diff --git a/sloth/gui/annotationscene.py b/sloth/gui/annotationscene.py
index 85a9bcc..4e7197f 100644
--- a/sloth/gui/annotationscene.py
+++ b/sloth/gui/annotationscene.py
@@ -410,7 +410,7 @@ def drawForeground(self, painter, rect):
 
             self._message_text_item.paint(painter, QStyleOptionGraphicsItem(), None)
 
-    # 
+    #
     # utility functions
     #
 
diff --git a/sloth/items/items.py b/sloth/items/items.py
index 2b41bc3..6e9c7a6 100644
--- a/sloth/items/items.py
+++ b/sloth/items/items.py
@@ -769,6 +769,7 @@ def __init__(self, model_item=None, prefix="", parent=None):
         self._polygon = None
 
         self._updatePolygon(self._dataToPolygon(self._model_item))
+
         LOG.debug("Constructed polygon %s for model item %s" %
                   (self._polygon, model_item))
 
@@ -830,3 +831,10 @@ def paint(self, painter, option, widget=None):
     def dataChange(self):
         polygon = self._dataToPolygon(self._model_item)
         self._updatePolygon(polygon)
+
+    def shape(self):
+        shape = QPainterPath()
+        for pt in self._polygon:
+            shape.lineTo(pt)
+        shape.lineTo(self._polygon[0])
+        return shape