--- a/flys-artifacts/src/main/java/de/intevation/flys/jfree/JFreeUtil.java	Tue Jun 05 14:56:57 2012 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/jfree/JFreeUtil.java	Tue Jun 05 15:03:11 2012 +0000
@@ -19,10 +19,13 @@
      * True if \param hotspot collides with a Entity in \param entities.
      * @param hotspot Shape to compare against other shapes (bounds only).
      * @param entities entities against which to compare shape.
-     * @param true if a collision (non-zero intersection) exists between
+     * @param exclusiveEntityClass If not null, consider only entities of
+     *        given class.
+     * @return true if a collision (non-zero intersection) exists between
      *        shapes.
      */
-    public static boolean collides(Shape hotspot, EntityCollection entities) {
+    public static boolean collides(Shape hotspot, EntityCollection entities,
+        Class exclusiveEntityClass) {
         if (entities == null) return false;
 
         Rectangle2D hotspotBox = hotspot.getBounds2D();
@@ -30,9 +33,13 @@
         for (Iterator i = entities.iterator(); i.hasNext(); ) {
             Object next = i.next();
             ChartEntity entity = (ChartEntity) next;
-            if (entity.getArea().intersects(hotspotBox)) {
-                // Found collision, early stop.
-                return true;
+            if (exclusiveEntityClass == null
+                || exclusiveEntityClass.isInstance(entity))
+                {
+                if (entity.getArea().intersects(hotspotBox)) {
+                    // Found collision, early stop.
+                    return true;
+                }
             }
         }