Registering with the System Media Transport Controls is what makes an app
a media app to the OS rather than a window that happens to make noise.
The card that the media-key overlay, the taskbar media flyout and the
lock screen all draw now carries our cover, title, artist and album; the
hardware media keys reach us with the window unfocused; and the transport
buttons on that card drive this app. Verified against the OS's own
session list: title/artist/album/albumArtist, type Music, a live
scrubber, a present thumbnail, and play disabled while playing.
Where each half of it comes from follows where the truth already lives.
Status and position are pushed by the backend's player event pump, which
already sees every transport change and every position tick — the card
is driven by the same events the UI is, so it cannot drift from the
window, and it costs no IPC at all. Metadata goes the other way, once per
track, published by the player bar: the queue lives in the frontend and
so does the derivation the bar displays, and publishing exactly what the
bar shows means the two can never disagree. Deriving it a second time in
Rust would guarantee that one day they do.
Button presses are forwarded as `soulseek:media-button` rather than
handled in Rust, because nextTrack knows about shuffle, repeat, the album
fill and re-sourcing a track restored from the last session, and none of
that is knowable from that side. They run the same functions the on-screen
transport runs — the play/pause branch moved into togglePlayPause() so
there is one implementation, not two that drift. Proven by driving the
app from the OS session: next advanced the queue, pause and play moved
the status, previous restarted the track on the >3s rule the app already
had.
Stop is deliberately disabled: this transport has no stop, only pause,
and a dead button on the card is worse than a missing one. Buffering maps
to Changing, which is what "finding best source…" honestly is. The
thumbnail is the bar's own data URL decoded into an in-memory stream —
no temp files — and it is explicitly cleared when a track has no cover,
because the previous track's art outliving it is worse than none.
The debug handle gains the local playback entry points beside the
streaming ones it already had. That is not only convenience: verifying
this end to end needs a track playing, and every run that reaches for
Soulseek to get one costs a login the server starts ignoring after a
burst.
Preview modal audio, five rounds:
- True track-change crossfade: scheduleSettle no longer silences the
outgoing clip at t=0; preview_load's equal-power fade owns both ramps,
gated on the incoming voice's first Playing event (audible_marks), with
failure/overstay fallbacks. CROSSFADE_MS = 340 — locked to the reel's
card-slide so audio and visuals land together.
- Two-neighbour lease prefetch + a 15-min on-disk clip byte-cache
(recent_clips): steps in BOTH directions crossfade in ~15 ms; revisits
never re-download.
- Adaptive settle (isolated steps fire immediately, bursts coalesce) and
anticipatory auto-advance (step at clip end minus 400 ms) so auto-play
crossfades over the tail instead of gapping.
- Session resume memory: revisited tracks continue where they left off
(decoder-level start offset via play_local_from/resume_at); finished
tracks restart from the top.
- Open/close crossfades with the MAIN player: fade-pause with the
desired-paused latch landing at ramp end, fade-resume from the paused
position; MAIN_FADE_GEN guards; focus handshake relaxation documented
in focusBridge.
Volume normalization (Settings > Playback, default on):
- Dependency-free BS.1770/EBU R128 meter in the player crate (K-weighting,
400 ms gated blocks, incremental) + analyzer that reads the same growing
file playback streams from — first plays are measured at download speed.
- Gain layered under user volume; audible start GATED on a preliminary
measurement (10 s of audio or 800 ms budget) so the level is right from
the first sample and never changes mid-track; prelim boosts capped 3 dB,
peak-aware clipping guard, persistent loudness-cache.json.
- Gapless boundaries get their own sample-accurate gain via
SetNextNormGainDb, fed by preload analysis.
Debug overlay (Ctrl+Shift+D): process-tree CPU / PDH GPU / working-set +
private-commit RAM / network rates / FPS / current-track download progress
read from the backend's own StreamProgress / live normalization state /
preview session phase. Polls only while visible.
131 JS + player + app tests green; every path verified live over CDP.
The previous .git directory was found gutted (only info/ remained), so
history is unrecoverable locally. This commit restores version control
with the tree exactly as it stands: the working app, the preview-tracks
launcher on the artist hero, the scrollable-track-previews design bundle
(docs + approved mockups), and the Phase 0 validation artifacts.
KeelrLeek