SMTCFunctionDef.js

function mediaPlaying() {
  // Update the SystemMediaTransportControl state.
  systemMediaControls.playbackStatus = Windows.Media.MediaPlaybackStatus.playing;
}
function mediaPaused() {
  // Update the SystemMediaTransportControl state.
  systemMediaControls.playbackStatus = Windows.Media.MediaPlaybackStatus.paused;
}
function mediaEnded() {
  // Update the SystemMediaTransportControl state.
  systemMediaControls.playbackStatus = Windows.Media.MediaPlaybackStatus.stopped;
}