[PyKDE] KTrader woes?
jbublitz at nwinternet.com
Thu Sep 11 04:30:01 BST 2003
On Wednesday September 10 2003 17:45, Sundance wrote:
> I heard Jim Bublitz said:
> I assume that it is not expected to work outside a
> KApplication, then? Maybe there should be a way to raise an
> exception rather than crash when this is called outside a
You'd have to talk to KDE and TrollTech about that - that's
built-in behaviour in the KDE/Qt C++ libs. Some things do throw
an exception/error msgs, like trying to use widgets without a
QApplication/KApplication instance exisiting (although the msg
usually complains about a missing QPainter instance). I would
imagine KTrader is looking for some other connection the
KApplication establishes with KDE.
> That was the behavior I expected anyway, so
> when I tried the KTrader trick on its own I assumed that it
> would either 1) work on its own, or 2) require some
> QApplication-like class to have been instanciated, in which
> case it would warn me.
> Guess I was wrong about the 'warn me' part.
Nah - you got a segfault. Just not a very delicate warning. :)
> > There are a couple of programs in examples/ that use KTrader
> > (pyParts.py, pyParts_1.py don't work too well at the moment
> > though). If you run examples/mimetype.py, the OfferList tab
> > results are from a KTrader call -- does that work?
> It does.
> I rewrote my little example above adding a KApplication
> instanciation just before the call to KTrader.self().query,
> and it works, whee!
> Well, more precisely, it works if I copy the KCmdLineArgs.init
> line from mimetype.py. If I call KApplication(, "SomeName")
> it dies. Apparently KApplication REQUIRES a non-empty list as
> its first argument, unlike QApplication (with which the 
> trick works).
PyKDE-3.8 (rc releases are at
http://www.sourceforge.net/projects/pykde) has a bunch of
application templates you can use to get started.
> Alright, so. Erm. :) I may be wrong about this as well, but I
> still sort of think there are more elegant ways to let the
> user know he's done something wrong than crash the full
> interpreter. =)
> Is there any way we can help make it so?
Seems pretty difficult - my guess would be the most appropriate
route would be a tutorial/better docs/more example programs -
that's in the works, but takes a while to accomplish. The KDE
libs classref docs are pretty good, even if C++ oriented. You
find them at http://www.kde.org in the documentation section,
along with a lot of tutorial stuff.
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