bitwarden-browser/apps/browser/src/background/idle.background.ts

import { NotificationsService } from "jslib-common/abstractions/notifications.service";
import { VaultTimeoutService } from "jslib-common/abstractions/vaultTimeout.service";

import { StateService } from "../services/abstractions/state.service";

const IdleInterval = 60 * 5; // 5 minutes

export default class IdleBackground {
  private idle: any;
  private idleTimer: number = null;
  private idleState = "active";

  constructor(
    private vaultTimeoutService: VaultTimeoutService,
    private stateService: StateService,
    private notificationsService: NotificationsService
  ) {
    this.idle = chrome.idle || (browser != null ? browser.idle : null);
  }

  async init() {
    if (!this.idle) {
      return;
    }

    const idleHandler = (newState: string) => {
      if (newState === "active") {
        this.notificationsService.reconnectFromActivity();
      } else {
        this.notificationsService.disconnectFromInactivity();
      }
    };
    if (this.idle.onStateChanged && this.idle.setDetectionInterval) {
      this.idle.setDetectionInterval(IdleInterval);
      this.idle.onStateChanged.addListener(idleHandler);
    } else {
      this.pollIdle(idleHandler);
    }

    if (this.idle.onStateChanged) {
      this.idle.onStateChanged.addListener(async (newState: string) => {
        if (newState === "locked") {
          // If the screen is locked or the screensaver activates
          const timeout = await this.stateService.getVaultTimeout();
          if (timeout === -2) {
            // On System Lock vault timeout option
            const action = await this.stateService.getVaultTimeoutAction();
            if (action === "logOut") {
              await this.vaultTimeoutService.logOut();
            } else {
              await this.vaultTimeoutService.lock(true);
            }
          }
        }
      });
    }
  }

  private pollIdle(handler: (newState: string) => void) {
    if (this.idleTimer != null) {
      window.clearTimeout(this.idleTimer);
      this.idleTimer = null;
    }
    this.idle.queryState(IdleInterval, (state: string) => {
      if (state !== this.idleState) {
        this.idleState = state;
        handler(state);
      }
      this.idleTimer = window.setTimeout(() => this.pollIdle(handler), 5000);
    });
  }
}