tempest-core 0.7.0

Renderer-agnostic UI core (IR, reconciler, state, style, widgets) shared by tempestroid and tempestweb.

tempest-core

📚 Documentation: Português (Brasil) · English (US) — bilingual, on GitHub Pages.

Renderer-agnostic UI core shared across the tempest stack — the engine behind both tempestroid (native renderers: Qt / Compose / Android) and tempestweb (DOM, WASM + server modes).

It is the one tree, many renderers core: the IR, the reconciler (build / diff), the state model (App), the typed style model (Style, Color, Edge), the widget and component trees, plus the cross-cutting helpers (animation, i18n, navigation, theme, validators). It carries no platform-coupled code — no Qt, no JNI, no Android, no DOM — so it imports cleanly under CPython, Pyodide and a headless server. Renderers live in the consumers; this package only produces and diffs the tree.

from tempest_core import App, Column, Text, Button, Style, build, diff

old = build(Column(children=[Text(content="Count: 0", key="label")]))
new = build(Column(children=[Text(content="Count: 1", key="label")]))
patches = diff(old, new)          # -> [Update(set_props={"content": "Count: 1"})]

Design system (Chakra-style variants → Material 3)

Components take Chakra-ergonomics props (variant/size/color_scheme) and a theme, and resolve a concrete Material 3 Style via pure resolvers in variants.py — resolve_variant (buttons), resolve_field_variant (text inputs / select / masked / autocomplete / pin), resolve_selection_variant (checkbox / switch), resolve_slider_variant (sliders), resolve_surface_variant (cards / surfaces — H3), resolve_badge_variant (badges / tags / chips — H4) and resolve_alert_variant (alerts / banners — H4). The interactive resolvers each ship a *_states sibling returning the per-state table (default/hover/pressed/ disabled/focus) the renderers apply on real events; surfaces and alerts are non-interactive, so there is no state table. The touch target is held ≥ 48dp and WCAG-AA contrast is preserved. An explicit style= is always merged on top.

from tempest_core import Alert, Badge, CardVariant, IconButton, Stat, Tabs, Theme
from tempest_core.components import AppBar, Card, HStack, NavBar, SearchBar, Surface, VStack
from tempest_core.widgets import Input, Spacer, Text
from tempest_core.style import AlertVariant, BadgeVariant, FieldVariant

field = Input(value="", field_variant=FieldVariant.FILLED, color_scheme="primary")
button = IconButton(icon="settings", color_scheme="primary", label="Open settings")

# H3 styled surface & layout kit: cards/surfaces (elevated/filled/outlined) +
# SwiftUI-style stacks with token-step gaps + a flex Spacer.
card = Card(variant=CardVariant.OUTLINED, color_scheme="primary", children=[
    HStack(gap="md", children=[Text(content="Title"), Spacer(), Text(content="42")]),
])

# H4 styled data-display & feedback kit: status families (success/warning/info) +
# badge/tag/chip + alert/banner + stat.
ok = Badge(label="LIVE", variant=BadgeVariant.SUBTLE, color_scheme="success")
note = Alert(title="Saved", body="Your changes are live.",
             variant=AlertVariant.LEFT_ACCENT, color_scheme="success")
metric = Stat(label="Active users", value="1.2k", delta="+12%", delta_up=True)

# H5 styled navigation kit: themed bars + an active accent pill / underline tab.
bar = AppBar(title="Inbox", color_scheme="primary", actions=[button])
search = SearchBar(value="", on_change=lambda e: None, color_scheme="primary")
nav = NavBar(items=["Home", "Search", "You"], active=0, on_select=lambda i: None)
tabs = Tabs(tabs=["Overview", "Activity"], active=0, on_select=lambda i: None)

The H3 surface kit (CardVariant, resolve_surface_variant, Surface, StyledContainer, HStack/VStack, Spacer) realizes Material 3 elevation as a Shadow mapped from the M3 level (elevation=0..5) — no new Style field. Card/Divider/ListTile/Accordion/Grid are themed off the tokens, and the old call sites stay backward-compatible.

The H4 data-display & feedback kit adds three Material 3 status color families — success / warning / info (new ColorRole members + ColorScheme fields, generated from fixed semantic seeds, fully back-compatible) — and two new variant resolvers/enums (BadgeVariant/resolve_badge_variant, AlertVariant/resolve_alert_variant). New components Alert, Stat, ProgressStepper and the Tag (a static Chip preset) join the re-themed Badge/Banner/Avatar/EmptyState/SegmentedControl/Rating/Chip. Because a saturated status role on white can fail WCAG-AA (e.g. success solid = 3.02), the subtle status surfaces use the tonal *_container / on_*_container pairing (AA- safe). Still no new Style field — status flows through color_scheme.

The H5 navigation kit is a pure skin pass over the existing navigation components — no new resolver, no new enum, no new Style field. AppBar / Footer / CollapsingAppBar / Sidebar / Drawer resolve their bar/panel surface via resolve_surface_variant (variant / color_scheme / elevation); NavBar paints the active item as an accent pill (resolve_badge_variant) over a ghost inactive item (resolve_variant); the new Tabs strip gives the active tab an underline indicator (a bottom SideBorder in the accent role); SearchBar resolves its field via resolve_field_variant and its clear button as an IconButton; Burger lowers to an IconButton (the menu icon); Header and Breadcrumb migrate to theme roles. Every old call site and explicit style= keeps working.

Install

pip install tempest-core

Requires Python >=3.11. Only hard dependency: pydantic>=2.

Status

Extracted from tempestroid's vendored core. tempestweb consumes it directly (no vendored copy). tempestroid's own migration to depend on this package — with its full Qt↔Compose conformance suite green — is the next phase.

Develop

uv sync --extra dev
ruff check . && ruff format --check .
mypy tempest_core
pytest -q