Keep screen on during listening sessions via Wake Lock API

Mårten Åsberg committed on 2026-05-24 at 11:50

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/routes/+page.svelte +25 -0

diff --git a/src/routes/+page.svelte b/src/routes/+page.svelte
index 781005d..21347b5 100644
@@ -13,8 +13,24 @@
  let sourceNode: MediaStreamAudioSourceNode | null = null;
  let stream: MediaStream | null = null;
  let sampleBuffer: Float32Array = new Float32Array(0);
  let wakeLock: WakeLockSentinel | null = null;
  async function acquireWakeLock(): Promise<void> {
    if (!("wakeLock" in navigator)) return;
    try {
      wakeLock = await navigator.wakeLock.request("screen");
    } catch {
      // not supported or permission denied — silent fail
    }
  }
  function releaseWakeLock(): void {
    wakeLock?.release();
    wakeLock = null;
  }
  async function startListening() {
    await acquireWakeLock();
    startSession();
    audioCtx = new AudioContext({ sampleRate: 48000 });
    await audioCtx.audioWorklet.addModule("/audio-processor.js");
@@ -55,6 +71,7 @@
  }
  function stopListening() {
    releaseWakeLock();
    workletNode?.disconnect();
    sourceNode?.disconnect();
    stream?.getTracks().forEach((t) => t.stop());
@@ -84,6 +101,14 @@
  }
</script>
<svelte:document
  onvisibilitychange={() => {
    if (document.visibilityState === "visible" && listening) {
      acquireWakeLock();
    }
  }}
/>
<PatchBanner text="BirdGO" />
{#if birdnet.predictions.length > 0}