eythaann/Seelen-UI · error · Error

Current monitor not found

Error message

Current monitor not found

What it means

The fancy-toolbar widget derives its current monitor by finding, in the `monitors` signal, the entry whose id matches `currentMonitorId`. If no monitor matches, `$derived.by` throws `Current monitor not found`. Since this runs inside a reactive derivation, the whole toolbar render fails until the monitor id resolves.

Source

Thrown at src/ui/svelte/fancy-toolbar/state/system.svelte.ts:9

import { FancyToolbarSide } from "@seelen-ui/lib/types";
import { currentMonitorId, monitors, mousePos, virtualDesktop } from "./getters.svelte.ts";

export { virtualDesktop };

const _currentMonitor = $derived.by(() => {
  const monitor = monitors.value.find((m) => m.id === currentMonitorId);
  if (!monitor) {
    throw new Error("Current monitor not found");
  }
  return monitor;
});

const _mouseAtEdge = $derived.by((): FancyToolbarSide | null => {
  const box = _currentMonitor.rect;
  const x = mousePos.value[0];
  const y = mousePos.value[1];

  if (x < box.left || x > box.right || y < box.top || y > box.bottom) {
    return null;
  }

  if (y === box.top) {
    return FancyToolbarSide.Top;
  }

  if (y === box.bottom - 1) {

View on GitHub (pinned to dee4aaa940)

Solutions

1. Guard the lookup: fall back to the first monitor or skip the derivation when not found instead of throwing.
2. Ensure `monitors` and `currentMonitorId` signals are initialized (LazySignal `.init()` awaited) before reactive UI consumes them.
3. Subscribe to monitor-change events and re-evaluate; verify the toolbar webview restarts/re-syncs on `MonitorsChanged`.

Example fix

// before
const monitor = monitors.value.find((m) => m.id === currentMonitorId);
if (!monitor) throw new Error("Current monitor not found");
// after
const monitor = monitors.value.find((m) => m.id === currentMonitorId)
  ?? monitors.value[0];
if (!monitor) return null;

const monitor = monitors.value.find((m) => m.id === currentMonitorId);
const isMonitorReady = Boolean(monitor); // check before consuming the derived monitor

function monitorExists(id: string): boolean {
  return monitors.value.some((m) => m.id === id);
}

// wrap consumers of the derived monitor
try {
  renderToolbar(_currentMonitor);
} catch (e) {
  if ((e as Error).message === "Current monitor not found") renderSkeleton();
  else throw e;
}

When it happens

Trigger: `monitors.value` has not been populated yet (initial load before the backend sends the monitor list) or `currentMonitorId` refers to a monitor that was unplugged/changed id (display hot-plug, monitor re-enumeration, sleep/resume).

Common situations: Toolbar starting up before the first `MonitorsChanged` event arrives; user unplugs an external display the toolbar was attached to; Windows display reconfiguration changing monitor ids.

Related errors

• Current monitor not found
• Current monitor not found
• LazyRune was not initialized
• no key provided to $t()
• Monitor settings not initialized ${device.id}

AI-assisted analysis of eythaann/Seelen-UI@dee4aaa940 (2026-09-03). Data as JSON: /api/errors/711b59b6fca7b4c3. Report an issue: GitHub.