RE: [ROOT] ROOT 4.01/04

From: Rene Brun (
Date: Sat Nov 20 2004 - 07:47:17 MET

Hi Jacek, Valeri,

On Sat, 20 Nov 2004, Jacek M. Holeczek wrote:

> Hi,
> > (...)
> > Including the Qt portion into the binary distribution with no actually Qt
> > itself implies ROOT team knows what the local Qt version is.
> > (..)
> > As soon as SLC3 is concern, it comes with Qt 3.1. It is very old version
> > (...)

Valeri, here is something wrong if you claim that the distribution of SLC3 
or Fedora come with an obsolete version of Qt.
It would be a major burden for installers and users.
On machines where it takes 10 minutes to install ROOT, it takes one hour
to install Qt! I do not even mention the problems with collaborations
who want to have versions of ROOT compiled with gcc2.95, gcc2.96, gcc3.2, 
gcc3.3,etc. You need the corresponding version of Qt!
When you say that Qt3.1 is obsolete, do you mean that the ROOT-QT 
interface will have problems with this version?
If the answer is yes, could you then make sure that this interface can 
work qith 3.1?

> I guess, the binary ROOT distribution should use the Qt version as
> provided by the OS distribution (as of the time the ROOT is compiled,
> assuming that the OS packages have been "upgraded" to the latest state).
> No matter how old it is ...
> If someone does not like it ... and wants to have a newer Qt version ...
> Well, he/she is free to recompile ROOT from scratch ... :-)

Jacek, I fully agree with you.
Otherwise I have to ship the qt libraries with the ROOT distribution.
This would be a non-sense.

> I personally do not need any sophisticated Qt features.
> I just have an application which requires it ... but ... basically from
> the whole application I mainly plan to use one shared library which is NOT
> Qt specific, so ... I need Qt to build everything (and maybe run the main
> application from time to time), but after the root file is created, I plan
> to use the "standard" root to analyze it ...
> (And considering that I will also need to use this library in a Geant4
> application ... I don't really want to create myself additional problems
> mixing ROOT + Geant4 + OpenGL + Qt ...)
> > Interesting  . . . "emit" is a CPP macro defined by Qt
> >
> > grep emit qobjectdefs.h
> > #define emit                                    // emit signal

As already answered by Fons, this is a bug in Qt. Trolltech should fix 
this bug. Meanwhile undefined "emit" after the inclusion of qtwidget.h

Rene Brun

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