mirror of https://github.com/marcoallegretti/WEFT_OS.git synced 2026-03-27 09:23:09 +00:00

Marco Allegretti fc5ada2079 feat(servo-shell): add servo-shell skeleton, system UI, service unit, and Wayland input audit

Includes winit Wayland input audit for servo-shell integration planning.

New files:
- crates/weft-servo-shell/: new workspace member
 - Cargo.toml: anyhow + tracing deps; no servo dep yet (requires git
 dependency on github.com/servo/servo with multi-minute build; deferred
 until embedder contract is confirmed)
 - src/main.rs: reads WAYLAND_DISPLAY and WEFT_SYSTEM_UI_HTML, locates
 system-ui.html from packaged path, calls embed_servo() stub that
 returns a descriptive error explaining the integration work remaining
- infra/shell/system-ui.html: system UI document per blueprint Section 5
 DOM structure (weft-desktop, weft-wallpaper, weft-taskbar, weft-launcher,
 weft-notification-center, weft-window); includes clock and launcher toggle
- infra/systemd/servo-shell.service: Requires+After weft-compositor.service,
 Type=simple, Restart=on-failure
- docs/architecture/winit-wayland-audit.md: audit of winit 0.30.x Wayland
 backend against WEFT input requirements; identifies keyboard shortcut
 inhibit gap, touch gesture gap, IME incomplete (zwp_text_input_v3),
 frame pacing absent (wp_presentation_time), DMA-BUF unverified;
 none block initial integration; all tracked as pre-GA work items

Modified:
- Cargo.toml: add weft-servo-shell to workspace members
- scripts/wsl-check.sh: switch to --workspace for all three gates

2026-03-11 00:34:26 +01:00

4.6 KiB

Raw Blame History

winit Wayland Input Audit

Audit of winit's Wayland backend against WEFT OS system shell input requirements. Required by Wave 4 gate: Servo Wayland input audit result assessed.

Source: blueprint Section 11, GAP 1. Servo version audited: main branch (2025). winit version audited: 0.30.x (smithay-client-toolkit backend).

Audit Scope

WEFT requires correct and reliable keyboard, mouse, touch, and IME input for the system shell. Input regressions are system-level failures because there is no fallback input path.

Servo delegates all windowing and input to winit. winit's Wayland backend uses smithay-client-toolkit (sctk) as the protocol implementation layer.

Findings

Keyboard input

Status: FUNCTIONAL with known limitation

Basic key events, modifiers, and repeat work correctly via xkb. The xdg_keyboard_shortcuts_inhibit protocol is not implemented in winit's Wayland backend, so system keyboard shortcuts (e.g. Alt+F4) cannot be inhibited by client surfaces. This affects the system shell if it needs to handle those key combinations before the compositor does.

Relevant winit issue: https://github.com/rust-windowing/winit/issues/2787 (open).

Pointer input

Status: FUNCTIONAL

Button, scroll, and motion events work correctly. zwp_relative_pointer_v1 (relative motion for pointer locking) is implemented. zwp_pointer_constraints_v1 (locked/confined pointer) is implemented in winit 0.30+. Frame-accurate pointer position via wl_pointer.frame is handled.

Touch input

Status: PARTIAL

Single-touch is functional. Multi-touch slots are tracked via wl_touch protocol. Gesture recognition is not implemented in winit — gestures from the compositor (zwp_pointer_gestures_v1) are not consumed. This affects swipe/pinch gesture handling in the system shell.

Relevant winit issue: not filed as of audit date.

IME (Input Method Editor)

Status: INCOMPLETE

zwp_text_input_v3 is implemented in sctk 0.18+ but winit's integration is incomplete. Specifically:

Pre-edit text display is not forwarded to the application's IME event stream in all cases.
done events with surrounding text are not always handled correctly.

This means CJK and other IME-dependent input in the system shell HTML will not work correctly.

Relevant sctk issue: https://github.com/Smithay/client-toolkit/issues/605 (open).

Frame pacing (vsync alignment)

Status: NOT IMPLEMENTED

winit does not implement wp_presentation_time (the Wayland presentation feedback protocol). Frame timing is based on wl_callback only. This means Servo cannot align rendering to compositor vsync, causing frame pacing issues on variable-refresh-rate displays and tearing on fixed-refresh displays.

This must be fixed before the system shell is suitable for production use. Relevant Servo issue: not filed as of audit date.

Status: UNVERIFIED

The Servo → WebRender → wgpu → wl_surface pipeline on Wayland may or may not use zwp_linux_dmabuf_v1 for zero-copy buffer sharing. This audit did not test it under the WEFT compositor (requires QEMU or real hardware). Must be verified when DRM backend testing is available.

Assessment

Input area	Status	Blocks Wave 4 skeleton?
Keyboard (basic)	Functional	No
Keyboard shortcuts	Gap	No (deferred)
Pointer	Functional	No
Touch (single)	Functional	No
Touch (gestures)	Gap	No (deferred)
IME	Incomplete	No (system shell uses minimal JS)
Frame pacing	Not impl.	No (deferred, required before GA)
DMA-BUF	Unverified	No (requires hardware test)

None of the identified gaps block the Wave 4 skeleton or initial integration. They block production readiness, as documented in the blueprint.

Gate decision: Wave 4 may proceed. The gaps above are tracked as known work items, not blocking conditions for skeleton implementation.

Required Follow-up

Before WEFT OS reaches GA:

Contribute wp_presentation_time support to winit (or contribute to Servo to work around it via the compositor's presentation feedback).
Contribute zwp_text_input_v3 fix to sctk and winit for correct IME.
File and track a winit issue for zwp_pointer_gestures_v1.
Verify DMA-BUF path under the WEFT DRM compositor (requires hardware).
File issues for all confirmed gaps in the Servo and winit issue trackers per the blueprint contribution workflow.

4.6 KiB Raw Blame History