feat(theme): themes as files (theme crate: toml subset + ints, contrast check, wire); whimsy dark + light; display reads themes/, serves THEME/THEME_NAME, init SET_THEME -> THEME_CHANGED to all windows, bar themed; k-ui follows; settings appearance; init keeps choice in sealed users/<id>/settings/, reapplies at sign-in + display restart

crates/theme/src/parse.rs

@@ -0,0 +1,126 @@
+//! A theme file, read strictly: every token present once, nothing unknown,
+//! every value in range. Contrast is `check`'s.
+
+use manifest::Error as Toml;
+use manifest::toml::{self, Value};
+
+use crate::{NAME_BYTES, Rgba, Theme};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum Error {
+    /// Not the TOML subset, a token given twice or unknown, or out of range.
+    Toml(Toml),
+    /// Two colours drawn on one another are too close: the pairing, and
+    /// the ratio they have, times 100.
+    Contrast { pair: &'static str, ratio_x100: u32 },
+}
+
+const COLOURS: [&str; 10] = [
+    "background",
+    "surface",
+    "surface_raised",
+    "accent",
+    "on_accent",
+    "text_primary",
+    "text_secondary",
+    "destructive",
+    "on_destructive",
+    "focus",
+];
+
+/// The whole numbers: table, key, and the range allowed.
+const NUMBERS: [(&str, &str, u32, u32); 9] = [
+    ("shape", "corner_radius", 0, 32),
+    ("spacing", "base", 2, 8),
+    ("motion", "duration_fast", 0, 2000),
+    ("motion", "duration_normal", 0, 2000),
+    ("motion", "spring_stiffness", 1, 2000),
+    ("motion", "spring_damping", 1, 200),
+    ("glass", "blur_radius", 0, 32),
+    ("glass", "panel_opacity", 0, 100),
+    ("glass", "highlight", 0, 100),
+];
+
+fn colour(s: &str) -> Option<Rgba> {
+    manifest::Accent::parse(s).map(|a| Rgba::rgb(a.0))
+}
+
+fn once<T>(slot: &mut Option<T>, value: Option<T>, line: usize) -> Result<(), Toml> {
+    if slot.is_some() {
+        return Err(Toml::Duplicate { line });
+    }
+    *slot = Some(value.ok_or(Toml::Invalid { line })?);
+    Ok(())
+}
+
+/// Reads a theme file. It is not checked for contrast here.
+pub fn parse(text: &str) -> Result<Theme, Error> {
+    let mut name: Option<([u8; NAME_BYTES], usize)> = None;
+    let mut colours: [Option<Rgba>; 10] = [None; 10];
+    let mut orbs: Option<[Rgba; 3]> = None;
+    let mut numbers: [Option<u32>; 9] = [None; 9];
+    toml::parse(text, |e| {
+        let line = e.line;
+        match (e.table, e.key, e.value) {
+            ("meta", "name", Value::Str(s)) => {
+                let fits = (1..=NAME_BYTES).contains(&s.len());
+                once(&mut name, fits.then(|| crate::name_bytes(s.as_bytes())), line)
+            }
+            ("colour", key, Value::Str(s)) => {
+                let i = COLOURS.iter().position(|k| *k == key).ok_or(Toml::Unknown { line })?;
+                once(&mut colours[i], colour(s), line)
+            }
+            ("wallpaper", "orbs", Value::List(list)) => {
+                let mut out = [Rgba::rgb(0); 3];
+                let mut n = 0;
+                for s in list.iter() {
+                    *out.get_mut(n).ok_or(Toml::Invalid { line })? = colour(s).ok_or(Toml::Invalid { line })?;
+                    n += 1;
+                }
+                once(&mut orbs, (n == 3).then_some(out), line)
+            }
+            (table, key, Value::Int(v)) => {
+                let i = NUMBERS.iter().position(|(t, k, ..)| *t == table && *k == key).ok_or(Toml::Unknown { line })?;
+                let (_, _, lo, hi) = NUMBERS[i];
+                once(&mut numbers[i], (lo..=hi).contains(&v).then_some(v), line)
+            }
+            ("meta" | "colour" | "wallpaper" | "shape" | "spacing" | "motion" | "glass", _, _) => Err(Toml::Invalid { line }),
+            _ => Err(Toml::Unknown { line }),
+        }
+    })
+    .map_err(Error::Toml)?;
+    let (name, name_len) = name.ok_or(Error::Toml(Toml::Missing("name")))?;
+    let mut c = [Rgba::rgb(0); 10];
+    for (i, slot) in colours.iter().enumerate() {
+        c[i] = slot.ok_or(Error::Toml(Toml::Missing(COLOURS[i])))?;
+    }
+    let mut n = [0u32; 9];
+    for (i, slot) in numbers.iter().enumerate() {
+        n[i] = slot.ok_or(Error::Toml(Toml::Missing(NUMBERS[i].1)))?;
+    }
+    Ok(Theme {
+        name,
+        name_len,
+        background: c[0],
+        surface: c[1],
+        surface_raised: c[2],
+        accent: c[3],
+        on_accent: c[4],
+        text_primary: c[5],
+        text_secondary: c[6],
+        destructive: c[7],
+        on_destructive: c[8],
+        focus: c[9],
+        orbs: orbs.ok_or(Error::Toml(Toml::Missing("orbs")))?,
+        corner_radius: n[0] as f32,
+        spacing_base: n[1] as f32,
+        // In range, so these fit.
+        duration_fast: n[2] as u16,
+        duration_normal: n[3] as u16,
+        spring_stiffness: n[4] as u16,
+        spring_damping: n[5] as u16,
+        blur_radius: n[6] as u8,
+        panel_opacity: n[7] as u8,
+        highlight: n[8] as u8,
+    })
+}