Accessibility problems



  • Hello everyone!

    I have some problems with the Qt Accessibility API, maybe some of you can help me with them.

    So first of all, my main problem is that I can't seem to be able to get any new feedback from the screen reader when calling the QAccessbile::updateAccessbility static method.

    For example, I have a Custom class that inherits QSlider and I'm updating the value of the slider. Shouldn't this code make the screen-reader tell the new value of the slider?
    @
    this->setValue(value()+10);
    QAccessibleValueChangeEvent event(this, value());
    QAccessible::updateAccessibility(&event);
    @
    Am I doing something wrong here?

    Other questions:

    1. Must a widget have focus when QAccessible::updateAccessibility method is called?
    2. If the answer to the previous question is yes, how can I make the screen-reader see the informations for QObjets since they can't get focus?
    3. Is there a way to send a string to the screen-reader and say something like "read this"?

    Thank you!
    Andrei


  • Lifetime Qt Champion

    Hi,

    Disclaimer: I'm no specialist in this field. There's currently work done to improve accessibility support, have a look at Qt's mailing list on the subject.

    AFAIK, QSlider should already be accessible aware, so I wonder if you really need to add that code. Anyway, something looks wrong here:

    @QAccessibleValueChangeEvent event(this, value());@

    None of the constructors take a value as a parameter.

    By the way, which version of Qt and on which OS are you working ?



  • Hello, SGaist! Thanks for your reply!

    I'm running Qt 5.3 on Windows 7.

    I know that there is still work being done, but I don't know what is finished and what isn't. I already tried the Accessibility mailing list, but nobody answered... After creating this post I also sent a bug report, because I've tried this for over a week now. I've uploaded the whole testing project there.
    https://bugreports.qt-project.org/browse/QTBUG-40313

    Yes, the QSlider already has accessibility implemented already, but this is just a project for testing. In the project that I'm supposed to add support for accessibility there are a lot of custom classes, that should have custom behavior, that's why I'm trying to implement this myself.

    The QAccessibleChangeEvent, has a QVariant as a second parameter. Isn't that the way to create it? I have to say that I don't understand completly how QVariant works, but I also tried instantiating other kinds of events that don't have it and don't work either.

    What I'm really interesed in telling the screen-reader that the accessibility informations have changed and I want it to read them. For example if I put a message in the status bar, I want it to read that message.

    Andrei


  • Lifetime Qt Champion

    QAccessibleChangeEvent ?



  • No such event...

    There is however the QAccessibleEvent(QObject o, QAccessible::Event)
    where I can set the Event type to anything I want. The code that I gave is just an example. I don't receive any update, no matter what type of event I'm using.

    But does the QAccessibleValueChangeEvent do anything for you? Or for that matter calling the QAccessible::updateAccessibility method? Does the screen-reader tell you anything new?

    Thank you!
    Andrei


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