window.addEventListener("DOMContentLoaded", function(){
// (A) GET ALL IMAGES
var all = document.querySelectorAll(".gallery img");
// (B) CLICK ON IMAGE TO TOGGLE FULLSCREEN
if (all.length>0) { for (let img of all) {
img.addEventListener("click", function(){
// EXIT FULLSCREEN
if (document.webkitFullscreenElement || document.fullscreenElement) {
if (document.exitFullscreen) { document.exitFullscreen(); }
else if (document.webkitExitFullscreen) { document.webkitExitFullscreen(); }
}
// ENGAGE FULLSCREEN
else {
if (this.requestFullscreen) { this.requestFullscreen(); }
else if (this.webkitRequestFullscreen) { this.webkitRequestFullscreen(); }
}
});
}}
});