How to know if the document is in protected mode programatically

I'm using C++ for building our Adobe Plugins. I want to disable one of  the toolbar buttons when the document is opened in protected mode and until we click on "Enable All Features".

We are using this call AVToolButtonSetComputeEnabledProc(cabinetButton, ASCallbackCreateProto(AVComputeEnabledProc, &CabinetEnabled), NULL); to enable/disable the button.

I'm checking for Active Doc in the call back CabinetEnabled using AVAppGetActiveDoc()

AVAppGetActiveDoc() is  returning null when the pdf is opened in protected mode until we enable all features where as  its not null when opened in Adobe DC.

Is there a way that we can figure out if the document is in protected mode. ?

Thanks in advance.