[Qt-creator] Custom widget not showing in Qt Designer on Linux

[Robert Wood]

Hi Friedemann,

Many thanks for that. It actually throws up questions!

Originally Creator was saying it couldn't find Qt Designer, so I
installed it [designer] from my (Mandriva) repositories and that works 
fine other than with the customer widget. So, I wondered whether it was 
this issue with different builds.

To be on the safe side I downloaded the latest sdk from the website and
have installed that, while uninstalling designer from the Mandriva 
repositories.

With 2010.02 sdk installed, once again, I cannot launch designer from 
creator. (By right clicking on the .ui file in the project explorer.) If 
I reinstall designer from my repositories I guess I will be able to. 
Creator just tells me:

'The application "Qt Designer" could not be found'.

I have put:

/opt/qtsdk-2010.02/qt/bin

in my PATH as that seems to be where designer lives. (I didn't 
previously realise it was in the sdk.)

If I try and launch designer from the command line I get this error:

makekdewidgets(12371)/kdecore (KSycoca) KSycocaPrivate::openDatabase: 
Trying to open ksycoca from  "/var/tmp/kdecache-robertw/ksycoca4"
designer: symbol lookup error: 
/usr/lib/kde4/plugins/phonon_backend/phonon_gstreamer.so: undefined 
symbol: _ZN6Phonon12PulseSupport11getInstanceEv

Is there something I am missing here or is designer broken on Linux with 
2010.02?

Thanks again,

Rob


Friedemann Kleint wrote:
> Hi,
> 
> here is an extract from the documentation we are planning to add to shed some 
> light onto the Qt Designer plugin issue. I hope it helps:
> 
> "...You can use Qt APIs to create plugins that extend Qt Designer. Qt Designer 
> fetches plugins from the standard locations and loads the plugins that match 
> its build key. For more information on how to create and locate plugins and to 
> change the default plugin path, see {How to Create Qt Plugins}.
> 
> Qt Designer is integrated into  Qt Creator and in addition comes as a 
> standalone application. The correct folder to place the plugins depends on 
> which you use. The integrated Qt Designer fetches plugins from the 
> %SDK%\bin\designer folder on Windows and Linux and 
> QtCreator.app/Contents/MacOS/designer folder on Mac. Choose Tools > Form 
> Editor > About Qt Designer Plugins.
> 
> The standalone Qt Designer is part of the Qt library used for building 
> projects, located under %SDK%/qt. Therefore, it fetches plugins from the 
> following folder: %SDK%\qt\plugins\designer. To check which plugins where 
> loaded successfully and which failed, choose Help > About Plugins in the Qt 
> Creator.
> 
> The Qt Creator that is included in pre-built SDK packages on Windows is built 
> with the Microsoft Visual Studio compiler, whereas the version of Qt shipped 
> for building applications is configured and built to use the MinGW/g++ 
> compiler. Plugins built by using this version of Qt cannot be loaded by Qt 
> Creator because the build-keys do not match. The plugins can only be used in 
> the standalone version of Qt Designer. Choose Help > About Qt Creator to check 
> the Qt version Qt Creator was built with.
> 
> If you want to use Qt Designer plugins that were built for the shipped Qt 
> version, you need to make sure that Qt Creator is built with the same compiler 
> by either recompiling Qt Creator using MinGW or recompiling Qt with Microsoft 
> Visual Studio, depending on which configuration you want to use for your 
> applications."
> 
> Regards,
> Friedemann