drilldown

Overview ¶

Package drilldown demonstrates a master-detail screen with async fetches at both levels, plus a third level via push:

• The cities list (left) loads on Init via tea.Tick. Until it resolves the pane spins; the detail pane sits idle.
• Pressing enter on a focused city fires another async fetch into the detail list (right). Each fetch is tagged with a request ID so hammering enter never races a slow response into the pane after a newer selection — the standard "stale-response cancel" pattern in Bubble Tea (you can't stop a tea.Cmd, so you discard its result on arrival instead).
• Pressing enter on a focused attribute pushes a child screen. Esc pops back with parent state intact (focus index, fetched detail, cursor) — that's free because screen.Stack keeps parent screens alive while a child is on top.

Enter has a single conceptual meaning across the whole screen — "open the focused selection" — with a different side effect per pane (load detail + shift focus right, or push child screen). Tab/shift-tab cycles focus explicitly.