[Interest] Crash in iOS 12 when Accessibility is ON

maitai maitai at virtual-winds.org
Fri Oct 26 09:00:58 CEST 2018


Hello,

There has been already 2 bug reports for that (QTBUG-70909 and 
QTBUG-70683), but it is not yet fixed and I am looking for a workaround, 
since lot of my users are complaining.

To make a long story short, iOS 12 is crashing in UIAccessibility 
_axuiElementForNotificationData when for instance Speak Screen is ON. 
This is because Qt doesn't check that the list of Accessibility items is 
empty, as I understood.

A workaround has been proposed, which consists in putting a non empty 
title to the main window. That is indeed OK for a QML application, but 
our app is still pure QWidget-based. Putting a title in MainWindow duly 
fixed the crash at startup, but now it only crashes later, whenever the 
user triggers a QAction from a QMenu. It crashes at the same place in 
UIAccessibility.

I have tried many things with no success, including:
- Add some setAccessibilityName etc in some relevant objects,
- In qappdelegate settings some flags supposed to ignore Accessibility, 
such as [aView setIsAccessibilityElement:NO]; and [aView 
accessibilityElementsHidden:YES];
- I even tried to override some QIOS functions but did not succeed.

Someone suggested to just add a dummy Accessibility item, so the list 
won't be empty. I have no idea how to do that.

I have of course tried 5.9.7 and 5.11.2, no luck.

If someone has some advices or ideas...

Thanks
Philippe Lelong



More information about the Interest mailing list