How to pass 2d Array to qml

[arlyn123]

I want to pass a c++ 2d sudoku empty grid (without numbers in it) to qml. I used a QAbstractTableModel. I do not have errors, only a warning of the unused parameter for the variable role and when I run the project the grid is not displayed in the qml file.

//Grid.h
#pragma once

#include <QAbstractTableModel>

class Grid : public QAbstractTableModel
{
   Q_OBJECT
   
public:
   explicit Grid(QObject *parent = nullptr);
   
   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;
   
   QVariant data(const QModelIndex &index, int role) const override;
};

#include "Grid.h"

Grid::Grid(QObject *parent)
    : QAbstractTableModel(parent)
{}

QModelIndex Grid::index(int row, int column, const QModelIndex &parent) const
{
    Q_UNUSED(parent);
    return createIndex(row, column);
}

QModelIndex Grid::parent(const QModelIndex &index) const
{
    Q_UNUSED(index);
    return QModelIndex();
}

int Grid::rowCount(const QModelIndex &parent) const
{
    Q_UNUSED(parent);
    return 9;
}

int Grid::columnCount(const QModelIndex &parent) const
{
    Q_UNUSED(parent);
    return 9;
}

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

import QtQuick 2.15
import QtQuick.Controls 2.15
import SudokuGrid 1.0

Window {
    visible: true
    width: 550
    height: 550
    title: "Game"

    GridView {
        id: grid
        anchors.fill: parent
        model: SudokuGrid
        cellWidth: 50
        cellHeight: 50

        delegate: Rectangle {
            width: 50
            height: 50
            color: model.row % 2 ? "lightgray" : "lightblue"
        }
    }
}

to pass the grid to qml I used this in main.cpp:
qmlRegisterUncreatableType<Grid>("SudokuGrid", 1, 0, "SudokuGrid", "Cannot display the grid");

[JoeCFD]

@arlyn123 said in How to pass 2d Array to qml:

qmlRegisterUncreatableType

Your class Grid is empty. What do you want to pass?

[arlyn123]

@JoeCFD I am beginner to both qml and c++. How can I fill the c Grid class?

[JoeCFD]

@arlyn123 I guess you want to display digits as strings. Create a 2D array of QString inside class Grid, assign values to it and override func data of QAbstractTableModel in class Grid. Display text inside delegate with default display role

[arlyn123]

@JoeCFD But I want to make a sudoku game with different game levels. Do I need to assign values for each grid?

[JoeCFD]

@arlyn123 You have only one GridView in your layout. You can change the values of arrays to update the display on GridView.

[arlyn123]

@JoeCFD But how do I do that? Do I need a separate method or a even a separate class?

[JoeCFD]

@arlyn123 add a func setData( int row, int column, const QString & value ) in class Grid()

[arlyn123]

@JoeCFD also can you please give me an example of how can I work with the data function as you suggested în your first comment

[JoeCFD]

@arlyn123 https://doc.qt.io/qt-6/qml-qtquick-tableview.html

[arlyn123]

@JoeCFD Thanks lot for giving me the table view documentation. I was able to use it instead of grid view