From f56dab0644d65a96a327f071f04e4d2417c14245 Mon Sep 17 00:00:00 2001
From: euzuro <euzuro@metacarta.com>
Date: Sat, 19 Aug 2006 05:37:07 +0000
Subject: [PATCH] just like r1308, we update virtual earth to use min/max
 zoomlevel, and update the example

git-svn-id: http://svn.openlayers.org/branches/openlayers/2.0@1309 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf
---
 examples/ve.html                     | 11 ++++---
 lib/OpenLayers/Layer/VirtualEarth.js | 46 +++++++++++++++++-----------
 2 files changed, 35 insertions(+), 22 deletions(-)

diff --git a/examples/ve.html b/examples/ve.html
index 52ea2a0d38..4d04215869 100644
--- a/examples/ve.html
+++ b/examples/ve.html
@@ -18,20 +18,23 @@
  
         var lon = 5;
         var lat = 40;
-        var zoom = 5;
+        var zoom = 15;
         var map, velayer, layer;
 
         function init(){
-            map = new OpenLayers.Map( $('map') );
+            map = new OpenLayers.Map( $('map') , 
+            {controls:[new OpenLayers.Control.MouseDefaults()]});
 
-            velayer = new OpenLayers.Layer.VirtualEarth( "VE"); 
+            velayer = new OpenLayers.Layer.VirtualEarth( "VE",
+            { minZoomLevel: 4, maxZoomLevel: 6 }); 
             map.addLayer(velayer);
             
             markers = new OpenLayers.Layer.Markers("markers");
             map.addLayer(markers);
 
-            map.setCenter(new OpenLayers.LonLat(lon, lat), 2);
+            map.setCenter(new OpenLayers.LonLat(lon, lat), zoom);
             map.addControl( new OpenLayers.Control.LayerSwitcher() );
+            map.addControl( new OpenLayers.Control.PanZoomBar() );
         }
         
         function add() {
diff --git a/lib/OpenLayers/Layer/VirtualEarth.js b/lib/OpenLayers/Layer/VirtualEarth.js
index a021b36d14..360cdcff82 100644
--- a/lib/OpenLayers/Layer/VirtualEarth.js
+++ b/lib/OpenLayers/Layer/VirtualEarth.js
@@ -15,7 +15,10 @@ OpenLayers.Layer.VirtualEarth.prototype =
     vemap: null,
     
     /** @type int */
-    numZoomLevels: 17,
+    minZoomLevel: 1,
+
+    /** @type int */
+    maxZoomLevel: 17,
     
     /**
      * @constructor
@@ -24,6 +27,8 @@ OpenLayers.Layer.VirtualEarth.prototype =
      */
     initialize:function(name) {
         OpenLayers.Layer.EventPane.prototype.initialize.apply(this, arguments);
+
+        this.numZoomLevels = this.maxZoomLevel - this.minZoomLevel + 1;
     },
 
     /** 
@@ -203,21 +208,26 @@ OpenLayers.Layer.VirtualEarth.prototype =
      */
     getZoomForExtent: function (bounds) {
 
-        var maxRes = this.map.getMaxResolution();
-        var viewSize = this.map.getSize();
-
-        var width = bounds.getWidth();
-        var height = bounds.getHeight();
-
-        var degPerPixel = (width > height) ? width / viewSize.w 
-                                           : height / viewSize.h;
-        
-        var zoom = Math.floor( (Math.log(maxRes/degPerPixel)) / Math.log(2) );
-
-        //make sure zoom is within bounds    
-        zoom = Math.min( Math.max(zoom, 0), 
-                         this.numZoomLevels-1);
-
+        var zoom = null;
+        if (this.vemap != null) {
+            var maxRes = this.map.getMaxResolution();
+            var viewSize = this.map.getSize();
+    
+            var width = bounds.getWidth();
+            var height = bounds.getHeight();
+    
+            var degPerPixel = (width > height) ? width / viewSize.w 
+                                               : height / viewSize.h;
+            
+            var veZoom = Math.floor( (Math.log(maxRes/degPerPixel)) / 
+                                     Math.log(2) );
+    
+            //make sure zoom is within bounds    
+            var veZoom = Math.min(Math.max(veZoom, this.minZoomLevel), 
+                                  this.maxZoomLevel);
+    
+            zoom = this.getOLZoomFromVEZoom(veZoom);         
+        }
         return zoom;
     },
  
@@ -245,7 +255,7 @@ OpenLayers.Layer.VirtualEarth.prototype =
     getOLZoomFromVEZoom: function(veZoom) {
         var zoom = null;
         if (veZoom != null) {
-            zoom = veZoom;
+            zoom = veZoom - this.minZoomLevel;
         }
         return zoom;
     },
@@ -260,7 +270,7 @@ OpenLayers.Layer.VirtualEarth.prototype =
     getVEZoomFromOLZoom: function(olZoom) {
         var zoom = null; 
         if (olZoom != null) {
-            zoom = olZoom;
+            zoom = olZoom + this.minZoomLevel;
         }
         return zoom;
     },