Martin Bauer
6ccb3e458f
The React UI is sluggish on the kiosk and the reasons are browser-shaped: a compositor deciding what gets its own layer, a requestAnimationFrame loop repainting the viewport, and a JPEG decode per album card per cold start. The last three commits chased that through the service worker and the cover pipeline. This is the other direction - the same backend, the same layout, the same German copy, without a browser. Browse and play only. The typing game, the room-lights page, parent mode and the IR-remote assignment stay web-only, and nothing here touches python-backend. Four things carry the performance claim, in rough order of how much they should matter: Covers are downscaled once, ever. The backend serves one size - 640px on the long edge, no ?size= - and a grid card is 180. src/covers.rs fetches each cover once on a worker thread, resizes it, and writes a JPEG thumbnail to ~/.cache/musicmouse-slint/covers/. Two tiers and only two, which is what makes the cache worth keeping: a per-widget pixel size would give each album a dozen near-identical files and a fresh decode for each. The cache is dropped when the websocket announces a rescan, because that is the one moment the backend rewrites the art behind an unchanged cover URL - the trap sw.js had to learn about the hard way. The grid is virtualized. Rust hands the UI the album list pre-chunked into rows and the view puts those in a ListView, which instantiates only what is on screen. A flat list of 660 cards gives it no rows to skip, hence the chunking. Same purpose as content-visibility: auto on .grid > .card. The progress bar animates between the 2 Hz pushes rather than running a clock, so interpolation costs a property evaluation per frame on the render side and there is no equivalent of usePlaybackClock. It is suppressed for the frame a track changes on, so a new track jumps instead of sliding across two unrelated positions. Nothing on screen animates by itself. The ambient canvas is not ported, for the reason lib/lowPower.ts already gives: a loop repainting the viewport is a floor you cannot get under while it runs at all. The device must not use FemtoVG. On Mesa V3D it draws every runtime-loaded Image as solid black (slint-ui/slint#11785, open), which here means every album cover; Skia and the software renderer are unaffected. So `kiosk` is linuxkms + Skia and FemtoVG stays the default only for desktop development. Both profiles are verified to build; the kiosk binary links libinput/libgbm/libdrm and no X11 or Wayland at all. lib/search.ts, lib/keyboard.ts and lib/format.ts were already pure functions with their own tests, so they port across as pure Rust with theirs: 43 tests, no window required. The .slint files are layout only - nothing in them formats a number or picks a word. Verified against the real 660-album library rather than a fixture. tools/headless-shots.sh renders the UI inside a nested headless compositor and grabs a frame per screen, which is how that was checked on a machine whose session was locked; a Slint window needs a real compositor, and under bare Xvfb nothing maps at all. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
65 lines
2.1 KiB
Nix
65 lines
2.1 KiB
Nix
# Dev shell for the Slint front-end.
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#
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# NixOS has no rustup-installed toolchain here, and Slint's renderers link against
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# system GL/X11/Wayland libraries that a plain `cargo build` cannot find on its own -
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# hence LD_LIBRARY_PATH below rather than just a list of buildInputs.
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{ pkgs ? import <nixpkgs> { } }:
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let
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# Everything the winit backend dlopen()s at runtime. Missing one of these shows up
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# as a panic inside winit, not as a link error, so they are easy to misdiagnose.
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runtimeLibs = with pkgs; [
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libGL
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libxkbcommon
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wayland
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xorg.libX11
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xorg.libXcursor
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xorg.libXi
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xorg.libXrandr
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fontconfig
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freetype
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];
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in
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pkgs.mkShell {
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nativeBuildInputs = with pkgs; [
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cargo
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rustc
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rustfmt
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clippy
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pkg-config
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# Only needed when building with --features skia: rust-skia compiles its own
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# bindings shim and wants a C++ toolchain plus python for the GN build.
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clang
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python3
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];
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# Nunito is the face the design is drawn in. The web front-end self-hosts it as
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# woff2, which Slint cannot read, so the dev shell points Slint at the TTF instead
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# (`SLINT_DEFAULT_FONT` takes one file and makes it the primary font). Without it
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# everything still renders, in whatever sans fontconfig hands back.
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SLINT_DEFAULT_FONT =
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"${pkgs.nunito}/share/fonts/truetype/Nunito/Nunito[wght].ttf";
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buildInputs = runtimeLibs ++ (with pkgs; [
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fontconfig
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# libinput/libdrm/libseat are the linuxkms (kiosk) backend's dependencies. They
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# cost nothing to have present on a desktop build.
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libinput
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libdrm
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seatd
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udev
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]);
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LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath runtimeLibs;
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# rust-skia downloads a prebuilt libskia rather than building it, when it can.
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SKIA_BINARIES_URL_TEMPLATE = null;
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shellHook = ''
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echo "musicmouse slint-frontend — cargo $(cargo --version | cut -d' ' -f2)"
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echo " cargo run # windowed, femtovg"
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echo " cargo run --features skia # windowed, skia (what the Pi uses)"
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echo " cargo build --features kiosk # linuxkms + skia, for the device"
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'';
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}
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