Scheduler

The scheduler is a 1 Hz Tokio loop in scheduler/run_loop.rs, part of the scheduler module. Every second it walks a priority cascade. First match wins; all other timers reset.

The cascade

1. Pause state — Running or PausedUntil(Option<Instant>). None means indefinite. Auto-resumes when the deadline expires and emits pause:changed.
2. Bedtime window — if active and local time is inside the window, fire a Sleep break every bedtime_interval_secs. Always enforceable.
3. Active hours — if work_window_enabled and local time is outside the window, skip.
4. Do Not Disturb — dnd::is_active() (macOS + Windows).
5. Camera in use — camera_active atomic, updated by a background monitor thread.
6. Idle reset — if idle longer than idle_reset_secs, skip and reset.
7. Micro / Long breaks — fire when the interval elapses, if the per-type *_enabled flag is on.

A pre-break notification fires prebreak_notification_seconds before each break (once per cycle, gated by prebreak_notification_enabled).

Break kinds

Kind	Duration	Dismissable	Used for
Micro	~20s	Yes	Eye, posture, small reset
Long	minutes	No (by default)	Real rest
Sleep	persistent	Snooze, not skip	Bedtime nudge

Multi-monitor overlay

fire_break picks the target monitors via the monitor_placement setting (primary, active, or all) and ensures one borderless overlay-N window per monitor, sized to that monitor's bounds. active resolves to whichever monitor currently contains the OS cursor (using cursor_position() + a containing-rect lookup); if the cursor lookup fails it falls back to the primary monitor. Existing overlay windows are reused across breaks; the first creation in a cycle gets a 200ms grace before emitting break:start so the React listener has time to register.

When a break's per-kind mode is windowed (see delivery_for and is_windowed_mode), each overlay is sized to 80% of its monitor's physical resolution and centered, and always_on_top is dropped so the surrounding desktop stays reachable. Bedtime (Sleep) is hard-coded to full-screen overlay and ignores this — sleep prompts should be hard to miss.

Never use native fullscreen on macOS

macOS opens a new Space per fullscreen window. That breaks multi-display coverage and feels awful. Size and position manually.

Tray pause

Pause for… is a submenu with seven options (15m / 30m / 1h / 2h / 4h / Until tomorrow 6am / Indefinitely). On pause, Resume enables and the submenu disables; reverse on resume. The pause:changed event keeps the Preferences window in sync.