Android ima strogi model rada sa nitima centriran na glavnoj (UI) niti — koja mora rukovati sučeljem i ostati responzivna. Razumijevanje rada sa nitima, zašto se posao mora premjestiti sa glavne niti, i alati (coroutines, i istorijski threads/handlers) su važni za responzivne aplikacije.
Pravilo glavne niti
Android has a single MAIN (UI) thread that:
→ handles ALL UI operations (drawing, events) — UI updates MUST happen on it
→ must stay RESPONSIVE — blocking it freezes the UI; >5s blocked = ANR (App Not Responding)
TWO key rules:
1. DON'T do long/blocking work on the main thread (network, DB, heavy compute) → move it off
2. DON'T update UI from a background thread → switch back to the main thread for UI
