Bring objects to front/send to back

The Front-to-back is determined by the z-order, which is stored in the NodeLocation attribute.  It is an integer, and can be positive or negative.  Nodes with larger Z-order display over nodes with lower Z-order.  When you select "Bring to Front" on the right-mouse context menu, it sets the Z-order to a number that is larger than the other z-orders on the same diagram.

Here is a UDF to do it:

Function Send_to_front(o : Object)

Definition:

Local z := NodeLocation::z of Contains of isin of o;
NodeLocation::z of o := Max([10,z+1])

Function Send_to_back(o : Object)

Local z := NodeLocation::z of Contains of isin of o;
NodeLocation::z of o := Min([-10,z-1])