Implement theme styling for Container

style/src/container.rs

@@ -3,7 +3,7 @@ use iced_core::{Background, Color};
 
 /// The appearance of a container.
 #[derive(Debug, Clone, Copy)]
-pub struct Style {
+pub struct Appearance {
     pub text_color: Option<Color>,
     pub background: Option<Background>,
     pub border_radius: f32,
@@ -11,7 +11,7 @@ pub struct Style {
     pub border_color: Color,
 }
 
-impl std::default::Default for Style {
+impl std::default::Default for Appearance {
     fn default() -> Self {
         Self {
             text_color: None,
@@ -23,37 +23,10 @@ impl std::default::Default for Style {
     }
 }
 
-/// A set of rules that dictate the style of a container.
+/// A set of rules that dictate the [`Appearance`] of a container.
 pub trait StyleSheet {
-    /// Produces the style of a container.
-    fn style(&self) -> Style;
-}
+    type Style: Default + Copy;
 
-struct Default;
-
-impl StyleSheet for Default {
-    fn style(&self) -> Style {
-        Style {
-            text_color: None,
-            background: None,
-            border_radius: 0.0,
-            border_width: 0.0,
-            border_color: Color::TRANSPARENT,
-        }
-    }
-}
-
-impl<'a> std::default::Default for Box<dyn StyleSheet + 'a> {
-    fn default() -> Self {
-        Box::new(Default)
-    }
-}
-
-impl<'a, T> From<T> for Box<dyn StyleSheet + 'a>
-where
-    T: StyleSheet + 'a,
-{
-    fn from(style_sheet: T) -> Self {
-        Box::new(style_sheet)
-    }
+    /// Produces the [`Appearance`] of a container.
+    fn appearance(&self, style: Self::Style) -> Appearance;
 }

style/src/theme.rs

@@ -5,6 +5,7 @@ pub use self::palette::Palette;
 use crate::application;
 use crate::button;
 use crate::checkbox;
+use crate::container;
 use crate::pane_grid;
 use crate::progress_bar;
 use crate::radio;
@@ -127,7 +128,6 @@ impl button::StyleSheet for Theme {
 /*
  * Checkbox
  */
-
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum Checkbox {
     Primary,
@@ -227,6 +227,50 @@ fn checkbox_appearance(
     }
 }
 
+/*
+ * Container
+ */
+#[derive(Clone, Copy)]
+pub enum Container {
+    Transparent,
+    Box,
+    Custom(fn(&Theme) -> container::Appearance),
+}
+
+impl Default for Container {
+    fn default() -> Self {
+        Self::Transparent
+    }
+}
+
+impl From<fn(&Theme) -> container::Appearance> for Container {
+    fn from(f: fn(&Theme) -> container::Appearance) -> Self {
+        Self::Custom(f)
+    }
+}
+
+impl container::StyleSheet for Theme {
+    type Style = Container;
+
+    fn appearance(&self, style: Self::Style) -> container::Appearance {
+        match style {
+            Container::Transparent => Default::default(),
+            Container::Box => {
+                let palette = self.extended_palette();
+
+                container::Appearance {
+                    text_color: None,
+                    background: palette.background.weak.color.into(),
+                    border_radius: 2.0,
+                    border_width: 0.0,
+                    border_color: Color::TRANSPARENT,
+                }
+            }
+            Container::Custom(f) => f(self),
+        }
+    }
+}
+
 /*
  * Slider
  */