Focus transmission rejecting

pr1321

I would like to reject the focus transfer from one widget to another input widget when the data is invalid.
I tried to process focusOutEvent, but at the same time I can "return" the focus, but not prohibit its transmission.

I am using qt 4.8.6.

Is it possible?

Thanks.

SGaist

Hi,

Wouldn't it be simpler to disable whatever cannot be accessed while the prior data are invalid ?

pr1321

I solved the problem by processing the KeyPressEvent for Key_Tab and Key_BackTab in the event filter and overriding the focusNextPrevChild method of the parent widget.

bool EditorGroup::eventFilter(QObject * obj, QEvent * event )
{
    ReportableBase * editor = dynamic_cast<ReportableBase *>(obj);
    if ( event->type() == QEvent::KeyPress )
    {
        QKeyEvent * keyEvent = static_cast<QKeyEvent *>(event);
        if( editor )
        {
            if( keyEvent->key() == Qt::Key_Return ||
                    keyEvent->key() == Qt::Key_Tab )
            {
                focusNextChild();
                return true;
            }
            else if ( keyEvent->key() == Qt::Key_Backtab )
            {
                focusPrev();
            }
        }
    }
    else if ( event->type() == QEvent::FocusIn )
    {
        if(editor)
        {
            focusWgt = editor->toWidget();
        }
    }
    return false;
}

bool EditorGroup::focusNextPrevChild( bool next )
{
    ReportableBase * editor = dynamic_cast<ReportableBase *>( focusWgt );
    if(editor)
    {
        QString message;
        if(editor->isDataValid(message))
        {
            ReportableBase * nextEditor = 0;
            while (nextEditor == 0)
            {
                focusWgt = next ?
                            focusWgt->nextInFocusChain() :
                            focusWgt->previousInFocusChain();
                nextEditor = dynamic_cast<ReportableBase *>(focusWgt);
            }
            focusWgt->setFocus( next ?
                                    Qt::TabFocusReason :
                                    Qt::BacktabFocusReason );
            return true;
        }
        else
        {
            editor->report_warning(message);
        }
    }
    return false;
}