source: src/django_gheat/website/static/heatmap.js@ 9186

function init(){

        var projection_wgs = new OpenLayers.Projection("EPSG:4326"); // WGS 1984

        map = new OpenLayers.Map('heatmap', {
                controls: [
                                new OpenLayers.Control.Navigation(),
                                new OpenLayers.Control.PanZoomBar(),
                                new OpenLayers.Control.ScaleLine(),
                                new OpenLayers.Control.LayerSwitcher(),
                                new OpenLayers.Control.MousePosition({ 'displayProjection' : projection_wgs }),
                ],
                maxExtent: new OpenLayers.Bounds(-20037508.3427892,-20037508.3427892,20037508.3427892,20037508.3427892), 
                numZoomLevels:16, 
                maxResolution:156543.0339, 
                units:'m', 
                projection: "EPSG:900913",
                displayProjection: new OpenLayers.Projection("EPSG:4326")
        });

        map.events.register('click', map, GetMousePos);
        function GetMousePos(pos) {
                var pixbuffer = 100;
                var sw = map.getLonLatFromPixel(new OpenLayers.Pixel(pos.xy.x+pixbuffer,pos.xy.y-pixbuffer));
                var ne = map.getLonLatFromPixel(new OpenLayers.Pixel(pos.xy.x-pixbuffer,pos.xy.y+pixbuffer));
                var pointsw = OpenLayers.Layer.SphericalMercator.inverseMercator(sw.lon, sw.lat);
                var pointne = OpenLayers.Layer.SphericalMercator.inverseMercator(ne.lon, ne.lat);
                getNodeList(pointsw, pointne);
        }

        layerMapnik = new OpenLayers.Layer.OSM.Mapnik("Mapnik");
        map.addLayer(layerMapnik);
        layerHeatmap = new OpenLayers.Layer.OSM.Overlay1("Overlay 1", {isBaseLayer: false, visibility: true});
        map.addLayer(layerHeatmap);

        layerHeatmap2 = new OpenLayers.Layer.OSM.Overlay2("All Access points", {isBaseLayer: false, visibility: true});
        map.addLayer(layerHeatmap2);

        layerHeatmap3 = new OpenLayers.Layer.OSM.Overlay3("Wireless Leiden Only", {isBaseLayer: false, visibility: true});
        map.addLayer(layerHeatmap3);
        
        var lon   = 4.48907;
        var lat   = 52.158431;
        var zoom  = 16;

        var lonLat = new OpenLayers.LonLat(lon, lat).transform(new OpenLayers.Projection("EPSG:4326"), map.getProjectionObject());
        map.setCenter (lonLat, zoom);
}

function getNodeList(sw, ne){
  var nodelist;
  if (window.XMLHttpRequest){
    // code for IE7+, Firefox, Chrome, Opera, Safari
    nodelist=new XMLHttpRequest();
  }
  else{
    // code for IE6, IE5
    nodelist=new ActiveXObject("Microsoft.XMLHTTP");
  }

  nodelist.onreadystatechange=function(){
    if (nodelist.readyState==4 && nodelist.status==200){
      txt=nodelist.responseText
      document.getElementById('nodelist').innerHTML=txt;
    }
  }

  nodelist.open("GET","/website/nodelist/" + sw.lat + "," + sw.lon + "," + ne.lat + "," + ne.lon,true);
  nodelist.send();
}