musicmouse/web/README.md

Musik Delphin — the web front-end

Browse the whole music collection and play any of it from a browser: the six figurines are only five of the twenty-odd albums on the shelf, and everything else was previously unreachable without swapping files around on disk.

Built from ../claude-design/Dolphin Beats.dc.html, which is a finished interaction and visual spec rather than a sketch. The keyboard model, the layout, the colours and the German copy are ported from it; what changed is that a real player sits behind it.

Running it

The backend serves the API. Either of these will do - --simulate needs no audio device and no libVLC at all, which makes it the easier one to develop against:

cd ../python-backend
python -m musicmouse --config ./config.yml --no-hardware   # real audio
python -m musicmouse --config ./config.yml --simulate      # fake player

Then:

npm install
npm run dev      # http://localhost:5173, /api and the websocket proxied to :8080

For the device, npm run build writes dist/, and general.web.static_dir in config.yml points at it so one process serves both.

Checks

npm run test          # vitest over src/lib
npx tsc --noEmit      # strict, noUncheckedIndexedAccess

Only the pure modules are tested - the search, the keyboard machine and the time formatting. That is where the behaviour lives; the components are mostly layout.

src/lib/search.ts builds its normalized search keys once per library payload (buildSearchIndex) rather than per keystroke. It matters more than it sounds: a real collection is 343 albums and 4969 tracks, and normalize() does a Unicode NFD decomposition, so track search used to mean five thousand of those before a single comparison - 4 ms per keystroke on a laptop, and this runs on a Pi. The same build also partitions albums by shelf and pre-sorts each shelf's categories, which App and BrowseView were otherwise deriving separately from the same data.

How it is put together

The split that matters: what is playing comes from the backend, what you are looking at lives in the browser. The mockup kept both in one state object, but a real player has other front-ends - the buttons on the mouse, a figurine on the reader, Home Assistant - and this UI has to follow them rather than assume it is in charge. So isPlaying, volume, the position and the current album all arrive over the websocket, and only search / mode / filter / category / selIndex / view / openAlbumId / showHelp are local.

Path	What it is
src/lib/keyboard.ts	The key map, as a pure function from a keypress to a list of actions. Testable without a DOM.
src/lib/search.ts	Filtering and the three-level browse hierarchy. The whole library is in memory, so this is instant - see the note on buildSearchIndex below.
src/lib/lowPower.ts	The ?pi=1 profile: what gets cheaper, and by how much.
src/lib/covers.ts	Generated cover art from the album's three colours, and the book-spine treatment.
src/hooks/usePlayerState.ts	The websocket, with reconnect-and-reseed.
src/hooks/usePlaybackClock.ts	Interpolates the 2 Hz position onto animation frames.
src/components/	Layout only.

src/api/types.ts mirrors musicmouse/services/web/schemas.py; the two are hand-kept in step.

Keyboard

The device is meant to be driven from a keyboard, so every screen is reachable without a pointer. F1 shows the same list in-app.

Key
SPACE	play / pause
CTRL+H / CTRL+L	previous / next track
CTRL+J / CTRL+K	quieter / louder
SHIFT+← / SHIFT+→	seek 15 s
A-Z, 0-9	search albums as you type
?	switch to searching individual tracks
TAB	cycle all / music / audiobooks
← ↑ ↓ →	move the selection while browsing; transport and volume while playing
ENTER	play the selection
ESC	back out one layer at a time
/	back to browsing
F1	this list

SHIFT+arrows is the one addition to the mockup: plain arrows were already taken, and seeking is the one thing a real player can do that the mockup could not.

The Raspberry Pi profile

?pi=1 loads the same app with the ambient canvas painting a quarter of the pixels. It exists for musicdolphin - a Pi 4 driving a 1920x1080 kiosk screen - where Firefox rasterizes 2D canvas in the content process, and the canvas repaints the whole screen every frame whether or not anything is playing.

Everything in src/lib/lowPower.ts was measured on the device. Sum of the Firefox process tree, idle on the browse screen, 15 s average:

	idle CPU
full app	53.5%
+ ambient canvas at half resolution	25.0%
+ 30 fps cap on top of that	25.0%
+ decorative CSS animation loops off	24.6%
+ backdrop-filter glass blur off	118.1%

Two things to take from that table. The canvas resolution is the whole win, and turning off the backdrop blur makes it five times worse - the blur is what promotes each glass panel to its own compositing layer, so a canvas frame underneath repaints only the canvas. Without it the canvas and the album grid above it share one layer and every frame repaints all of it. The most expensive-looking CSS in the app is what keeps the rest of it cheap; SHOW_GLASS_BLUR stays on everywhere, and so do the decorative loops, which measured as noise.

So the profile is one real change plus three caps that only bite while something is playing, and are therefore not in the table: 30 fps on the canvas, 60 bubbles alive at once, and ten progress-bar re-renders a second instead of sixty (usePlaybackClock pushes a React setState per animation frame, into both PlayView and PlayerBar).

The flag is read once at module load from the URL and nowhere else - no persistence, no auto-detection. That is what makes "is this the profile or the hardware?" answerable by editing the address bar. The kiosk gets it from pi_kiosk_url in the ansible repo.

Parent mode

?parentMode=1 opens a settings panel - volume limits, the rotary step, button brightness, and a button to re-read the library. Saving writes the device's config.yml.

It is hidden from the child, not protected from them: there is no authentication on the endpoints behind it. See ../python-backend/README.md.

Installing it on a phone

It is a PWA: public/manifest.webmanifest, icons generated from the mascot, and a small service worker in public/sw.js. On iOS, Share → Zum Home-Bildschirm; it then opens full-screen with no Safari chrome, because iOS reads the apple-mobile-web-app-* meta tags in index.html rather than the manifest.

Two things worth knowing:

• The service worker only registers over HTTPS or on localhost. At http://<mouse>:8080 on the LAN, iOS will still install the icon and run it standalone - that part is the meta tags - but there is no offline caching. Put the mouse behind a TLS-terminating proxy if you want that.
• The worker deliberately caches very little: the app shell, the font and cover art. Not /api/state, not the library, not anything else live. A player that shows stale state is worse than one that says it cannot reach the mouse.

Nunito is self-hosted in public/fonts/ (one variable file per subset, ~74 kB) rather than pulled from Google. The mouse may have no internet, and a cached shell rendering in a fallback face looks broken.

Not implemented

The mockup's second page, "Mein Zimmer" (Hue lights, a roller shutter and scenes), is not built. Nothing here depends on it.