Table model question

Perdrix

I have a table model which has many columns of data. Some to them display differently depending on the setting of a variables in a class/struct stored in mydata (a vector).

So, my data mf has code that looks like:

            case Column::dXCol:
                if (mydata[row].m_PictureType != PICTURETYPE_LIGHTFRAME)
                    return QString("N/A");
                else
                {
                    if (mydata[row].m_bDeltaComputed)
                        return QString("%1").arg(mydata[row].m_dX, 0, 'f', 2);
                    else
                        return QString("NC");
                };
                break;
            case Column::dYCol:
                if (mydata[row].m_PictureType != PICTURETYPE_LIGHTFRAME)
                    return QString("N/A");
                else
                {
                    if (mydata[row].m_bDeltaComputed)
                        return QString("%1").arg(mydata[row].m_dY, 0, 'f', 2);
                    else
                        return QString("NC");
                };
                break;
            case Column::AngleCol:
                if (mydata[row].m_PictureType != PICTURETYPE_LIGHTFRAME)
                    return QString("N/A");
                else
                {
                    if (mydata[row].m_bDeltaComputed)
                        return QString("%1 °").arg(mydata[row].m_fAngle * 180.0 / M_PI, 0, 'f', 2);
                    else
                        return QString("NC");
                };
                break;

So, if m_bDeltaComputed is changed, the display of a number of columns needs to be refreshed.

What's the best way to handle this?

I thought of adding a mf that tells the TableView that ALL the model data has changed which I think should look like:

        int rowCount(const QModelIndex& parent) const
        {
            // Return number of images we know about
            return static_cast<int>(mydata.size());
        };

        int columnCount(const QModelIndex& parent) const
        {
            // Pretty simple really
            return static_cast<int>(Column::MAX_COLS);
        };
       void emitAllChanged()
        {
            QModelIndex start{ QAbstractItemModel::createIndex(0, 0)};
            QModelIndex end{ QAbstractItemModel::createIndex(rowCount(start), columnCount(start)) };
            emit dataChanged(start, end);
        }

Would that heavy handed approach work (and did I even code it correctly)?

Is there a better approach?

Many thanks
David

SGaist

Hi,

Depending on the size of your model you should rather sequentially send the dataChanged signal for the concerned columns.