How installEventFilter and eventFilter works ? why when return true in event filter not load qml ?

[Qt embedded developer]

@Qt-embedded-developer

I want to know why qml not get loaded due to below type of implementation.

calling the below line into class constructor :

pPtr->installEventFilter(this);

And i have written the below function def:

bool Bapplication::eventFilter(QObject *watched, QEvent *event)
{

return true;
}

[JonB]

@Qt-embedded-developer
Although I know nothing about QML, if eventFilter() always returns true then no events are passed are passed to any object. You need to return false (at least sometimes) to let the application see any events, at present it does not. I imagine that stops QML working/loading?

[Qt embedded developer]

@JonB Yes this happening. So it's quite difficult to debug this type of code.

1. Can you give reference to avoid this type of problem in code.

2. i also want to understand that why when pass true at that time it not allow to load qml ? If any reference link is there it will helpful.

3. I also want to know when this type of scenario come to not allow loading of qml. any real time example.

[Christian Ehrlicher]

@Qt-embedded-developer I really wonder what's so hard looking into the documentation ... esp. since you would get an answer much earlier.
RTM: https://doc.qt.io/qt-6/eventsandfilters.html#event-filters