How could I insert The row with multiple column in Qml - c++

Question

I am trying to prepare a tree Model and I have done this:
treemodel.h
#include <QStandardItemModel>
class TreeModel : public QStandardItemModel
{
Q_OBJECT
public:
TreeModel( QObject *parent = nullptr );
private:
QVector<TreeModel *> child_items;
TreeModel* parent_item;
static const int DisplayName;
static const int DisplayInfo;
static const int DisplayId;
};
treemodel.cpp
#include "treemodel.h"
#include <QStandardItemModel>
#include <QStandardItem>
#include <QAbstractItemModel>
#include <QString>
#include <QTreeView>
#include <iostream>
#include <QList>
#include <QModelIndex>
const int TreeModel::DisplayName = Qt::UserRole+1;
const int TreeModel::DisplayInfo = Qt::UserRole+2;
const int TreeModel::DisplayId = Qt::UserRole+3;
TreeModel::TreeModel( QObject *parent ) : QStandardItemModel(parent)
{
QStandardItem *parentItem = this->invisibleRootItem();
QHash<int, QByteArray> roles = roleNames();
roles.insert(DisplayName, "A");
roles.insert(DisplayInfo, "B");
roles.insert(DisplayId, "C");
setItemRoleNames(roles);
QStandardItem *c1 = new QStandardItem;
c1->setData("Sudip", DisplayName);
QStandardItem *c2 = new QStandardItem;
c2->setData("Ghimire", DisplayInfo);
QStandardItem *c3 = new QStandardItem;
c3->setData("Bahadur", DisplayId);
QList<QStandardItem *> r1 { c1, c2, c3};
parentItem->insertRow(0, r1);
}
main.qml
import QtQuick 2.12
import QtQuick.Controls 2.5
import QtQuick.Controls 1.4
import QtQuick.Controls 2.0
import QtQuick.Layouts 1.3
import QtQuick.Window 2.12
import QtQuick 2.0
Window {
visible: true
width: 640
height: 480
title: qsTr("Tree View Example")
id: root
TreeView{
id: tree_view
model: TreeModel
Layout.fillHeight: true
Layout.fillWidth: true
width: root.width
height: root.height
sortIndicatorVisible: true
alternatingRowColors: false
backgroundVisible: false
TableViewColumn{
role: "A"
title: "Elements"
width: 300
}
TableViewColumn{
role: "B"
title: "more"
width: 300
}
TableViewColumn{
role: "C"
title: "I am some title"
width: 300
}
/*
MouseArea{
anchors.fill: tree_view
hoverEnabled: true
onHoveredChanged: function(){
}
}
*/
}
}
main.cpp
QQmlApplicationEngine engine;
TreeModel t_model;
engine.rootContext()->setContextProperty("TreeModel", &t_model);
But the reasult is
But I want to fill all column by a row. I think appendRow in treemodel.cpp should have done the wok. But its wired.

Answer 1

This is because ur model doesn't know how to deal with your custom user role when QStandardItemModel::data() called to bind value in QML. So what you have to do is, override the data() function your TreeModel class and return the data for ur custom roles. You should add below code to ur TreeModel class.
QVariant TreeModel::data(const QModelIndex &index, int role) const
{
QVariant value;
if (index.isValid()) {
if (role <= Qt::UserRole) {
value = QStandardItemModel::data(index, role);
}
else if(role == DisplayName)
{
value = QStandardItemModel::data(index, DisplayName);
}
else if(role == DisplayInfo)
{
int columnIdx = role - Qt::UserRole - 1;
QModelIndex modelIndex = this->index(index.row(), columnIdx);
value = QStandardItemModel::data(modelIndex, DisplayInfo);
}
else if(role == DisplayId)
{
int columnIdx = role - Qt::UserRole - 1;
QModelIndex modelIndex = this->index(index.row(), columnIdx);
value = QStandardItemModel::data(modelIndex, DisplayId);
}
else
{
// undefined role.
}
}
return value;
}