Architecture

Architecture

Homebase is a Rust workspace: one app crate with a Slint UI, and a set of focused library crates. The full write-up, with diagrams and data-flow examples, is in docs/ARCHITECTURE.md.

Crates

Crate	Responsibility
app	The Homebase executable: Slint UI (app/ui), focus model, orchestrator (app/src/state.rs)
hb-core	Shared vocabulary: ids, models, input actions, settings, theme tokens, errors
hb-store	SQLite storage with migrations; the only owner of the database
hb-sys	Every Windows API: launching, windows and focus, media sessions, audio, power, display, icons, UI Automation
hb-input	SDL3 controllers, keyboard, remotes, gestures, bindings and input injection
hb-appexp	App experiences: launching apps and websites, exact window tracking, controller verbs, the pointer thread
hb-providers	Steam (library folders, owned-games cache, artwork), local games, the media/app catalog, site icons
hb-session	Game session state machine and identity-verified process tracking
hb-policy	Profiles, ratings, time limits and approvals
hb-audio	UI sounds
hb-ext	.hbpkg packages
xtask	Build, package and install automation

Rules the code follows

• All Win32/WinRT calls live in hb-sys; everything above it is portable.
• hb-core defines vocabulary only and does no IO.
• hb-store is the only code that touches SQLite.
• The UI thread never blocks: scans, downloads, UI Automation and shell opens run on worker threads and report back through channels.
• Input to apps is only sent after verifying the app's own window is in front.

Threads

Thread	Job
UI	Slint event loop, plus a 16 ms pump that drains every channel
Gamepad	Owns SDL3; posts input events and publishes stick positions
Pointer	Moves the mouse and scrolls for apps at about 250 Hz, straight from the stick
Session trackers	Follow game processes and play time
Workers	Library scans, artwork downloads, text-field checks, shell opens
Watchdog	Logs a warning if the UI thread ever stalls