documenting that Layer.VirtualEarth requires restrictedExtent to be set, and changing the examples accordingly. p=marcjansen (closes #3123)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@11503 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

examples/bing.html

@@ -14,7 +14,16 @@
         var map;
  
         function init(){
-            map = new OpenLayers.Map("map");
+            // setting restrictedExtent so that we can use the 
+            // VirtualEarth-layers, see e.g. 
+            // http://dev.openlayers.org/apidocs/files/OpenLayers/Layer/VirtualEarth-js.html
+            var restrictedExtent = new OpenLayers.Bounds(-20037508, -20037508, 
+                20037508, 20037508);
+            
+            map = new OpenLayers.Map("map", {
+                restrictedExtent: restrictedExtent
+            });
+            
             map.addControl(new OpenLayers.Control.LayerSwitcher());
 
             var shaded = new OpenLayers.Layer.VirtualEarth("Shaded", {

examples/spherical-mercator.html

@@ -31,57 +31,61 @@
 OpenLayers.IMAGE_RELOAD_ATTEMPTS = 3;
 
 function init(){
+    var maxExtent = new OpenLayers.Bounds(-20037508, -20037508, 20037508, 20037508),
+        restrictedExtent = maxExtent.clone(-20037508, -20037508, 20037508, 20037508),
+        maxResolution = 156543.0339;
+    
     var options = {
         projection: new OpenLayers.Projection("EPSG:900913"),
         displayProjection: new OpenLayers.Projection("EPSG:4326"),
         units: "m",
         numZoomLevels: 18,
-                maxResolution: 156543.0339,
-                maxExtent: new OpenLayers.Bounds(-20037508, -20037508,
-                                                 20037508, 20037508.34)
+        maxResolution: maxResolution,
+        maxExtent: maxExtent,
+        restrictedExtent: restrictedExtent
     };
     map = new OpenLayers.Map('map', options);
 
     // create Google Mercator layers
     var gmap = new OpenLayers.Layer.Google(
         "Google Streets",
-                {'sphericalMercator': true}
+        {sphericalMercator: true}
     );
     var gsat = new OpenLayers.Layer.Google(
         "Google Satellite",
-                {type: G_SATELLITE_MAP, 'sphericalMercator': true, numZoomLevels: 22}
+        {type: G_SATELLITE_MAP, sphericalMercator: true, numZoomLevels: 22}
     );
     var ghyb = new OpenLayers.Layer.Google(
         "Google Hybrid",
-                {type: G_HYBRID_MAP, 'sphericalMercator': true}
+        {type: G_HYBRID_MAP, sphericalMercator: true}
     );
 
     // create Virtual Earth layers
     var veroad = new OpenLayers.Layer.VirtualEarth(
         "Virtual Earth Roads",
-                {'type': VEMapStyle.Road, 'sphericalMercator': true}
+        {'type': VEMapStyle.Road, sphericalMercator: true}
     );
     var veaer = new OpenLayers.Layer.VirtualEarth(
         "Virtual Earth Aerial",
-                {'type': VEMapStyle.Aerial, 'sphericalMercator': true}
+        {'type': VEMapStyle.Aerial, sphericalMercator: true}
     );
     var vehyb = new OpenLayers.Layer.VirtualEarth(
         "Virtual Earth Hybrid",
-                {'type': VEMapStyle.Hybrid, 'sphericalMercator': true}
+        {'type': VEMapStyle.Hybrid, sphericalMercator: true}
     );
 
     // create Yahoo layer
     var yahoo = new OpenLayers.Layer.Yahoo(
         "Yahoo Street",
-                {'sphericalMercator': true}
+        {sphericalMercator: true}
     );
     var yahoosat = new OpenLayers.Layer.Yahoo(
         "Yahoo Satellite",
-                {'type': YAHOO_MAP_SAT, 'sphericalMercator': true}
+        {'type': YAHOO_MAP_SAT, sphericalMercator: true}
     );
     var yahoohyb = new OpenLayers.Layer.Yahoo(
         "Yahoo Hybrid",
-                {'type': YAHOO_MAP_HYB, 'sphericalMercator': true}
+        {'type': YAHOO_MAP_HYB, sphericalMercator: true}
     );
 
     // create OSM layer

lib/OpenLayers/Layer/VirtualEarth.js

@@ -13,6 +13,10 @@
 
 /**
  * Class: OpenLayers.Layer.VirtualEarth
+ * Instances of OpenLayers.Layer.VirtualEarth are used to display the data from
+ *     the Bing Maps AJAX Control (see e.g. 
+ *     http://msdn.microsoft.com/library/bb429619.aspx). Create a VirtualEarth 
+ *     layer with the <OpenLayers.Layer.VirtualEarth> constructor.
  *     
  * Inherits from:
  *  - <OpenLayers.Layer.EventPane>
@@ -94,6 +98,22 @@ OpenLayers.Layer.VirtualEarth = OpenLayers.Class(
 
     /** 
      * Constructor: OpenLayers.Layer.VirtualEarth
+     * Creates a new instance of a OpenLayers.Layer.VirtualEarth. If you use an
+     *     instance of OpenLayers.Layer.VirtualEarth in you map, you should set 
+     *     the <OpenLayers.Map> option restrictedExtent to a meaningful value,
+     *     e.g.:
+     * (code)
+     * var map = new OpenLayers.Map( 'map', {
+     *     // other map options
+     *     restrictedExtent : OpenLayers.Bounds(-20037508, -20037508, 20037508, 20037508)
+     * } );
+     * 
+     * var veLayer = new OpenLayers.Layer.VirtualEarth (
+     *     "Virtual Earth Layer"
+     * );
+     * 
+     * map.addLayer( veLayer );
+     * (end)
      * 
      * Parameters:
      * name - {String}