The positionAlign property of the VTTCue interface is used to determine what VTTCue.position is anchored to.
A string containing one of the following values:
"line-left"Line-left alignment.
"center"Center alignment.
"line-right"Line-right alignment.
"auto"Automatic alignment, which depends on the text alignment of the cue, interpreted as follows:
In the following example a new VTTCue is created, then the value of positionAlign is set to "line-right". The value is then printed to the console.
let video = document.querySelector("video");
let track = video.addTextTrack("captions", "Captions", "en");
track.mode = "showing";
let cue = new VTTCue(0, 0.9, "Hildy!");
cue.positionAlign = "line-right";
console.log(cue.positionAlign);
track.addCue(cue);