how to color a cell in a QTableView

[venomj]

just overide the data function in your model, it looks like this

QVariant MyTestModel::data(const QModelIndex &index, int role) const
{
    switch(role)
    {
    case Qt::DisplayRole:
        return QVariant(QString(tr("%1")).arg((index.column() + 1) * 1000 + index.row() + 1));
    case Qt::BackgroundRole:
        switch(index.column() % 3)
        {
        case 0:
            return QVariant(QColor(Qt::red));
        case 1:
            return QVariant(QColor(Qt::green));
        case 2:
            return QVariant(QColor(Qt::blue));
        default://only to disable warning
            return QVariant(QColor(Qt::white));
        }
 
        break;
    default:
        return QVariant();
    }
}

QVariant MyTestModel::data(const QModelIndex &index, int role) const
{
    switch(role)
    {
    case Qt::DisplayRole:
        return QVariant(QString(tr("%1")).arg((index.column() + 1) * 1000 + index.row() + 1));
    case Qt::BackgroundRole:
        switch(index.column() % 3)
        {
        case 0:
            return QVariant(QColor(Qt::red));
        case 1:
            return QVariant(QColor(Qt::green));
        case 2:
            return QVariant(QColor(Qt::blue));
        default://only to disable warning
            return QVariant(QColor(Qt::white));
        }

        break;
    default:
        return QVariant();
    }
}

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the BackgroundRole for the item's background color
the ForegroundRole for the text color

[SykeS]

Reassuming:

How to set font-color to red if value in specified cell is for example not in specified range (int)?

[pilpi]

Just a sidenote - from a usability point of view, in a majority of cases you probably don't want to paint the entire background.

Screenshot: 2015-09-09 13_37_16-voima - Forceproof Analyst.png

In many cases, using a Qt:: DecorationRole is more aesthetic and less obtrusive than filling the entire cell background. The text is still readable; you don't have to think about the contrast between changed foreground and background colours, since DecorationRole only paints a small rectangle of the color you selected, inside the cell.

QVariant MyModel::data(const QModelIndex &index, int role) const
{
        int column=index.column();
        if((role==Qt::DecorationRole)){
            if(column==firstVisibleColumnIndex){
                // figure out correct color for current row here
                return QColor(100,255,255);
            }
         }
}

QVariant MyModel::data(const QModelIndex &index, int role) const
{
        int column=index.column();
        if((role==Qt::DecorationRole)){
            if(column==firstVisibleColumnIndex){
                // figure out correct color for current row here
                return QColor(100,255,255);
            }
         }
}

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