Qt QML TableView Header not displaying [duplicate] - c++

Question

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
}
}

Answer 1

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.

Answer 2

If you're using Qt 5.15, you can use a HorizontalHeaderView for column labels.
https://doc.qt.io/qt-5/qml-qtquick-controls2-horizontalheaderview.html
There's also VerticalHeaderView for row labeling.
https://doc.qt.io/qt-5/qml-qtquick-controls2-verticalheaderview.html

Answer 3

I'm new to the QML. I came to the answer of eyllanesc so many times through my struggle with the new TableView (qt 5.12+), so I wanna thank you and share what helped me even more.
It's this video:
Shawn Rutledge - TableView and DelegateChooser: new in Qt 5.12
part of Qt Virtual Tech Summit 2019
The discussed code
It's a bit long but he covers
the differences between old and new TableView
how to create universal model for the views
resizable headers
different representation per column type - DelegateChooser
sortable columns
column reorder