Timeline editing

Read from the current Project

Render timeline rows from session.getSnapshot() and stable entity IDs. Commands should be prepared against the current revision, not a stale component copy.

Core item commands

• Move changes timeline placement and optionally track/order.
• Trim changes an edge while preserving valid source mapping and transitions.
• Split creates a right-hand item at an interior time and partitions supported owned data.
• Slip keeps placement but moves the source window.
• Ripple shifts affected neighbors according to the command scope.
• Roll moves a shared edit point between neighbors.
• Slide moves an item while adjusting adjacent boundaries.

Commands reject missing source handles, unsupported nonlinear mapping, locked/incompatible tracks, transition conflicts, and owned data without a deterministic policy.

Linked A/V

Imported video and audio may share a link group. Pass the linked-edit option when the product promises synchronized behavior. Explicit unlink is preferable to silently editing only one member.

Tracks and markers

Use track commands for add/remove/reorder, visibility, lock, mute, and solo behavior. Markers are non-rendering time annotations and can be sequence- or item-scoped.

Smooth drag behavior

Keep pointer state and the proposed position in view state. Open one history interaction group, throttle/coalesce command submission, reject stale results, and commit or cancel the group at pointer-up. Do not create one undo entry per pointer event.

Refresh after commits

Subscribe to committed change sets, read the matching snapshot, update normalized selectors, and invalidate only affected thumbnails/waveforms. Map stable COMMAND_* and REVISION_CONFLICT diagnostics to actionable UI.

Exact parameters and return values are listed in Editing Commands.