small re-org of Marker layer innards

git-svn-id: http://svn.openlayers.org/trunk/openlayers@248 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Layer/Marker.js

@@ -25,10 +25,7 @@ OpenLayers.Layer.Marker.prototype =
     */
     moveTo: function(bounds, zoomChanged) {
         if (zoomChanged) {
-            this.div.innerHTML = "";
+            this.redraw();
-            for(i=0; i < this.markers.length; i++) {
-                this.drawMarker(this.markers[i]);
-            }
         }
     },
 
@@ -42,15 +39,40 @@ OpenLayers.Layer.Marker.prototype =
         }
     },
 
-    /**
+
+    /** clear all the marker div's from the layer and then redraw all of them.
+    *    Use the map to recalculate new placement of markers.
+    */
+    redraw: function() {
+
+        this.clear();
+        for(i=0; i < this.markers.length; i++) {
+            this.drawMarker(this.markers[i]);
+        }
+
+    },
+
+    /** This function clears the visual display of the markers, without
+    *    removing them from memory (this.markers array). 
+    *
+    * @private
+    */
+    clear: function() {
+        this.div.innerHTML = "";
+    },
+
+
+    /** Calculate the screen pixel location for the marker, create it, and 
+    *    add it to the layer's div
+    * 
     * @private 
     * 
     * @param {OpenLayers.Marker} marker
     */
     drawMarker: function(marker) {
         var px = this.map.getPixelFromLonLat(marker.lonlat);
-        var m = marker.generateMarker(px);
+        var markerDiv = marker.generateMarker(px);
-        this.div.appendChild(m);
+        this.div.appendChild(markerDiv);
     },
     
     /** @final @type String */