Add serial facade (#4402)

* Add serial facade

* Fix websocket connection

* Refactor

* Fix unplug

* Fix reboot / unplug reconnect issue

* The real deal (detail has no value)

src/js/protocols/VirtualSerial.js

@@ -0,0 +1,51 @@
+const VIRTUAL = "virtual";
+
+/**
+ * Stripped down version of previous nwjs based serial port implementation
+ * which is required to still have virtual serial port support in the
+ * browser.
+ */
+class VirtualSerial {
+    constructor() {
+        this.connected = false;
+        this.connectionId = false;
+        this.openCanceled = false;
+        this.bitrate = 0;
+        this.bytesReceived = 0;
+        this.bytesSent = 0;
+        this.failed = 0;
+        this.connectionType = VIRTUAL;
+        this.transmitting = false;
+        this.outputBuffer = [];
+    }
+    connect(callback) {
+        if (!this.openCanceled) {
+            this.connected = true;
+            this.connectionId = VIRTUAL;
+            this.bitrate = 115200;
+            callback();
+        }
+    }
+    disconnect(callback) {
+        this.connected = false;
+        this.outputBuffer = [];
+        this.transmitting = false;
+        if (this.connectionId) {
+            this.connectionId = false;
+            this.bitrate = 0;
+            if (callback) {
+                callback(true);
+            }
+        }
+    }
+    getConnectedPort() {
+        return this.connectionId;
+    }
+    getDevices() {
+        return new Promise((resolve) => {
+            resolve([{ path: VIRTUAL }]);
+        });
+    }
+}
+
+export default VirtualSerial;