J-Cake

let isMainWindow = false; // keep track of main instance.
// Of course the main instance should be kept track of in a better way than this, perhaps find a way of uniquely identifying the tabs
// and storing the ID of the active tab in localStorage.

window.addEventListener('load', e => {

  if (!window.localStorage.mainWindowVacant) window.localStorage.mainWindowVacant = "true"; // initialsise window.localStorage
  if (!window.localStorage.openInstances) window.localStorage.mainWindowVacant = "true"; // initialsise window.localStorage

  if (window.localStorage.mainWindowVacant !== "false") {

J-Cake

import React, {Component} from 'react';
import {View, Text, Dimensions} from 'react-native';
import styles from './styles.js';
import LinearGradient from 'react-native-linear-gradient';
import utils from './utils.js';
const d = Dimensions.get('window'),
	width = d.width,
	height = d.height;

export default class BrightnessSlider extends Component {