Draft out skeleton for minimal custom themes.

For now, custom themes will use constant structs like in Sniffnet's
original code. Custom themes will be self contained instead of polluting
the original code base. This should make it easier for contributors to
modify or add any extra themes without having to change code in too many
files.

src/gui/styles/style_constants.rs

@@ -180,6 +180,7 @@ pub fn get_color_mix_chart(style: StyleType) -> f64 {
     match style {
         StyleType::Night | StyleType::DeepSea => 0.3,
         StyleType::Day | StyleType::MonAmour => 0.8,
+        StyleType::Custom(style) => style.to_ext().color_mixing,
     }
 }
 
@@ -216,6 +217,7 @@ pub fn get_starred_color(style: StyleType) -> Color {
             b: 39.0 / 255.0,
             a: 0.8,
         },
+        StyleType::Custom(style) => style.to_ext().starred,
     }
 }
 
@@ -224,5 +226,6 @@ pub fn get_color_mix_filter_badge(style: StyleType) -> f32 {
         StyleType::Night | StyleType::DeepSea => 0.2,
         StyleType::Day => 0.7,
         StyleType::MonAmour => 0.5,
+        StyleType::Custom(style) => style.to_ext().badge_alpha,
     }
 }

src/gui/styles/types/custom_palette.rs

@@ -0,0 +1,50 @@
+use std::fmt;
+
+use iced::Color;
+use serde::{Deserialize, Serialize};
+
+use super::palette::Palette;
+
+/// Extension color for themes.
+pub struct PaletteExtension {
+    /// Color of favorites star
+    pub starred: Color,
+    /// Badge/logo alpha
+    pub badge_alpha: f32,
+    /// Traffic chart color mixing
+    pub color_mixing: f64,
+}
+
+/// Custom style with any relevant metadata
+// pub struct CustomPalette {
+//    name: &'static str,
+//    palette: Palette,
+//    extension: PaletteExtension,
+//}
+
+#[derive(Clone, Copy, Serialize, Deserialize, Debug, Hash, PartialEq)]
+pub enum ExtraStyles {
+    Dracula,
+}
+
+impl ExtraStyles {
+    pub fn to_palette(self) -> Palette {
+        match self {
+            ExtraStyles::Dracula => unimplemented!(),
+        }
+    }
+
+    pub fn to_ext(self) -> PaletteExtension {
+        match self {
+            ExtraStyles::Dracula => unimplemented!(),
+        }
+    }
+}
+
+impl fmt::Display for ExtraStyles {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match *self {
+            ExtraStyles::Dracula => write!(f, "Dracula"),
+        }
+    }
+}

src/gui/styles/types/mod.rs

@@ -1,3 +1,4 @@
+pub mod custom_palette;
 pub mod element_type;
 pub mod palette;
 pub mod style_tuple;

src/gui/styles/types/palette.rs

@@ -35,28 +35,13 @@ pub struct Palette {
     pub round_containers: Color,
 }
 
-/// Extension color for themes.
-pub struct PaletteExtension {
-    /// Color of favorites star
-    pub starred: Color,
-    /// Badge/logo alpha
-    pub badge_alpha: f32,
-    /// Traffic chart color mixing
-    pub color_mixing: f64
-}
-
-pub struct CustomPalette {
-    name: &'static str,
-    palette: Palette,
-    extension: PaletteExtension
-}
-
 pub fn get_colors(style: StyleType) -> Palette {
     match style {
         StyleType::Night => NIGHT_STYLE,
         StyleType::Day => DAY_STYLE,
         StyleType::DeepSea => DEEP_SEA_STYLE,
         StyleType::MonAmour => MON_AMOUR_STYLE,
+        StyleType::Custom(style) => style.to_palette()
     }
 }
 

src/gui/styles/types/style_type.rs

@@ -1,12 +1,15 @@
 use serde::{Deserialize, Serialize};
 
+use super::custom_palette::ExtraStyles;
+
 /// Used to specify the kind of style of the application
 #[derive(Clone, Copy, Serialize, Deserialize, Debug, Hash, PartialEq)]
 pub enum StyleType {
     Night,
     Day,
     DeepSea,
     MonAmour,
+    Custom(ExtraStyles)
 }
 
 impl Default for StyleType {