Struct Theme 

#[non_exhaustive]
pub struct Theme {

    pub primary: Color,
    pub secondary: Color,
    pub accent: Color,
    pub text: Color,
    pub text_dim: Color,
    pub border: Color,
    pub bg: Color,
    pub success: Color,
    pub warning: Color,
    pub error: Color,
    pub selected_bg: Color,
    pub selected_fg: Color,
    pub surface: Color,
    pub surface_hover: Color,
    pub surface_text: Color,
    pub is_dark: bool,
    pub spacing: Spacing,
}

A color theme that flows through all widgets automatically.

Construct with Theme::dark() or Theme::light(), or use Theme::builder() for custom themes. Pass via crate::RunConfig and every widget picks up the colors without any extra wiring.

Example

use slt::{Color, Theme};

let theme = Theme::builder()
    .primary(Color::Rgb(255, 107, 107))
    .build();

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

primary: Color

Primary accent color, used for focused borders and highlights.

secondary: Color

Secondary accent color, used for less prominent highlights.

accent: Color

Accent color for decorative elements.

text: Color

Default foreground text color.

text_dim: Color

Dimmed text color for secondary labels and hints.

border: Color

Border color for unfocused containers.

bg: Color

Background color. Typically Color::Reset to inherit the terminal background.

success: Color

Color for success states (e.g., toast notifications).

warning: Color

Color for warning states.

error: Color

Color for error states.

selected_bg: Color

Background color for selected list/table rows.

selected_fg: Color

Foreground color for selected list/table rows.

surface: Color

Subtle surface color for card backgrounds and elevated containers.

surface_hover: Color

Hover/active surface color, one step brighter than surface.

Used for interactive element hover states. Should be visually distinguishable from both surface and border.

surface_text: Color

Secondary text color guaranteed readable on surface backgrounds.

Use this instead of text_dim when rendering on surface-colored containers. text_dim is tuned for the main bg; on surface it may lack contrast.

is_dark: bool

Whether this theme is a dark theme. Used to initialize dark mode in Context.

spacing: Spacing

Spacing scale for consistent padding, margin, and gap values.

Implementations

impl Theme

pub fn resolve(&self, token: ThemeColor) -> Color

Resolve a ThemeColor token to a concrete Color.

pub fn contrast_text_on(&self, bg: Color) -> Color

Return a text color with guaranteed contrast against the given background.

Delegates to Color::contrast_fg.

pub fn overlay(&self, color: Color, alpha: f32) -> Color

Blend a color with the theme’s background at the given alpha.

alpha = 0.0 returns self.bg, alpha = 1.0 returns color unchanged.

pub const fn dark() -> Self

Create a dark theme with cyan primary and white text.

pub const fn light() -> Self

Create a light theme with high-contrast dark text on light backgrounds.

pub const fn builder() -> ThemeBuilder

Create a ThemeBuilder for configuring a custom theme.

Unset fields fall back to Theme::dark() defaults. Use Theme::builder_from to start from a different base, or Theme::light_builder for a light-base shorthand.

Example

use slt::{Color, Theme};

let theme = Theme::builder()
    .primary(Color::Rgb(255, 107, 107))
    .accent(Color::Cyan)
    .build();

pub const fn builder_from(base: Theme) -> ThemeBuilder

Create a ThemeBuilder pre-filled with every field from base.

Only fields explicitly overridden via builder methods will differ from base; unset fields keep base’s value (rather than falling back to Theme::dark() defaults as plain Theme::builder does). Useful for deriving variants from any preset.

Example

use slt::{Color, Theme};

// Nord variant: keep all Nord colors but override primary.
let custom_nord = Theme::builder_from(Theme::nord())
    .primary(Color::Rgb(255, 0, 0))
    .build();
assert_eq!(custom_nord.bg, Theme::nord().bg);
assert_eq!(custom_nord.primary, Color::Rgb(255, 0, 0));

pub const fn light_builder() -> ThemeBuilder

Convenience: builder pre-filled with all Theme::light() fields.

Equivalent to Theme::builder_from(Theme::light()).

Example

use slt::{Color, Theme};

let my_light = Theme::light_builder()
    .primary(Color::Rgb(0, 100, 200))
    .build();
assert!(!my_light.is_dark);
assert_eq!(my_light.primary, Color::Rgb(0, 100, 200));
// bg stays light (not dark()'s Reset)
assert_eq!(my_light.bg, Theme::light().bg);

pub fn dracula() -> Self

Dracula theme — purple primary on dark gray.

pub fn catppuccin() -> Self

Catppuccin Mocha theme — lavender primary on dark base.

pub fn nord() -> Self

Nord theme — frost blue primary on polar night.

pub fn solarized_dark() -> Self

Solarized Dark theme — blue primary on dark base.

pub fn solarized_light() -> Self

Solarized Light theme — warm ochre primary on light base.

pub fn tokyo_night() -> Self

Tokyo Night theme — blue primary on dark storm base.

pub fn gruvbox_dark() -> Self

Gruvbox Dark theme — warm, retro tones on dark background.

pub const fn compact() -> Self

Compact density preset — base spacing = 1 (matches v0.19 default behavior).

Use when terminal space is tight or you want maximum information density. Built on Theme::dark() colors with Spacing::new(1).

Example

use slt::Theme;

let theme = Theme::compact();
assert_eq!(theme.spacing.xs(), 1);

pub const fn comfortable() -> Self

Comfortable density preset — base spacing = 2.

Widgets use roughly twice the padding/margin of Theme::compact, improving readability in spacious terminals at the cost of fitting less content per screen.

Example

use slt::Theme;

let theme = Theme::comfortable();
assert_eq!(theme.spacing.xs(), 2);
assert_eq!(theme.spacing.sm(), 4);

pub const fn spacious() -> Self

Spacious density preset — base spacing = 3.

Tripled padding/margin compared to Theme::compact — best for presentations, demos, or very wide terminals where “breathing room” matters more than density.

Example

use slt::Theme;

let theme = Theme::spacious();
assert_eq!(theme.spacing.xs(), 3);
assert_eq!(theme.spacing.sm(), 6);

pub const fn with_spacing(self, spacing: Spacing) -> Self

Apply a Spacing scale on top of the current theme, returning a new theme.

All other fields are preserved. Useful to adapt any preset (Nord, Dracula, custom) to a new density without rebuilding the colors.

Example

use slt::{Spacing, Theme};

let dense_nord = Theme::nord().with_spacing(Spacing::new(2));
assert_eq!(dense_nord.spacing.xs(), 2);
// Nord colors preserved.
assert_eq!(dense_nord.bg, Theme::nord().bg);

pub fn one_dark() -> Self

One Dark theme (Atom) — cool blues and purples on dark gray.

Trait Implementations

impl Clone for Theme

fn clone(&self) -> Theme

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Theme

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Theme

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Theme

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Theme

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Copy for Theme