Function index

Scripts/ButSystem.py:10283–10295

index. Route handler or application helper. This docstring was expanded to make future maintenance easier. Returns: Varies.

()

    let lastErr = null;
    for (const constraints of seq){
      try { return await navigator.mediaDevices.getUserMedia(constraints); }
      catch(err){ lastErr = err; }
    }
    throw lastErr || new Error('camera_failed');
  }

  async function waitForVideo(){
    if(videoEl.readyState >= 2 && videoEl.videoWidth > 0) return;
    await new Promise((resolve, reject) => {
      let done = false;
      const ok = () => { if(done) return; done = true; cleanup(); resolve(); };
      const bad = () => { if(done) return; done = true; cleanup(); reject(new Error('video_not_ready')); };
      const cleanup = () => { videoEl.removeEventListener('loadedmetadata', ok); videoEl.removeEventListener('canplay', ok); clearTimeout(timer); };
      videoEl.addEventListener('loadedmetadata', ok, {once:true});
      videoEl.addEventListener('canplay', ok, {once:true});
      const timer = setTimeout(bad, 6000);