

</html>

-Nino