From 15d3d9fc21b0e7bbdd144d1b8ddeb54e7f601501 Mon Sep 17 00:00:00 2001
From: euzuro <euzuro@metacarta.com>
Date: Wed, 16 Aug 2006 15:53:33 +0000
Subject: [PATCH] do not update invisible baselayers as the user navigates
 around. only update them when they are made visible.

git-svn-id: http://svn.openlayers.org/trunk/openlayers@1239 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf
---
 lib/OpenLayers/Map.js | 31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/lib/OpenLayers/Map.js b/lib/OpenLayers/Map.js
index 7cdeba2462..fb78f23cad 100644
--- a/lib/OpenLayers/Map.js
+++ b/lib/OpenLayers/Map.js
@@ -358,23 +358,31 @@ OpenLayers.Map.prototype = {
           
             // is newBaseLayer an already loaded layer?
             var foundLayer = (this.layers.indexOf(newBaseLayer) != -1);    
-            
             if (foundLayer) {
-                
+
+                var oldExtent = null;
+                                
                 // make the old base layer invisible 
                 if (this.baseLayer != null) {
+                    oldExtent = this.baseLayer.getExtent();
                     this.baseLayer.setVisibility(false, noEvent);
                 }
-                        
-                // set new baselayer
+
+                // set new baselayer and move it to the old layer's extent
                 this.baseLayer = newBaseLayer;
-    
-                // make the new one visible
+                if (oldExtent != null) {
+                    this.baseLayer.moveTo(oldExtent);
+                }
+
+                // make the new baselayer visible
                 this.baseLayer.setVisibility(true, noEvent);
                 
-                // now go back and reproject
+                // now go back and reproject the overlays
                 for(var i=0; i < this.layers.length; i++) {
-                    this.layers[i].reproject();
+                    var layer = this.layers[i];
+                    if (!layer.isBaseLayer) {
+                        layer.reproject();
+                    }
                 }
 
                 if ((noEvent == null) || (noEvent == false)) {
@@ -599,10 +607,13 @@ OpenLayers.Map.prototype = {
                 }
             }    
 
-            //send the move call to all the layers    
+            //send the move call to the baselayer and all the overlays    
             var bounds = this.getExtent();
             for (var i = 0; i < this.layers.length; i++) {
-                this.layers[i].moveTo(bounds, zoomChanged, minor);
+                var layer = this.layers[i];
+                if ((layer == this.baseLayer) || !layer.isBaseLayer) {
+                    layer.moveTo(bounds, zoomChanged, minor);
+                }
             }
             
             this.events.triggerEvent("move");