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, {
  48             attribution: "Data by <a href='http://openstreetmap.org/'>OpenStreetMap</a>",
  49             maxExtent: new OpenLayers.Bounds(-20037508,-20037508,20037508,20037508),
  50             maxResolution: 156543,
  51             units: "m",
  52             projection: "EPSG:41001"
  53         });
  54         OpenLayers.Layer.TMS.prototype.initialize.apply(this, arguments);
  55     },
  56
  57     /**
  58      * Method: getUrl
  59      *
  60      * Parameters:
  61      * bounds - {<OpenLayers.Bounds>}
  62      *
  63      * Returns:
  64      * {String} A string with the layer's url and parameters and also the
  65      *          passed-in bounds and appropriate tile size specified as
  66      *          parameters
  67      */
  68     getURL: function (bounds) {
  69         var res = this.map.getResolution();
  70         var x = Math.round((bounds.left - this.maxExtent.left) / (res * this.tileSize.w));
  71         var y = Math.round((this.maxExtent.top - bounds.top) / (res * this.tileSize.h));
  72         var z = this.map.getZoom();
  73         var limit = Math.pow(2, z);
  74
  75         if (y < 0 || y >= limit)
  76         {
  77             return OpenLayers.Util.OSM.MISSING_TILE_URL;
  78         }
  79         else
  80         {
  81             x = ((x % limit) + limit) % limit;
  82
  83             var url = this.url;
  84             var path = z + "/" + x + "/" + y + ".png";
  85
  86             if (url instanceof Array)
  87             {
  88                 url = this.selectUrl(path, url);
  89             }
  90
  91             return url + path;
  92         }
  93     },
  94
  95     CLASS_NAME: "OpenLayers.Layer.OSM"
  96 });
  97
  98 /**
  99  * Class: OpenLayers.Layer.OSM.Mapnik
 100  *
 101  * Inherits from:
 102  *  - <OpenLayers.Layer.OSM>
 103  */
 104 OpenLayers.Layer.OSM.Mapnik = OpenLayers.Class(OpenLayers.Layer.OSM, {
 105     /**
 106      * Constructor: OpenLayers.Layer.OSM.Mapnik
 107      *
 108      * Parameters:
 109      * name - {String}
 110      * options - {Object} Hashtable of extra options to tag onto the layer
 111      */
 112     initialize: function(name, options) {
 113         var url = [
 114             "http://a.tile.openstreetmap.org/",
 115             "http://b.tile.openstreetmap.org/",
 116             "http://c.tile.openstreetmap.org/"
 117         ];
 118         options = OpenLayers.Util.extend(options, { numZoomLevels: 19 });
 119         var newArguments = [name, url, options];
 120         OpenLayers.Layer.OSM.prototype.initialize.apply(this, newArguments);
 121     },
 122
 123     CLASS_NAME: "OpenLayers.Layer.OSM.Mapnik"
 124 });
 125
 126 /**
 127  * Class: OpenLayers.Layer.OSM.Osmarender
 128  *
 129  * Inherits from:
 130  *  - <OpenLayers.Layer.OSM>
 131  */
 132 OpenLayers.Layer.OSM.Osmarender = OpenLayers.Class(OpenLayers.Layer.OSM, {
 133     /**
 134      * Constructor: OpenLayers.Layer.OSM.Osmarender
 135      *
 136      * Parameters:
 137      * name - {String}
 138      * options - {Object} Hashtable of extra options to tag onto the layer
 139      */
 140     initialize: function(name, options) {
 141         var url = [
 142             "http://a.tah.openstreetmap.org/Tiles/tile.php/",
 143             "http://b.tah.openstreetmap.org/Tiles/tile.php/",
 144             "http://c.tah.openstreetmap.org/Tiles/tile.php/"
 145         ];
 146         options = OpenLayers.Util.extend(options, { numZoomLevels: 18 });
 147         var newArguments = [name, url, options];
 148         OpenLayers.Layer.OSM.prototype.initialize.apply(this, newArguments);
 149     },
 150
 151     CLASS_NAME: "OpenLayers.Layer.OSM.Osmarender"
 152 });