Source code
Revision control
Copy as Markdown
Other Tools
<!DOCTYPE html>
<html>
<head>
<title>Web Audio audibility page</title>
</head>
<body>
<button id="start">start</button>
<script>
let ac;
let osc;
let gain;
// Triggered from the test by clicking the button (which also synthesizes a
// user gesture so the AudioContext is allowed to start without autoplay
// rejection).
document.getElementById("start").addEventListener("click", () => {
ac = new AudioContext();
osc = ac.createOscillator();
gain = ac.createGain();
gain.gain.value = 0.05;
osc.connect(gain);
gain.connect(ac.destination);
osc.start();
});
// Expose state to the test.
window.getAudioContextState = () => ac && ac.state;
window.waitForAudioContextState = expected =>
new Promise(resolve => {
if (!ac) {
resolve(null);
return;
}
if (ac.state === expected) {
resolve(ac.state);
return;
}
ac.addEventListener("statechange", function listener() {
if (ac.state === expected) {
ac.removeEventListener("statechange", listener);
resolve(ac.state);
}
});
});
window.resumeAudioContext = () => ac && ac.resume();
</script>
</body>
</html>