- PanelKind::Viewer(n): more Composition viewers (panels::viewers). One is active (the full
interactive viewer, showing the active comp); the others show their own comp's frame at that
comp's current time (CPU or GPU frames, their own textures) and become active on a click or
their tab, their comp becoming the active comp.
- view.newViewer (View menu, the Composition panel menu, Alt+Shift+N): a new viewer of the
active comp next to the one in use, which is locked. Opening a comp while the active viewer
is locked shows it in an unlocked viewer, or a new one when every viewer is locked. Closing
the active viewer hands over to another with its comp. Tabs are named after their comp, with
their own lock and swatch; Preview full screen maximizes the active viewer.
- UI state: viewers (comp per viewer) and active_viewer (serde).
- Tests: ui_viewers (lock on New Viewer, routing, click to activate, all locked → new viewer,
close hand-over, tab titles; an ignored snapshot). The bounded-drag frames test asserts what
holds when freed addresses are reused. Docs: parity, control protocol.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>