cross-browser fullscreen utils

fullscreen.js

// see https://developer.mozilla.org/en-US/docs/Web/API/Fullscreen_API

/** @private */
const ERR_NO_API = 'The Fullscreen API not supported on this device';

export function requestFullscreen(elem) {
    if (elem.requestFullscreen) {
        elem.requestFullscreen();
    } else if (elem.msRequestFullscreen) {
        elem.msRequestFullscreen();
    } else if (elem.mozRequestFullScreen) {
        elem.mozRequestFullScreen();
    } else if (elem.webkitRequestFullscreen) {
        elem.webkitRequestFullscreen();
    } else {
        console.warn(ERR_NO_API);
    }
}

export function exitFullscreen() {
    const d = document;
    if (d.exitFullscreen) {
        d.exitFullscreen();
    } else if (d.msExitFullscreen) {
        d.msExitFullscreen();
    } else if (d.mozCancelFullScreen) {
        d.mozCancelFullScreen();
    } else if (d.webkitExitFullscreen) {
        d.webkitExitFullscreen();
    } else {
        console.warn(ERR_NO_API);
    }
}
export function getFullscreenElement() {
    return (
        document.fullscreenElement ||
        document.mozFullScreenElement ||
        document.webkitFullscreenElement ||
        document.msFullscreenElement
    );
}
/**
 * @return {boolean} true if going into fullscreen, false if leaving fullscreen
 */
export function toggleFullscreen(elem) {
    if (getFullscreenElement() === elem) {
        exitFullscreen(elem);
        return false;
    } else {
        requestFullscreen(elem);
        return true;
    }
}
export function isFullscreen(elem) {
    if (elem) {
        return getFullscreenElement() === elem;
    }
    return !!getFullscreenElement();
}

export function isFullscreenEnabled() {
    return (
        document.fullscreenEnabled ||
        document.webkitFullscreenEnabled ||
        document.mozFullScreenEnabled ||
        document.msFullscreenEnabled
    );
}

export function addFullscreenChangeListener(callback) {
    document.addEventListener('fullscreenchange', callback);
    document.addEventListener('webkitfullscreenchange', callback);
    document.addEventListener('mozfullscreenchange', callback);
    document.addEventListener('MSFullscreenChange', callback);
}
export function removeFullscreenChangeListener(callback) {
    document.removeEventListener('fullscreenchange', callback);
    document.removeEventListener('webkitfullscreenchange', callback);
    document.removeEventListener('mozfullscreenchange', callback);
    document.removeEventListener('MSFullscreenChange', callback);
}