ElectronMCLauncher/index.js

// Requirements
const {app, BrowserWindow, ipcMain} = require('electron')
const autoUpdater                   = require('electron-updater').autoUpdater
const ejse                          = require('ejs-electron')
const fs                            = require('fs')
const isDev                         = require('electron-is-dev')
const path                          = require('path')
const semver                        = require('semver')
const url                           = require('url')

// Setup auto updater.
function initAutoUpdater(event, data) {

    if(data){
        autoUpdater.allowPrerelease = true
    } else {
        // Defaults to true if application version contains prerelease components (e.g. 0.12.1-alpha.1)
        // autoUpdater.allowPrerelease = true
    }
    
    if(isDev){
        autoUpdater.autoInstallOnAppQuit = false
        autoUpdater.updateConfigPath = path.join(__dirname, 'dev-app-update.yml')
    }
    autoUpdater.on('update-available', (info) => {
        event.sender.send('autoUpdateNotification', 'update-available', info)
    })
    autoUpdater.on('update-downloaded', (info) => {
        event.sender.send('autoUpdateNotification', 'update-downloaded', info)
    })
    autoUpdater.on('update-not-available', (info) => {
        event.sender.send('autoUpdateNotification', 'update-not-available', info)
    })
    autoUpdater.on('checking-for-update', () => {
        event.sender.send('autoUpdateNotification', 'checking-for-update')
    })  
}

// Open channel to listen for update actions.
ipcMain.on('autoUpdateAction', (event, arg, data) => {
    switch(arg){
        case 'initAutoUpdater':
            console.log('Initializing auto updater.')
            initAutoUpdater(event, data)
            event.sender.send('autoUpdateNotification', 'ready')
            break
        case 'checkForUpdate':
            autoUpdater.checkForUpdates()
                .catch(err => {
                    event.sender.send('autoUpdateNotification', 'realerror', err)
                })
            break
        case 'allowPrereleaseChange':
            if(!data){
                const preRelComp = semver.prerelease(app.getVersion())
                if(preRelComp != null && preRelComp.length > 0){
                    autoUpdater.allowPrerelease = true
                } else {
                    autoUpdater.allowPrerelease = data
                }
            } else {
                autoUpdater.allowPrerelease = data
            }
            break
        case 'installUpdateNow':
            autoUpdater.quitAndInstall()
            break
        default:
            console.log('Unknown argument', arg)
            break
    }
})
// Redirect distribution index event from preloader to renderer.
ipcMain.on('distributionIndexDone', (event, res) => {
    event.sender.send('distributionIndexDone', res)
})

// Disable hardware acceleration.
// https://electronjs.org/docs/tutorial/offscreen-rendering
app.disableHardwareAcceleration()

// Keep a global reference of the window object, if you don't, the window will
// be closed automatically when the JavaScript object is garbage collected.
let win

function createWindow() {

    win = new BrowserWindow({
        width: 980,
        height: 552,
        icon: getPlatformIcon('WesterosSealSquare'),
        frame: false,
        webPreferences: {
            preload: path.join(__dirname, 'app', 'assets', 'js', 'preloader.js')
        },
        backgroundColor: '#171614'
    })

    ejse.data('bkid', Math.floor((Math.random() * fs.readdirSync(path.join(__dirname, 'app', 'assets', 'images', 'backgrounds')).length)))

    win.loadURL(url.format({
        pathname: path.join(__dirname, 'app', 'app.ejs'),
        protocol: 'file:',
        slashes: true
    }))

    /*win.once('ready-to-show', () => {
        win.show()
    })*/

    win.setMenu(null)

    win.setResizable(true)

    win.on('closed', () => {
        win = null
    })
}

function getPlatformIcon(filename){
    const opSys = process.platform
    if (opSys === 'darwin') {
        filename = filename + '.icns'
    } else if (opSys === 'win32') {
        filename = filename + '.ico'
    } else {
        filename = filename + '.png'
    }

    return path.join(__dirname, 'app', 'assets', 'images', filename)
}

app.on('ready', createWindow);

app.on('window-all-closed', () => {
    // On macOS it is common for applications and their menu bar
    // to stay active until the user quits explicitly with Cmd + Q
    if (process.platform !== 'darwin') {
        app.quit()
    }
})

app.on('activate', () => {
    // On macOS it's common to re-create a window in the app when the
    // dock icon is clicked and there are no other windows open.
    if (win === null) {
        createWindow()
    }
})