@ElementPath

using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Text; using System.Threading; using System.Threading.Tasks; using System.Net; using System.Net.WebSockets; namespace Ooui { public static class UI { static CancellationTokenSource serverCts; static readonly Dictionary> publishedPaths = new Dictionary> (); static readonly Dictionary styles = new Dictionary (); static readonly StyleSelectors rules = new StyleSelectors (); public static StyleSelectors Styles => rules; static readonly byte[] clientJsBytes; public static string Template { get; set; } = $@" @ElementPath

"; static string host = "*"; public static string Host { get => host; set { if (!string.IsNullOrWhiteSpace (value) && host != value) { host = value; Restart (); } } } static int port = 8080; public static int Port { get => port; set { if (port != value) { port = value; Restart (); } } } static UI () { var asm = typeof(UI).Assembly; // System.Console.WriteLine("ASM = {0}", asm); // foreach (var n in asm.GetManifestResourceNames()) { // System.Console.WriteLine(" {0}", n); // } using (var s = asm.GetManifestResourceStream ("Ooui.Client.js")) { using (var r = new StreamReader (s)) { clientJsBytes = Encoding.UTF8.GetBytes (r.ReadToEnd ()); } } } public static void Publish (string path, Func elementCtor) { Console.WriteLine ($"PUBLISH {path}"); lock (publishedPaths) publishedPaths[path] = elementCtor; Start (); } public static void Publish (string path, Element element) { Publish (path, () => element); } public static void Present (string path, object presenter = null) { var localHost = host == "*" ? "localhost" : host; var url = $"http://{localHost}:{port}{path}"; Console.WriteLine ($"PRESENT {url}"); var cmd = url; var args = ""; var osv = Environment.OSVersion; if (osv.Platform == PlatformID.Unix) { cmd = "open"; args = url; } // var vs = Environment.GetEnvironmentVariables (); // foreach (System.Collections.DictionaryEntry kv in vs) { // System.Console.WriteLine($"K={kv.Key}, V={kv.Value}"); // } Console.WriteLine ($"EXEC {cmd} {args}"); try { System.Diagnostics.Process.Start (cmd, args); } catch (Exception ex) { System.Console.WriteLine("FAILED TO EXEC"); System.Console.WriteLine(ex); } } static void Start () { if (serverCts != null) return; serverCts = new CancellationTokenSource (); var token = serverCts.Token; var listenerPrefix = $"http://{host}:{port}/"; Task.Run (() => RunAsync (listenerPrefix, token), token); } static void Stop () { var scts = serverCts; if (scts == null) return; serverCts = null; Console.ForegroundColor = ConsoleColor.Green; Console.WriteLine ($"Stopping..."); Console.ResetColor (); scts.Cancel (); } static void Restart () { if (serverCts == null) return; Stop (); Start (); } static async Task RunAsync (string listenerPrefix, CancellationToken token) { HttpListener listener = null; var started = false; while (!started && !token.IsCancellationRequested) { try { listener = new HttpListener (); listener.Prefixes.Add (listenerPrefix); listener.Start (); started = true; } catch (System.Net.Sockets.SocketException ex) when (ex.SocketErrorCode == System.Net.Sockets.SocketError.AddressAlreadyInUse) { var wait = 5; Console.WriteLine ($"{listenerPrefix} is in use, trying again in {wait} seconds..."); await Task.Delay (wait * 1000).ConfigureAwait (false); } } Console.ForegroundColor = ConsoleColor.Green; Console.WriteLine ($"Listening at {listenerPrefix}..."); Console.ResetColor (); while (!token.IsCancellationRequested) { var listenerContext = await listener.GetContextAsync ().ConfigureAwait (false); if (listenerContext.Request.IsWebSocketRequest) { ProcessWebSocketRequest (listenerContext, token); } else { ProcessRequest (listenerContext, token); } } } static void ProcessRequest (HttpListenerContext listenerContext, CancellationToken token) { var url = listenerContext.Request.Url; var path = url.LocalPath; Console.WriteLine ($"{listenerContext.Request.HttpMethod} {url.LocalPath}"); var response = listenerContext.Response; Func ctor; if (path == "/ooui.js") { response.ContentLength64 = clientJsBytes.LongLength; response.ContentType = "application/javascript"; response.ContentEncoding = Encoding.UTF8; response.AddHeader ("Cache-Control", "public, max-age=3600"); using (var s = response.OutputStream) { s.Write (clientJsBytes, 0, clientJsBytes.Length); } } else { var found = false; lock (publishedPaths) found = publishedPaths.TryGetValue (path, out ctor); if (found) { WriteElementHtml (path, response); } else { response.StatusCode = 404; response.Close (); } } } static string RenderTemplate (string elementPath) { return Template.Replace ("@ElementPath", elementPath).Replace ("@Styles", rules.ToString ()); } static void WriteElementHtml (string elementPath, HttpListenerResponse response) { response.StatusCode = 200; response.ContentType = "text/html"; response.ContentEncoding = Encoding.UTF8; var html = Encoding.UTF8.GetBytes (RenderTemplate (elementPath)); response.ContentLength64 = html.LongLength; using (var s = response.OutputStream) { s.Write (html, 0, html.Length); } response.Close (); } static async void ProcessWebSocketRequest (HttpListenerContext listenerContext, CancellationToken serverToken) { // // Find the element // var url = listenerContext.Request.Url; var path = url.LocalPath; Func ctor; var found = false; lock (publishedPaths) found = publishedPaths.TryGetValue (path, out ctor); if (!found) { listenerContext.Response.StatusCode = 404; listenerContext.Response.Close (); return; } Element element = null; try { element = ctor (); } catch (Exception ex) { listenerContext.Response.StatusCode = 500; listenerContext.Response.Close(); Error ("Failed to create element", ex); return; } // // Connect the web socket // WebSocketContext webSocketContext = null; WebSocket webSocket = null; try { webSocketContext = await listenerContext.AcceptWebSocketAsync (subProtocol: "ooui").ConfigureAwait (false); webSocket = webSocketContext.WebSocket; Console.WriteLine ("WEBSOCKET {0}", listenerContext.Request.Url.LocalPath); } catch (Exception ex) { listenerContext.Response.StatusCode = 500; listenerContext.Response.Close(); Error ("Failed to accept WebSocket", ex); return; } // // Create a new session and let it handle everything from here // try { var session = new Session (webSocket, element, serverToken); await session.RunAsync ().ConfigureAwait (false); } catch (WebSocketException ex) when (ex.WebSocketErrorCode == WebSocketError.ConnectionClosedPrematurely) { // The remote party closed the WebSocket connection without completing the close handshake. } catch (Exception ex) { Error ("Web socket failed", ex); } finally { webSocket?.Dispose (); } } static void Error (string message, Exception ex) { Console.ForegroundColor = ConsoleColor.Red; Console.WriteLine ("{0}: {1}", message, ex); Console.ResetColor (); } class Session { readonly WebSocket webSocket; readonly Element element; readonly Action handleElementMessageSent; readonly CancellationTokenSource sessionCts = new CancellationTokenSource (); readonly CancellationTokenSource linkedCts; readonly CancellationToken token; readonly HashSet createdIds; readonly List queuedMessages = new List (); readonly System.Timers.Timer sendThrottle; DateTime lastTransmitTime = DateTime.MinValue; readonly TimeSpan throttleInterval = TimeSpan.FromSeconds (1.0 / 30); // 30 FPS max public Session (WebSocket webSocket, Element element, CancellationToken serverToken) { this.webSocket = webSocket; this.element = element; // // Create a new session cancellation token that will trigger // automatically if the server shutsdown or the session shutsdown. // linkedCts = CancellationTokenSource.CreateLinkedTokenSource (serverToken, sessionCts.Token); token = linkedCts.Token; // // Keep a list of all the elements for which we've transmitted the initial state // createdIds = new HashSet { "window", "document", "document.body", }; // // Preparse handlers for the element // handleElementMessageSent = QueueMessage; // // Create a timer to use as a throttle when sending messages // sendThrottle = new System.Timers.Timer (throttleInterval.TotalMilliseconds); sendThrottle.Elapsed += (s, e) => { // System.Console.WriteLine ("TICK SEND THROTTLE FOR {0}", element); if ((e.SignalTime - lastTransmitTime) >= throttleInterval) { sendThrottle.Enabled = false; lastTransmitTime = e.SignalTime; TransmitQueuedMessages (); } }; } public async Task RunAsync () { // // Start watching for changes in the element // element.MessageSent += handleElementMessageSent; try { // // Add it to the document body // QueueMessage (Message.Call ("document.body", "appendChild", element)); // // Start the Read Loop // var receiveBuffer = new byte[64*1024]; while (webSocket.State == WebSocketState.Open && !token.IsCancellationRequested) { var receiveResult = await webSocket.ReceiveAsync(new ArraySegment(receiveBuffer), token).ConfigureAwait (false); if (receiveResult.MessageType == WebSocketMessageType.Close) { await webSocket.CloseAsync (WebSocketCloseStatus.NormalClosure, "", token).ConfigureAwait (false); sessionCts.Cancel (); } else if (receiveResult.MessageType == WebSocketMessageType.Binary) { await webSocket.CloseAsync (WebSocketCloseStatus.InvalidMessageType, "Cannot accept binary frame", token).ConfigureAwait (false); sessionCts.Cancel (); } else { var size = receiveResult.Count; while (!receiveResult.EndOfMessage) { if (size >= receiveBuffer.Length) { await webSocket.CloseAsync (WebSocketCloseStatus.MessageTooBig, "Message too big", token).ConfigureAwait (false); return; } receiveResult = await webSocket.ReceiveAsync (new ArraySegment(receiveBuffer, size, receiveBuffer.Length - size), token).ConfigureAwait (false); size += receiveResult.Count; } var receivedString = Encoding.UTF8.GetString (receiveBuffer, 0, size); try { // Console.WriteLine ("RECEIVED: {0}", receivedString); var message = Newtonsoft.Json.JsonConvert.DeserializeObject (receivedString); element.Receive (message); } catch (Exception ex) { Error ("Failed to process received message", ex); } } } } finally { element.MessageSent -= handleElementMessageSent; } } void QueueStateMessages (EventTarget target) { if (target == null) return; foreach (var m in target.StateMessages) { QueueMessage (m); } } void QueueMessage (Message message) { // // Make sure all the referenced objects have been created // if (message.MessageType == MessageType.Create) { createdIds.Add (message.TargetId); } else { if (!createdIds.Contains (message.TargetId)) { createdIds.Add (message.TargetId); QueueStateMessages (element.GetElementById (message.TargetId)); } if (message.Value is Array a) { for (var i = 0; i < a.Length; i++) { // Console.WriteLine ($"A{i} = {a.GetValue(i)}"); if (a.GetValue (i) is EventTarget e && !createdIds.Contains (e.Id)) { createdIds.Add (e.Id); QueueStateMessages (e); } } } } // // Add it to the queue // lock (queuedMessages) queuedMessages.Add (message); sendThrottle.Enabled = true; } async void TransmitQueuedMessages () { try { // // Dequeue as many messages as we can // var messagesToSend = new List (); lock (queuedMessages) { messagesToSend.AddRange (queuedMessages); queuedMessages.Clear (); } if (messagesToSend.Count == 0) return; // // Now actually send this message // var json = Newtonsoft.Json.JsonConvert.SerializeObject (messagesToSend); var outputBuffer = new ArraySegment (Encoding.UTF8.GetBytes (json)); await webSocket.SendAsync (outputBuffer, WebSocketMessageType.Text, true, token).ConfigureAwait (false); } catch (Exception ex) { Error ("Failed to send queued messages, aborting session", ex); element.MessageSent -= handleElementMessageSent; sessionCts.Cancel (); } } } public class StyleSelectors { public Style this[string selector] { get { Style r; var key = selector ?? ""; lock (styles) { if (!styles.TryGetValue (key, out r)) { r = new Style (); styles.Add (key, r); } return r; } } set { var key = selector ?? ""; lock (styles) { if (value == null) { styles.Remove (key); } else { styles[key] = value; } } } } public void Clear () { lock (styles) { styles.Clear (); } } public override string ToString() { lock (styles) { var q = from s in styles let v = s.Value.ToString () where v.Length > 0 select s.Key + " {" + s.Value.ToString () + "}"; return String.Join ("\n", q); } } } } }