add displayProjection API Property on the Map, and on relevant controls.

Spherical mercator example now makes use of this, displaying coordinates 
in lon/lat instead of meters, and permalink/argparser now work in lon/lat
as well. this functionality will make using SphericalMercator easier for
a number of applications. 
r=tschaub (Closes #1036)


git-svn-id: http://svn.openlayers.org/trunk/openlayers@5519 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Control/ArgParser.js

@@ -30,6 +30,20 @@ OpenLayers.Control.ArgParser = OpenLayers.Class(OpenLayers.Control, {
      * {Array(<OpenLayers.Layer>)}
      */
     layers: null,
+    
+    /** 
+     * APIProperty: displayProjection
+     * {<OpenLayers.Projection>} Requires proj4js support. 
+     *     Projection used when reading the coordinates from the URL. This will
+     *     reproject the map coordinates from the URL into the map's
+     *     projection.
+     *
+     *     If you are using this functionality, be aware that any permalink
+     *     which is added to the map will determine the coordinate type which
+     *     is read from the URL, which means you should not add permalinks with
+     *     different displayProjections to the same map. 
+     */
+    displayProjection: null, 
 
     /**
      * Constructor: OpenLayers.Control.ArgParser
@@ -56,6 +70,14 @@ OpenLayers.Control.ArgParser = OpenLayers.Class(OpenLayers.Control, {
             var control = this.map.controls[i];
             if ( (control != this) &&
                  (control.CLASS_NAME == "OpenLayers.Control.ArgParser") ) {
+                
+                // If a second argparser is added to the map, then we 
+                // override the displayProjection to be the one added to the
+                // map. 
+                if (control.displayProjection != this.displayProjection) {
+                    this.displayProjection = control.displayProjection;
+                }    
+                
                 break;
             }
         }
@@ -97,7 +119,12 @@ OpenLayers.Control.ArgParser = OpenLayers.Class(OpenLayers.Control, {
             //dont need to listen for this one anymore
             this.map.events.unregister('changebaselayer', this, 
                                        this.setCenter);
-                                       
+            
+            if (this.displayProjection) {
+                this.center.transform(this.displayProjection, 
+                                      this.map.getProjectionObject()); 
+            }      
+
             this.map.setCenter(this.center, this.zoom);
         }
     },

lib/OpenLayers/Control/MousePosition.js

@@ -51,6 +51,13 @@ OpenLayers.Control.MousePosition = OpenLayers.Class(OpenLayers.Control, {
      * {<OpenLayers.LonLat>}
      */
     lastXy: null,
+
+    /**
+     * APIProperty: displayProjection
+     * {<OpenLayers.Projection>} A projection that the 
+     * mousecontrol will display.
+     */
+    displayProjection: null, 
     
     /**
      * Constructor: OpenLayers.Control.MousePosition
@@ -113,7 +120,12 @@ OpenLayers.Control.MousePosition = OpenLayers.Class(OpenLayers.Control, {
                 // map has not yet been properly initialized
                 return;
             }    
+            if (this.displayProjection) {
+                lonLat.transform(this.map.getProjectionObject(), 
+                                 this.displayProjection );
+            }      
             this.lastXy = evt.xy;
+            
         }
         
         var digits = parseInt(this.numdigits);

lib/OpenLayers/Control/Permalink.js

@@ -25,6 +25,18 @@ OpenLayers.Control.Permalink = OpenLayers.Class(OpenLayers.Control, {
      */
     base: '',
 
+    /** 
+     * APIProperty: displayProjection
+     * {<OpenLayers.Projection>} Requires proj4js support.  Projection used
+     *     when creating the coordinates in the link. This will reproject the
+     *     map coordinates into display coordinates. If you are using this
+     *     functionality, the permalink which is last added to the map will
+     *     determine the coordinate type which is read from the URL, which
+     *     means you should not add permalinks with different
+     *     displayProjections to the same map. 
+     */
+    displayProjection: null, 
+
     /**
      * Constructor: OpenLayers.Control.Permalink
      *
@@ -67,11 +79,20 @@ OpenLayers.Control.Permalink = OpenLayers.Class(OpenLayers.Control, {
         for(var i=0; i< this.map.controls.length; i++) {
             var control = this.map.controls[i];
             if (control.CLASS_NAME == "OpenLayers.Control.ArgParser") {
+                
+                // If a permalink is added to the map, and an ArgParser already
+                // exists, we override the displayProjection to be the one
+                // on the permalink. 
+                if (control.displayProjection != this.displayProjection) {
+                    this.displayProjection = control.displayProjection;
+                }    
+                
                 break;
             }
         }
         if (i == this.map.controls.length) {
-            this.map.addControl(new OpenLayers.Control.ArgParser());       
+            this.map.addControl(new OpenLayers.Control.ArgParser(
+                { 'displayProjection': this.displayProjection }));       
         }
 
     },
@@ -112,9 +133,20 @@ OpenLayers.Control.Permalink = OpenLayers.Class(OpenLayers.Control, {
         var params = OpenLayers.Util.getParameters(this.base);
         
         params.zoom = this.map.getZoom(); 
-        params.lat = Math.round(center.lat*100000)/100000;
-        params.lon = Math.round(center.lon*100000)/100000;
-
+        var lat = center.lat;
+        var lon = center.lon;
+        
+        if (this.displayProjection) {
+            var mapPosition = OpenLayers.Projection.transform(
+              { x: lon, y: lat }, 
+              this.map.getProjectionObject(), 
+              this.displayProjection );
+            lon = mapPosition.x;  
+            lat = mapPosition.y;  
+        }       
+        params.lat = Math.round(lat*100000)/100000;
+        params.lon = Math.round(lon*100000)/100000;
+        
         params.layers = '';
         for(var i=0; i< this.map.layers.length; i++) {
             var layer = this.map.layers[i];