// JavaScript Document

//<![CDATA[

    if (GBrowserIsCompatible()) { 
      var map = new GMap2(document.getElementById("map"));
      map.setUIToDefault();
      map.setCenter(new GLatLng(51.452777,-2.593932),16);
      var side_bar_html = "";
      var gmarkers = [];
      var htmls = [];
      var i = 0;
	  
      function createMarker(point,name,html,ico) {
		  var baseIcon = new GIcon(G_DEFAULT_ICON);
          baseIcon.image = ico;
		  baseIcon.iconSize = new GSize(64, 64);
		  baseIcon.iconAnchor = new GPoint(15, 64);
		  baseIcon.infoWindowAnchor = new GPoint(33, 15);
		  baseIcon.imageMap = [0,0, 64,0, 64,64, 0,64]
		  baseIcon.shadowSize = new GSize(0, 0)
 		  markerOptions = { icon:baseIcon };
        var marker = new GMarker(point, markerOptions);
        GEvent.addListener(marker, "click", function() {
          marker.openInfoWindowHtml(html);
        });
      
        gmarkers[i] = marker;
        htmls[i] = html;
      
        side_bar_html += '<li><a href="javascript:myclick(' + i + ')">' + name + '<\/a></li>';
        i++;
        return marker;
      }


       function myclick(i) {
        gmarkers[i].openInfoWindowHtml(htmls[i]);
      }

       
      var request = GXmlHttp.create();
      request.open("GET", "walkdata.xml", true);
      request.onreadystatechange = function() {
        if (request.readyState == 4) {
          var xmlDoc = GXml.parse(request.responseText);
          var markers = xmlDoc.documentElement.getElementsByTagName("marker");
          
          for (var i = 0; i < markers.length; i++) {
            // obtain the attribues of each marker
            var lat = parseFloat(markers[i].getAttribute("lat"));
            var lng = parseFloat(markers[i].getAttribute("lng"));
            var point = new GLatLng(lat,lng);
            var html = GXml.value(markers[i].getElementsByTagName("infowindow")[0]);
            var label = markers[i].getAttribute("label");
			var ico = markers[i].getAttribute("ico");
            var marker = createMarker(point,label,html,ico);
            map.addOverlay(marker);
          }
          document.getElementById("side_bar").innerHTML = side_bar_html;
          
           var lines = xmlDoc.documentElement.getElementsByTagName("line");
       
          for (var a = 0; a < lines.length; a++) {
            var colour = lines[a].getAttribute("colour");
            var width  = parseFloat(lines[a].getAttribute("width"));
            var points = lines[a].getElementsByTagName("point");
            var pts = [];
			
            for (var i = 0; i < points.length; i++) {
               pts[i] = new GLatLng(parseFloat(points[i].getAttribute("lat")),
                                   parseFloat(points[i].getAttribute("lng")));
            }
            map.addOverlay(new GPolyline(pts,colour,width));
          }
         }
      }
      request.send(null);

    }
    
  else {
      alert("Sorry, the Google Maps API is not compatible with this browser");
    }

   

    //]]>