///|
/// Theme resolver. Turns a `ThemeSpec` plus the current system color scheme
/// into a fully resolved, drawable `Theme` (palette + scales + components).
///
/// `core` only resolves the `Minimal` preset itself. Branded presets
/// (Material/Carbon/Primer/Fluent) are resolved by the `moui_theme` addon,
/// which calls `resolve_minimal_theme` for the base scales and then overlays
/// its own palette/components. The resolver is the single place that applies
/// density scaling, contrast adjustment, and reduced-motion zeroing, so every
/// path that rebuilds a theme (host `ThemeChanged`, app preset switch, a11y
/// change) gets consistent post-processing.
///|
/// Resolve a `ThemeSpec` against a system color scheme. For branded presets
/// this resolves the Minimal base; branded addons must call
/// `resolve_minimal_theme` and then replace the palette/components themselves.
pub fn resolve_theme(spec : ThemeSpec, system_scheme : ColorScheme) -> Theme {
// `core` only owns Minimal. Branded presets are resolved by the addon; if a
// branded spec reaches here (e.g. the addon is not linked), fall back to
// Minimal so the app still renders.
resolve_minimal_theme(spec, system_scheme)
}
///|
/// Resolve the Minimal preset. This is the canonical resolver: it picks the
/// palette by scheme, applies density to spacing, applies contrast adjustment,
/// zeroes motion when reduced motion is requested, and derives default
/// `ComponentThemes` from the resolved palette.
pub fn resolve_minimal_theme(
spec : ThemeSpec,
system_scheme : ColorScheme,
) -> Theme {
let scheme = spec.resolve_scheme(system_scheme)
let palette = match spec.seed {
Some(seed) => ColorPalette::from_seed(primary=seed, scheme)
None =>
match scheme {
Light => ColorPalette::light()
Dark => ColorPalette::dark()
}
}
// High-contrast override: pure black/white surfaces with thick outlines.
let palette = match spec.contrast {
High => high_contrast_palette(palette, scheme)
Standard => palette
}
let spacing_scale = apply_density(SpacingScale::default(), spec.density)
let radius_scale = RadiusScale::default()
let typography = TypographyScale::default()
let shadow_scale = ShadowScale::default(scheme~)
let motion = match spec.reduced_motion {
true =>
{ ..MotionScale::default(), fast_ms: 0.0, normal_ms: 0.0, slow_ms: 0.0 }
false => MotionScale::default()
}
let surfaces = SurfaceScale::default(palette, scheme)
let components = minimal_components(
palette, scheme, spacing_scale, radius_scale, typography,
)
{
scheme,
palette,
spacing_scale,
radius_scale,
typography,
shadow_scale,
motion,
surfaces,
components,
}
}
///|
fn apply_density(base : SpacingScale, density : ThemeDensity) -> SpacingScale {
let m = density.multiplier()
{
xs: base.xs * m,
sm: base.sm * m,
md: base.md * m,
lg: base.lg * m,
xl: base.xl * m,
}
}
///|
/// High-contrast palette: snap surfaces to pure black/white, outlines to the
/// foreground, and semantic colors to their maximum-saturation forms so edges
/// and state stay legible regardless of the base palette's subtle alphas.
fn high_contrast_palette(
palette : ColorPalette,
scheme : ColorScheme,
) -> ColorPalette {
match scheme {
Light =>
{
..palette,
background: Color::white(),
surface: Color::white(),
surface_variant: Color::rgba(r=0.92, g=0.92, b=0.92),
foreground: Color::black(),
on_surface: Color::black(),
on_surface_variant: Color::rgba(r=0.22, g=0.22, b=0.22),
outline: Color::black(),
outline_variant: Color::black(),
scrim: Color::rgba(r=0.0, g=0.0, b=0.0, a=1.0),
success: Color::rgba(r=0.00, g=0.42, b=0.12),
warning: Color::rgba(r=0.62, g=0.36, b=0.00),
danger: Color::rgba(r=0.75, g=0.00, b=0.00),
info: Color::rgba(r=0.00, g=0.24, b=0.86),
}
Dark =>
{
..palette,
background: Color::black(),
surface: Color::black(),
surface_variant: Color::rgba(r=0.10, g=0.10, b=0.10),
foreground: Color::white(),
on_surface: Color::white(),
on_surface_variant: Color::rgba(r=0.82, g=0.82, b=0.82),
outline: Color::white(),
outline_variant: Color::white(),
scrim: Color::rgba(r=0.0, g=0.0, b=0.0, a=1.0),
success: Color::rgba(r=0.58, g=1.0, b=0.58),
warning: Color::rgba(r=1.0, g=0.86, b=0.30),
danger: Color::rgba(r=1.0, g=0.58, b=0.58),
info: Color::rgba(r=0.48, g=0.82, b=1.0),
}
}
}
///|
/// Derive default `ComponentThemes` for the Minimal preset from a palette +
/// scales. This mirrors the neutral control styles the legacy
/// `@views.ButtonStyle::filled/tonal/outline/ghost` helpers produced, but
/// expressed as token sets so controls can resolve variant/state at paint time
/// without a `style?` argument.
fn minimal_components(
palette : ColorPalette,
scheme : ColorScheme,
spacing : SpacingScale,
radius : RadiusScale,
typography : TypographyScale,
) -> ComponentThemes {
let transparent = Color::rgba(r=0.0, g=0.0, b=0.0, a=0.0)
let state_layer = minimal_state_layer(palette)
let button = {
primary: ControlStateTokens::new(
foreground=palette.on_primary,
background=palette.primary,
border=palette.primary,
border_width=0.0,
radius=radius.md,
),
tonal: ControlStateTokens::new(
foreground=palette.primary,
background=palette.surface.lerp(palette.primary, 0.12),
border=palette.surface_variant,
border_width=0.0,
radius=radius.md,
),
outline: ControlStateTokens::new(
foreground=palette.foreground,
background=transparent,
border=palette.outline.multiply_alpha(0.8),
border_width=1.0,
radius=radius.md,
),
ghost: ControlStateTokens::new(
foreground=palette.foreground,
background=transparent,
border=transparent,
border_width=0.0,
radius=radius.md,
),
// Minimal aliases subtle/subtle-brand to ghost/tonal so the 6-variant
// surface stays uniform; Fluent fills them distinctly.
subtle: ControlStateTokens::new(
foreground=palette.foreground,
background=transparent,
border=transparent,
border_width=0.0,
radius=radius.md,
),
subtle_brand: ControlStateTokens::new(
foreground=palette.primary,
background=transparent,
border=transparent,
border_width=0.0,
radius=radius.md,
),
state_layer,
}
let text_field = {
normal: ControlStateTokens::new(
foreground=palette.foreground,
background=palette.surface,
border=palette.outline.multiply_alpha(0.85),
border_width=1.0,
radius=radius.md,
),
focused: ControlStateTokens::new(
foreground=palette.foreground,
background=palette.surface,
border=palette.focus,
border_width=2.0,
radius=radius.md,
),
disabled: ControlStateTokens::new(
foreground=palette.muted,
background=palette.surface_variant,
border=palette.outline.multiply_alpha(0.38),
border_width=1.0,
radius=radius.md,
),
placeholder: palette.muted,
cursor: palette.focus,
font: typography.body,
appearance: TextFieldAppearance::Outline,
}
let surface = {
base_padding: spacing.md,
raised_padding: spacing.lg,
overlay_padding: spacing.md,
base_radius: radius.md,
raised_radius: radius.lg,
overlay_radius: radius.lg,
base_shadow: None,
raised_shadow: None,
overlay_shadow: None,
}
let choice_control = {
foreground: palette.foreground,
selected_color: palette.primary,
disabled_foreground: palette.muted,
disabled_selected_color: palette.primary.multiply_alpha(0.42),
control_size: 20.0,
box_shape: ChoiceControlShape::Square,
check_style: CheckMarkStyle::Checkmark,
}
let progress = {
foreground: palette.primary,
background: palette.surface_variant,
radius: radius.pill,
}
let slider = {
foreground: palette.primary,
background: palette.surface_variant,
thumb_color: palette.primary,
track_height: 4.0,
thumb_size: 18.0,
radius: radius.pill,
thumb_shape: ThumbShape::Circle,
}
let picker = {
font: typography.control,
foreground: palette.foreground,
background: Brush::solid(palette.surface),
radius: radius.md,
popup_max_height: 200.0,
}
let feedback_background_alpha = match scheme {
Light => 0.14
Dark => 0.24
}
let feedback = {
neutral: tone_tokens(palette.muted, feedback_background_alpha, 0.78),
info: tone_tokens(palette.info, feedback_background_alpha, 0.78),
success: tone_tokens(palette.success, feedback_background_alpha, 0.78),
warning: tone_tokens(palette.warning, feedback_background_alpha, 0.78),
danger: tone_tokens(palette.danger, feedback_background_alpha, 0.78),
radius: radius.md,
padding: spacing.sm,
}
let badge = {
neutral: {
foreground: palette.foreground,
background: palette.surface_variant,
border: palette.outline.multiply_alpha(0.42),
},
accent: tone_tokens(palette.info, 1.0, 1.0),
success: tone_tokens(palette.success, 1.0, 1.0),
warning: tone_tokens(palette.warning, 1.0, 1.0),
danger: tone_tokens(palette.danger, 1.0, 1.0),
radius: radius.pill,
padding: 3.0,
}
let form_validation = {
foreground: palette.danger,
background: palette.danger.multiply_alpha(0.12),
border: palette.danger.multiply_alpha(0.72),
radius: radius.md,
padding: spacing.md,
}
{
button,
text_field,
surface,
choice_control,
progress,
slider,
picker,
feedback,
badge,
form_validation,
}
}
///|
fn minimal_state_layer(palette : ColorPalette) -> StateLayerTokens {
{
color: palette.primary,
hover_alpha: 0.08,
focus_alpha: 0.12,
pressed_alpha: 0.12,
dragged_alpha: 0.16,
selected_alpha: 0.10,
disabled_alpha: 0.38,
}
}
///|
fn tone_tokens(
foreground : Color,
background_alpha : Double,
border_alpha : Double,
) -> ToneTokens {
{
foreground,
background: foreground.multiply_alpha(background_alpha),
border: foreground.multiply_alpha(border_alpha),
}
}