Creating tree kind of model from QAbstractItemModel or QAbstractListModel - qt

Question

As per the below code, I need to create a model which will have N number of "System", and each "System" will have N number of "SytemDatabase" and each "SytemDatabase" will have N number of "CoresData".
This N number will come to know during the launch time of application.
struct CoresData {
int m_iCoreSpeed;
bool m_bCoreAvailable;
};
class SytemDatabase {
public:
SytemDatabase();
bool m_bDatabaseVisible;
int m_iDatabaseNumber;
QList<CoresData> m_listCoresData;
};
class Sytem {
public:
Sytem();
bool m_bSystemAvailable;
int m_iSystemNumber;
QList<SytemDatabase> m_listSytemDatabase;
};
class SytemTree : public QAbstractItemModel {
Q_OBJECT
public:
explicit SytemTree( QObject *parent = nullptr);
~SytemTree();
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 &index) const override;
int rowCount(const QModelIndex &parent = QModelIndex()) const override;
int columnCount(const QModelIndex &parent = QModelIndex()) const override;
private:
void addSytemDatabase(Sytem &data);
QList<Sytem> m_listSystem;
};
Currently I have designed this model using a ListModel and its working fine. Now for some reason i need to move this model to cpp side and pass that model to qml.
Below is the QML code for reference
SytemTree.append({ "iSystemNumber": systemNumber, "bSystemAvailable": false, "SytemDatabase":[{ "iDatabaseNumber": databaseNumber, "bDatabaseVisible": false,"CoresData": []}]})
for( var lp = 0; lp < totalcoreData; ++lp) {
SytemTree.get(systemNumber).SytemDatabase.get(iDatabaseNumber).CoresData.append({ "bCoreAvailable": true, "bCoreAvailable": true, "iCoreNumber": coreNumber})
}
consider the model is developed in cpp side with reference to above cpp classes Sytem, SytemDatabase and CoresData , and the same model is passed and used like below in the qml code
Repeater {
id: repeaterRootSystem
model: SytemTree
delegate: customRectangle {---
visible: systemAvailable
value: systemNumber
----
Repeater {
id: repeaterDatabase
model: SytemTree.get(index).SytemDatabase
delegate: customRectangle {---
visible: databaseVisible
value: databaseNumber
---
Repeater {
id: repeaterCoresData
model: SytemTree.get(index).SytemDatabase.get(index).CoresData
delegate: customRectangle {--
visible: coreAvailable
value: coreNumber
speed: coreSpeed
----
}
}
}
}
}
}
I have gone through concepts QAbstractListModel, QAbstractItemModel and QAbstractTableModel.
But am looking for a model like one list model, and each list element will contain a tree like structure as mentioned above in the classes.
Requesting anyone to suggest how to create a model which will have tree like structure. and which QAbstractxxxxxmodel will be correct to implement this concept.
and in QML side i want to access the data through the index untill coresData , same like above QML code.
Thanks in advance.

Answer 1

Check out this similar question for some ideas.
If you're not adamant about using a QAbstractItemModel, here is a qml-based solution I've used before:
import QtQuick 2.9
import QtQuick.Window 2.2
import UISettings 1.0
import QtQuick.Controls 2.2
import QtQuick.Layouts 1.3
import QtQuick.Controls 1.4 as SV
Window {
visible: true
width: 640
height: 480
title: qsTr("Hello World")
Flickable {
id: flick
anchors.fill: parent
clip: true
contentHeight: col.implicitHeight
property var mymodel: {
"animals": {
"big": {
"land": "elephants",
"water": "whales"
},
"small": {
"land": "mice",
"water": "fish"
}
},
"plants": {
"trees": "evergreens"
}
}
Column {
id: col
Component.onCompleted: componentListView.createObject(this, {"objmodel":flick.mymodel});
}
Component {
id: componentListView
Repeater {
id: repeater
property var objmodel: ({})
model: Object.keys(objmodel)
ColumnLayout {
Layout.leftMargin: 50
Button {
property var sprite: null
text: modelData
onClicked: {
if(sprite === null) {
if(typeof objmodel[modelData] === 'object')
sprite = componentListView.createObject(parent, {"objmodel":objmodel[modelData]});
}
else
sprite.destroy()
}
}
}
}
}
}
}