bind to model data on other role from item delegate

[Alexander_Lanin]

It seems dataChanged doesnt affect qml in my case. I'm trying to bind a delegate to data from another model role (see code). Is there any workaround? Am I doing it wrong or is this a bug?
My model is a QAbstractListModel.

    TableView
    {
        TableViewColumn
        {
            title: "X"
            role: "x"

            delegate: Rectangle
            {
                // both ways do not update after initial drawing:
                //color: model["y"] ? "red" : "transparent"
                Component.onCompleted: color = Qt.binding(function() { return model["y"] ? "red" : "transparent" })

                Text {
                    text: styleData.value
                    color: styleData.textColor
                    anchors.verticalCenter: parent.verticalCenter
                    elide: styleData.elideMode
                    leftPadding: 1
                    rightPadding: 1
                }
            }
        }

        model: myModel
    }

I've printed some of my dataChanged calls which obviously have no effect in this case. I added trace calls to data() so I'm sure it's not called again.

emit dataChanged(index(0), index(11259), { (int)Roles::y });
emit dataChanged(index(0), index(11259), { (int)Roles::y });
emit dataChanged(index(0), index(11259), { (int)Roles::y });