Trey T
de7a70b198
Targeted every hitch in the live-tracker flow:
1) Async DB loading. AircraftDatabase (1.5MB JSON) and
AircraftRegistry (200KB JSON) were parsing synchronously on the
main thread the first time anything touched them — typically when
the user first opened the Live tab. Both now bootstrap with a
safe fallback in init() and parse the full JSON on a background
Task at app launch (FlightsApp.init calls preload() on both).
Reads are NSLock-guarded with lock.withLock {} (async-safe).
2) Crossfade suppression on refresh. The 15s auto-refresh swaps the
`aircraft` array wholesale, which made SwiftUI try to crossfade
every annotation. Wrapped the assignment in a Transaction with
disablesAnimations = true so the swap is instant.
3) Cached filtered aircraft. `filteredAircraft` was a computed
property running through every aircraft on every body re-render
(e.g. while a sheet was animating in). Moved to @State,
recomputed via .onChange handlers on each dependency.
4) Lighter pin view. AircraftPin no longer carries the full
LiveAircraft struct or contains a conditional ZStack — just the
minimal {tint, rotation, isSelected} props, conforms to
Equatable so SwiftUI can skip diffing identical pins, and uses
.animation(nil) on the tint to prevent color crossfades during
refresh.
5) Coarse relative-time bucketing. The footer's "updated 5s ago"
text was ticking every second, which dirtied the footer subtree
on every body pass. Now snaps to {just now, <30s ago, <1m ago,
Nm ago} — no second-by-second ticks.
Net effect: tab opening is instant (DBs are warm), refreshes don't
flicker, filter sheet animation is smooth, map panning isn't fighting
view-tree rebuilds.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>