From kde-core-devel  Wed Dec 22 20:33:53 2004
From: nf <nf2 () scheinwelt ! at>
Date: Wed, 22 Dec 2004 20:33:53 +0000
To: kde-core-devel
Subject: Porting kio-slaves to GnomeVFS modules
Message-Id: <1103747632.1039.200.camel () limac>
X-MARC-Message: https://marc.info/?l=kde-core-devel&m=110375792709165

Hi!

AFAIK KDE seems to offer more VFS modules (io-slaves) than Gnome-VFS at
the moment. It would be interesting if their code could be reused in Gnome-VFS
modules instead of writing everything from scratch. 

One way of doing that would be to write a C++ wrapper on top of the
Gnome-VFS-module API which acts like the KIO::SlaveBase class.

Things that need to be looked at:

1) The SlaveBase::special() method. KIO can invoke this method on io-slaves for
advanced operations. Perhaps Gnome-VFS needs an equivalent for that: An additional
function, which passes customized structs, just like the callback structs.

I don't know how many io-slaves use this method extensively - kio_http seems 
to be one of the worst in that respect. Perhaps http should just be excluded
from the Common-VFS agenda at the moment...

2) Dependencies to KConfig of certain slaves to store configuration
data. (smb for instance).

3) Dependencies to Password storage via DCOP. But that's easier to solve,
because SlaveBase has a well defined API for that purpose.

4) Additional GVFS-Callback structures might be needed - but again that
should be easy, because the API for calling back to the client seems to
be "well-defined" in KIOs SlaveBase.

5) Metadata

6) "Q"-code inside io-slaves:

Because QT is split into QTCore and QTGui in Qt4 a dependency 
of those modules to QtCore shouldn't be a problem. The GPL license also, 
because the ported slaves link to Qt and Gnome-VFS, and not the other way round...

Alternatively KWIG could be used to mimic the "Q" stuff...

+++ Resources:

KIO:
http://developer.kde.org/documentation/library/3.3-api/kio/html/index.html
http://webcvs.kde.org/kdelibs/kio/
http://webcvs.kde.org/kdelibs/kio/kio/ (slavebase.h/cpp in particular)

Code of the kioslaves:

http://webcvs.kde.org/kdelibs/kioslave/
http://webcvs.kde.org/kdebase/kioslave/

KWIG:
http://gtk-webcore.sourceforge.net/

Gnome-VFS:
http://developer.gnome.org/doc/API/2.0/gnome-vfs-2.0/

http://cvs.gnome.org/viewcvs/gnome-vfs/libgnomevfs/

Callback Types
http://cvs.gnome.org/viewcvs/gnome-vfs/libgnomevfs/gnome-vfs-standard-callbacks.h

Module Methods
http://cvs.gnome.org/viewcvs/gnome-vfs/libgnomevfs/gnome-vfs-method.h

KIO->GnomeVFS bridge.
http://www.scheinwelt.at/~norbertf/common-vfs/

Just some thoughts, really don't know if that would make sense...

Norbert