How to know if the events are generated by application or Qt
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Hello all,
bool MyClass:event( QEvent * event ) { qDebug() << "Event type: " << event->type(); return QWidget::event(event); }With the above code snippet, I can understand the type of event. Is there a way that I can know if the event is generated by Qt or by the application?
Thanks!
--Kumar
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Hello all,
bool MyClass:event( QEvent * event ) { qDebug() << "Event type: " << event->type(); return QWidget::event(event); }With the above code snippet, I can understand the type of event. Is there a way that I can know if the event is generated by Qt or by the application?
Thanks!
@kumararajas What are you trying to do in general? Are you going to hook into the main even loop to filter out some events you send from somewhere else?
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Nope, just want to understand how to differentiate between the events that are generated by Qt vs by the application.
Reason is not clear, but I can make decisions accordingly, if needed.
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Nope, just want to understand how to differentiate between the events that are generated by Qt vs by the application.
Reason is not clear, but I can make decisions accordingly, if needed.
@kumararajas Ok, my advice is not to do this and use an independent road to a) save resources and b) have clearer design.
That being said, since QEvent has a virtual dtor, it is save to inherit from it. That way you simple try to dynamic_cast it to your custom type. If the casting is not successful, then it is simply not you custom type and you simply return.
Untested:
class MyBigEvent : public QEvent
{
int importantInt;
}Your object dealing with it:
bool MainWindow::eventFilter(QObject *obj, QEvent *event)
{
MyBigEvent * p dynamic_cast< MyBigEvent * >( event );if( not p )
return QObject::eventFilter(obj, event); // give your parent a chance to deal with it// do cool stuff with your event here
return true;
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@kumararajas Ok, my advice is not to do this and use an independent road to a) save resources and b) have clearer design.
That being said, since QEvent has a virtual dtor, it is save to inherit from it. That way you simple try to dynamic_cast it to your custom type. If the casting is not successful, then it is simply not you custom type and you simply return.
Untested:
class MyBigEvent : public QEvent
{
int importantInt;
}Your object dealing with it:
bool MainWindow::eventFilter(QObject *obj, QEvent *event)
{
MyBigEvent * p dynamic_cast< MyBigEvent * >( event );if( not p )
return QObject::eventFilter(obj, event); // give your parent a chance to deal with it// do cool stuff with your event here
return true;
@c64zottel Okay, cool, Thanks for the thoughts! :)
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Hello all,
bool MyClass:event( QEvent * event ) { qDebug() << "Event type: " << event->type(); return QWidget::event(event); }With the above code snippet, I can understand the type of event. Is there a way that I can know if the event is generated by Qt or by the application?
Thanks!
@kumararajas said in How to know if the events are generated by application or Qt:
Is there a way that I can know if the event is generated by Qt or by the application?
Not really, no. You can "know" if the event originated from the window manager/OS (i.e. outside of Qt or your app) by querying if the event's spontaneous - QEvent::spontaneous.
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@kumararajas said in How to know if the events are generated by application or Qt:
Is there a way that I can know if the event is generated by Qt or by the application?
Not really, no. You can "know" if the event originated from the window manager/OS (i.e. outside of Qt or your app) by querying if the event's spontaneous - QEvent::spontaneous.
@kshegunov This is a cool stuff! I like it. This answers me and solves my problem technically! Thank you! I can try out and keep you posted with the results. The outcome should be good as per the feel!
