WebSockets: improve support for callbacks in JS client lib

3 files changed, 72 insertions, 31 deletions

diff --git a/share/web_surfaces/shared/ardour.js b/share/web_surfaces/shared/ardour.js
index ce0bb2069b..77e6bf49b9 100644
--- a/share/web_surfaces/shared/ardour.js
+++ b/share/web_surfaces/shared/ardour.js
@@ -22,36 +22,39 @@ import { MessageChannel } from './channel.js';
 export class Ardour {
 
 	constructor () {
-		this._channel = new MessageChannel(location.host);
-		this._channel.errorCallback = (error) => this.errorCallback();
-		this._channel.messageCallback = (msg) => this._onChannelMessage(msg);
+		this._callbacks = [];
 		this._pendingRequest = null;
+		this._channel = new MessageChannel(location.host);
+
+		this._channel.onError = (error) => {
+			this._fireCallbacks('error', error);
+		};
+
+		this._channel.onMessage = (msg) => {
+			this._onChannelMessage(msg);
+		};
+	}
+
+	addCallback (callback) {
+		this._callbacks.push(callback);
 	}
 
 	async open () {
-		this._channel.closeCallback = () => {
-			this.errorCallback(new Error('Message channel unexpectedly closed'));
+		this._channel.onClose = () => {
+			this._fireCallbacks('error', new Error('Message channel unexpectedly closed'));
 		};
 
 		await this._channel.open();
 	}
 
 	close () {
-		this._channel.closeCallback = () => {};
+		this._channel.onClose = () => {};
 		this._channel.close();
 	}
 
 	send (msg) {
 		this._channel.send(msg);
 	}
-	
-	errorCallback (error) {
-		// empty
-	}
-
-	messageCallback (msg) {
-		// empty
-	}
 
 	// Surface metadata API over HTTP
 
@@ -73,7 +76,8 @@ export class Ardour {
 			const xmlDoc = new DOMParser().parseFromString(xmlText, 'text/xml');
 			return {
 				name: xmlDoc.getElementsByTagName('Name')[0].getAttribute('value'),
-				description: xmlDoc.getElementsByTagName('Description')[0].getAttribute('value')
+				description: xmlDoc.getElementsByTagName('Description')[0].getAttribute('value'),
+				version: xmlDoc.getElementsByTagName('Version')[0].getAttribute('value')
 			}
 		} else {
 			throw this._fetchResponseStatusError(response.status);
@@ -151,7 +155,21 @@ export class Ardour {
 			this._pendingRequest.resolve(msg.val);
 			this._pendingRequest = null;
 		} else {
-			this.messageCallback(msg);
+			this._fireCallbacks('message', msg);
+			this._fireCallbacks(msg.node, ...msg.addr, ...msg.val);
+		}
+	}
+
+	_fireCallbacks (name, ...args) {
+		// name_with_underscores -> onNameWithUnderscores
+		const method = 'on' + name.split('_').map((s) => {
+			return s[0].toUpperCase() + s.slice(1).toLowerCase();
+		}).join('');
+
+		for (const callback of this._callbacks) {
+			if (method in callback) {
+				callback[method](...args)
+			}
 		}
 	}
 
diff --git a/share/web_surfaces/shared/callback.js b/share/web_surfaces/shared/callback.js
new file mode 100644
index 0000000000..1328f49ffb
--- /dev/null
+++ b/share/web_surfaces/shared/callback.js
@@ -0,0 +1,31 @@
+/*
+ * Copyright © 2020 Luciano Iam <lucianito@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+ export class ArdourCallback {
+
+	onTempo (bpm) {}
+	onStripGain (stripId, db) {}
+	onStripPan (stripId, value) {}
+	onStripMute (stripId, value) {}
+	onStripPluginEnable (stripId, pluginId, value) {}
+	onStripPluginParamValue (stripId, pluginId, paramId, value) {}
+
+ 	onMessage (msg) {}	
+ 	onError (error) {}
+
+ }
diff --git a/share/web_surfaces/shared/channel.js b/share/web_surfaces/shared/channel.js
index bb67c3bec4..bc5ce704c5 100644
--- a/share/web_surfaces/shared/channel.js
+++ b/share/web_surfaces/shared/channel.js
@@ -29,19 +29,19 @@ export class MessageChannel {
 		return new Promise((resolve, reject) => {
 			this._socket = new WebSocket(`ws://${this._host}`);
 
-			this._socket.onclose = () => this.closeCallback();
+			this._socket.onclose = () => this.onClose();
 
-			this._socket.onerror = (error) => this.errorCallback(error);
+			this._socket.onerror = (error) => this.onError(error);
 
 			this._socket.onmessage = (event) => {
-				this.messageCallback (Message.fromJsonText(event.data));
+				this.onMessage (Message.fromJsonText(event.data));
 			};
 
 			this._socket.onopen = resolve;
 		});
 	}
 
-	async close () {
+	close () {
 		this._socket.close();
 	}
 
@@ -53,16 +53,8 @@ export class MessageChannel {
 		}
 	}
 
-	closeCallback () {
-		// empty
-	}
-	
-	errorCallback (error) {
-		// empty
-	}
-
-	messageCallback (msg) {
-		// empty
-	}
+	onClose () {}
+	onError (error) {}
+	onMessage (msg) {}
 
 }