status features

app/index.html

@@ -36,12 +36,14 @@
 			<span class="artist"></span>
 			<span class="album"></span>
 			<span class="time1"></span>/<span class="time2"></span>
-			<button class="status"></button>
-			<button class="stop"></button>
-			<button class="prev"></button>
-			<button class="next"></button>
-			<button class="repeat"></button>
-			<button class="random"></button>
+			<span class="status">
+				<button class="play">play</button>
+				<button class="pause">pause</button>
+			</span>
+			<button class="prev">prev</button>
+			<button class="next">next</button>
+			<button class="repeat">repeat</button>
+			<button class="random">random</button>
 		</footer>		
 		<script type="module" src="js/app.js"></script>
 	</body>

app/js/app.js

@@ -6,11 +6,6 @@ async function init() {
 	await mpd.init();
 	status.init();
 	window.mpd = mpd;
-	art.get("NAS/ABBA/Greatest Hits/01 Dancing Queen.mp3").then(src => {
-		let image = document.createElement("img");
-		image.src = src;
-		document.querySelector("main").appendChild(image);
-	});
 }
 
 init();

app/js/art.js

@@ -10,8 +10,6 @@ async function getImageData(songUrl) {
 	while (1) {
 		let params = ["albumart", `"${mpd.escape(songUrl)}"`, offset];
 		let lines = await mpd.command(params.join(" "));
-		if (lines.length == 1) { return null; }
-
 		data = data.concat(lines[2]);
 		let metadata = parser.linesToStruct(lines.slice(0, 2));
 		if (data.length >= Number(metadata["size"])) { return data; }
@@ -38,14 +36,27 @@ async function resize(image) {
 	return new Promise(resolve => canvas.toBlob(resolve));
 }
 
-export async function get(songUrl) {
-	if (songUrl in cache) { return cache[songUrl]; }
+export async function get(artist, album, songUrl = null) {
+	let key = `${artist}-${album}`;
+	if (key in cache) { return cache[key]; }
 
-	let data = await getImageData(songUrl);
-	let bytes = new Uint8Array(data);
-	let image = await bytesToImage(bytes);
-	let blob = await resize(image);
-	let url = URL.createObjectURL(blob);
-	cache[songUrl] = url;
-	return url;
+	if (!songUrl) { return null; }
+
+	// promise to be returned in the meantime
+	let resolve;
+	let promise = new Promise(res => resolve = res);
+	cache[key] = promise;
+
+	try {
+		let data = await getImageData(songUrl);
+		let bytes = new Uint8Array(data);
+		let image = await bytesToImage(bytes);
+		let blob = await resize(image);
+		let url = URL.createObjectURL(blob);
+		cache[key] = url;
+		resolve(url);
+	} catch (e) {
+		cache[key] = null;
+	}
+	return cache[key];
 }

app/js/mpd.js

@@ -2,12 +2,18 @@ import * as parser from "./parser.js";
 
 let ws;
 let commandQueue = [];
-let pendingResolve;
+let current;
 
 function onMessage(e) {
-	if (pendingResolve) {
-		pendingResolve(JSON.parse(e.data)); // FIXME tady test na ACK
-		pendingResolve = null;
+	if (current) {
+		let lines = JSON.parse(e.data);
+		let last = lines.pop();
+		if (last.startsWith("OK")) {
+			current.resolve(lines);
+		} else {
+			current.reject(last);
+		}
+		current = null;
 	}
 	processQueue();
 }
@@ -23,11 +29,9 @@ function onClose(e) {
 }
 
 function processQueue() {
-	if (pendingResolve || commandQueue.length == 0) { return; }
-	let {cmd, resolve} = commandQueue.shift();
-	pendingResolve = resolve;
-	if (cmd instanceof Array) { cmd = ["command_list_begin", ...cmd, "command_list_end"].join("\n"); }
-	ws.send(cmd);
+	if (current || commandQueue.length == 0) { return; }
+	current = commandQueue.shift();
+	ws.send(current.cmd);
 }
 
 export function escape(str) {
@@ -35,24 +39,30 @@ export function escape(str) {
 }
 
 export async function command(cmd) {
-	return new Promise(resolve => {
-		commandQueue.push({cmd, resolve});
+	if (cmd instanceof Array) { cmd = ["command_list_begin", ...cmd, "command_list_end"].join("\n"); }
+
+	return new Promise((resolve, reject) => {
+		commandQueue.push({cmd, resolve, reject});
 		processQueue();
 	});
 }
 
-export async function getStatus() {
+export async function commandAndStatus(cmd) {
+	let lines = await command([cmd, "status", "currentsong"]);
+	return parser.linesToStruct(lines);
+}
+
+export async function status() {
 	let lines = await command(["status", "currentsong"]);
-	lines.pop(); // "OK"
 	return parser.linesToStruct(lines);
 }
 
 export async function init() {
 	return new Promise((resolve, reject) => {
 		try {
-			ws = new WebSocket("ws://localhost:8080?server=raspberrypi.local");
+			ws = new WebSocket("ws://localhost:8080");
 		} catch (e) { reject(e); }
-		pendingResolve = resolve;
+		current = {resolve, reject};
 
 		ws.addEventListener("error", onError);
 		ws.addEventListener("message", onMessage);

app/js/status.js

@@ -1,18 +1,52 @@
 import * as mpd from "./mpd.js";
+import * as art from "./art.js";
 
 const DELAY = 2000;
 const DOM = {};
 
+let current = {};
+
 async function tick() {
-	let data = await mpd.getStatus();
-	DOM.title.textContent = data["Title"];
+	let data = await mpd.status();
+
+	update(data);
+
 //	console.log(data);
 	setTimeout(tick, DELAY);
 }
 
+function update(data) {
+	if (data["Title"] != current["Title"]) { DOM.title.textContent = data["Title"]; }
+
+	if (data["Artist"] != current["Artist"] || data["Album"] != current["Album"]) {
+		DOM.art.innerHTML = "";
+		art.get(data["Artist"], data["Album"], data["file"]).then(src => {
+			if (!src) { return; }
+			let image = document.createElement("img");
+			image.src = src;
+			DOM.art.appendChild(image);
+		});
+	}
+
+	current = data;
+}
+
+async function play() {
+	let data = await mpd.commandAndStatus("pause 0");
+	update(data);
+}
+
+async function pause() {
+	let data = await mpd.commandAndStatus("pause 1");
+	update(data);
+}
+
 export function init() {
-	let node = document.querySelector("footer");
-	DOM.title = node.querySelector(".title");
+	let all = document.querySelectorAll("footer [class]");
+	Array.from(all).forEach(node => DOM[node.className] = node);
+
+	DOM.play.addEventListener("click", e => play());
+	DOM.pause.addEventListener("click", e => pause());
 
 	tick();
 }