function pipSupported() {
	return window.documentPictureInPicture && document.pictureInPictureEnabled;
}

function pipEnabled() {
	return pipSupported() && localStorage.getItem("pip-enabled") != 0;
}

function setPipEnabled(enabled) {
	localStorage.setItem("pip-enabled", +enabled);
}

function openPipWindow(link, w, h) {
	return new Promise(function(resolve) {
		window.documentPictureInPicture.requestWindow({ width: w, height: h }).then(function(win) {
			var iframe = document.createElement("iframe");
			iframe.src = link;
			iframe.style.width = w + "px";
			iframe.style.height = h + "px";
			iframe.style.border = "none";

			win.document.body.style.margin = "0";
			win.document.body.style.overflow = "hidden";

			win.document.body.appendChild(iframe);

			win.onpagehide = resolve;
			win.onresize = function() {
				iframe.style.width = win.innerWidth + "px";
				iframe.style.height = win.innerHeight + "px";
			}
		});
	});
}