Creating the tiles

This step places the game tiles randomly.

C++

Change the main function and includes in src/main.cpp to the following:

#include <random> // Added

int main()
{
    auto main_window = MainWindow::create();
    auto old_tiles = main_window->get_memory_tiles();
    std::vector<TileData> new_tiles;
    new_tiles.reserve(old_tiles->row_count() * 2);
    for (int i = 0; i < old_tiles->row_count(); ++i) {
        new_tiles.push_back(*old_tiles->row_data(i));
        new_tiles.push_back(*old_tiles->row_data(i));
    }
    std::default_random_engine rng {};
    std::shuffle(new_tiles.begin(), new_tiles.end(), rng);
    auto tiles_model = std::make_shared<slint::VectorModel<TileData>>(new_tiles);
    main_window->set_memory_tiles(tiles_model);

    main_window->run();
}

The code takes the list of tiles, duplicates it, and shuffles it, accessing the memory_tiles property through the C++ code.

For each top-level property, Slint generates a getter and a setter function. In this case get_memory_tiles and set_memory_tiles. Since memory_tiles is a Slint array, it’s represented as a std::shared_ptr<slint::Model> ↗.

You can’t change the model generated by Slint, but you can extract the tiles from it and put them in a slint::VectorModel ↗ which inherits from Model. VectorModel lets you make changes and you can use it to replace the static generated model.

NodeJS

Change main.js to the following:

import * as slint from "slint-ui";
const ui = slint.loadFile(new URL("./ui/app-window.slint", import.meta.url));
const mainWindow = new ui.MainWindow();

const initial_tiles = mainWindow.memory_tiles;
const tiles = initial_tiles.concat(
    initial_tiles.map((tile) => Object.assign({}, tile)),
);

for (let i = tiles.length - 1; i > 0; i--) {
    const j = Math.floor(Math.random() * i);
    [tiles[i], tiles[j]] = [tiles[j], tiles[i]];
}

const model = new slint.ArrayModel(tiles);
mainWindow.memory_tiles = model;

await mainWindow.run();

The code takes the list of tiles, duplicates it, and shuffles it, accessing the memory_tiles property through the JavaScript code.

As memory_tiles is an array, it’s represented as a JavaScript Array ↗. You can’t change the model generated by Slint, but you can extract the tiles from it and put them in a slint.ArrayModel ↗ which implements the Model ↗ interface. ArrayModel allows you to make changes and you can use it to replace the static generated model.

Rust

The code uses the rand dependency for the randomization. Add it to the Cargo.toml file using the cargo command.

cargo add rand@0.8

Change the main function to the following:

fn main() {
    use slint::Model;

    let main_window = MainWindow::new().unwrap();

    // Fetch the tiles from the model
    let mut tiles: Vec<TileData> = main_window.get_memory_tiles().iter().collect();
    // Duplicate them to ensure that we have pairs
    tiles.extend(tiles.clone());

    // Randomly mix the tiles
    use rand::seq::SliceRandom;
    let mut rng = rand::thread_rng();
    tiles.shuffle(&mut rng);

    // Assign the shuffled Vec to the model property
    let tiles_model = std::rc::Rc::new(slint::VecModel::from(tiles));
    main_window.set_memory_tiles(tiles_model.clone().into());

    main_window.run().unwrap();
}