add new vector style property "graphicOpacity"

enabling mixing non-opaque vector geometries with opaque external graphics on the same vector layer
(closes #873)


git-svn-id: http://svn.openlayers.org/trunk/openlayers@4114 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Renderer/VML.js

@@ -210,7 +210,12 @@ OpenLayers.Renderer.VML = OpenLayers.Class(OpenLayers.Renderer.Elements, {
                 fill = this.createNode('v:fill', node.id + "_fill");
                 node.appendChild(fill);
             }
-            if (style.fillOpacity) {
+            // if graphicOpacity is set use it in priority for external graphic
+            if (node._geometryClass == "OpenLayers.Geometry.Point" &&
+                style.externalGraphic &&
+                style.graphicOpacity) {
+                fill.setAttribute("opacity", style.graphicOpacity);
+            } else if (style.fillOpacity) {
                 fill.setAttribute("opacity", style.fillOpacity);
             }
         }