fnx_web/res/include/script/file_viewer/Toolbar.js

function Toolbar(viewer) {
	this.viewer = viewer;
	this.visible = false;
	this.sharebarVisible = false;

	this.divToolbar       = document.getElementById("toolbar");
	this.divFilePreview   = document.getElementById("filepreview");
	this.downloadFrame    = document.getElementById("download_frame");
	this.spanViews        = document.getElementById("stat_views");
	this.spanDownloads    = document.getElementById("stat_downloads");
	this.spanSize         = document.getElementById("stat_size");

	this.btnToggleToolbar = document.getElementById("btn_toggle_toolbar");
	this.btnDownload      = document.getElementById("btn_download");
	this.btnCopyLink      = document.getElementById("btn_copy");
	this.spanCopyLink     = document.querySelector("#btn_copy > span");
	this.btnShare         = document.getElementById("btn_share");
	this.divSharebar      = document.getElementById("sharebar");

	this.btnToggleToolbar.addEventListener("click", () => { this.toggle(); });
	this.btnDownload.addEventListener("click",      () => { this.download(); });
	this.btnCopyLink.addEventListener("click",      () => { this.copyUrl(); });
	this.btnShare.addEventListener("click",         () => { this.toggleSharebar(); });
}

Toolbar.prototype.toggle = function() {
	if (this.visible) {
		if (this.sharebarVisible) { this.toggleSharebar(); }

		this.divToolbar.style.left = "-8em";
		this.divFilePreview.style.left = "0px";
		this.btnToggleToolbar.classList.remove("button_highlight");
		this.visible = false;
	} else {
		this.divToolbar.style.left = "0px";
		this.divFilePreview.style.left = "8em";
		this.btnToggleToolbar.classList.add("button_highlight");
		this.visible = true;
	}
}

Toolbar.prototype.toggleSharebar = function() {
	if (navigator.share) {
		navigator.share({
			title: this.viewer.title,
			text: "Download " + this.viewer.title + " here",
			url: window.location.href
		});
		return;
	}

	if(this.sharebarVisible){
		this.divSharebar.style.left = "-8em";
		this.btnShare.classList.remove("button_highlight")
		this.sharebarVisible = false;
	}else{
		this.divSharebar.style.left = "8em";
		this.btnShare.classList.add("button_highlight")
		this.sharebarVisible = true;
	}
}

Toolbar.prototype.download = function() {
	let triggerDL = (captchaResp = "") => {
		if (captchaResp === "") {
			this.downloadFrame.src = apiEndpoint+"/file/"+
				this.viewer.currentFile+"?download";
		} else {
			this.downloadFrame.src = apiEndpoint+"/file/"+
				this.viewer.currentFile+"?download&recaptcha_response="+captchaResp;
		}
	}

	if (captchaKey === "none"){
		// If the server doesn't support captcha there's no use in checking
		// availability
		triggerDL();
		return;
	}
	if (recaptchaResponse !== "") {
		// Captcha already filled in. Use the saved captcha responsse to
		// download the file
		triggerDL(recaptchaResponse);

		// Reset the key
		recaptchaResponse = "";
		return;
	}

	fetch(apiEndpoint+"/file/"+this.viewer.currentFile+"/availability").then(resp => {
		return resp.json();
	}).then(resp => {
		let popupDiv = document.getElementById("captcha_popup");
		let popupTitle = document.getElementById("captcha_popup_title");
		let popupContent = document.getElementById("captcha_popup_content");

		let showCaptcha = () => {
			// Load the recaptcha script with a load function
			let script = document.createElement("script");
			script.src = "https://www.google.com/recaptcha/api.js?onload=loadCaptcha&render=explicit";
			document.body.appendChild(script);

			// Show the popup
			popupDiv.style.opacity = "1";
			popupDiv.style.visibility = "visible";
		}

		if (resp.value === "file_rate_limited_captcha_required") {
			popupTitle.innerText = "Rate limiting enabled!";
			popupContent.innerText = "This file is using a suspicious "+
				"amount of bandwidth relative to its popularity. To "+
				"continue downloading this file you will have to "+
				"prove that you're a human first.";
			showCaptcha();
		} else if (resp.value === "virus_detected_captcha_required") {
			popupTitle.innerText = "Malware warning!";
			popupContent.innerText = "According to our scanning "+
				"systems this file may contain a virus  of type '"+
				resp.extra+"'. You can continue downloading this file at "+
				"your own risk, but you will have to prove that you're a "+
				"human first.";
			showCaptcha();
		} else {
			console.warn("resp.value not valid: "+resp.value);
			triggerDL();
		}
	}).catch(e => {
		console.warn("fetch availability failed: "+e);
		triggerDL();
	});
}

Toolbar.prototype.copyUrl = function() {
	if(copyText(window.location.href)) {
		console.log('Text copied');
		this.spanCopyLink.innerText = "Copied!";
		this.btnCopyLink.classList.add("button_highlight")
	} else {
		console.log('Copying not supported');
		this.spanCopyLink.innerText = "Error!";
		alert("Your browser does not support copying text.");
	}

	// Return to normal
	setTimeout(() => {
		this.spanCopyLink.innerText = "Copy";
		this.btnCopyLink.classList.remove("button_highlight")
	}, 60000);
}

Toolbar.prototype.setStats = function(file) {
	this.spanViews.innerText = file.views
	this.spanDownloads.innerText = Math.round((file.bandwidth_used/file.size)*10)/10;
	this.spanSize.innerText = formatDataVolume(file.size, 3);
}


// Called by the google recaptcha script
let recaptchaResponse = "";
function loadCaptcha(){
	grecaptcha.render("captcha_popup_captcha", {
		sitekey: captchaKey,
		theme: "dark",
		callback: token => {
			recaptchaResponse = token;
			document.getElementById("btn_download").click();

			// Hide the popup
			setTimeout(() => {
				let popupDiv = document.getElementById("captcha_popup");
				popupDiv.style.opacity = "0";
				popupDiv.style.visibility = "hidden";
			}, 1000)
		}
	});
}