Qt 5.11 - QML - show XML file in treeView as QAbstractItemModel - c++

Question

I'm trying to show a simple XML file in a QML treeView through the QAbstractItemModel class, but I can't find any decent tutorial on how to do so online. The best I managed to find is a tutorial about how to do it in QWidget, but I want to do it in QML. I tried anyway with all the bits I could find here and there but couldn't even manage to get a tree to show up.
Code compiles, but my model is null. I'm not even sure if I'm actually reading my XML file.
There's very likely a lot of things I am missing or doing wrong. Can anyone help ?
DomItem.h
#ifndef DOMITEM_H
#define DOMITEM_H
#include <QDomNode>
#include <QHash>
class DomItem
{
public:
DomItem(const QDomNode &node, int row, DomItem *parent = nullptr);
~DomItem();
DomItem *child(int i);
DomItem *parent();
QDomNode node() const;
int row() const;
private:
QDomNode domNode;
QHash<int, DomItem *> childItems;
DomItem *parentItem;
int rowNumber;
};
#endif // DOMITEM_H
DomItem.cpp
#include "DomItem.h"
DomItem::DomItem(const QDomNode &node, int row, DomItem *parent)
: domNode(node),
parentItem(parent),
rowNumber(row)
{
}
DomItem::~DomItem()
{
qDeleteAll(childItems);
}
DomItem *DomItem::parent()
{
return parentItem;
}
int DomItem::row() const
{
return rowNumber;
}
QDomNode DomItem::node() const
{
return domNode;
}
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;
}
DomModel.h
#ifndef DOMMODEL_H
#define DOMMODEL_H
#include <QObject>
#include <QModelIndex>
#include <QAbstractItemModel>
#include <QDomDocument>
#include <QFile>
#include "DomItem.h"
class DomModel : public QAbstractItemModel
{
Q_OBJECT
public:
enum DomModelRoles
{
DomModelRoleName = Qt::UserRole + 1,
DomModelRoleAttributes,
DomModelRoleValue
};
explicit DomModel(const QDomDocument &document, QObject *parent = nullptr);
~DomModel();
QVariant data(const QModelIndex &index, int role) const override;
Qt::ItemFlags flags(const QModelIndex &index) const override;
QVariant headerData(int section, Qt::Orientation orientation,
int role = Qt::DisplayRole) const override;
QModelIndex index(int row, int column,
const QModelIndex &parent = QModelIndex()) const override;
QModelIndex parent(const QModelIndex &child) const override;
int rowCount(const QModelIndex &parent = QModelIndex()) const override;
int columnCount(const QModelIndex &parent = QModelIndex()) const override;
void loadXml(QString xmlFilePath);
void reload();
QHash<int, QByteArray> roleNames() const override;
private:
QDomDocument domDocument;
DomItem *rootItem;
QString xmlSource;
};
#endif // DOMMODEL_H
DomModel.cpp
#include "DomModel.h"
DomModel::DomModel(const QDomDocument &document, QObject *parent)
: QAbstractItemModel(parent),
domDocument(document)
{
rootItem = new DomItem(domDocument, 0);
}
DomModel::~DomModel()
{
delete rootItem;
}
int DomModel::columnCount(const QModelIndex &parent) const
{
Q_UNUSED(parent);
return 3;
}
Qt::ItemFlags DomModel::flags(const QModelIndex &index) const
{
if (!index.isValid())
return Qt::NoItemFlags;
return QAbstractItemModel::flags(index);
}
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();
}
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());
DomItem *childItem = parentItem->child(row);
if (childItem)
return createIndex(row, column, childItem);
return QModelIndex();
}
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();
}
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);
}
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();
switch (role)
{
case DomModelRoleName:
return node.nodeName();
case DomModelRoleAttributes:
{
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 DomModelRoleValue:
return node.nodeValue().split('\n').join(' ');
default:
break;
}
return QVariant();
}
void DomModel::loadXml(QString xmlFilePath)
{
xmlFilePath.replace("file:///","");
// on parse le xml de l'environnement
QFile file(xmlFilePath);
if (!file.open(QIODevice::ReadOnly| QFile::Text)){
//QMessageBox::critical(this, "ParserFichierXML", "Error");
}
else{
domDocument.clear();
if (!domDocument.setContent(&file)) {
//QMessageBox::critical(this, "ParserFichierXML", "Error");
}
file.close();
}
reload();
}
void DomModel::reload()
{
beginResetModel();
delete rootItem;
rootItem = new DomItem(domDocument, 0,false);
endResetModel();
}
QHash<int, QByteArray> DomModel::roleNames() const
{
QHash<int, QByteArray> roles;
roles[DomModelRoleName] = "Name";
roles[DomModelRoleAttributes] = "Attributes";
roles[DomModelRoleValue] = "Value";
return roles;
}
main.cpp
#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QDomDocument>
#include <QQmlContext>
#include "DomModel.h"
int main(int argc, char *argv[])
{
#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
#endif
QGuiApplication app(argc, argv);
QQmlApplicationEngine engine;
const QUrl url(QStringLiteral("qrc:/main.qml"));
QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
&app, [url](QObject *obj, const QUrl &objUrl) {
if (!obj && url == objUrl)
QCoreApplication::exit(-1);
}, Qt::QueuedConnection);
QQmlContext *ctx = engine.rootContext();
QFile file("./test.xml");
if (file.open(QIODevice::ReadOnly))
{
QDomDocument document;
if (document.setContent(&file))
{
DomModel *model = new DomModel(document);
ctx->setContextProperty("theModel", model);
}
}
file.close();
engine.load(url);
return app.exec();
}
main.qml
import QtQuick 2.7
import QtQuick.Window 2.2
import QtQuick.Layouts 1.3
import QtQuick.Dialogs 1.2
import QtLocation 5.3
import QtQuick.Controls 1.4
import QtQuick.Controls 2.0
import QtQuick.Controls.Styles 1.4
import QtQml 2.0
Window {
width: 640
height: 480
visible: true
title: qsTr("Hello World")
TreeView
{
id:treeView
anchors.fill: parent
model: theModel
itemDelegate: TreeDelegate
{
id: treeDeleg
}
style: TreeViewStyle
{
id: styleTree
}
TableViewColumn
{
id:column1
role: "Name"
title: "Name"
width: 450
}
TableViewColumn
{
id:column3
role: "Value"
title: "Value"
width: 400
}
Component.onCompleted:
{
treeView.model = Qt.binding(function()
{
if (typeof theModel !== "undefined")
{
console.log("Model loaded");
return theModel;
}
else
{
console.log("Couldn't load model");
return null;
}
});
}
}
}
TreeDelegate.qml
import QtQuick.Controls 2.1
import QtQuick.Layouts 1.3
import QtQuick 2.7
import QtQml 2.0
Item
{
id: item
width : parent.width
height: 25
TextEdit
{
id: text1
font.pixelSize: 14
readOnly: true
focus: false
width : parent.width
height: 25 * lineCount
anchors.left: parent.left
wrapMode: TextEdit.Wrap
text: styleData.value
verticalAlignment: Text.AlignVCenter
horizontalAlignment: Text.AlignLeft
}
}