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livetrax/share/web_surfaces/shared/ardour.js
2021-06-14 10:25:45 +02:00

153 lines
3.7 KiB
JavaScript

/*
* Copyright © 2020 Luciano Iam <oss@lucianoiam.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.
*/
import { Component } from './base/component.js';
import { StateNode } from './base/protocol.js';
import MessageChannel from './base/channel.js';
import Mixer from './components/mixer.js';
import Transport from './components/transport.js';
function getOption (options, key, defaultValue) {
return options ? (key in options ? options[key] : defaultValue) : defaultValue;
}
export default class ArdourClient extends Component {
constructor (options) {
super(new MessageChannel(getOption(options, 'host', location.host)));
if (getOption(options, 'components', true)) {
this._mixer = new Mixer(this);
this._transport = new Transport(this);
this._components = [this._mixer, this._transport];
} else {
this._components = [];
}
this._autoReconnect = getOption(options, 'autoReconnect', true);
this._connected = false;
this.channel.onMessage = (msg, inbound) => this._handleMessage(msg, inbound);
this.channel.onError = (err) => this.notifyObservers('error', err);
}
// Access to the object-oriented API (enabled by default)
get mixer () {
return this._mixer;
}
get transport () {
return this._transport;
}
// Low level control messages flow through a WebSocket
async connect () {
this.channel.onClose = async () => {
if (this._connected) {
this._setConnected(false);
}
if (this._autoReconnect) {
await this._sleep(1000);
await this._connect();
}
};
await this._connect();
}
disconnect () {
this.channel.onClose = () => {};
this.channel.close();
this._connected = false;
}
send (msg) {
this.channel.send(msg);
}
async sendAndReceive (msg) {
return await this.channel.sendAndReceive(msg);
}
// Surface metadata API goes over HTTP
async getAvailableSurfaces () {
const response = await fetch('/surfaces.json');
if (response.status == 200) {
return await response.json();
} else {
throw this._fetchResponseStatusError(response.status);
}
}
async getSurfaceManifest () {
const response = await fetch('manifest.xml');
if (response.status == 200) {
const manifest = {};
const xmlText = await response.text();
const xmlDoc = new DOMParser().parseFromString(xmlText, 'text/xml');
for (const child of xmlDoc.children[0].children) {
manifest[child.tagName.toLowerCase()] = child.getAttribute('value');
}
return manifest;
} else {
throw this._fetchResponseStatusError(response.status);
}
}
// Private methods
async _sleep (t) {
return new Promise(resolve => setTimeout(resolve, t));
}
async _connect () {
await this.channel.open();
this._setConnected(true);
}
_setConnected (connected) {
this._connected = connected;
this.notifyPropertyChanged('connected');
}
_handleMessage (msg, inbound) {
this.notifyObservers('message', msg, inbound);
if (inbound) {
for (const component of this._components) {
if (component.handleMessage(msg)) {
break;
}
}
}
}
_fetchResponseStatusError (status) {
return new Error(`HTTP response status ${status}`);
}
}