Electron Window Manager

main.js

const WindowManager = require('./WindowManager()')
const {
	app,
	globalShortcut,
  //ipcMain allows us to recieve requests from index.js using the ipc rendering (kinda sets a listener)
  ipcMain
}, electron = require('electron');

const path = require('path');

const url = require('url');

//This configuration tool allows us to save general config settings to a JS file in the app data folder
const configuration = require('./configuration');

// utilities and composables
const because = (test, cb) => test ? cb() : void(0)

const formatURL = filename => url.format({
  pathname: path.join(__dirname, filename),
  protocol: 'file:',
  slashes: true
})


const createSplash = () => {
	const win = WindowManager.createWindow('splash')
	win.once('ready-to-show', () => {
    win.show()
  })
	return win
}

const createMain = () => {
	const win = WindowManager.createWindow('main')
	win.once('ready-to-show', () => {
		WindowManager.grab('splash').hide()
    win.show()
  })
  return win
}


app.on('ready', function() {

  // Create the splash Window
  const splash = createSplash()

  let fptr = 'splashWindow.html'
	if (!configuration.readSettings('firstRun')) {
    fptr = 'firstRun.html'
  }

	WindowManager.loadFileForWindow(formatURL(fptr), splash)
  WindowManager.activate(splash)

  // Create The Main Window
  // though this might need to be its own function
	const main = createMain();

  const ret = globalShortcut.register('CommandOrControl+X', () => {
		console.log('CommandOrControl+X is pressed');
		splash.close();
		main.close();
	});

});

// Quit when all windows are closed.
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 (!WindowManager.checkWindowExists('main')) {
		createMain()
	}
});

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

app.on('before-quit', () => {
	const win = WindowManager.grab('main')
	win.removeAllListeners('close');
	win.close();
});

WindowManager.js

const {BrowserWindow} = require('electron')
const {lebab, keys} = require('./utils')
const debug = require('debug')

const log = debug('WindowManager:log')
var windowID = 0

class WindowManager {
  constructor() {
    this.windows = {}
    this.active = null
  }
  checkWindowExists(name) {
    return !!this.windows[name]
  }
 
  /**
   * returns a window's id from either an id or a BrowserWindow Object
   * helper method
   * @method getID
   * @param  {String | BrowserWindow} winRef - areference to a BrowserWindow object
   * @return {String} the window's id
   */
  getID(winRef) {
    if(typeof winRef == 'String') {
      const ref = lebab(winRef)
      if(this.checkWindowExists(ref)) {
        return ref
      } else {
        throw new ReferenceError('No Window Named ${winRef} exists')
      }
    } else {
      const id = winRef.__name
      if(!id) {
        throw new ReferenceError('The given window is not managed by the window Manager. Please add() it first.')
      }
    }
  }


  grab(name) {
    const id = lebab(name)
    const win = this.windows[id]
    if(!this.checkWindowExists(id)) {
      throw new ReferenceError(`No Window Named ${name} exists`)
    }
    return this.windows[id]
  }
  loadFileForWindow(fptr, winRef) {
    const id = getID(windRef)
    const win = this.grab(id)
    win.loadURL(fptr)
  }
  
  addWindow(name, win) {
    const id = lebab(name)
    if(typeof wind !== BrowserWindow) {
      throw new TypeError(`Error: Can not add object named ${name}. Only BrowserWindow instances are allowed`)
    }
    if(this.checkWindowExists(id)) {
      throw new ReferenceError(`Cannot add a new window named ${name} as it already exists`)
    }

    win.__id = windowID++
    win.__name = id
    this.windows[id] = win

    win.on('closed', () => this.destroy(win))
    log('added window named:', name)
    return win
  }
  createWindow(name) {
    const id = lebab(name)
    let win = this.windows[id]
    if(win) {
      log('destroying old window named:', name)
      this.destroy(win)
    }
    const win =  new BrowserWindow({
  		frame: false,
  		kiosk: false,
  		show: false,
  		width: 1920,
  		height: 1080,
  		resizable: false,
  		backgroundColor: '#000000'
  	});
    // cleanup
    win.on('closed', () => this.destroy(win))
    win.__name = name
    win.__id = windowID++
    log('created new window named:', name)
  }

  destroy(winRef) {
    const id = this.getID(winRef)
      try {
        this.windows[id].destroy()
      } catch(err) {
        log('failed to destory window:', id)
        throw err
      }
    }

  activate(winRef) {
    const id = this.getID(winRef)
    const win = this.grab(id)
    this.active = win
  }

  sendCommand(cmd, data) {
    this.active.webContents.send(cmd, data)
  }
}

module.exports = new WindowManager()