fix for #60

conversions to/from lonlat/px need to take into account
the offset of the layersContainerDiv. 


I have introduced the following functions for converting
between layer and screen pixel values:

getLayerPxFromScreenPx() and getScreenPxFromLayerPx()

they are pretty self-explanitory.


I then renamed:

getPixelFromLonLat() and getLonLatFromPixel()

to:

getScreenPxFromLonLat() and getLonLatFroScreenmPx()

and added:

getLayerPxFromLonLat() and getLonLatFromLayerPx()


updates were made throughout the code, demos, and tests
so everything should still run smoothly.

-e-

git-svn-id: http://svn.openlayers.org/trunk/openlayers@329 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

examples/markerss.html

@@ -8,7 +8,7 @@
             border: 1px solid black;
         }
     </style>
-    <script src="lib/OpenLayers.js"></script>
+    <script src="../lib/OpenLayers.js"></script>
     <script type="text/javascript">
         <!--
         var map, layer, popup;
@@ -21,6 +21,15 @@
                 "http://octo.metacarta.com/cgi-bin/mapserv",
                 {map: '/mapdata/vmap_wms.map', layers: 'basic', format: 'image/jpeg'} );
                 
+
+            map.addLayer(
+            new OpenLayers.Layer.WMS("NASA Mosaic", 
+                         "http://wms.jpl.nasa.gov/wms.cgi",
+                         {"EXCEPTIONS" : "application/vnd.ogc.se_inimage",
+                          "format" : "image/jpeg",
+                          layers:"modis,global_mosaic"}
+                         ));
+
             map.addLayer(layer);
 
             markers = new OpenLayers.Layer.Markers( "Markers" );
@@ -31,13 +40,17 @@
         }
         
         function changer() {
-    
-
+            var lon = map.getLonLatFromLayerPx(new OpenLayers.Pixel(0,0)).lon;
+            var lat = map.getLonLatFromLayerPx(new OpenLayers.Pixel(0,0)).lat;
+            var slon = map.getLonLatFromScreenPx(new OpenLayers.Pixel(0,0)).lon;
+            var slat = map.getLonLatFromScreenPx(new OpenLayers.Pixel(0,0)).lat;
+            alert("lon=" + lon + " lat=" + lat 
+                  + "slon=" + slon + " slat=" + slat);
         }
 
         function add() {
             var icon = new OpenLayers.Icon('http://boston.openguides.org/markers/AQUA.png',new OpenLayers.Size(10,17));
-            marker = new OpenLayers.Marker(new OpenLayers.LonLat(180,90), icon);
+            marker = new OpenLayers.Marker(new OpenLayers.LonLat(0,00), icon);
             markers.addMarker(marker);
             
         }        
@@ -58,7 +71,7 @@
     <h1>OpenLayers Example</h1>
     <div id="map"></div>
     <div style="background-color:purple" onclick="add()"> click to add popup to map</div>
-    <div style="background-color:blue" onclick="changer()"> click to modify popup's attributes</div>
+    <div style="background-color:blue" onclick="changer()"> click to get lon/lat for pixel point(0,0)</div>
     <div style="background-color:red" onclick="destroy()"> click to destroy the popup</div>
     <div style="background-color:green" onclick="remove()"> click to remove the popup from map</div>
   </body>