[QGIS-Developer] Catch qgis exit

[Nyall Dawson]

On Mon, 29 Jun 2020 at 14:39, Jan Růžička <jan.ruzicka.vsb at gmail.com> wrote:
>
> Thank you. As you wrote, the problem is that this works only for the Widged of the plugin. There is not a way to override the closeEvent() method of the main QGIS Window from the plugin, since the plugin has only an interface given by the QGIS.
>
> I have decided to use the workaround for now, so when the QGIS is closed it will start again. The solution is not so perfect, but at least it is a solution.
>
> Another way to do this is to rewrite C++ code. The code is not so complicated and I can rewrite it, but then I have to build QGIS for all police stations and keep it updated and it is not so simple for me.

Not sure how to intercept the quit action cleanly, but you can
intercept the "X" button click:

class NoClose(QObject):

    def __init__(self, parent=None):
        super().__init__(parent)

    def ok_to_close(self):
        return False

    def eventFilter(self, object, event):
        if isinstance(event, QCloseEvent):
            if not self.ok_to_close():
                event.ignore()
                return True

        return super().eventFilter( object, event )

no_close = NoClose()
iface.mainWindow().installEventFilter(no_close)




>
> Thank you again
>
> Jan Růžička, Ph.D.
> freelancer, researcher and volontaire
> Geoinformatics
> tel: +420 775 032 091
> e-mail: jan.ruzicka.vsb at gmail.com
> http://github.com/ruz76/
> http://gismentors.eu/
> http://dolnilhota.info/
>
>
> Le ven. 26 juin 2020 à 09:09, Ujaval Gandhi <ujaval at spatialthoughts.com> a écrit :
>>
>> The way to achieve this would be to override the closeEvent() method of the main QGIs Window. I don't know how to do that. But you can do that on your plugin widget - which will at least prevent that dialog to be closed if certain conditions are not met.
>>
>>     def closeEvent(self, event):
>>       if condition:
>>         event.accept()
>>       else:
>>         event.ignore()
>> Ujaval Gandhi
>> Spatial Thoughts
>> mobile: +91-8095684687
>> email: ujaval at spatialthoughts.com
>>
>> Subscribe to our newsletter http://bit.ly/spatialthoughts-newsletter
>>
>>
>>
>> On Fri, Jun 26, 2020 at 10:02 AM Jan Růžička <jan.ruzicka.vsb at gmail.com> wrote:
>>>
>>> Thank you very much, the same is possible in the unload method of the plugin, but the question is how to stop QGIS to exit.
>>> I need to inform the user that he did not enter the result of the search and keep QGIS open for the user to enter the result.
>>>
>>> The possible workaround may be, to run the QGIS again, when it quits, but I thought that there may be some better way.
>>>
>>> Jan Růžička, Ph.D.
>>> freelancer, researcher and volontaire
>>> Geoinformatics
>>> tel: +420 775 032 091
>>> e-mail: jan.ruzicka.vsb at gmail.com
>>> http://github.com/ruz76/
>>> http://gismentors.eu/
>>> http://dolnilhota.info/
>>>
>>>
>>> Le jeu. 25 juin 2020 à 17:25, Ujaval Gandhi <ujaval at spatialthoughts.com> a écrit :
>>>>
>>>> I saw that there is a aboutToQuit signal emitted just before a QApplication exists. The following works from QGIS Python Console.
>>>>
>>>> def test():
>>>>     with open('/tmp/test.txt', 'w') as f:
>>>>         f.write('wrote while exiting')
>>>>
>>>> qApp.aboutToQuit.connect(test)
>>>> Ujaval Gandhi
>>>> Spatial Thoughts
>>>> mobile: +91-8095684687
>>>> email: ujaval at spatialthoughts.com
>>>>
>>>> Subscribe to our newsletter http://bit.ly/spatialthoughts-newsletter
>>>>
>>>>
>>>>
>>>> On Thu, Jun 25, 2020 at 5:00 PM Jan Růžička <jan.ruzicka.vsb at gmail.com> wrote:
>>>>>
>>>>> Dear developers,
>>>>>
>>>>> I have developed a plugin for the Police of the Czech Republic for Search and Rescue operations. It works quite well, but one important feature is missing.
>>>>>
>>>>> After the search event is finished the user should enter the result of the search.
>>>>>
>>>>> I was not able to find a way to catch an event when the user closes the whole QGIS. I need similar functionality like when closing in the case of a dirty project (no all changes were saved).
>>>>>
>>>>> I have searched a lot and did not find any solution. I was able to catch the unload event of the plugin, but I did not find a way to keep QGIS opened.
>>>>>
>>>>> Any help appreciated
>>>>> Jan Růžička, Ph.D.
>>>>> freelancer, researcher and volontaire
>>>>> Geoinformatics
>>>>> tel: +420 775 032 091
>>>>> e-mail: jan.ruzicka.vsb at gmail.com
>>>>> http://github.com/ruz76/
>>>>> http://gismentors.eu/
>>>>> http://dolnilhota.info/
>>>>> _______________________________________________
>>>>> QGIS-Developer mailing list
>>>>> QGIS-Developer at lists.osgeo.org
>>>>> List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer
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>
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