AcLyLayerFilter

AcHeapOperators
AcRxObject
    AcLyLayerFilter
        AcLyLayerGroup

class AcLyLayerFilter : public AcRxObject, public AcHeapOperators;

acly.h

This is the main layer filter class. It allows the client to specify and retrieve the filter expression and to nest filters.

The following rules apply when deriving custom filters from AcLyLayerFilter:

Define the class using the ACRX_CONS_DEFINE_MEMBERS macro, not ACRX_DXF_DEFINE_MEMBERS.
Don't forget to call rxInit().
When implementing readFrom() and writeTo(), don't use any of the DXF subclass marker functionality of the filer, as this will make DXF files invalid.
DXF subclass functionality includes pFiler->writeItem(AcDb::kDxfSubclass, ...) and pFiler->atSubclassData(...).
For custom (AcLyLayerFilter-derived) filter classes, the readLegacyFrom() and writeLegacyTo() methods are never called because custom filters cannot be represented in AutoCAD 2004 and previous releases.