EcmQt4To5Porting

[Stephen Kelly]

David Faure wrote:

> On Wednesday 02 October 2013 14:07:31 Martin Klapetek wrote:
>> There were 2 files recently removed from ECM which broke attica's build,
>> this puts the removed files as local cmake modules.
>> 
>> 
>> Diffs
>> -----
>> 
>>   CMakeLists.txt e0efb9b
>>   cmake/modules/ECMQt4To5Porting.cmake PRE-CREATION
>>   cmake/modules/FindQt5Transitional.cmake PRE-CREATION
> 
> I'm confused. Why have they been removed from ECM?
> (and where was this explained/announced).
> 
> Attica surely isn't the only module which is going to want to build with
> both Qt4 and Qt5, right?

Right. I copied them into the kdelibs repo, so anything using that can make 
use of them.

They're not a long term solution because they're so catch-all. 
QT_QTCORE_LIBRARIES contains the QtConcurrent library also, etc. 

They're only a temporary solution so that you don't have to change eg 
qt4_wrap_ui to qt5_wrap_ui before trying to build your c++ code. I don't 
think they should be maintained/supported long-term. I was considering 
adding EcmQt4To5Porting to Qt as a documentation page, which doesn't need to 
maintain compatibility.

> Or if there's a better way to do this, shouldn't attica be ported to the
> better way, before other modules copy these files too?

The better way is:

* Start with a Qt4 based repo
* Add the files
* Make whatever changes needed to port the c++ code to Qt 5
* Port away from the files (eg s/qt4_wrap_ui/qt5_wrap_ui/ )
* Remove the files

Thanks,

Steve.