VersionControl:PRs/rabbithole/9

rabbithole#9: Player: one ensemble element, rendered into for every song

State	🟣 merged 2026-11-05 19:55:45
Worked on by	magent, skyler, justin
Moods	#rabbithole
Deploy	pickipedia
Branch	fix/ensemble-twice → main, by magent-cryptograss
Opened · last pushed	2026-11-05 05:05:02 · 2026-11-05 19:51:17

Skyler saw every musician card twice in Firefox. Two fixes before this one removed the duplicate or guarded the timer; Justin asked why the ensemble isn't simply one container whose contents are replaced. It is now.

**What changed (`src/player/rabbithole-player.js` only):**
- The ensemble element and its Packery grid are created once, when Webamp's window first exists (`createEnsembleAfterMainWindow`). `this.ensembleEl` holds it for the life of the player.
- One card builder, `renderEnsembleCards(container)`, used by both modes. It replaces the container's contents with a card per musician in the current track data.
- `loadNewSong` calls `renderSong()`: cards, parts strip, Packery `reloadItems()`, state at 0:00. Nothing is removed, nothing is scheduled. A song loaded before the element exists is picked up by the build, which reads `trackData` when it runs.
- Gone, because the rebuild they existed for is gone: `isLoadingNewSong`; the 100-try poll for cards that had just been appended synchronously; the `innerHTML` rewrite in `updateMusicianCard` (so a card's children, including the rabbit icon and any click handler, persist; the two hand re-adds of the rabbit go with it); a new MutationObserver per song load (one now, disconnected in `cleanup()`); and the unused `oldPositions` measurement that threw when `#ensemble-display` was absent.
- `currentSolo` is normalised to `null`, so "no solo" to "no solo" no longer counts as a solo change on the first tick.

**Checked on pickipedia.xyz** with this branch's player routed in:
- first load: 1 ensemble, 5 cards, 21 parts, Packery-positioned
- `loadNewSong` twice 20ms apart: still 1 ensemble, 5 cards, same element (was 2 and 10)
- a real switch to Victory through the pane's Listen button: same element, 6 cards, 17 parts
- play into Kyle Tuttle's solo: lead class on Kyle, pane follows to Kyle Tuttle
- no page errors other than Webamp's own ReadableStream one, which appears on main too

**Tests:** 4 new in `tests/player/ensemble.test.js` with a toy DOM (render into the element, two loads leave one, a load before the element waits for the build, a card update keeps its children). 89/89 pass.

This is the first of the three structural changes in [26350517 Rabbithole player audit](https://pickipedia.xyz/wiki/26350517_Rabbithole_player_audit). Card-click delegation (audit item 6) waits for #10 to merge, since it touches the same lines.

Deploy: pickipedia
Worked on by: magent, skyler, justin, in #rabbithole