+ /* if this is 1.0, we move the right boundary
+ of the item frame so that it is 1 pixel
+ after the end of the item. This gives nice
+ effects when splitting items.
+
+ if this is zero, the right edge coincides
+ with the end of the item, and things don't
+ look so nice.
+
+ this exists to allow easy debugging of the
+ two scenarios.
+ */
+ static const double RIGHT_EDGE_SHIFT;
+