getting rid of unnecessary, undocumented 'drawn' property on marker. replacing it with accessor function isDrawn(), and putting an isDrawn() in icon as well. all tests pass r=elemoine (Closes #1759)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@8091 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Icon.js

@@ -193,6 +193,22 @@ OpenLayers.Icon = OpenLayers.Class({
     display: function(display) {
         this.imageDiv.style.display = (display) ? "" : "none"; 
     },
+    
+
+    /**
+     * APIMethod: isDrawn
+     * 
+     * Returns:
+     * {Boolean} Whether or not the icon is drawn.
+     */
+    isDrawn: function() {
+        // nodeType 11 for ie, whose nodes *always* have a parentNode
+        // (of type document fragment)
+        var isDrawn = (this.imageDiv && this.imageDiv.parentNode && 
+                       (this.imageDiv.parentNode.nodeType != 11));    
+
+        return isDrawn;   
+    },
 
     CLASS_NAME: "OpenLayers.Icon"
 });

lib/OpenLayers/Layer/Markers.js

@@ -125,7 +125,6 @@ OpenLayers.Layer.Markers = OpenLayers.Class(OpenLayers.Layer, {
             if ((marker.icon != null) && (marker.icon.imageDiv != null) &&
                 (marker.icon.imageDiv.parentNode == this.div) ) {
                 this.div.removeChild(marker.icon.imageDiv);    
-                marker.drawn = false;
             }
         }
     },
@@ -156,10 +155,9 @@ OpenLayers.Layer.Markers = OpenLayers.Class(OpenLayers.Layer, {
         if (px == null) {
             marker.display(false);
         } else {
-            var markerImg = marker.draw(px);
-            if (!marker.drawn) {
+            if (!marker.isDrawn()) {
+                var markerImg = marker.draw(px);
                 this.div.appendChild(markerImg);
-                marker.drawn = true;
             }
         }
     },

lib/OpenLayers/Marker.js

@@ -129,6 +129,17 @@ OpenLayers.Marker = OpenLayers.Class({
         this.lonlat = this.map.getLonLatFromLayerPx(px);
     },
 
+    /**
+     * APIMethod: isDrawn
+     * 
+     * Returns:
+     * {Boolean} Whether or not the marker is drawn.
+     */
+    isDrawn: function() {
+        var isDrawn = (this.icon && this.icon.isDrawn());
+        return isDrawn;   
+    },
+
     /**
      * Method: onScreen
      *