Stage 6d — Vector Status Icons

Why this stage exists

The first demo bar proved its service adapters by printing values such as BAT 64%, VOL 8%, and NET 69%. Those labels were useful diagnostics, but they made a 32-logical-pixel shell bar feel like a test fixture rather than a compact status surface.

This stage changes only the demo composition. Patin still does not ship a bar or prescribe icons, and the optional service adapters still return reusable data rather than presentation.

Structured state through the scene

examples/demo_bar/services.rs::StatusSnapshot now retains BatterySnapshot, VolumeSnapshot, and NetworkSnapshot directly. Removing the demo’s formatting functions avoids discarding useful state such as charging, mute, and transport strengths before the scene renders it.

examples/demo_bar/scene.rs converts that state into compact icons:

• battery fill represents charge, with warning and charging colors;
• zero through three bars represent volume, with a mute strike;
• concentric signal arcs represent wifi, linked nodes represent wired, and ascending bars represent cellular strength.

The helpers use only existing DrawCommand::Fill and DrawCommand::RoundedFill primitives. This makes the icons scale with the Wayland surface and avoids emoji rendering, private-use glyphs, bundled assets, or an icon-font dependency. The clock deliberately remains text.

The demo row keeps the textual clock and optional volume icon in fixed slots growing inward from the inset left edge. Active wifi, wired, cellular, and battery indicators use fixed slots growing inward from the inset right edge. A flexible spacer between the clusters keeps the output center empty, avoiding centered obstructions without branching on a hardware or compositor name. The 12-logical-pixel outer inset is scale independent: the Wayland backend applies the output scale later when it creates the buffer. A value change alters its icon commands and damages only that status slot.

Changed files and important functions

• examples/demo_bar/services.rs preserves provider snapshots instead of converting them to labels.
• examples/demo_bar/scene.rs renders battery_icon, volume_icon, wifi_icon, wired_icon, and cellular_icon, with shared centering and shape helpers plus state- and layout-regression tests.
• README.md and docs/status-services.md describe the visible behavior and retain the toolkit/example boundary.
• docs/SUMMARY.md links this chapter.

Verification

Verified on 31 July 2026:

$ cargo fmt --all -- --check
(no output, exit 0)

$ cargo test --workspace --all-targets
all passed

$ cargo clippy --workspace --all-targets --all-features -- -D warnings
Finished, no warnings

$ mdbook build
INFO HTML book written to `/home/vdzee/proj/patin/book`

$ git diff --check
(no output, exit 0)

The automated demo test confirms that all four status components emit shape commands rather than text and that battery charging and volume mute produce different command sets. A live visual check on the phone test target remains to be recorded.

The inset end layout was verified on 1 August 2026:

$ cargo fmt --all -- --check
(no output, exit 0)

$ cargo test --workspace --all-targets
28 passed, 0 failed

$ cargo clippy --workspace --all-targets --all-features -- -D warnings
Finished, no warnings

$ mdbook build
INFO HTML book written to `/home/vdzee/proj/patin/book`

$ git diff --check
(no output, exit 0)

The new regression test uses the phone’s 509-by-32 logical bar size and checks that the clock starts at the left inset, the battery slot ends at the right inset, and a 64-logical-pixel area around the output center contains no status slot.

The same revision was then built natively on the aarch64 phone test target with its existing xkbcommon development path:

$ cargo build --release --locked --example demo_bar
Finished `release` profile; produced target/release/examples/demo_bar

$ systemctl --user is-active patin-bar.service
active

The installed ~/.local/bin/patin remained active as a Wayland client after a fresh SSH connection. The transient user service was used only to preserve the live test process after SSH disconnected; normal session startup remains the documented exec_once = ~/.local/bin/patin compositor configuration.