extlib/leaflet/src/layer/LayerGroup.js

   1 /*
   2  * L.LayerGroup is a class to combine several layers so you can manipulate the group (e.g. add/remove it) as one layer.
   3  */
   4
   5 L.LayerGroup = L.Class.extend({
   6         initialize: function(layers) {
   7                 this._layers = {};
   8
   9                 if (layers) {
  10                         for (var i = 0, len = layers.length; i < len; i++) {
  11                                 this.addLayer(layers[i]);
  12                         }
  13                 }
  14         },
  15
  16         addLayer: function(layer) {
  17                 var id = L.Util.stamp(layer);
  18                 this._layers[id] = layer;
  19
  20                 if (this._map) {
  21                         this._map.addLayer(layer);
  22                 }
  23                 return this;
  24         },
  25
  26         removeLayer: function(layer) {
  27                 var id = L.Util.stamp(layer);
  28                 delete this._layers[id];
  29
  30                 if (this._map) {
  31                         this._map.removeLayer(layer);
  32                 }
  33                 return this;
  34         },
  35
  36         clearLayers: function() {
  37                 this._iterateLayers(this.removeLayer, this);
  38                 return this;
  39         },
  40
  41         onAdd: function(map) {
  42                 this._map = map;
  43                 this._iterateLayers(map.addLayer, map);
  44         },
  45
  46         onRemove: function(map) {
  47                 this._iterateLayers(map.removeLayer, map);
  48                 delete this._map;
  49         },
  50
  51         _iterateLayers: function(method, context) {
  52                 for (var i in this._layers) {
  53                         if (this._layers.hasOwnProperty(i)) {
  54                                 method.call(context, this._layers[i]);
  55                         }
  56                 }
  57         }
  58 });