import fscreen from 'fscreen'; const element = document.createElement('div'); if (fscreen.fullscreenEnabled) { fscreen.addEventListener('fullscreenchange', handler, false); fscreen.requestFullscreen(element); } function handler() { if (fscreen.fullscreenElement !== null) { // Entered fullscreen mode } else { // Exited fullscreen mode } } fscreen.requestFullscreen(element); fscreen.requestFullscreenFunction(element); fscreen.exitFullscreen(); fscreen.onfullscreenchange = handler; fscreen.addEventListener('fullscreenchange', handler); fscreen.removeEventListener('fullscreenchange', handler); fscreen.onfullscreenerror = handler; fscreen.addEventListener('fullscreenerror', handler); fscreen.removeEventListener('fullscreenerror', handler);