class CenteredBox { constructor() { this._centeredBox = document.querySelector('#centeredBox'); this._centeredBoxVisibility = true; this.showCenteredBox = this.showCenteredBox.bind(this); this.hideCenteredBox = this.hideCenteredBox.bind(this); this.toggleCenteredBox = this.toggleCenteredBox.bind(this); } showCenteredBox = () => { this._centeredBox.classList.remove('hiddenBox'); this._centeredBoxVisibility = !this._centeredBoxVisibility; } hideCenteredBox = () => { this._centeredBox.classList.add('hiddenBox'); this._centeredBoxVisibility = !this._centeredBoxVisibility; } toggleCenteredBox = () => { if (this._centeredBoxVisibility) { // hide centered box this.hideCenteredBox(); } else { // Show centered box this.showCenteredBox(); } } }