Shared UI catalog

The template ships a working app. Reuse before generating. Free-form code is a last resort, not a first move. Every component in this catalog is battle-tested for TV focus, performance, and platform splits.

The rule

For every screen the planner requests:

1. Find the closest existing screen in packages/shared-ui/screens/. Use it as-is if the difference is just data binding.
2. If the layout matches but composition differs, compose existing components into a new screen file.
3. Only if neither (1) nor (2) applies, write a new screen — and then look at existing screens for patterns before starting.

If you find yourself writing a <View> with a <FlatList> from scratch, stop. The template has Grid. Use it.

Component reference

<Drawer>

Purpose: Left-side collapsible navigation. Hosts the app's primary routes. When to use: Always. It is the app's chrome. Don't replace it unless the planner explicitly says navigation.type !== "drawer". Customize: Items via navigation/routes.ts; theme tokens for background, accent, focused-item style. Do not: Reimplement as tabs. If the planner asks for tabs, swap the navigator at the navigation layer, don't fork the drawer.

<Hero>

Purpose: Top-of-screen dynamic banner. Updates as the user focuses tiles in the row below. When to use: Any "browse" screen with a featured item. Home, category landing. Inputs: focusedItem (auto-wired by parent), image URL, title, description, CTA. Gotcha: Updates on focus change — too many state writes can drop frames. The component already debounces; don't add another debounce on top.

<Grid>

Purpose: Responsive grid of tiles. Handles focus, virtualization, edge wrapping. When to use: Any catalog view — categories, search results, watchlist. Inputs: items, renderItem (optional; defaults to <Tile>), columns (auto by screen size). Gotcha: Pass stable keyExtractor. Without it, focus jumps on re-render. The template defaults to item.id; if your manifest uses a different key, supply one.

<Rail>

Purpose: Horizontal scrolling row of tiles (Netflix-style). When to use: Home-page sections, "more like this" recommendations. Inputs: title, items, onItemFocus (often used to drive the parent <Hero>). Gotcha: Focus restoration on return — the template handles this via <TVFocusGuide> internally. Don't wrap it in another guide.

<Tile>

Purpose: Single content card. Thumbnail, title, focus ring. When to use: Inside Grid or Rail. Rarely standalone. Customize via theme: Focus border color, scale-on-focus amount, label visibility. Anti-pattern: Building your own card. The focus behavior here is non-trivial; don't recreate it.

<Player>

Purpose: Full-screen video player based on react-native-video. When to use: The player screen. That's it. Inputs: source (URL + type), metadata (title, etc.), onClose. Customize: Controls overlay, scrub-bar style. Player core logic — don't. Platform notes: Vega has its own player. See video-player.md.

<DetailHeader>, <EpisodeList>, <RelatedRail>

Purpose: Composable pieces of the detail screen. When to use: Building detail variants (movie vs series vs live).

Existing screens

Decision tree: which screen do I add?

Planner says layout: "hero+rails" → use existing Home. Pass different data via the route param. Planner says layout: "grid" → use existing Category. Provide a category ID. Planner says layout: "detail" → use existing Detail. Provide an item ID. Planner says layout: "player" → use existing Player. Always. Planner says layout: "search" → use existing Search. Planner says layout: "settings" → use existing Settings.

None of the above → write a new screen by composing components. Start by copying the closest existing screen as scaffolding.

When to write a new component

Bar is high. New component only if:

• The visual pattern appears in at least two screens in the AppSpec.
• It can't be achieved by composing existing components.
• It has non-trivial focus behavior that warrants encapsulation.

Otherwise: inline it in the screen, and let it earn promotion to a component on the next iteration when it gets reused.

Anti-patterns

• Reimplementing the drawer as a custom sidebar. Always loses focus edge cases.
• Wrapping <Rail> or <Grid> in your own <TVFocusGuide>. They already use one. Nested guides trap focus.
• Custom <Tile> with <TouchableOpacity>. Use <Pressable> so the template's focus styles work; better yet, use <Tile>.
• Adding a fourth navigation pattern (e.g. bottom tabs on TV). Bottom tabs don't work with D-pad. If the planner emits this, override and ask.