Can QGraphicsItems be layered between children of other QGraphicsItems?

As default behavior of the QGraphicsItems "Z Values", independent Top-Level QGraphicsItems apparently can't be drawn between distinct "Z" layers of the nested QGrahpicsItem children of other Top-Level QGraphicsItems.

This Qt 4.6.3 example shows these QGraphicsItems:

1. Top-Level QGraphicsRectItem .. Z = 1.0
2. ... Child QGraphicsTextItem .. Z = 3.0
3. Top-Level QGraphicsLineItem .. Z = 2.0

Notice that the Line Item obscures the Text Item, even though the Text Item has a higher Z-Value (but does not have the same parent QGraphicsItem). [Qt 4.6.3, 12-2010].

Are there any QGraphicsScene or QGraphicsItem configuration properties which modify this behavior?

• Qt 4.6 C++ EXAMPLE CODE.
• Screenshot of problem in the RiverWare program.

• ZProblem.cpp.txt -- Qt 4.6 C++ TEST PROGRAM