Theia USB Service

// browser/fusb-service-contribution.ts

import { interfaces } from "inversify";
import { UsbService, workspacePath } from "../../common/usb-service-protocol";
import { WebSocketConnectionProvider } from "@theia/core/lib/browser";

export function bindUsbService(bind: interfaces.Bind): void {
    bind(UsbService).toDynamicValue(ctx => {
        const provider = ctx.container.get(WebSocketConnectionProvider);
        return provider.createProxy<UsbService>(workspacePath);
    }).inSingletonScope();
};


// common/usb-service-protocol.ts

import { Event } from "@theia/core";
import { Device } from "usb";
export const workspacePath = '/services/ves/usb';

export const UsbService = Symbol('UsbService');
export interface UsbService {
    onDeviceConnected: Event<Device>;
}


// node/usb-service-module.ts

import { ContainerModule } from 'inversify';
import { ConnectionHandler, JsonRpcConnectionHandler } from '@theia/core';
import { DefaultUsbService } from './default-usb-service';
import { UsbService, workspacePath } from '../common/usb-service-protocol';

export default new ContainerModule(bind => {
    bind(DefaultUsbService).toSelf().inSingletonScope();
    bind(UsbService).toService(DefaultUsbService);

    bind(ConnectionHandler).toDynamicValue(ctx =>
        new JsonRpcConnectionHandler(workspacePath, () => {
            return ctx.container.get(UsbService);
        })
    ).inSingletonScope()
});


// node/default-usb-service.ts

import { injectable, postConstruct } from "inversify";
import { UsbService } from "../common/usb-service-protocol";
import { Device, on } from "usb";
import { Emitter } from "@theia/core";

@injectable()
export class DefaultUsbService implements UsbService {
    protected readonly onDeviceConnectedEmitter = new Emitter<Device>();
    readonly onDeviceConnected = this.onDeviceConnectedEmitter.event;

    @postConstruct()
    protected init(): void {
        const self = this;
        on('attach', async function (device) {
            console.log('attach');
            self.onDeviceConnectedEmitter.fire(device);
        });
    }
}


// somewhere in frontend

this.usbService.onDeviceConnected(() => console.log("connected!"));


// error

root INFO attach
root ERROR TypeError: Cannot read property 'apply' of undefined