OptionalsetSupplies the CSS bodies of the track's WebVTT STYLE blocks (which carry
::cue rules), so the renderer can style cue classes. Optional — a
renderer may ignore authored styles.
Renders the active cues of track, listening for cue changes. Passing
null clears anything rendered and detaches from the previous track.
Renders a text track's cues. Injected into the player so an application can paint captions itself (as HTML) instead of relying on the browser's native
TextTrackrendering — giving full control over styling and placement.The controller hands the renderer the DOM
TextTrack(set to'hidden', so the browser tracks cue timing but does not paint); the renderer listens for the track's active cues and draws them. See HtmlTextTrackRenderer for the built-in HTML implementation.