How do I get the properties of a class from c++ into QML

Question

I have a vector in c++, where each element is a object of the same class. The properties of these objects are strings and integers.
Now I want to create rectangles in QML depending on how many elements are in the vector (1 rectangle per element) and the rectangle's features (x and y position for example) depend on the values of properties of the objects in the vector (the integer properties). My question is: how do I import this data from c++ into QML? And how do I use the x/y Positions to create rectangles on these values?
This is a example of the cpp file:

#include <iostream>
#include <vector>
#include <string>

class myClass{
    public:
        int xPosition;
        int yPosition;
        std::string color;

        myClass(int xPosition_, int yPosition_, std::string color_){
            xPosition = xPosition_;
            yPosition = yPosition_;
            color = color_;
        }
};

int createVec(){
    myClass objectOne(100, 100, "red");
    myClass objectTwo(200, 200, "blue");
    myClass objectThree(300, 300, "green");
    myClass objectFour(400, 400, "black");


    std::vector<myClass> vec;
    vec.push_back(objectOne);
    vec.push_back(objectTwo);
    vec.push_back(objectThree);
    vec.push_back(objectFour);

    for (int i = 0; i < vec.size(); i++){
        std::cout << vec[i].xPosition << " " << vec[i].yPosition << " " <<vec[i].color << std::endl;
    }
}

Edit: I tried to solve my problem mainly by doing something similar to this post. However I'm running into multiple different problems, since I'm very new to QML, qt and c++. First of all I don't know how to convert my class into a Q_OBJECT, secondly I don't know what eatyourgreens meant with:

In the QML code, the properties of Thing can be accessed through the model as model.modelData.size and model.modelData.name.

This issue is widely covered in the Qt documentation as well as at SO. Did you try to get an answer using that before asking? [Integrating QML and C++](https://doc.qt.io/qt-5/qtqml-cppintegration-topic.html), [Interacting with QML Objects from C++](https://doc.qt.io/qt-5/qtqml-cppintegration-interactqmlfromcpp.html) — folibis, Jun 08 '20 at 17:31
Yes I tried fixing my problems for days by reading the documentation and trying several things, but I just can't get it to work unfortunately. That's why I'm asking for help here now. — Vipr0, Jun 08 '20 at 21:15

score 0 · Answer 1 · answered Jun 09 '20 at 05:13

You might use

YourClass *yourClass = new YourClass();
    qmlView->rootContext()->setContextProperty("myClass", yourClass);
note: where your system calling the qml (it might be in main.cpp)

inside qml file. you may get the property or method that has return value like this

myClass.getFloorProperty();

How do I get the properties of a class from c++ into QML

1 Answers1