QStringListModel, AccessibleTextRole and NVDA (Braille Displays and Speech)

trumpton

I have an application with a ListView, which uses a QStringListModel to store / manage the data, and am using the application on a Windows PC, using NVDA screen reader with a braille display.

The entries in the ListView contain dates and times, e.g. "Sun 14 Aug 12:30", and I'd like to see the same text as on the screen displayed on the braille display, and a more understandable version spoken, e.g. "Sunday the 14th August, twelve thirty pm".

I realised that if the QStringListModel is overridden, I can add responses for additional roles, and have managed to add a response for the Qt::AccessibleTextRole, which means that the ListView shows one thing on the screen, and speaks another thing - however, the braille display now shows the spoken 'view', rather than the screen view.

**Q: What can I do to have the same output on the screen and Braille display, but override the spoken output?

Q: Is it something I can do with roles in the overridden QStringListModel?**

I've attached my "working" AccessibleStringListModel class - this class shows one thing on the screen (Qt::DisplayRole), but both speaks and displays on the braille display the other (Qt::AccessibleTextRole).

Thanks, Steve

#include "accessiblestringlistmodel.h"

AccessibleStringListModel::AccessibleStringListModel()
{

}


bool AccessibleStringListModel::insertRow(int row, const QModelIndex &parent)
{
    QList<QVariant> newentry ;
    newentry.append(QVariant(""));
    newentry.append(QVariant(""));
    newentry.append(QVariant(""));
    modeldata.insert(row, newentry) ;
    return true ;
}

bool AccessibleStringListModel::setData(const QModelIndex &index, QVariant data, int role)
{
    int row = index.row() ;
    if (row<0 || row>=modeldata.size()) return false ;

    const QList<QVariant>& selected = modeldata.at(row) ;
    switch (role) {

    case Qt::DisplayRole: {
            QVariant& item = (QVariant&)selected.at(0) ;
            item.setValue(data) ;
            emit dataChanged(index, index) ;
            return true ;
        }
        break ;

    case Qt::AccessibleTextRole: {
            QVariant& item = (QVariant&)selected.at(1) ;
            item.setValue(data) ;
            emit dataChanged(index, index) ;
            return true ;
        }
        break ;

    case Qt::UserRole: {
            QVariant& item = (QVariant&)selected.at(2) ;
            item.setValue(data) ;
            emit dataChanged(index, index) ;
            return true ;
        }
        break ;

    default:
        return false ;
        break ;

    }
}

QVariant AccessibleStringListModel::data(const QModelIndex &index, int role) const
{
    int row = index.row() ;
    if (row<0 || row>=modeldata.size()) return QVariant() ;
    const QList<QVariant>& selected = modeldata.at(row) ;
    switch (role){
        case Qt::DisplayRole:
            return selected.at(0) ;
            break ;
        case Qt::AccessibleTextRole:
            return selected.at(1) ;
            break ;
        case Qt::UserRole:
            return selected.at(2) ;
            break ;
        default: return QVariant() ;
    }
}


QModelIndex AccessibleStringListModel::index(int row, int column, const QModelIndex &parent) const
{
    Q_UNUSED(parent) ;
    Q_UNUSED(column) ;
    return createIndex(row, column) ;
}

int AccessibleStringListModel::rowCount(const QModelIndex &parent) const
{
    Q_UNUSED(parent) ;
    return modeldata.size() ;
}

Qt::ItemFlags AccessibleStringListModel::flags(const QModelIndex &index) const
{
    if (!index.isValid()) return 0;
    return Qt::ItemIsEnabled | Qt::ItemIsSelectable;
}

VRonin

I have no way of testing but try setting the string you want spoken out to Qt::AccessibleDescriptionRole and Qt::AccessibleTextRole to the same as Qt::DisplayRole for the braille.

P.S.
AccessibleStringListModel::insertRow is wrong:

You forgot to call beginInsertRows/endInsertRow
insertRow is not virtual, insertRows is. You should override that method instead

trumpton

Thanks for the reply, and for the ps hints!

I did try both the AccessibleTextRole and the AccessibleDescriptionRole, but in each case, the spoken output matches the displayed output.

DisplayRole & AccessibleTextRole:

QListWidget: DisplayRole Text
Braille Display: AccessibleTextRole Text
Spoken: AccessibleTextRole Text

DisplayRole & AccessibleDescriptionRole

QListWidget: DisplayRole Text
Braille Display: DisplayRole Text then AccessibleTextRoleText
Spoken: DisplayRole Text then AccessibleTextRoleText

I am beginning to think that it is not possible to differentiate these accessible string outputs within Qt - is that right?

Steve

SGaist

Hi and welcome to devnet,

To have a definite answer, you should bring your question to the interest mailing list. The developers behind the accessibility features are there. This is more a user forum.