Introduces a new `core/windows` module (`Nebula.Windows`) with `WindowService`, window/workspace models, and a Sway IPC backend for live window tracking and control (focus, close, move/resize, snap, maximize/restore, minimize, workspace switch). The desktop shell now links this module, uses compositor focus for top-bar active app text, and adds an Open Windows section in the launcher with focus/close actions. Also updates application metadata handling to parse `StartupWMClass` and map window `app_id`/class to friendly names and icons, and revises Sway config/docs for the new floating-first Desktop 0.2 behavior with temporary compositor-provided decorations.
Nebula Windows
Shared C++ window-management service. Desktop, the future Bigscreen shell, and a future Nebula compositor backend should all talk to this library rather than to a compositor directly.
Nebula QML
↓
WindowService
↓
generic WindowBackend
↓
Sway IPC now
Nebula compositor later
QML must not run swaymsg. Sway-specific protocol, socket handling, and tree parsing stay in backends/sway/.
Behaviour
- Connects to the compositor IPC socket from
SWAYSOCK. The path is never hard-coded. - If IPC is missing or fails, the shell keeps running and WindowService stays empty. A development warning is logged.
- Subscribes to
window,workspace, andoutputevents instead of polling. - Exposes
WindowModel(QAbstractListModel) andWorkspaceModel. - Tracks the focused normal application window. Layer-shell chrome (desktop, top bar, launcher) is not treated as the active app.
- Resolves a user-facing name via
ApplicationServicewhen possible, then a small identifier humanizer (footclient→ Foot,org.mozilla.firefox→ Firefox).
QML module URI: Nebula.Windows.
Operations
focusWindow, closeWindow, maximizeWindow, restoreWindow, setWindowFloating, plus moveWindow / resizeWindow / snapWindow / switchWorkspace.
closeWindow asks the compositor to close the client. It does not kill the process.
Maximise fills the current workspace usable area (below the Nebula exclusive zone) using compositor-relative sizing. Restore returns the previous floating geometry when WindowService saved it.
Minimise is implemented for the Sway backend using scratchpad semantics, but the UI must not mention scratchpad. The user-facing idea is only hide / show.
Snap edges (SnapLeft, SnapRight, SnapMaximize) are prepared for a later Snap Layouts UI.
See shells/desktop/README.md and compositor/README.md for session behaviour.