node_helper.js

/* MagicMirror²
 * Node Helper: MMM-KeyBindings
 *
 * By shbatm
 * MIT Licensed.
 */
/* jshint node: true, esversion: 6*/

const NodeHelper = require("node_helper");
const Log = require("logger");

var evdev;
var udev;

module.exports = NodeHelper.create({
  start: function () {
    Log.log("MMM-KeyBindings helper has started…");
    this.evdevMonitorCreated = false;
  },

  stop: function () {
    if (this.evdevMonitorCreated) {
      Log.log("EVDEV: Closing monitor and reader");
      try {
        this.udevMonitor.close();
      } catch (e) {
        if (
          e.toString().indexOf("Cannot read property 'close' of undefined") ===
          -1
        ) {
          Log.error(e);
        }
      }
      try {
        this.evdevReader.close();
      } catch (e) {
        Log.error(e);
      }
    }
  },

  waitForDevice: function () {
    this.udevMonitor = udev.monitor();
    this.udevMonitor.on("add", (device) => {
      if (
        "DEVLINKS" in device &&
        device.DEVLINKS === this.evdevConfig.eventPath
      ) {
        Log.log("UDEV: Device connected.");
        this.udevMonitor.close();
        this.setupDevice();
      }
    });
  },

  setupDevice: function () {
    this.device = this.evdevReader.open(this.evdevConfig.eventPath);
    this.device.on("open", () => {
      Log.log(`EVDEV: Connected to device: ${JSON.stringify(this.device.id)}`);
    });
    this.device.on("close", () => {
      Log.debug(`EVDEV: Connection to device has been closed.`);
      this.waitForDevice();
    });
  },

  startEvdevMonitor: function () {
    evdev = require("evdev");
    udev = require("udev");

    this.evdevMonitorCreated = true;
    this.evdevReader = new evdev();
    this.pendingKeyPress = {};

    this.evdevReader
      .on("EV_KEY", (data) => {
        // Log.log("key : ", data.code, data.value);
        if (data.value > 0) {
          this.pendingKeyPress.code = data.code;
          this.pendingKeyPress.value = data.value;
        } else {
          if (
            "code" in this.pendingKeyPress &&
            this.pendingKeyPress.code === data.code
          ) {
            Log.log(
              `${this.pendingKeyPress.code} ${
                this.pendingKeyPress.value === 2 ? "long " : ""
              }pressed.`
            );
            this.sendSocketNotification("KEYPRESS", {
              keyName: data.code,
              keyState:
                this.pendingKeyPress.value === 2
                  ? "KEY_LONGPRESSED"
                  : "KEY_PRESSED"
            });
          }
          this.pendingKeyPress = {};
        }
      })
      .on("error", (e) => {
        if (e.code === "ENODEV" || e.code === "ENOENT") {
          Log.info(
            `EVDEV: Device not connected, nothing at path ${e.path}, waiting for device…`
          );
          this.waitForDevice();
        } else {
          Log.error("EVDEV: ", e);
        }
      });

    this.setupDevice();
  },

  socketNotificationReceived: function (notification, payload) {
    if (notification === "ENABLE_EVDEV") {
      if (!this.evdevMonitorCreated) {
        this.evdevConfig = payload;
        this.startEvdevMonitor();
      }
    }
  }
});