theme/lib.rs
1//! The app theme — two concrete appearances, one token set.
2//!
3//! Colors are precomputed from an oklch-derived neutral scale (perceptually even
4//! lightness steps; the same scale the reference Tailwind theme used) into gpui
5//! [`Hsla`](gpui::Hsla).
6//! **Numbers drive layout, colors are paint**: layout constants live in
7//! `theme/layout.rs` as plain numbers and never depend on which color is painted.
8//!
9//! # Light is designed, not inverted
10//!
11//! Mirroring lightness produces the classic "washed-out inverted" look, for three
12//! reasons this module handles explicitly:
13//!
14//! 1. **Surface order flips meaning.** In dark, the main content panel is the
15//! *darkest* plane and raised surfaces get *lighter*. In light, the content
16//! panel is *white* and the shell/sidebar goes *grey* — chrome recedes by
17//! getting darker, not lighter. Popovers stay white and earn separation from a
18//! border and shadow rather than from lightness.
19//! 2. **Elevation reverses.** On dark, a faint *white* wash means "raised". Its
20//! literal translation — a faint *black* wash on white — means "recessed", so
21//! the composer read as a dent instead of a plate. Light lifts with white plus
22//! a border and shadow ([`Theme::input_bg`], the elevation ladder). Fill
23//! *alphas* carry over unchanged ([`INK_FILL_SCALE`]); only hairlines scale, so
24//! a 1px edge survives a bright surround ([`INK_HAIRLINE_SCALE`]).
25//! 3. **Accents must move down the scale.** The dark palette's 400-level accents
26//! (red/amber, and whatever hue an app sets [`Theme::accent`] to) are chosen
27//! for contrast against near-black; on white they fall to 2–4:1 and fail WCAG
28//! AA. Light mode uses the 600-level siblings at the same hue, which restores
29//! the *contrast ratio* the dark token had.
30//!
31//! Text tones are chosen so each light token lands within ~0.5 of its dark
32//! counterpart's contrast ratio against its own background — the pairing is
33//! verified in `tests/theme.rs`, not eyeballed.
34//!
35//! Installed as a gpui [`Global`](gpui::Global) at boot; read with [`Theme::of`].
36
37mod app;
38pub use app::AppExt;
39
40pub mod appearance;
41
42mod brand;
43mod color;
44mod paint;
45mod platform;
46mod theme;
47
48pub use brand::{BASE_COLORS, Brand, Ink, TextInk, Tint, Vibrancy};
49
50pub use platform::{LENSED, frosted_window};
51
52pub use color::{
53 contrast_ratio, flatten, grey, hsl_to_rgb, lightness, mix, neutral, oklch, oklch_to_srgb,
54 relative_luminance, rgb_to_hsl, tint,
55};
56pub use paint::{
57 INK_FILL_SCALE, INK_HAIRLINE_SCALE, SCRIM_ALPHA_DARK, band, card_selected_bg,
58 card_selected_shadows, current_appearance, frame_shadows, glass_selected_bg,
59 glass_selected_shadows, hairline, ink, lock_appearance, scrim, set_current_appearance,
60 surface_shadows, theme_generation, user_bubble_bg, wash,
61};
62pub use theme::{
63 ControlSize, Glass, HighlightKind, Material, MaterialSpec, Metrics, Sizing, SurfaceSpec,
64 SurfaceStyle, SyntaxPalette, TextStyle, Theme, Typeset, base_text_size,
65};
66
67/// The carrier seam for catalog traits: any type holding a [`Theme`] exposes
68/// it through this one method, and every component group
69/// (`ui::widgets::Scaffolding`, …) extends it, so group methods read
70/// the environment through `self.theme()`.
71pub trait ThemeExt {
72 fn theme(&self) -> &Theme;
73}
74
75impl ThemeExt for Theme {
76 fn theme(&self) -> &Theme {
77 self
78 }
79}
80
81/// Which appearance the app is painting.
82#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Default)]
83pub enum Appearance {
84 #[default]
85 Dark,
86 Light,
87}
88
89impl Appearance {
90 pub fn is_dark(self) -> bool {
91 matches!(self, Self::Dark)
92 }
93
94 pub fn is_light(self) -> bool {
95 matches!(self, Self::Light)
96 }
97
98 /// Map a gpui window appearance onto ours (both vibrant variants are just
99 /// the blurred flavour of the same tone).
100 pub fn from_window(appearance: gpui::WindowAppearance) -> Self {
101 use gpui::WindowAppearance::*;
102 match appearance {
103 Light | VibrantLight => Self::Light,
104 Dark | VibrantDark => Self::Dark,
105 }
106 }
107}