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livetrax/share/web_surfaces/shared/channel.js

134 lines
3.0 KiB
JavaScript

/*
* 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 const JSON_INF = 1.0e+128;
export const ANode = Object.freeze({
TEMPO: 'tempo',
STRIP_DESC: 'strip_desc',
STRIP_METER: 'strip_meter',
STRIP_GAIN: 'strip_gain',
STRIP_PAN: 'strip_pan',
STRIP_MUTE: 'strip_mute',
STRIP_PLUGIN_DESC: 'strip_plugin_desc',
STRIP_PLUGIN_ENABLE: 'strip_plugin_enable',
STRUP_PLUGIN_PARAM_DESC: 'strip_plugin_param_desc',
STRIP_PLUGIN_PARAM_VALUE: 'strip_plugin_param_value'
});
export function nodeAddressHash(node, addr) {
return [node].concat(addr || []).join('_');
}
export class MessageChannel {
constructor (host) {
// https://developer.mozilla.org/en-US/docs/Web/API/URL/host
this.host = host;
}
async open () {
return new Promise((resolve, reject) => {
this.socket = new WebSocket(`ws://${this.host}`);
this.socket.onclose = () => this.closeCallback();
this.socket.onerror = (error) => this.errorCallback(error);
this.socket.onmessage = (event) => {
this.messageCallback (Message.fromJsonText(event.data));
};
this.socket.onopen = resolve;
});
}
send (msg) {
if (this.socket) {
this.socket.send(msg.toJsonText());
} else {
throw Error('MessageChannel: cannot call send() before open()');
}
}
closeCallback () {
// empty
}
errorCallback (error) {
// empty
}
messageCallback (msg) {
// empty
}
}
export class Message {
constructor (node, addr, val) {
this.node = node;
this.addr = addr;
this.val = [];
for (const i in val) {
if (val[i] >= JSON_INF) {
this.val.push(Infinity);
} else if (val[i] <= -JSON_INF) {
this.val.push(-Infinity);
} else {
this.val.push(val[i]);
}
}
}
static fromJsonText (jsonText) {
let rawMsg = JSON.parse(jsonText);
return new Message(rawMsg.node, rawMsg.addr || [], rawMsg.val);
}
toJsonText () {
let val = [];
for (const i in this.val) {
if (this.val[i] == Infinity) {
val.push(JSON_INF);
} else if (this.val[i] == -Infinity) {
val.push(-JSON_INF);
} else {
val.push(this.val[i]);
}
}
return JSON.stringify({node: this.node, addr: this.addr, val: val});
}
get hash () {
return nodeAddressHash(this.node, this.addr);
}
toString () {
return `${this.node} (${this.addr}) = ${this.val}`;
}
}