function PanoramioLayerCallback(json, panoLayer) {
  this.panoLayer = panoLayer;

  for (var i = 0; i < json.photos.length; i++) {
    var photo = json.photos[i];
    if (!panoLayer.ids[photo.photo_id]) {
      var marker = this.createMarker(photo, panoLayer.markerIcon);
      panoLayer.mgr.addMarker(marker, 0);
      panoLayer.ids[photo.photo_id] = "exists";
      panoLayer.mgr.addMarker(marker, panoLayer.map.getZoom());
    }
  }
}

PanoramioLayerCallback.prototype.formImgUrl = function(photoId, imgType) {
  return 'http://www.panoramio.com/photos/' + imgType + '/' + photoId + '.jpg';
}
 
PanoramioLayerCallback.prototype.formPageUrl = function(photoId) {
  return 'http://www.panoramio.com/photo/' + photoId;
}

PanoramioLayerCallback.prototype.createMarker = function(photo, baseIcon) {
  var me = this;
  var markerIcon = new GIcon(baseIcon);
  markerIcon.image = this.formImgUrl(photo.photo_id, "mini_square");
  var marker = new GMarker(new GLatLng(photo.latitude, photo.longitude), {icon: markerIcon, title: photo.photo_title});

  if (photo.photo_title.length > 33) {
    photo.photo_title = photo.photo_title.substring(0, 33) + "&#8230;";
  }
  var html = "<div id='infowin' style='height:320px; width:240px;'>" +
            "<p><a href='http://www.panoramio.com/' target='_blank'>" + 
             "<img src='http://www.panoramio.com/img/logo-small.gif' border='0' width='119px' height='25px' alt='Panoramio logo' /><\/a></p>" +
             "<a id='photo_infowin' target='_blank' href='" + photo.photo_url + "'>" +                
             "<img border='0' width='" + photo.width + "' height='" + photo.height + "' src='" + photo.photo_file_url + "'/><\/a>" +
             "<div style='overflow: hidden; width: 240px;'>" +
             "<p><a target='_blank' class='photo_title' href='" + photo.photo_url +
             "'><strong>" + photo.photo_title + "<\/strong><\/a></p>" +
             "<p>Posted by <a target='_blank' href='" + photo.owner_url + "'>" +
             photo.owner_name + "<\/a></p><\/div>" +
             "<\/div>";

  marker.html = html;

  GEvent.addListener(marker, "click", function() {
    me.panoLayer.map.openInfoWindow(marker.getLatLng(), marker.html, {noCloseOnClick: true});
  });
 
  return marker;
}


function PanoramioLayer(map, opt_opts) {
  var me = this;
  me.map = map;
  me.ids = {};
  me.mgr = new MarkerManager(map, {maxZoom: 19});

  var icon = new GIcon();
  icon.image = "http://www.panoramio.com/img/panoramio-marker.png"; 
  icon.shadow = "";  
  icon.iconSize = new GSize(24, 24); 
  icon.shadowSize = new GSize(22, 22); 
  icon.iconAnchor = new GPoint(9, 9);  
  icon.infoWindowAnchor = new GPoint(9, 0); 

  me.markerIcon = icon;
  me.enabled = false;

  GEvent.addListener(map, "moveend", function() {
    if (me.enabled) {
      var bounds = map.getBounds();
      var southWest = bounds.getSouthWest();
      var northEast = bounds.getNorthEast();
      me.load(me, {maxy: northEast.lat(), miny: southWest.lat(), maxx: northEast.lng(), minx: southWest.lng()});
    }
  });
}

PanoramioLayer.prototype.enable = function() {
  this.enabled = true;
  GEvent.trigger(map, "moveend");
}

PanoramioLayer.prototype.disable = function() {
  this.enabled = false;
  this.mgr.clearMarkers();
  this.ids = {};
}

PanoramioLayer.prototype.getEnabled = function() {
  return this.enabled;
}

PanoramioLayer.prototype.load = function(panoLayer, userOptions) {
  var options = {
    order: "popularity",
    set: "public",
    from: "0",
    to: "10",
    minx: "-180",
    miny: "-90",
    maxx: "180",
    maxy: "90",
    size: "small"
  };
 
  for (optionName in userOptions) {
    if (userOptions.hasOwnProperty(optionName)) {
      options[optionName] = userOptions[optionName];
    }
  }
 
  var url = "http://www.panoramio.com/map/get_panoramas.php?";
  var uniqueID = "";
 
  for (optionName in options) {
    if (options.hasOwnProperty(optionName)) {
      var optionVal = "" + options[optionName] + "";
      url += optionName + "=" + optionVal + "&";
      uniqueID += optionVal.replace(/[^\w]+/g,"");
    }
  }
  var callbackName = "PanoramioLayerCallback.loader" + uniqueID; //ask dion
  eval(callbackName + " = function(json) { var pa = new PanoramioLayerCallback(json, panoLayer);}");
 
  var script = document.createElement('script');
  script.setAttribute('src', url + 'callback=' + callbackName);
  script.setAttribute('id', 'jsonScript');
  script.setAttribute('type', 'text/javascript');
  document.documentElement.firstChild.appendChild(script);
}