main.js

const path = require('path');
const url = require('url');
const electron = require('electron');
const BrowserWindow = electron.BrowserWindow;
const app = electron.app;
const Menu = electron.Menu;

let mainWindow = null;

const isSecondInstance = app.makeSingleInstance(
    (commandLine, workingDirectory) => {
        if (mainWindow) {
            if (mainWindow.isMinimized()) {
                mainWindow.restore();
            }
            mainWindow.focus();
        }
    },
);

if (isSecondInstance) {
    app.quit();
}

function initialize() {
    app.on('ready', function() {
        createWindow();
    });

    app.on('window-all-closed', function() {
        app.quit();
    });

    app.on('activate', function() {
        if (mainWindow === null) {
            createWindow();
        }
    });
}

function createWindow() {
    const windowOptions = {
        title: app.getName(),
        //resizable: true,
        width: 1280,
        height: 720,
        minWidth: 1280,
        minHeight: 720,
        maxWidth: 1280,
        webPreferences: {
            webSecurity: false,
        },
    };

    if (process.platform === 'linux') {
        windowOptions.icon = path.join(__dirname, '/front/assets/app-icon.svg');
    }

    mainWindow = new BrowserWindow(windowOptions);
    mainWindow.loadURL(
        url.format({
            protocol: 'file',
            slashes: true,
            pathname: path.join(__dirname, 'docs/index.html'),
        }),
    );

    mainWindow.on('closed', function() {
        mainWindow = null;
    });

    // Create the Application's main menu
    const template = [
        {
            label: 'Electron',
            submenu: [
                {
                    label: 'Quit',
                    accelerator: 'Command+Q',
                    click: function() {
                        app.quit();
                    },
                },
            ],
        },
        {
            label: 'Edit',
            submenu: [
                {
                    label: 'Undo',
                    accelerator: 'Command+Z',
                    selector: 'undo:',
                },
                {
                    label: 'Redo',
                    accelerator: 'Shift+Command+Z',
                    selector: 'redo:',
                },
                {
                    type: 'separator',
                },
                {
                    label: 'Cut',
                    accelerator: 'Command+X',
                    selector: 'cut:',
                },
                {
                    label: 'Copy',
                    accelerator: 'Command+C',
                    selector: 'copy:',
                },
                {
                    label: 'Paste',
                    accelerator: 'Command+V',
                    selector: 'paste:',
                },
                {
                    label: 'Select All',
                    accelerator: 'Command+A',
                    selector: 'selectAll:',
                },
            ],
        },
        {
            label: 'View',
            submenu: [
                {
                    label: 'Reload',
                    accelerator: 'Command+R',
                    click: function() {
                        mainWindow.reload();
                    },
                },
                {
                    label: 'Toggle DevTools',
                    accelerator: 'Alt+Command+I',
                    click: function() {
                        mainWindow.toggleDevTools();
                    },
                },
            ],
        },
    ];

    const menu = Menu.buildFromTemplate(template);
    Menu.setApplicationMenu(menu);
}

initialize();