How to Insert checkbox in root of Qtreeview. Treeview is created by using QDOMDocument reading XML file.

[Aviral 0]

DomModel.cpp

#include "DomModel.h"
#include "DOMItem.h"
#include "mainwindow.h"
#include <QtXml>
#include<QCheckBox>

//! [0]
DomModel::DomModel(const QDomDocument &document, QObject *parent)
    : QAbstractItemModel(parent),
      domDocument(document),
      rootItem(new DomItem(domDocument, 0))
{
}
//! [0]

//! [1]
DomModel::~DomModel()
{
    delete rootItem;
}
//! [1]

//! [2]
int DomModel::columnCount(const QModelIndex &parent) const
{
    Q_UNUSED(parent);
    return 3;
}
//! [2]

//! [3]
QVariant DomModel::data(const QModelIndex &index, int role) const
{
    if (!index.isValid())
        return QVariant();

    if (role != Qt::DisplayRole)
        return QVariant();

    const DomItem *item = static_cast<DomItem*>(index.internalPointer());

    const QDomNode node = item->node();
//! [3] //! [4]

    switch (index.column()) {
        case 0:
            return node.nodeName();
        case 1:
        {
            const QDomNamedNodeMap attributeMap = node.attributes();
            QStringList attributes;
            for (int i = 0; i < attributeMap.count(); ++i) {
                QDomNode attribute = attributeMap.item(i);
                attributes << attribute.nodeName() + "=\""
                              + attribute.nodeValue() + '"';
            }
            return attributes.join(' ');
        }
        case 2:
            return node.nodeValue().split('\n').join(' ');
        default:
            break;
    }
    return QVariant();
}
//! [4]

//! [5]
Qt::ItemFlags DomModel::flags(const QModelIndex &index) const
{
    if (!index.isValid())
        return Qt::NoItemFlags;

    return QAbstractItemModel::flags(index);
}
//! [5]

//! [6]
QVariant DomModel::headerData(int section, Qt::Orientation orientation,
                              int role) const
{
    if (orientation == Qt::Horizontal && role == Qt::DisplayRole) {
        switch (section) {
            case 0:
                return tr("Name");
            case 1:
                return tr("Attributes");
            case 2:
                return tr("Value");
            default:
                break;
        }
    }
    return QVariant();
}
//! [6]

//! [7]
QModelIndex DomModel::index(int row, int column, const QModelIndex &parent) const
{
    if (!hasIndex(row, column, parent))
        return QModelIndex();

    DomItem *parentItem;

    if (!parent.isValid())
        parentItem = rootItem;
    else
        parentItem = static_cast<DomItem*>(parent.internalPointer());
//! [7]

//! [8]
    DomItem *childItem = parentItem->child(row);
    if (childItem)
        return createIndex(row, column, childItem);
    return QModelIndex();
}
//! [8]

//! [9]
QModelIndex DomModel::parent(const QModelIndex &child) const
{
    if (!child.isValid())
        return QModelIndex();

    DomItem *childItem = static_cast<DomItem*>(child.internalPointer());
    DomItem *parentItem = childItem->parent();

    if (!parentItem || parentItem == rootItem)
        return QModelIndex();

    return createIndex(parentItem->row(), 0, parentItem);
}
//! [9]

//! [10]
int DomModel::rowCount(const QModelIndex &parent) const
{
    if (parent.column() > 0)
        return 0;

    DomItem *parentItem;

    if (!parent.isValid())
        parentItem = rootItem;
    else
        parentItem = static_cast<DomItem*>(parent.internalPointer());

    return parentItem->node().childNodes().count();
}
//! [10]

DomItem.cpp

#include "DOMItem.h"
#include <QtXml>

//! [0]
DomItem::DomItem(const QDomNode &node, int row, DomItem *parent)
    : domNode(node),
//! [0]
      // Record the item's location within its parent.
//! [1]
      parentItem(parent),
      rowNumber(row)
{}
//! [1]

//! [2]
DomItem::~DomItem()
{
    qDeleteAll(childItems);
}
//! [2]

//! [3]
QDomNode DomItem::node() const
{
    return domNode;
}
//! [3]

//! [4]
DomItem *DomItem::parent()
{
    return parentItem;
}
//! [4]

//! [5]
DomItem *DomItem::child(int i)
{
    DomItem *childItem = childItems.value(i);
    if (childItem)
        return childItem;

    // if child does not yet exist, create it
    if (i >= 0 && i < domNode.childNodes().count()) {
        QDomNode childNode = domNode.childNodes().item(i);
        childItem = new DomItem(childNode, i, this);
        childItems[i] = childItem;
    }
    return childItem;
}
//! [5]

//! [6]
int DomItem::row() const
{
    return rowNumber;
}
//! [6]

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

#include "DomModel.h"

#include <QDomDocument>
#include <QTreeView>
#include <QMenuBar>
#include <QFileDialog>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent),
      model(new DomModel(QDomDocument(), this)),
      view(new QTreeView(this))
{
    fileMenu = menuBar()->addMenu(tr("&File"));
    fileMenu->addAction(tr("&Open..."), this, &MainWindow::openFile, QKeySequence::Open);
    fileMenu->addAction(tr("E&xit"), this, &QWidget::close, QKeySequence::Quit);

    view->setModel(model);

    setCentralWidget(view);
    setWindowTitle(tr("QTreeViewXML"));
    setWindowIcon(QIcon("C:\\Users\arpit.k\\Documents\\QT\\build-QTreeViewXML-Desktop_Qt_6_2_4_MinGW_64_bit-Debug\\Accordlogo.png"));
}

void MainWindow::openFile()
{
    QString filePath = QFileDialog::getOpenFileName(this, tr("Open File"),
        xmlPath, tr("XML files (*.xml);;HTML files (*.html);;"
                    "SVG files (*.svg);;User Interface files (*.ui)"));

    if (!filePath.isEmpty()) {
        QFile file(filePath);
        if (file.open(QIODevice::ReadOnly)) {
            QDomDocument document;
            if (document.setContent(&file)) {
                DomModel *newModel = new DomModel(document, this);
                view->setModel(newModel);
                delete model;
                model = newModel;
                xmlPath = filePath;
            }
            file.close();
        }
    }
}

main.cpp

#include "mainwindow.h"

#include <QApplication>


int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    MainWindow window;
    window.resize(640, 480);
    window.show();
    return app.exec();
}

[JonB]

@Aviral-0
Hello and welcome.

Your first task is to change both your DomModel::data() & DomModel::flags() methods to support showing checkable items/checkboxes. The code in https://stackoverflow.com/a/8178567 shows how to do this. You need then to alter that to only return checkable/a checkbox for the root item, e.g. QModelIndex QAbstractItemView::rootIndex() const.

[Aviral 0]

@JonB Thankyou for your solution.
Brother I am very new to coding and I don't think I can modify these code on my own, can you help me and Do this, I know its too much to ask and time consuming. I have to submit it tomorrow. Please brother help me! I would really appreciate your effort.

[Aviral 0]

@JonB I have modified
QVariant TreeModel::data
Qt::ItemFlags TreeModel::flags
But now the Treeview is not showing any content text and checkboxes are also not checkable.

[JonB]

@Aviral-0
Then that would depend on what code you have written....

[Aviral 0]

Hi, I have done this, still not able to make check boxes work and not able to make checkboxes at the root only.

DomItem.cpp

#include "DOMItem.h"
#include<QCheckBox>
#include <QtXml>

//! [0]
DomItem::DomItem(const QDomNode &node, int row, DomItem *parent)
    : domNode(node),
//! [0]
      // Record the item's location within its parent.
//! [1]
      parentItem(parent),
      rowNumber(row)
{}
//! [1]

//! [2]
DomItem::~DomItem()
{
    qDeleteAll(childItems);
}
//! [2]

//! [3]
QDomNode DomItem::node() const
{
    return domNode;
}
//! [3]

//! [4]
DomItem *DomItem::parent()
{
    return parentItem;
}
//! [4]

//! [5]
DomItem *DomItem::child(int i)
{
    DomItem *childItem = childItems.value(i);
    if (childItem)
        return childItem;

    // if child does not yet exist, create it
    if (i >= 0 && i < domNode.childNodes().count()) {
        QDomNode childNode = domNode.childNodes().item(i);
        childItem = new DomItem(childNode, i, this);
        childItems[i] = childItem;
    }
    return childItem;
}
//! [5]

//! [6]
int DomItem::row() const
{
    return rowNumber;
}
//! [6]
QVariant DomItem::data(int column) const
{
    return itemData.value(column);
}

DomModel.cpp

#include "DomModel.h"
#include "DOMItem.h"
//#include "mainwindow.h"
#include <QtXml>
#include<QCheckBox>

//! [0]
DomModel::DomModel(const QDomDocument &document, QObject *parent)
    : QAbstractItemModel(parent),
      domDocument(document),
      rootItem(new DomItem(domDocument, 0))
{
}
//! [0]

//! [1]
DomModel::~DomModel()
{
    delete rootItem;
}
//! [1]

//! [2]
int DomModel::columnCount(const QModelIndex &parent) const
{
    Q_UNUSED(parent);
    return 3;
}
//! [2]

/*/! [3]
QVariant DomModel::data(const QModelIndex &index, int role) const
{
    if (!index.isValid())
        return QVariant();

    if (role != Qt::DisplayRole)
        return QVariant();

    const DomItem *item = static_cast<DomItem*>(index.internalPointer());

    const QDomNode node = item->node();
//! [3] //! [4]

    switch (index.column()) {
        case 0:
            return node.nodeName();
        case 1:
        {
            const QDomNamedNodeMap attributeMap = node.attributes();
            QStringList attributes;
            for (int i = 0; i < attributeMap.count(); ++i) {
                QDomNode attribute = attributeMap.item(i);
                attributes << attribute.nodeName() + "=\""
                              + attribute.nodeValue() + '"';
            }
            return attributes.join(' ');
        }
        case 2:
            return node.nodeValue().split('\n').join(' ');
        default:
            break;
    }
    return QVariant();
}
//! [4] */

QVariant DomModel::data(const QModelIndex &index, int role) const
{
    if (!index.isValid())
        return QVariant();

    DomItem *item = static_cast<DomItem*>(index.internalPointer());
    const QDomNode node = item->node();


    if ( role == Qt::CheckStateRole && index.column() == 0 )
        return static_cast< int >( item->isChecked() ? Qt::Checked : Qt::Unchecked );

    if (role != Qt::DisplayRole)
        return QVariant();

    switch (index.column()) {
        case 0:
            return node.nodeName();
        case 1:
        {
            const QDomNamedNodeMap attributeMap = node.attributes();
            QStringList attributes;
            for (int i = 0; i < attributeMap.count(); ++i) {
                QDomNode attribute = attributeMap.item(i);
                attributes << attribute.nodeName() + "=\""
                              + attribute.nodeValue() + '"';
            }
            return attributes.join(' ');
        }
        case 2:
            return node.nodeValue().split('\n').join(' ');
        default:
            break;
    }
    return item->data(index.column());
}

/*
//! [5]
Qt::ItemFlags DomModel::flags(const QModelIndex &index) const
{
    if (!index.isValid())
        return Qt::NoItemFlags;

    return QAbstractItemModel::flags(index);
}
//! [5]
*/
Qt::ItemFlags DomModel::flags(const QModelIndex &index) const
{
    if (!index.isValid())
        return Qt::NoItemFlags;

    Qt::ItemFlags flags = Qt::ItemIsEnabled | Qt::ItemIsSelectable;

    if ( index.column() == 0 )
        flags |= Qt::ItemIsUserCheckable;

    return flags;
}
//! [6]
QVariant DomModel::headerData(int section, Qt::Orientation orientation,
                              int role) const
{
    if (orientation == Qt::Horizontal && role == Qt::DisplayRole) {
        switch (section) {
            case 0:
                return tr("Name");
            case 1:
                return tr("Attributes");
            case 2:
                return tr("Value");
            default:
                break;
        }
    }
    return QVariant();
}
//! [6]

//! [7]
QModelIndex DomModel::index(int row, int column, const QModelIndex &parent) const
{
    if (!hasIndex(row, column, parent))
        return QModelIndex();

    DomItem *parentItem;

    if (!parent.isValid())
        parentItem = rootItem;
    else
        parentItem = static_cast<DomItem*>(parent.internalPointer());
//! [7]

//! [8]
    DomItem *childItem = parentItem->child(row);
    if (childItem)
        return createIndex(row, column, childItem);
    return QModelIndex();
}
//! [8]

//! [9]
QModelIndex DomModel::parent(const QModelIndex &child) const
{
    if (!child.isValid())
        return QModelIndex();

    DomItem *childItem = static_cast<DomItem*>(child.internalPointer());
    DomItem *parentItem = childItem->parent();

    if (!parentItem || parentItem == rootItem)
        return QModelIndex();

    return createIndex(parentItem->row(), 0, parentItem);
}
//! [9]

//! [10]
int DomModel::rowCount(const QModelIndex &parent) const
{
    if (parent.column() > 0)
        return 0;

    DomItem *parentItem;

    if (!parent.isValid())
        parentItem = rootItem;
    else
        parentItem = static_cast<DomItem*>(parent.internalPointer());

    return parentItem->node().childNodes().count();
}
//! [10]

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

#include "DomModel.h"

#include <QDomDocument>
#include <QTreeView>
#include <QMenuBar>
#include <QFileDialog>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent),
      model(new DomModel(QDomDocument(), this)),
      view(new QTreeView(this))
{
    fileMenu = menuBar()->addMenu(tr("&File"));
    fileMenu->addAction(tr("&Open..."), this, &MainWindow::openFile, QKeySequence::Open);
    fileMenu->addAction(tr("E&xit"), this, &QWidget::close, QKeySequence::Quit);

    view->setModel(model);

    setCentralWidget(view);
    setWindowTitle(tr("QTreeViewXML"));
    setWindowIcon(QIcon("C:\\Users\arpit.k\\Documents\\QT\\build-QTreeViewXML-Desktop_Qt_6_2_4_MinGW_64_bit-Debug\\Accordlogo.png"));
}

void MainWindow::openFile()
{
    QString filePath = QFileDialog::getOpenFileName(this, tr("Open File"),
        xmlPath, tr("XML files (*.xml);;HTML files (*.html);;"
                    "SVG files (*.svg);;User Interface files (*.ui)"));

    if (!filePath.isEmpty()) {
        QFile file(filePath);
        if (file.open(QIODevice::ReadOnly)) {
            QDomDocument document;
            if (document.setContent(&file)) {
                DomModel *newModel = new DomModel(document, this);
                view->setModel(newModel);
                delete model;
                model = newModel;
                xmlPath = filePath;
            }
            file.close();
        }
    }
}

Please help!

[JonB]

@Aviral-0 said in How to Insert checkbox in root of Qtreeview. Treeview is created by using QDOMDocument reading XML file.:

still not able to make check boxes work

What exactly does this mean? Do you get to see any checkboxes? You do but they are not checkable? Or what?

make checkboxes at the root only.

I do not see anything in your data() method, CheckStateRole case, which attempts to only return the checked state for the root item, rather than for all/any item. I suggested you look at QAbstractItemView::rootIndex(), but I don't see that or any equivalent code.

[Aviral 0]

@JonB Yes, the checkbox appeared but not working as check or unchecked.

[JonB]

@Aviral-0
Your DomModel::data() method has correct code to look at item->isChecked() to see whether to show checked/unchecked. But I do not see anywhere in your code which sets any DomItem (or its QDomNode returned by node()) to record that it has been checked. You have to store that somewhere. And if DomModel::data() looks at item->isChecked() for CheckStateRole I think I would expect you to have a corresponding setData() with case for CheckStateRole which calls an item->setChecked().

[Aviral 0]

@JonB Thankyou, using setData() method the items are now checkable.
Just one thing I am not understanding. you said about
QModelIndex QAbstractItemView::rootIndex() const
I am not able to understand how to use it and where to use it.
as on website its not indepth elaboration about it.

[JonB]

@Aviral-0

Qt::ItemFlags DomModel::flags(const QModelIndex &index) const
{
    if ( index.column() == 0 )
        flags |= Qt::ItemIsUserCheckable;

You said, I believe, that you only want a checkbox if it is the root index. You want to know whether index is the root index here. I realize now that QModelIndex QAbstractItemView::rootIndex() const is a method of the QTreeView and not available in model flags code. Is the root index row 0 in the model (I don't know)? So you would need maybe && index.row() == 0?

[Aviral 0]

@JonB Using
&& index.row() == 0
also didn't worked. I think index contains the current item location in tree

[JonB]

@Aviral-0
Your QTreeView has a root index, the one you want a checkbox against, right? How did that get set? You want to know that index in the model code so that you can check for it your data() code, right?

[Aviral 0]

@JonB Sorry Jon, I really didn't understand. I am very new to coding.
In simple terms, yes I need checkbox only at root node.
Should I send you my updated code?

[Aviral 0]

@JonB Please have a look at it.
https://github.com/aviralarpit/QTDomDoc.git

[JonB]

@Aviral-0
class DomModel has QModelIndex rootIndex() const; (though can't see an implementation?) or DomItem *rootItem you can use to identify the root item.

[Aviral 0]

@JonB I tried to use rootIndex() function but didn't understood how to.
Its just declaration.

[JonB]

@Aviral-0 Which is what I thought and why I suggested you try recognising if the item is the rootItem.

[Aviral 0]

@JonB I know its alot to ask, but can you tell me what change should I do specifically to make it work. It will be so nice of you taking your time to help me. Thankyou Brother.

[JonB]

@Aviral-0
I'm not your Brother!

I think you want in flags():

    DomItem *item = static_cast<DomItem*>(index.internalPointer());
    if (item == rootItem)
        flags |= Qt::ItemIsUserCheckable;

to make it so only the root item is checkable.