Share karbon format filters between karbon and flow

[Yue Liu]

Hi,

I'm trying to find a way to make Karbon format filters work also in Flow.
After KoPart/KoDocument split, Karbon filters ImageExport, SvgExport,
SvgImport, and WmfExport still require Karbon object KarbonDocument
and KarbonKoDocument (derived from KoDocument). So those cannot be
used by Flow.

First I think KarbonDocument and KarbonKoDocument can be merged to
single KarbonDocument.

Then we can create an abstract class KoGraphicsDocument, define the
interface with methods used in filters, then derive FlowDocument from
KoPADocument and KoGraphicsDocument, make KarbonDocument also inherit
KoGraphicsDocument.

Now the problem is filters require access of shapes(layers) of a page,
but I'm not sure how to access shapes(layers) from KoPAPage. What is
the recommended way to do that?

Best regards,
Yue Liu