Integration of Exposed model into ListModel QML

Question

I have exposed successfully a list that contain 3 integer from C++ to my main.qml using ListView in main.qml

ListView {
width: 200; height: 250
required model
delegate: Text {
    required property int longitude
    required property int latitude
    required property int height_
    text: "Data: " + longitude + ", " + latitude +","+ height_
}}

What I actually need to do is to integrate my C++ model into ItemModelSurfaceDataProxy that takes ListModel like this

   ListModel {
            id: myModel
              ListElement{ longitude: "0"; latitude: "0"; height_: "124"; }   
    }}

main.qml using qtdatavisualization-qmlsurface-example ,, example_source_code

Rectangle {
id: mainview
width: 1024
height: 768
color: surfacePlot.theme.windowColor

Item {
    id: surfaceView
    width: mainview.width
    height: mainview.height
    anchors.top: mainview.top
    anchors.left: mainview.left
    Surface3D {
        id: surfacePlot
        width: surfaceView.width
        height: surfaceView.height
        Surface3DSeries {
            id: surfaceSeries
            flatShadingEnabled: false
            drawMode: Surface3DSeries.DrawSurface

            ItemModelSurfaceDataProxy {
                itemModel: myModel **// this needs to be replaced by C++ model**
                rowRole: "longitude"
                columnRole: "latitude"
                yPosRole: "height_"
            }
            onDrawModeChanged: checkState()
        }
    }
    ListModel { **//This is the model that needs to be replaced by C++ Model**
            id: myModel
    }
  }}

main.cpp

   int main(int argc, char *argv[])
   {
    QGuiApplication app(argc, argv);
    AnimalModel model;
    model.addAnimal(Animal(1, 2,3));
    model.addAnimal(Animal(2,4,5));
    model.addAnimal(Animal(3,4,6));
    QQuickView viewer;
    viewer.setResizeMode(QQuickView::SizeRootObjectToView);
    viewer.setInitialProperties({{"model", QVariant::fromValue(&model)}});
    viewer.setSource(QUrl("qrc:/qml/qml/qmlsurface/main.qml"));
    viewer.setTitle(QStringLiteral("Egyptolict "));
    viewer.show();
    return app.exec();
   }

model.cpp using QT example

#include "model.h"
Animal::Animal(const int &longitude, const int &latitude,const int &height_)
: m_longitude(longitude), m_latitude(latitude) ,m_height(height_){}

int Animal::longitude() const{
  return m_longitude;}
int Animal::latitude() const{
  return m_latitude;}
int Animal::height_() const{
  return m_height;}
AnimalModel::AnimalModel(QObject *parent)
: QAbstractListModel(parent)
{
 }
void AnimalModel::addAnimal(const Animal &animal)
{
beginInsertRows(QModelIndex(), rowCount(), rowCount());
m_animals << animal;
endInsertRows();
}
 int AnimalModel::rowCount(const QModelIndex & parent) const {
Q_UNUSED(parent);
return m_animals.count();
}
QVariant AnimalModel::data(const QModelIndex & index, int role) const {
if (index.row() < 0 || index.row() >= m_animals.count())
    return QVariant();

const Animal &animal = m_animals[index.row()];
if (role == longitudeRole)
    return animal.longitude();
else if (role == latitudeRole)
    return animal.latitude();
else if (role == heightRole)
    return animal.height_();
return QVariant();
}
QHash<int, QByteArray> AnimalModel::roleNames() const {
QHash<int, QByteArray> roles;
roles[longitudeRole] = "longitude";
roles[latitudeRole] = "latitude";
roles[heightRole] = "height_";
return roles;
}

model.h using qt example

#include <QAbstractListModel>
#include <QStringList>
class Animal
{public:
Animal(const int &longitude, const int &latitude , const int &height_);
 int longitude() const;
 int latitude() const;
 int height_() const;
private:
 int m_longitude;
 int m_latitude;
 int m_height;
  };

 class AnimalModel : public QAbstractListModel
 {
  Q_OBJECT
 public:
  enum AnimalRoles {
    longitudeRole = Qt::UserRole + 1,
    latitudeRole,
    heightRole
   };

   AnimalModel(QObject *parent = 0);

  void addAnimal(const Animal &animal);
 int rowCount(const QModelIndex & parent = QModelIndex()) const;
 QVariant data(const QModelIndex & index, int role = Qt::DisplayRole) const;
 QHash<int, QByteArray> roleNames() const;
 private:
  QList<Animal> m_animals;
  };

Answer 1

You should set the property on the rootContext :

int main(int argc, char *argv[])
{
   QGuiApplication app(argc, argv);
   AnimalModel model;
   model.addAnimal(Animal(1, 2,3));
   model.addAnimal(Animal(2,4,5));
   model.addAnimal(Animal(3,4,6));
   
   QQuickView viewer;
   viewer.setResizeMode(QQuickView::SizeRootObjectToView);
   viewer.rootContext()->setContextProperty("model", &model);
   viewer.setSource(QUrl("qrc:/qml/qml/qmlsurface/main.qml"));
   viewer.setTitle(QStringLiteral("Egyptolict "));
   viewer.show();
   return app.exec();

}

The setInitialProperties function tries to set properties on the object (in this case you 'main.qml' file), had you added property var model to 'main.qml' it could have worked.

PS, if you don't want to mix up property 'height', you could use 'altitude';-)

Answer 2

Thanks to @Amfasis It worked by setting the property on the rootContext

viewer.rootContext()->setContextProperty("model", &model);

and added property var model under Item

Item { 
      property var model
      ....
      }