feat: optional serde feature

`Serialize` is implemented for `Theme` and related structs.

Cargo.toml

@@ -14,9 +14,11 @@ keywords = ["palette", "color-scheme", "material-you"]
 ahash = "0.8.11"
 indexmap = "2.2.5"
 image = { version = "0.25.0", optional = true }
+serde = { version = "1.0.197", features = ["derive"], optional = true }
 
 [features]
 image = ["dep:image"]
+serde = ["dep:serde"]
 
 [profile.dev]
 opt-level = 1

src/hct.rs

@@ -3,6 +3,9 @@ use core::fmt;
 use core::hash::Hash;
 use core::hash::Hasher;
 
+#[cfg(feature = "serde")]
+use serde::Serialize;
+
 use crate::utils::color::lstar_from_argb;
 use crate::utils::color::lstar_from_y;
 use crate::utils::color::Argb;
@@ -16,6 +19,7 @@ pub mod solver;
 pub mod viewing_conditions;
 
 #[derive(Clone, Copy, Debug, PartialOrd)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
 pub struct Hct {
     _hue: f64,
     _chroma: f64,

src/palettes/tonal.rs

@@ -1,4 +1,6 @@
 use core::fmt;
+#[cfg(feature = "serde")]
+use serde::Serialize;
 
 use crate::hct::Hct;
 use crate::utils::color::Argb;
@@ -13,6 +15,7 @@ use crate::utils::color::Argb;
 /// is not enforced. [get] will only return the input colors, corresponding to
 /// [commonTones].
 #[derive(Clone, Copy, Debug, PartialOrd)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
 pub struct TonalPalette {
     _hue: f64,
     _chroma: f64,
@@ -54,11 +57,7 @@ impl TonalPalette {
 
     /// Create a Tonal Palette from hue and chroma, which generates a key color.
     pub fn from_hue_and_chroma(hue: f64, chroma: f64) -> Self {
-        Self::new(
-            hue,
-            chroma,
-            TonalPalette::create_key_color(hue, chroma),
-        )
+        Self::new(hue, chroma, TonalPalette::create_key_color(hue, chroma))
     }
 
     /// Create colors using [hue] and [chroma].
@@ -119,7 +118,7 @@ impl TonalPalette {
         Hct::from(self.hue(), self.chroma(), tone as f64).into()
     }
 
-    pub fn get_hct(&self, tone: f64) -> Hct {        
+    pub fn get_hct(&self, tone: f64) -> Hct {
         Hct::from(self.hue(), self.chroma(), tone)
     }
 }

src/scheme.rs

@@ -1,4 +1,6 @@
 #![allow(clippy::too_many_arguments)]
+#[cfg(feature = "serde")]
+use serde::Serialize;
 
 use core::array::IntoIter;
 use core::fmt;
@@ -20,6 +22,7 @@ pub mod tonal_spot;
 pub mod vibrant;
 
 #[derive(Debug, PartialEq, Eq)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
 pub struct Scheme {
     pub primary: Argb,
     pub on_primary: Argb,

src/utils/theme.rs

@@ -3,11 +3,14 @@ use crate::palettes::core::CorePalette;
 use crate::palettes::tonal::TonalPalette;
 use crate::scheme::tonal_spot::SchemeTonalSpot;
 use crate::scheme::Scheme;
+#[cfg(feature = "serde")]
+use serde::Serialize;
 
 use super::color::Argb;
 
 /// Custom color used to pair with a theme
 #[derive(Debug)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
 pub struct CustomColor {
     pub value: Argb,
     pub name: String,
@@ -16,6 +19,7 @@ pub struct CustomColor {
 
 /// Color group
 #[derive(Debug)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
 pub struct ColorGroup {
     pub color: Argb,
     pub on_color: Argb,
@@ -25,6 +29,7 @@ pub struct ColorGroup {
 
 /// Custom Color Group
 #[derive(Debug)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
 pub struct CustomColorGroup {
     pub color: CustomColor,
     pub value: Argb,
@@ -33,12 +38,14 @@ pub struct CustomColorGroup {
 }
 
 #[derive(Debug)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
 pub struct Schemes {
     pub light: Scheme,
     pub dark: Scheme,
 }
 
 #[derive(Debug)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
 pub struct Palettes {
     pub primary: TonalPalette,
     pub secondary: TonalPalette,
@@ -50,6 +57,7 @@ pub struct Palettes {
 
 // Theme
 #[derive(Debug)]
+#[cfg_attr(feature = "serde", derive(Serialize))]
 pub struct Theme {
     pub source: Argb,
     pub schemes: Schemes,