MediaSession.setPositionState()

The MediaSession method setPositionState() is used to update the current document's media playback position and speed for presentation by user's device in any kind of interface that provides details about ongoing media. This can be particularly useful if your code implements a player for type of media not directly supported by the browser.

Call this method on the navigator object's mediaSession object.

Syntax

navigator.mediaSession.setPositionState(stateDict);

Parameters

stateDict Optional

An object conforming to the MediaPositionState dictionary, providing updated information about the playback position and speed of the document's ongoing media. If the object is empty, the existing playback state information is cleared.

Return value

undefined.

Exceptions

TypeError

This error can occur in an array of circumstances:

• The specified MediaPositionState object's duration is missing, negative, or null.
• position is missing or null, or is either negative or greater than duration.
• The playbackRate is zero.

Example

In this example, a player for a non-standard media file format, written in JavaScript, uses setInterval() to establish a callback which fires once per second to refresh the position information by calling setPositionState(). If the media is still playing when the interval is fired, setPositionState() is called with an object that specifies the duration, playback rate, and position as reported by a myMedia object that describes the track being played.

If the media is not playing, clearInterval() is used to remove the interval handler.

let positionInterval = window.setInterval(() => {
  if (myMedia.isPlaying) {
    navigator.mediaSession.setPositionState({
      duration: myMedia.trackDurationInSeconds,
      playbackRate: myMedia.playbackRate,
      position: myMedia.trackPlayPositionInSeconds
    });
  } else {
    window.clearInterval(positionInterval);
  }
}, 1000);

Specifications

Browser compatibility

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.