Class TimelineImpl

Unique identifier for this timeline instance.

Stream of all events emitted by this timeline instance, including lifecycle events (TimelineEventType.TIMELINE_READY), viewport changes (TimelineEventType.TIMELINE_SCROLL, TimelineEventType.TIMELINE_ZOOM, TimelineEventType.TIMELINE_SLOT_SCROLL), and interaction events (TimelineEventType.TIMELINE_TIMECODE_CLICK, TimelineEventType.TIMELINE_SCRUBBER_MOVE, TimelineEventType.TIMELINE_PLAYHEAD_MOVE).

ScrubberLane instance.

Current runtime state of the timeline.

Current style configuration of the timeline. Reflects the active visual settings such as dimensions, colours, and playhead appearance.

Adds TimelineLaneApi instance to a slot.

Adds multiple instantiated TimelineLaneApi instances to a slot.

Live mode only. Clamps a seek target to both edges of what's actually reachable right now — mirroring the same bounds the player itself already enforces on every seek (see HlsPlayerController.constrainSeekTime's [liveStartTime, liveSyncPosition] clamp), so the timeline UI never visually promises a position the player would silently redirect away from:

• Below _liveTrueStartTime: inside [_liveDisplayOrigin, _liveTrueStartTime) — genuinely only a non-empty range under TimelineConfig.liveHistoryRetention — content is still rendered (thumbnails, markers, ticks) but no longer actually reachable: its segments are already evicted upstream, exactly like EvictedRegionOverlay marks.
• Above liveSyncPosition: inside LiveEdgeOverlay's reserved/locked region — not evicted, just not live yet.

Called from every seek entry point that originates from a user interaction with the timeline (scrubber/timecode click, playhead drag, timecode edit) — see call sites.

Destroys Timeline and it's dependencies

Forces a full catch-up of the rendered left bound to the true, current liveStartTime — closing the gap completely, unlike TimelineConfig.liveHistoryRetention's automatic behavior, which only ever maintains a bounded (at-most-threshold) trailing gap and never fully closes it on its own. A no-op if there's nothing to evict (including whenever no threshold is configured, since the left bound already tracks liveStartTime exactly in that case).

Absolute canvas Y of a lane's own slot's top-left, accounting for HEADER/MAIN/FOOTER vertical stacking. Used to translate a "spans the whole timeline" geometry into a slot's own local coordinate space (HEADER is 0, FOOTER is header+main height, etc.).

Which slot a lane currently lives in. Falls back to MAIN if the lane isn't attached.

Get a slot by type — HEADER (adaptive height, stacked above MAIN), MAIN (bounded/scrollable height, the primary content area), or FOOTER (adaptive height, stacked below MAIN).

Height of the HEADER + MAIN + FOOTER content, i.e. getStageHeight minus the outer vertical TimelineStyle.padding. Components anchored inside _spanningContainer (the playhead, scrubber, live edge overlay) span exactly this content region — not the raw stage, which would bleed into the padding above HEADER and below FOOTER.

Absolute canvas y where the HEADER + MAIN + FOOTER content begins, i.e. the outer top TimelineStyle.padding edge. Pairs with getSpanningContentHeight for anything that needs to span that same content region in absolute/canvas coordinates.

Same as getTimecodedFloatingDimension(), but scoped to the slot that owns the given lane (HEADER/FOOTER lanes have their own content height, distinct from MAIN's).

Returns lanes in the given slot, defaulting to MAIN (backward-compatible).

Maximize timeline lanes

Minimize timeline lanes

Removes all timeline lanes

Removes TimelineLaneApi instance by id

Removes TimelineLaneApi instances by ids

Scrolls timeline

Scrolls timeline to playhead position

Shows or hides Timeline description pane

Shows or hides Timeline description pane

Explicit user-controlled visibility toggle for a slot's vertical scrollbar. Only MAIN has a mounted scrollbar today — no-op for HEADER/FOOTER.

Live-updates the timeline's style. Only the provided fields are changed; everything else keeps its current value. Propagates to the playhead, scrubber, vertical scrollbar, thumbnail hover preview, slots, and every timeline lane, and emits TimelineEventType.TIMELINE_STYLE_CHANGE.

Recalculates and settles layout, called on window resize event

Toggles Timeline description pane

Toggles Timeline description pane

Toggles the CTI between its interactive and read-only state

Zoom in. Zoom scale in single method call is defined with TimelineConfig.zoomScale

Zoom out. Zoom scale in single method call is defined with TimelineConfig.zoomScale

Timeline zoom

Timeline zoom

Zoom to max resolution