Renderer coverage (Qt vs Compose)¶

tempestroid has one reconciler and two leaf renderers: Qt (desktop simulator) and Compose (Android device, Kotlin). This page is the matrix of which widget each renderer handles — the reference for what runs on the device beyond the simulator.

What each column means

Qt (simulator) — the widget has a render path in the Qt renderer (tempestroid/renderers/qt/).
Compose (device) — the Kotlin renderer (android-host/.../TempestRenderer.kt) has an explicit case building a real Composable for the node's type (it does not fall through to the Box/Popup fallback).
This matrix reflects code-level coverage (a handler exists). Per-widget on-device verification (a screenshot of each one on hardware) happens in the E-phase device-verify runs and is ongoing work — where it has not been exercised, it is flagged.

Summary

Every exported primitive widget has a handler in both renderers. The Compose renderer has 62 primitive cases + 7 overlay cases; any type without a case falls into a forward-compat Box/Popup (never breaks). The composite components (tempestroid/components/) are lowered to primitives in Python (Component.render) before serialization — so they never reach Kotlin: they render through their primitive children on both sides.

Layout¶

Widget	Qt (simulator)	Compose (device)	Notes
`Column`	✅	✅
`Row`	✅	✅
`Container`	✅	✅	On Compose it hits the forward-compat `Box` (style + children).
`Stack`	✅	✅	Z-order; `position=ABSOLUTE` anchors by insets.
`SafeArea`	✅	✅	Compose insets against `WindowInsets.safeDrawing`.
`Wrap`	✅	✅	Line wrap pinned by conformance (`flex_wrap`).
`AspectRatio`	✅	✅
`PageView`	✅	✅	Emits `PageChangeEvent`.
`ScrollView`	✅	✅
`KeyboardAvoidingView`	✅	✅

Text, action and indicators¶

Widget	Qt (simulator)	Compose (device)	Notes
`Text`	✅	✅
`Button`	✅	✅
`Icon`	✅	✅	Named Material icons.
`Image`	✅	✅	Compose via Coil.
`ProgressBar`	✅	✅
`Spinner`	✅	✅

Inputs and forms¶

Widget	Qt (simulator)	Compose (device)	Notes
`Input`	✅	✅
`TextArea`	✅	✅
`Checkbox`	✅	✅
`Switch`	✅	✅
`Slider`	✅	✅
`RangeSlider`	✅	✅	Qt: two `QSlider`s; Compose: M3 `RangeSlider`.
`Dropdown` / `Select`	✅	✅
`TimePicker`	✅	✅	Qt: inline spinner; Compose: M3 dialog.
`DatePicker`	✅	✅
`FilePicker`	✅	✅
`Autocomplete`	✅	✅
`PinInput`	✅	✅
`MaskedInput`	✅	✅
`FormField`	✅	✅	Validation runs in Python; the renderer only draws the error.
`Form`	✅	✅

Virtualized lists¶

Widget	Qt (simulator)	Compose (device)	Notes
`LazyColumn`	✅	✅	Window materialized by the app; see divergences.
`LazyRow`	✅	✅
`LazyGrid`	✅	✅
`SectionList`	✅	✅	Sticky header: floating `QLabel` (Qt) vs `stickyHeader` (Compose).
`RefreshControl`	✅	✅	Qt: `refreshing` prop (no pull gesture); Compose: `PullToRefreshBox`.

Widget	Qt (simulator)	Compose (device)	Notes
`Navigator`	✅	✅	Qt: `QStackedWidget` + `QPropertyAnimation`; Compose: `AnimatedContent`.
`TabView`	✅	✅
`TabBar`	✅	✅
`RouteDrawer`	✅	✅	Compose: `ModalDrawer`.

Overlays and feedback¶

Widget	Qt (simulator)	Compose (device)	Notes
`Dialog`	✅	✅	Compose: M3 `AlertDialog`.
`BottomSheet`	✅	✅	Compose: `ModalBottomSheet`.
`ActionSheet`	✅	✅
`Toast`	✅	✅
`Menu`	✅	✅	Compose: `DropdownMenu`.
`Popover`	✅	✅
`Tooltip`	✅	✅

Animation¶

Widget	Qt (simulator)	Compose (device)	Notes
`Animated`	✅	✅	Frame clock crosses the bridge (`FRAME_TOKEN`).
`AnimatedList`	✅	✅
`Shimmer`	✅	✅
`Skeleton`	✅	✅
`Hero`	✅	✅	Shared transition across screens.

Gestures¶

Widget	Qt (simulator)	Compose (device)	Notes
`GestureDetector`	✅	✅	`on_tap` / `on_double_tap` / `on_long_press` / `on_swipe`.
`PanHandler`	✅	✅
`ScaleHandler`	✅	✅	Pinch/zoom.
`DoubleTapHandler`	✅	✅
`Draggable`	✅	✅
`DragTarget`	✅	✅
`Dismissible`	✅	✅	Swipe-to-delete.
`ReorderableList`	✅	✅
`InteractiveViewer`	✅	✅

Media and graphics¶

Widget	Qt (simulator)	Compose (device)	Notes
`Canvas`	✅	✅	Identical JSON command list (conformance).
`Svg`	✅	✅
`Blur` / `BackdropFilter`	✅	✅
`ClipPath`	✅	✅
`VideoPlayer`	✅	✅	Compose via `AndroidView`.
`WebView`	✅	✅	Compose via `AndroidView`.
`CameraPreview`	⚠️ placeholder	✅ device	Qt shows a flagged placeholder; real camera is device-only.
`QrScanner`	⚠️ placeholder	✅ device	same — QR scanning is device-only.
`MapView`	⚠️ placeholder	✅ device	same — a real map is device-only.

Composite components¶

Everything in tempestroid/components/ (AppBar, Scaffold, NavBar, Sidebar, Footer, Header, Card, Drawer, Calendar, Clock, the BR form components, etc.) is lowered to primitives in Python by Component.render before the diff. The reconciler never serializes a Component type to the device — Kotlin only sees the primitive children. So components inherit the coverage of the primitives they emit, identical on both renderers.

Documented divergences¶

The two renderers match in behavior and event payload but use different native mechanisms. The divergences pinned by the conformance suite (phase D) and described in CLAUDE.md:

Lists: the Qt scroll area spans only the materialized window (no reserved virtual extent); Compose's LazyColumn reports layoutInfo against the full itemCount.
Overlays: Qt uses QDialog/QMenu/QTimer; Compose uses Material3 (AlertDialog/ModalBottomSheet/DropdownMenu), which manage their own scrim and WindowInsets.safeDrawing.
Navigation: Qt animates with QPropertyAnimation; Compose with AnimatedContent/ModalDrawer. The Android back button is the device path (vs Esc in the simulator).
Device-only media: camera, QR and map are flagged placeholders on Qt and real only on the device.

Source of truth

The Compose (device) column is derived straight from the when (node.type) in android-host/app/src/main/java/.../TempestRenderer.kt (primary + overlay dispatch). When adding a new widget, ensure a case there and a row in this matrix.