public/openlayers/OpenStreetMap.js

   1 /**
   2  * Namespace: Util.OSM
   3  */
   4 OpenLayers.Util.OSM = {};
   5
   6 /**
   7  * Constant: MISSING_TILE_URL
   8  * {String} URL of image to display for missing tiles
   9  */
  10 OpenLayers.Util.OSM.MISSING_TILE_URL = "http://openstreetmap.org/openlayers/img/404.png";
  11
  12 /**
  13  * Property: originalOnImageLoadError
  14  * {Function} Original onImageLoadError function.
  15  */
  16 OpenLayers.Util.OSM.originalOnImageLoadError = OpenLayers.Util.onImageLoadError;
  17
  18 /**
  19  * Function: onImageLoadError
  20  */
  21 OpenLayers.Util.onImageLoadError = function() {
  22     if (this.src.match(/^http:\/\/[abc]\.[a-z]+\.openstreetmap\.org/)) {
  23         this.src = OpenLayers.Util.OSM.MISSING_TILE_URL;
  24     } else {
  25         OpenLayers.Util.OSM.originalOnImageLoadError;
  26     }
  27 };
  28
  29 /**
  30  * @requires OpenLayers/Layer/TMS.js
  31  *
  32  * Class: OpenLayers.Layer.OSM
  33  *
  34  * Inherits from:
  35  *  - <OpenLayers.Layer.TMS>
  36  */
  37 OpenLayers.Layer.OSM = OpenLayers.Class(OpenLayers.Layer.TMS, {
  38     /**
  39      * Constructor: OpenLayers.Layer.OSM
  40      *
  41      * Parameters:
  42      * name - {String}
  43      * url - {String}
  44      * options - {Object} Hashtable of extra options to tag onto the layer
  45      */
  46     initialize: function(name, url, options) {
  47         options = OpenLayers.Util.extend(options, { attribution: "Powered by <a href='http://openstreetmap.org/'>OpenStreetMap</a>" });
  48         OpenLayers.Layer.TMS.prototype.initialize.apply(this, arguments);
  49     },
  50
  51     /**
  52      * Method: getUrl
  53      *
  54      * Parameters:
  55      * bounds - {<OpenLayers.Bounds>}
  56      *
  57      * Returns:
  58      * {String} A string with the layer's url and parameters and also the
  59      *          passed-in bounds and appropriate tile size specified as
  60      *          parameters
  61      */
  62     getURL: function (bounds) {
  63         var res = this.map.getResolution();
  64         var x = Math.round((bounds.left - this.maxExtent.left) / (res * this.tileSize.w));
  65         var y = Math.round((this.maxExtent.top - bounds.top) / (res * this.tileSize.h));
  66         var z = this.map.getZoom();
  67         var limit = Math.pow(2, z);
  68
  69         if (y < 0 || y >= limit)
  70         {
  71             return OpenLayers.Util.OSM.MISSING_TILE_URL;
  72         }
  73         else
  74         {
  75             x = ((x % limit) + limit) % limit;
  76
  77             var url = this.url;
  78             var path = z + "/" + x + "/" + y + ".png";
  79
  80             if (url instanceof Array)
  81             {
  82                 url = this.selectUrl(path, url);
  83             }
  84
  85             return url + path;
  86         }
  87     },
  88
  89     CLASS_NAME: "OpenLayers.Layer.OSM"
  90 });
  91
  92 /**
  93  * Class: OpenLayers.Layer.OSM.Mapnik
  94  *
  95  * Inherits from:
  96  *  - <OpenLayers.Layer.OSM>
  97  */
  98 OpenLayers.Layer.OSM.Mapnik = OpenLayers.Class(OpenLayers.Layer.OSM, {
  99     /**
 100      * Constructor: OpenLayers.Layer.OSM.Mapnik
 101      *
 102      * Parameters:
 103      * name - {String}
 104      * options - {Object} Hashtable of extra options to tag onto the layer
 105      */
 106     initialize: function(name, options) {
 107         var url = [
 108             "http://a.tile.openstreetmap.org/",
 109             "http://b.tile.openstreetmap.org/",
 110             "http://c.tile.openstreetmap.org/"
 111         ];
 112         var newArguments = [name, url, options];
 113         OpenLayers.Layer.OSM.prototype.initialize.apply(this, newArguments);
 114     },
 115
 116     CLASS_NAME: "OpenLayers.Layer.OSM.Mapnik"
 117 });
 118
 119 /**
 120  * Class: OpenLayers.Layer.OSM.Osmarender
 121  *
 122  * Inherits from:
 123  *  - <OpenLayers.Layer.OSM>
 124  */
 125 OpenLayers.Layer.OSM.Osmarender = OpenLayers.Class(OpenLayers.Layer.OSM, {
 126     /**
 127      * Constructor: OpenLayers.Layer.OSM.Osmarender
 128      *
 129      * Parameters:
 130      * name - {String}
 131      * options - {Object} Hashtable of extra options to tag onto the layer
 132      */
 133     initialize: function(name, options) {
 134         var url = [
 135             "http://a.tah.openstreetmap.org/Tiles/tile.php/",
 136             "http://b.tah.openstreetmap.org/Tiles/tile.php/",
 137             "http://c.tah.openstreetmap.org/Tiles/tile.php/"
 138         ];
 139         var newArguments = [name, url, options];
 140         OpenLayers.Layer.OSM.prototype.initialize.apply(this, newArguments);
 141     },
 142
 143     CLASS_NAME: "OpenLayers.Layer.OSM.Osmarender"
 144 });