Accumulated qt-frontend work from the 2026-08-11/12 sessions (cc),
uncommitted until now: the app-wide dynamic background in both modes
(AmbientField with GPU/Canvas arms, AppShell layering, ambient palette
pipeline), the wave-1 clip/batch sweep across the tree (alpha batches
449 -> 327, reproducible), the rounded-cover and icon-tint arms, and
scripts/qt-batches.sh (batches + presents/s sampler).
The GPU behaviour of these pieces was finalized in the follow-up pulse
commits; see qbz-nix-docs/qt-frontend/2026-08-11-scenegraph-batches/
GPU-COST-INVESTIGATION.md for the full campaign.
km
Two defects with one cause: a tint name that means a frozen hex.
"primary" is the legacy alias of literal #ffffff, not Theme.text-primary,
so every control passing it drew a white glyph. On the eleven light
themes that is white-on-light -- the header back/forward chevrons, the
sidebar toggle and the carousel arrows the owner marked. They now pass
the theme-following names, which icon_tint_qt bakes at runtime.
The stale `hslLightness > 0.5 ? "primary" : "black"` workarounds that
predate the runtime tinter collapse into those names, and the qrc floor
underneath them becomes polarity-aware: dir_for() returns "" whenever
the cache dir is unavailable, a bake fails or the theme document has not
been published, and that path used to resolve textPrimary straight back
to the white bake -- reproducing the bug it was fixing, app-wide, in the
degraded state.
On accent fills the fix is a deviation from Slint, approved by the owner
after measurement. A fixed white glyph on Theme.accent falls under 2.6:1
on 16 of the 35 shipped palettes, including high-contrast at 1.70:1 and
wcag-dark at 1.82:1 -- the two themes whose reason to exist is contrast.
Slint hardcodes #ffffff there (CircleAction.slint:72 and three others),
so the bug is upstream. accentText alone is not the answer either: it is
picked for the theme's text ramp and gives 2.56:1 on Rose Pine Dawn,
worse than the black it replaces. So QbzTheme picks the best-contrast
tint by real sRGB luminance against the live accent, and the labels
beside those glyphs use its colour twin -- BrowseGenreButton and
LibraryView were drawing a white glyph next to an accentText label
inside the same pill.
Rounds out the two parity items the same files owe: QbzNavButton gains
the ambient arm from Carousel.slint (wired at the six carousel sites,
not left dead), and QbzCircleAction rounds its glyph to whole pixels the
way CircleAction.slint does.
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**The scaled-cover fix from the last round produced nothing.** The seam ran —
462 requests in one offscreen smoke — and wrote zero files, so the owner was
right that nothing improved. The artwork cache stores files as `.img`, and
`image::open` picks its decoder from the EXTENSION, so every call failed
silently. Sniffing the content instead yields 101 derivatives on the same run.
The header atmosphere had the identical bug and had therefore never produced an
image either, which is why the flat fallback was all anyone ever saw.
Reported as fixed last round without checking that it ran. Verified by effect
this time, not by reading the diff.
The rest came through an analyse / refute / implement / verify pipeline, and the
adversarial passes earned their keep:
- The sidebar mini rail: icons sat left of centre because their slot kept its
fixed 24px width while the rail collapsed, so the hit target was rectangular
and off-axis. The rail narrows, rows are square, and the mini state gains the
folder flyout and tooltips it never had. The reviewer caught a comment
claiming the width change was a one-token revert when it is two — corrected
rather than left to mislead the next reader.
- Playback context now travels from every producer, not the handful that
happened to stamp it.
- Collapsible per-tab search in Library, and label artwork.
- Every View-all destination Home offers, plus the label page and its releases.
- Collapsing the sidebar drops a Large bar back to New, live, without
overwriting the user's persisted preference.
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**Deferred external rows.** The album page awaited the Last.fm row before
publishing anything, so the tracklist waited on an external service plus
MusicBrainz. It publishes in stages now — header and tracks first, then each
Qobuz rail as it lands, then Last.fm — with every patch merged under a
generation counter so a late reply for album A cannot paint onto album B. The
artist page was already staged this way; its views were the part still showing
bare "Loading…" text.
**Skeletons as the standard.** One control, new variants rather than new
components, mounted across the views. Its second job is the one the owner
named: cleanup. A cover that never resolves settles the placeholder once and
reveals the card's own empty state instead of shimmering forever — local albums
with no embedded art produce no artwork entry at all, so a placeholder gated
only on "not arrived yet" would never stop.
**Local artwork streams.** Fifteen seconds to first cover on a 1274-album grid
was one batch emitted after the whole window resolved. Each cover emits as it
resolves now, visible band before prefetch margin.
**Lyrics migrated.** Smooth sync instead of a 1 Hz tick, word-level karaoke
where the document carries it, the surrounding-line dimming, the controls
flyout and the translation layer the v10 backend already supported. Exactly one
row subscribes to the 30 Hz output; the timer drops to 250ms when paused or
hidden.
**Navigation by mouse and touchpad.** Side buttons and a two-finger horizontal
swipe, matching #653 — including the part that matters, which is that a swipe
over a carousel scrolls the carousel. The layer is declared first in the shell
so everything else gets first refusal.
**Context menus.** Brought to the Slint inventory, Play later included, with
right-click opening the same menu as the button everywhere. Entries whose seam
does not exist are hidden rather than shipped inert.
Two controls that rendered and no-opped are now honestly disabled: the My QBZ
nav row, which routes to a view the shell has no case for, and three sidebar
menu entries with no backing call.
The sidebar caret was never a condition bug. The row is a positioner and the
name cell's width ignored the count label, so a folder WITH content pushed the
chevron past the clip — which is why it vanished exactly when it mattered.
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The card rendered neither an image nor any hover affordance. Root cause of the
missing artwork: the logo was gated on `item.imageUrl` while its source came
from the host-resolved artwork map, so any mount that resolves covers into a
side map without republishing the item drew nothing. Artwork is now driven by
the resolved source alone and `imageUrl` only chooses the placeholder arm.
The container is round, per the owner, matching ArtistCard rather than the
square art the Slint reference uses; the contain-fit box is inset so a wide
wordmark is not clipped by the circle, keeping the reference's "label logos
are never cropped" rule. The hover row carries a single disc: labels are
opened, not played, and the Slint reference offers exactly one label action.
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Two fronts of the modularization, both gated green before this commit.
QML leaves the flat qml/ directory for seven modules: cards, controls,
rows, settings, shell, theme, views. Only Main.qml and LoginScreen.qml
stay at the root. build.rs matches the tree exactly (55 files), relative
imports and asset paths were re-anchored for the new depth.
The QbzBridge God-object starts breaking up: QbzSession, QbzShell,
QbzPlayer, QbzQueue and QbzHome are now their own #[cxx_qt::bridge]
singletons, each with its own OnceLock<CxxQtThread> and ui() hop, booted
in order from Main.qml. Bridge files stay directly under src/ because
cxx-qt-build only accepts rust_files from one directory (QTBUG-93443).
bridge.rs keeps 5.5 domains (library, album/artist, settings,
integrations, search, playlist) and dies once they are split out.
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