PropertyHandle :: IsValidForParent - Is subhandle valid for parent passed

The function checks, whether the property handle is a sub-handle of the parent property handle passed to the function. When an application uses dynamical property hierarchies, in which property handle may change, the function can be used in order to check, whether a handle in the hierarchy is still valid.

When the property handle is not valid, the function returns 0. When the parent property handle is not valid and the current property handle does not got a parent, the function returns 1. When both are not valid, the function returns 0.

When the property handle is a valid sub property handle but not directly subordinated (e.g. a sub sub property handle), the function returns the distance to its parent (level of subordination).