Qt bindings compilation

[Alexey Morozov]

Hello!

I'm trying to compile dbus-0.23 w/ qt bindings enabled, and got a lot of 
errors.
While problems w/ configure/qt-detection stage are relatively simple to 
solve (and probably distro-specific), there're other errors, which I 
think either mean that current Qt-bindings are fundamentally broken or I 
do smth really wrong.

First of all there're two 'typo' errors at lines 39 and 60 of 
qt/dbus-qthread.cpp
(http://cvs.freedesktop.org/dbus/dbus/qt/dbus-qthread.cpp?annotate=1.4&only_with_tag=DBUS_0_23)

There're certainly typos (a dot instead of comma after *mutex at line 
39, and missing comma after dbus_qmutex_unlock at line 60). These two 
typos are trivially to fix, not a big problem indeed.

There're also some constants clash, DBUS_THREAD_FUNCTIONS_NEW_MASK is 
now called (well, _perhaps_, called) 
DBUS_THREAD_FUNCTIONS_MUTEX_NEW_MASK and so that 
DBUS_THREAD_FUNCTIONS_FREE_MASK and DBUS_THREAD_FUNCTIONS_FREE_MASK. 
Also a rather trivial fix.

Later I encountered w/ some C++-specific errors like this:

dbus-qthread.cpp: In function `DBusMutex* dbus_qmutex_new()':
dbus-qthread.cpp:74: error: invalid static_cast from type `QMutex*' to 
type `DBusMutex*'
...

I took a look at the code, and found (beside some other typos like 
'timeout_msec' spelled as 'timout_msec', at line 133 and obviously 
'mutex' instead' of 'qmutex' at 81)
expressions like the following:

static void
dbus_qmutex_free   (DBusMutex *mutex)
{
  QMutex * qmutex = static_cast<QMutex*>(mutex);
...

Well, I'm not a C++-hacker (anymore), but it seems that reinterpret_cast 
instead of static_cast is what the code writer(s) meant. static_cast is 
a type-safe casting, used mainly for derived-to-base class casts, while 
reinterpret_cast is a unsafe cast used to blindly convert a pointer of 
one type to a pointer to another.

There were a bunch of changes related to such static_cast. Also wakeOne 
and wakeAll methods of QWaitCondition have no arguments, so I changed that.

Well, now dbus-qthread.cpp can be compiled and since it's mostly a 
wrapper for corresponding Qt methods, it should even work now. There're 
minor issues w/ code style (this code is evidently exception-unsafe and 
potentially leaking but it's not that important right now).

There're also a bunch of 'code reaches the end of non-void function' 
warnings (actually, errors) in message.cpp (yet another trivial fix) and 
a couple more serious problems, like unimplemented class Message copy 
constructor.

Nevertheless, I can see that some vendors (Mdk, PLD, Suse contribs) do 
provide RPM packages of dbus-qt. This either means that they avoided all 
these, well, serious compilation problems or they built smth else. Also 
I can see that tools like KVM (KDE Volume Manager in KDE non beta) 
requires 'dbus-qt'. So my questions are:

1. Are Qt-bindings for dbus [theoretically] alive?
2. Does development of these bindings occur in dbus CVS, 
http://cvs.freedesktop.org/dbus/dbus/qt/ or maybe some other place?
3. Is there anybody who really uses it for some apps?

If dbus-qt is really what comes w/ dbus releases and can be downloaded 
from dbus CVS, I'll provide all patches I have created so far to 
configure and compile entire lib.

Yours sincerely,
Alexey Morozov