[Development] Allowing event delivery prior to and after QCoreApplication

[Thiago Macieira]

On Wednesday 15 April 2015 08:20:31 Thiago Macieira wrote:
> Thanks André. The above contains two use-cases for overriding notify():
> 
> 1) catching exceptions, logging and resuming work
> 2) debugging / inspecting events
> 

So far, given the responses in the interest mailing list, it appears that 
applications would break imperceptibly for notify() no longer being called in 
the auxiliary threads. Therefore, I'm redesigning the solution. I'm proposing 
then the following:

1) deprecate use of notify() in auxiliary threads, with the functionality 
getting removed in Qt 6 (this is a documentation change only)

2) add a way for threads to individually enable delivery past the 
QCoreApplication's lifetime, which implies notify() is skipped. I will add 
this as a private API only.

3) add new mechanisms for filtering and logging events

4) add a mechanism to catch, log and gracefully act on exceptions thrown from 
event handlers and slots

5) after 3 and 4 are in, deprecate overriding of notify() altogether, with the 
possibility removed altogether in Qt 6.

Since I only need 1 & 2 for my needs, I will not implement 3-5 any time soon 
(or ever). Exercise left to the reader.

-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center