How to create a tableview (5.12 )with column headers?

I am creating a Table using the new qml tableview (Qt 5.12). I am able to create a model in C++ and able to populate the model in tabular format along with scrollbar.How do I add column headers to this table? Code:

import QtQuick 2.12
import QtQuick.Controls 2.5
import Qt.labs.qmlmodels 1.0
//import QtQuick.Controls.Styles 1.4
import TableModel 0.1
Rectangle {
    id:table
    border.width: 3
    border.color: 'dark blue'
    QtObject{
        id:internals
        property int rows:0
        property int col:0
        property int colwidth:0
        property var columnName:[]
    }

    function setRows(num){ internals.rows = num}
    function setCols(num){ internals.col =  num}
    function setColWidth(num){internals.colwidth = num}

    function setColNames(stringlist){
        if(stringlist.length > 1)
            internals.col = stringlist.length

    dataModel.setColumnName(stringlist);
    }

    function addRowData(stringlist){
        var len = stringlist.length

         if(len >0)
         {
             dataModel.addData(stringlist)
         }
    }

    TableModel {
        id:dataModel
    }

    TableView{
            id:tbl
            anchors.top: headerCell
            anchors.fill: parent
            //columnSpacing: 1
            //rowSpacing: 1
            clip: true

           ScrollBar.horizontal: ScrollBar{}
           ScrollBar.vertical: ScrollBar{}

            model:dataModel

            Component{
                id:datacell
                Rectangle {
                    implicitWidth: 100
                    implicitHeight: 20
                    color: 'white'
                    border.width: 1
                    border.color: 'dark grey'
                    Text {
                        id:txtbox
                        anchors.fill: parent
                        wrapMode:                           Text.NoWrap
                        clip:                               true
                        verticalAlignment:                  Text.AlignVCenter
                        horizontalAlignment:                Text.AlignHCenter
                        text: display
                    }
                }
            }

        }

        function init(){
            console.log("Calling init")
            tbl.delegate= datacell
        }

}

Solution

Currently TableView does not have headers so you should create it, in this case use Row, Column and Repeater.

On the other hand you must implement the headerData method and you must do it Q_INVOKABLE.

class TableModel : public QAbstractTableModel
{
    Q_OBJECT

public:
    // ...
    Q_INVOKABLE QVariant headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const override;
    // ...

TableView {
    id: tableView
    model: table_model
    // ...
    Row {
        id: columnsHeader
        y: tableView.contentY
        z: 2
        Repeater {
            model: tableView.columns > 0 ? tableView.columns : 1
            Label {
                width: tableView.columnWidthProvider(modelData)
                height: 35
                text: table_model.headerData(modelData, Qt.Horizontal)
                color: '#aaaaaa'
                font.pixelSize: 15
                padding: 10
                verticalAlignment: Text.AlignVCenter

                background: Rectangle { color: "#333333" }
            }
        }
    }
    Column {
        id: rowsHeader
        x: tableView.contentX
        z: 2
        Repeater {
            model: tableView.rows > 0 ? tableView.rows : 1
            Label {
                width: 60
                height: tableView.rowHeightProvider(modelData)
                text: table_model.headerData(modelData, Qt.Vertical)
                color: '#aaaaaa'
                font.pixelSize: 15
                padding: 10
                verticalAlignment: Text.AlignVCenter

                background: Rectangle { color: "#333333" }
            }
        }
    }

The complete example you find here.