[Qt-interest] Asynchronous quitting of Symbian application

[Bo Elmgreen]

Hi all,

Well, I have now tried out different suggestions, but unfortunately none 
of them worked for me. I tried to listen to the QWidget::closeEvent(), 
but as far as I have been able to find out, this one is only called if 
the user presses the default exit (right) soft key. As I have set up my 
own action for the right soft key, closeEvent() is not called. And when 
the application is closed from the task manager, closeEvent() is not 
supposed to be called at all, as the "UI has already been torn down by 
the UI framework", see: 
http://qt.gitorious.org/qt-labs/nacl/commit/8aec69a/diffs.

Another suggestion was to use the Session Management framework, but as 
far as I can determine, it is not enabled by default on the Symbian 
platform. At least, if you override the appropriate methods in your 
derived QApplication, they are not called when closing the application.

There was a suggestion in the qt.gitorious link above to re-implement 
the platform specific event filter, in order to catch the EEikCmdExit 
command. If I find time, I will give that a try.

Cheers,
Bo

On 27/09/2011 16:49, Bo Elmgreen wrote:
> Hi Pritam,
>
> That indeed looks like what I was searching for. Thanks!
>
> BR,
> Bo
>
> On 27/09/2011 16:22, Pritam Ghanghas wrote:
>> On Tue, 2011-09-27 at 17:16 +0530, Bo Elmgreen wrote:
>>> Hi all,
>>>
>>> I am developing an application for Symbian and I have come across a
>>> problem, where I could use some advice :-)
>>>
>>> My application is divided in two: A (widget-based) UI part and some
>>> "middleware" components, that run in their own (Q)Thread, that
>>> communicate with some servers over a data connection. The communication
>>> between the UI and the middleware is done via signals and slots.
>>>
>>> The problem arises, when it is time to quit the application in a 
>>> special
>>> situation. If the user selects the "Exit" option in the UI, the UI
>>> components can dispose of the middleware and exit the application when
>>> the middleware has signalled that this has completed. But if the
>>> application is closed from the task manager, the application will not
>>> know what is happening before either 1) the main window destructor is
>>> called or 2) it listens to the aboutToQuit signal. But in both cases it
>>> appears as though the application has to quit synchronously, leaving me
>>> with the problem that I cannot wait for the middleware to exit 
>>> properly :-(
>>>
>>> I guess that I am not the only one having this kind of design, so 
>>> how is
>>> this situation "normally" handled?
>> Look at documentation of QWidget::closeEvent().
>> handle this event and quit when you are ready.
>>
>>> Thanks in advance!
>>>
>>> Best Regards,
>>> Bo
>>>
>>> _______________________________________________
>>> Qt-interest mailing list
>>> Qt-interest at qt.nokia.com
>>> http://lists.qt.nokia.com/mailman/listinfo/qt-interest
>>
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