Leverage DefaultStyle traits instead of Default

src/application.rs

@@ -3,7 +3,7 @@ use crate::{Command, Element, Executor, Settings, Subscription};
 
 use crate::shell::application;
 
-pub use application::{default, Appearance, Style};
+pub use application::{default, Appearance, DefaultStyle};
 
 /// An interactive cross-platform application.
 ///
@@ -95,7 +95,7 @@ pub use application::{default, Appearance, Style};
 /// ```
 pub trait Application: Sized
 where
-    Style<Self::Theme>: Default,
+    Self::Theme: DefaultStyle,
 {
     /// The [`Executor`] that will run commands and subscriptions.
     ///
@@ -153,11 +153,9 @@ where
         Self::Theme::default()
     }
 
-    /// Returns the current `Style` of the [`Theme`].
+    /// Returns the current [`Appearance`] of the [`Application`].
-    ///
-    /// [`Theme`]: Self::Theme
     fn style(&self, theme: &Self::Theme) -> Appearance {
-        Style::default().resolve(theme)
+        theme.default_style()
     }
 
     /// Returns the event [`Subscription`] for the current state of the
@@ -221,12 +219,12 @@ where
 struct Instance<A>(A)
 where
     A: Application,
-    application::Style<A::Theme>: Default;
+    A::Theme: DefaultStyle;
 
 impl<A> crate::runtime::Program for Instance<A>
 where
     A: Application,
-    application::Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     type Message = A::Message;
     type Theme = A::Theme;
@@ -244,7 +242,7 @@ where
 impl<A> application::Application for Instance<A>
 where
     A: Application,
-    application::Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     type Flags = A::Flags;
 

src/multi_window.rs

@@ -2,7 +2,7 @@
 use crate::window;
 use crate::{Command, Element, Executor, Settings, Subscription};
 
-pub use crate::application::{default, Appearance, Style};
+pub use crate::application::{Appearance, DefaultStyle};
 
 /// An interactive cross-platform multi-window application.
 ///
@@ -67,7 +67,7 @@ pub use crate::application::{default, Appearance, Style};
 /// [`Sandbox`]: crate::Sandbox
 pub trait Application: Sized
 where
-    Style<Self::Theme>: Default,
+    Self::Theme: DefaultStyle,
 {
     /// The [`Executor`] that will run commands and subscriptions.
     ///
@@ -133,7 +133,7 @@ where
     ///
     /// [`Theme`]: Self::Theme
     fn style(&self, theme: &Self::Theme) -> Appearance {
-        Style::default().resolve(theme)
+        Self::Theme::default_style(theme)
     }
 
     /// Returns the event [`Subscription`] for the current state of the
@@ -198,12 +198,12 @@ where
 struct Instance<A>(A)
 where
     A: Application,
-    Style<A::Theme>: Default;
+    A::Theme: DefaultStyle;
 
 impl<A> crate::runtime::multi_window::Program for Instance<A>
 where
     A: Application,
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     type Message = A::Message;
     type Theme = A::Theme;
@@ -224,7 +224,7 @@ where
 impl<A> crate::shell::multi_window::Application for Instance<A>
 where
     A: Application,
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     type Flags = A::Flags;
 

src/sandbox.rs

@@ -122,7 +122,9 @@ pub trait Sandbox {
 
     /// Returns the current [`application::Appearance`].
     fn style(&self, theme: &Theme) -> application::Appearance {
-        crate::shell::application::default(theme)
+        use application::DefaultStyle;
+
+        theme.default_style()
     }
 
     /// Returns the scale factor of the [`Sandbox`].

widget/src/button.rs

@@ -68,7 +68,7 @@ where
         content: impl Into<Element<'a, Message, Theme, Renderer>>,
     ) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
     {
         let content = content.into();
         let size = content.as_widget().size_hint();
@@ -80,7 +80,7 @@ where
             height: size.height.fluid(),
             padding: Padding::new(5.0),
             clip: false,
-            style: Style::default(),
+            style: Theme::default_style(),
         }
     }
 
@@ -121,7 +121,7 @@ where
 
     /// Sets the style variant of this [`Button`].
     pub fn style(mut self, style: fn(&Theme, Status) -> Appearance) -> Self {
-        self.style = Style(style);
+        self.style = style;
         self
     }
 
@@ -301,7 +301,7 @@ where
             Status::Active
         };
 
-        let styling = (self.style.0)(theme, status);
+        let styling = (self.style)(theme, status);
 
         if styling.background.is_some()
             || styling.border.width > 0.0
@@ -424,26 +424,23 @@ impl std::default::Default for Appearance {
 }
 
 /// The style of a [`Button`].
-#[derive(Debug, PartialEq, Eq)]
+pub type Style<Theme> = fn(&Theme, Status) -> Appearance;
-pub struct Style<Theme>(fn(&Theme, Status) -> Appearance);
 
-impl<Theme> Clone for Style<Theme> {
+/// The default style of a [`Button`].
-    fn clone(&self) -> Self {
+pub trait DefaultStyle {
-        *self
+    /// Returns the default style of a [`Button`].
+    fn default_style() -> Style<Self>;
+}
+
+impl DefaultStyle for Theme {
+    fn default_style() -> Style<Self> {
+        primary
     }
 }
 
-impl<Theme> Copy for Style<Theme> {}
+impl DefaultStyle for Appearance {
-
+    fn default_style() -> Style<Self> {
-impl Default for Style<Theme> {
+        |appearance, _status| *appearance
-    fn default() -> Self {
-        Style(primary)
-    }
-}
-
-impl<Theme> From<fn(&Theme, Status) -> Appearance> for Style<Theme> {
-    fn from(f: fn(&Theme, Status) -> Appearance) -> Self {
-        Style(f)
     }
 }
 

widget/src/checkbox.rs

@@ -71,7 +71,7 @@ where
     ///   * a boolean describing whether the [`Checkbox`] is checked or not
     pub fn new(label: impl Into<String>, is_checked: bool) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
     {
         Checkbox {
             is_checked,
@@ -91,7 +91,7 @@ where
                 line_height: text::LineHeight::default(),
                 shaping: text::Shaping::Basic,
             },
-            style: Style::default(),
+            style: Theme::default_style(),
         }
     }
 
@@ -175,7 +175,7 @@ where
 
     /// Sets the style of the [`Checkbox`].
     pub fn style(mut self, style: fn(&Theme, Status) -> Appearance) -> Self {
-        self.style = Style(style);
+        self.style = style;
         self
     }
 }
@@ -301,7 +301,7 @@ where
             Status::Active { is_checked }
         };
 
-        let appearance = (self.style.0)(theme, status);
+        let appearance = (self.style)(theme, status);
 
         {
             let layout = children.next().unwrap();
@@ -424,26 +424,23 @@ pub struct Appearance {
 }
 
 /// The style of a [`Checkbox`].
-#[derive(Debug, PartialEq, Eq)]
+pub type Style<Theme> = fn(&Theme, Status) -> Appearance;
-pub struct Style<Theme>(fn(&Theme, Status) -> Appearance);
 
-impl<Theme> Clone for Style<Theme> {
+/// The default style of a [`Checkbox`].
-    fn clone(&self) -> Self {
+pub trait DefaultStyle {
-        *self
+    /// Returns the default style of a [`Checkbox`].
+    fn default_style() -> Style<Self>;
+}
+
+impl DefaultStyle for Theme {
+    fn default_style() -> Style<Self> {
+        primary
     }
 }
 
-impl<Theme> Copy for Style<Theme> {}
+impl DefaultStyle for Appearance {
-
+    fn default_style() -> Style<Self> {
-impl Default for Style<Theme> {
+        |appearance, _status| *appearance
-    fn default() -> Self {
-        Style(primary)
-    }
-}
-
-impl<Theme> From<fn(&Theme, Status) -> Appearance> for Style<Theme> {
-    fn from(f: fn(&Theme, Status) -> Appearance) -> Self {
-        Style(f)
     }
 }
 

widget/src/combo_box.rs

@@ -62,9 +62,9 @@ where
         on_selected: impl Fn(T) -> Message + 'static,
     ) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
     {
-        let style = Style::<Theme>::default();
+        let style = Theme::default_style();
 
         let text_input = TextInput::with_style(
             placeholder,
@@ -762,7 +762,7 @@ where
         .collect()
 }
 
-/// The appearance of a [`ComboBox`].
+/// The style of a [`ComboBox`].
 #[derive(Debug, PartialEq, Eq)]
 pub struct Style<Theme> {
     /// The style of the [`TextInput`] of the [`ComboBox`].
@@ -772,6 +772,14 @@ pub struct Style<Theme> {
     menu: menu::Style<Theme>,
 }
 
+impl Style<Theme> {
+    /// The default style of a [`ComboBox`].
+    pub const DEFAULT: Self = Self {
+        text_input: text_input::default,
+        menu: menu::Style::<Theme>::DEFAULT,
+    };
+}
+
 impl<Theme> Clone for Style<Theme> {
     fn clone(&self) -> Self {
         *self
@@ -780,16 +788,14 @@ impl<Theme> Clone for Style<Theme> {
 
 impl<Theme> Copy for Style<Theme> {}
 
-impl Default for Style<Theme> {
+/// The default style of a [`ComboBox`].
-    fn default() -> Self {
+pub trait DefaultStyle: Sized {
-        default()
+    /// Returns the default style of a [`ComboBox`].
-    }
+    fn default_style() -> Style<Self>;
 }
 
-/// The default style of a [`ComboBox`].
+impl DefaultStyle for Theme {
-pub fn default() -> Style<Theme> {
+    fn default_style() -> Style<Self> {
-    Style {
+        Style::<Self>::DEFAULT
-        text_input: text_input::default,
-        menu: menu::Style::default(),
     }
 }

widget/src/container.rs

@@ -47,9 +47,9 @@ where
         content: impl Into<Element<'a, Message, Theme, Renderer>>,
     ) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
     {
-        Self::with_style(content, Style::default().0)
+        Self::with_style(content, Theme::default_style())
     }
 
     /// Creates a [`Container`] with the given content and style.
@@ -71,7 +71,7 @@ where
             vertical_alignment: alignment::Vertical::Top,
             clip: false,
             content,
-            style: Style(style),
+            style,
         }
     }
 
@@ -137,7 +137,7 @@ where
 
     /// Sets the style of the [`Container`].
     pub fn style(mut self, style: fn(&Theme, Status) -> Appearance) -> Self {
-        self.style = Style(style);
+        self.style = style;
         self
     }
 
@@ -275,7 +275,7 @@ where
             Status::Idle
         };
 
-        let style = (self.style.0)(theme, status);
+        let style = (self.style)(theme, status);
 
         if let Some(clipped_viewport) = bounds.intersection(viewport) {
             draw_background(renderer, &style, bounds);
@@ -546,40 +546,23 @@ pub enum Status {
 }
 
 /// The style of a [`Container`].
-#[derive(Debug, PartialEq, Eq)]
+pub type Style<Theme> = fn(&Theme, Status) -> Appearance;
-pub struct Style<Theme>(fn(&Theme, Status) -> Appearance);
 
-impl<Theme> Style<Theme> {
+/// The default style of a [`Container`].
-    /// Resolves the [`Style`] with the given `Theme` and [`Status`] to
+pub trait DefaultStyle {
-    /// produce an [`Appearance`].
+    /// Returns the default style of a [`Container`].
-    pub fn resolve(self, theme: &Theme, status: Status) -> Appearance {
+    fn default_style() -> Style<Self>;
-        (self.0)(theme, status)
+}
+
+impl DefaultStyle for Theme {
+    fn default_style() -> Style<Self> {
+        transparent
     }
 }
 
-impl<Theme> Clone for Style<Theme> {
+impl DefaultStyle for Appearance {
-    fn clone(&self) -> Self {
+    fn default_style() -> Style<Self> {
-        *self
+        |appearance, _status| *appearance
-    }
-}
-
-impl<Theme> Copy for Style<Theme> {}
-
-impl Default for Style<Theme> {
-    fn default() -> Self {
-        Style(transparent)
-    }
-}
-
-impl Default for Style<Appearance> {
-    fn default() -> Self {
-        Style(|appearance, _status| *appearance)
-    }
-}
-
-impl<Theme> From<fn(&Theme, Status) -> Appearance> for Style<Theme> {
-    fn from(f: fn(&Theme, Status) -> Appearance) -> Self {
-        Style(f)
     }
 }
 

widget/src/helpers.rs

@@ -58,8 +58,8 @@ pub fn container<'a, Message, Theme, Renderer>(
     content: impl Into<Element<'a, Message, Theme, Renderer>>,
 ) -> Container<'a, Message, Theme, Renderer>
 where
+    Theme: container::DefaultStyle,
     Renderer: core::Renderer,
-    container::Style<Theme>: Default,
 {
     Container::new(content)
 }
@@ -104,8 +104,8 @@ pub fn scrollable<'a, Message, Theme, Renderer>(
     content: impl Into<Element<'a, Message, Theme, Renderer>>,
 ) -> Scrollable<'a, Message, Theme, Renderer>
 where
+    Theme: scrollable::DefaultStyle,
     Renderer: core::Renderer,
-    scrollable::Style<Theme>: Default,
 {
     Scrollable::new(content)
 }
@@ -117,8 +117,8 @@ pub fn button<'a, Message, Theme, Renderer>(
     content: impl Into<Element<'a, Message, Theme, Renderer>>,
 ) -> Button<'a, Message, Theme, Renderer>
 where
+    Theme: button::DefaultStyle,
     Renderer: core::Renderer,
-    button::Style<Theme>: Default,
 {
     Button::new(content)
 }
@@ -134,8 +134,8 @@ pub fn tooltip<'a, Message, Theme, Renderer>(
     position: tooltip::Position,
 ) -> crate::Tooltip<'a, Message, Theme, Renderer>
 where
+    Theme: container::DefaultStyle,
     Renderer: core::text::Renderer,
-    container::Style<Theme>: Default,
 {
     Tooltip::new(content, tooltip, position)
 }
@@ -160,8 +160,8 @@ pub fn checkbox<'a, Message, Theme, Renderer>(
     is_checked: bool,
 ) -> Checkbox<'a, Message, Theme, Renderer>
 where
+    Theme: checkbox::DefaultStyle,
     Renderer: core::text::Renderer,
-    checkbox::Style<Theme>: Default,
 {
     Checkbox::new(label, is_checked)
 }
@@ -177,9 +177,9 @@ pub fn radio<Message, Theme, Renderer, V>(
 ) -> Radio<Message, Theme, Renderer>
 where
     Message: Clone,
+    Theme: radio::DefaultStyle,
     Renderer: core::text::Renderer,
     V: Copy + Eq,
-    radio::Style<Theme>: Default,
 {
     Radio::new(label, value, selected, on_click)
 }
@@ -193,8 +193,8 @@ pub fn toggler<'a, Message, Theme, Renderer>(
     f: impl Fn(bool) -> Message + 'a,
 ) -> Toggler<'a, Message, Theme, Renderer>
 where
+    Theme: toggler::DefaultStyle,
     Renderer: core::text::Renderer,
-    toggler::Style<Theme>: Default,
 {
     Toggler::new(label, is_checked, f)
 }
@@ -208,8 +208,8 @@ pub fn text_input<'a, Message, Theme, Renderer>(
 ) -> TextInput<'a, Message, Theme, Renderer>
 where
     Message: Clone,
+    Theme: text_input::DefaultStyle,
     Renderer: core::text::Renderer,
-    text_input::Style<Theme>: Default,
 {
     TextInput::new(placeholder, value)
 }
@@ -222,8 +222,8 @@ pub fn text_editor<Message, Theme, Renderer>(
 ) -> TextEditor<'_, core::text::highlighter::PlainText, Message, Theme, Renderer>
 where
     Message: Clone,
+    Theme: text_editor::DefaultStyle,
     Renderer: core::text::Renderer,
-    text_editor::Style<Theme>: Default,
 {
     TextEditor::new(content)
 }
@@ -239,7 +239,7 @@ pub fn slider<'a, T, Message, Theme>(
 where
     T: Copy + From<u8> + std::cmp::PartialOrd,
     Message: Clone,
-    slider::Style<Theme>: Default,
+    Theme: slider::DefaultStyle,
 {
     Slider::new(range, value, on_change)
 }
@@ -255,7 +255,7 @@ pub fn vertical_slider<'a, T, Message, Theme>(
 where
     T: Copy + From<u8> + std::cmp::PartialOrd,
     Message: Clone,
-    vertical_slider::Style<Theme>: Default,
+    Theme: vertical_slider::DefaultStyle,
 {
     VerticalSlider::new(range, value, on_change)
 }
@@ -273,8 +273,8 @@ where
     L: Borrow<[T]> + 'a,
     V: Borrow<T> + 'a,
     Message: Clone,
+    Theme: pick_list::DefaultStyle,
     Renderer: core::text::Renderer,
-    pick_list::Style<Theme>: Default,
 {
     PickList::new(options, selected, on_selected)
 }
@@ -290,8 +290,8 @@ pub fn combo_box<'a, T, Message, Theme, Renderer>(
 ) -> ComboBox<'a, T, Message, Theme, Renderer>
 where
     T: std::fmt::Display + Clone,
+    Theme: combo_box::DefaultStyle,
     Renderer: core::text::Renderer,
-    combo_box::Style<Theme>: Default,
 {
     ComboBox::new(state, placeholder, selection, on_selected)
 }
@@ -317,7 +317,7 @@ pub fn vertical_space() -> Space {
 /// [`Rule`]: crate::Rule
 pub fn horizontal_rule<Theme>(height: impl Into<Pixels>) -> Rule<Theme>
 where
-    rule::Style<Theme>: Default,
+    Theme: rule::DefaultStyle,
 {
     Rule::horizontal(height)
 }
@@ -327,7 +327,7 @@ where
 /// [`Rule`]: crate::Rule
 pub fn vertical_rule<Theme>(width: impl Into<Pixels>) -> Rule<Theme>
 where
-    rule::Style<Theme>: Default,
+    Theme: rule::DefaultStyle,
 {
     Rule::vertical(width)
 }
@@ -344,7 +344,7 @@ pub fn progress_bar<Theme>(
     value: f32,
 ) -> ProgressBar<Theme>
 where
-    progress_bar::Style<Theme>: Default,
+    Theme: progress_bar::DefaultStyle,
 {
     ProgressBar::new(range, value)
 }
@@ -364,7 +364,7 @@ pub fn image<Handle>(handle: impl Into<Handle>) -> crate::Image<Handle> {
 #[cfg(feature = "svg")]
 pub fn svg<Theme>(handle: impl Into<core::svg::Handle>) -> crate::Svg<Theme>
 where
-    crate::svg::Style<Theme>: Default,
+    Theme: crate::svg::DefaultStyle,
 {
     crate::Svg::new(handle)
 }
@@ -390,7 +390,7 @@ where
 #[cfg(feature = "qr_code")]
 pub fn qr_code<Theme>(data: &crate::qr_code::Data) -> crate::QRCode<'_, Theme>
 where
-    crate::qr_code::Style<Theme>: Default,
+    Theme: crate::qr_code::DefaultStyle,
 {
     crate::QRCode::new(data)
 }

widget/src/overlay/menu.rs

@@ -58,7 +58,7 @@ where
         on_option_hovered: Option<&'a dyn Fn(T) -> Message>,
     ) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
     {
         Self::with_style(
             state,
@@ -66,7 +66,7 @@ where
             hovered_option,
             on_selected,
             on_option_hovered,
-            Style::default(),
+            Theme::default_style(),
         )
     }
 
@@ -234,7 +234,7 @@ where
                     text_line_height,
                     text_shaping,
                     padding,
-                    style: style.menu,
+                    style: style.list,
                 },
                 scrollable::Direction::default(),
                 style.scrollable,
@@ -327,7 +327,7 @@ where
     ) {
         let bounds = layout.bounds();
 
-        let appearance = (self.style.menu)(theme);
+        let appearance = (self.style.list)(theme);
 
         renderer.fill_quad(
             renderer::Quad {
@@ -598,15 +598,23 @@ pub struct Appearance {
     pub selected_background: Background,
 }
 
-/// The definiton of the default style of a [`Menu`].
+/// The style of the different parts of a [`Menu`].
 #[derive(Debug, PartialEq, Eq)]
 pub struct Style<Theme> {
-    /// The style of the [`Menu`].
+    /// The style of the list of the [`Menu`].
-    menu: fn(&Theme) -> Appearance,
+    list: fn(&Theme) -> Appearance,
     /// The style of the [`Scrollable`] of the [`Menu`].
     scrollable: fn(&Theme, scrollable::Status) -> scrollable::Appearance,
 }
 
+impl Style<Theme> {
+    /// The default style of a [`Menu`] with the built-in [`Theme`].
+    pub const DEFAULT: Self = Self {
+        list: default,
+        scrollable: scrollable::default,
+    };
+}
+
 impl<Theme> Clone for Style<Theme> {
     fn clone(&self) -> Self {
         *self
@@ -615,16 +623,19 @@ impl<Theme> Clone for Style<Theme> {
 
 impl<Theme> Copy for Style<Theme> {}
 
-impl Default for Style<Theme> {
+/// The default style of a [`Menu`].
-    fn default() -> Self {
+pub trait DefaultStyle: Sized {
-        Self {
+    /// Returns the default style of a [`Menu`].
-            menu: default,
+    fn default_style() -> Style<Self>;
-            scrollable: scrollable::default,
+}
-        }
+
+impl DefaultStyle for Theme {
+    fn default_style() -> Style<Self> {
+        Style::<Theme>::DEFAULT
     }
 }
 
-/// The default style of a [`Menu`].
+/// The default style of the list of a [`Menu`].
 pub fn default(theme: &Theme) -> Appearance {
     let palette = theme.extended_palette();
 

widget/src/pane_grid.rs

@@ -126,7 +126,7 @@ where
         view: impl Fn(Pane, &'a T, bool) -> Content<'a, Message, Theme, Renderer>,
     ) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
     {
         let contents = if let Some((pane, pane_state)) =
             state.maximized.and_then(|pane| {
@@ -158,7 +158,7 @@ where
             on_click: None,
             on_drag: None,
             on_resize: None,
-            style: Style::default(),
+            style: Theme::default_style(),
         }
     }
 
@@ -219,7 +219,7 @@ where
 
     /// Sets the style of the [`PaneGrid`].
     pub fn style(mut self, style: fn(&Theme) -> Appearance) -> Self {
-        self.style = Style(style);
+        self.style = style;
         self
     }
 
@@ -677,7 +677,7 @@ where
             None
         };
 
-        let appearance = (self.style.0)(theme);
+        let appearance = (self.style)(theme);
 
         for ((id, (content, tree)), pane_layout) in
             contents.zip(layout.children())
@@ -1146,26 +1146,23 @@ pub struct Line {
 }
 
 /// The style of a [`PaneGrid`].
-#[derive(Debug, PartialEq, Eq)]
+pub type Style<Theme> = fn(&Theme) -> Appearance;
-pub struct Style<Theme>(fn(&Theme) -> Appearance);
 
-impl<Theme> Clone for Style<Theme> {
+/// The default style of a [`PaneGrid`].
-    fn clone(&self) -> Self {
+pub trait DefaultStyle {
-        *self
+    /// Returns the default style of a [`PaneGrid`].
+    fn default_style() -> Style<Self>;
+}
+
+impl DefaultStyle for Theme {
+    fn default_style() -> Style<Self> {
+        default
     }
 }
 
-impl<Theme> Copy for Style<Theme> {}
+impl DefaultStyle for Appearance {
-
+    fn default_style() -> Style<Self> {
-impl Default for Style<Theme> {
+        |appearance| *appearance
-    fn default() -> Self {
-        Style(default)
-    }
-}
-
-impl<Theme> From<fn(&Theme) -> Appearance> for Style<Theme> {
-    fn from(f: fn(&Theme) -> Appearance) -> Self {
-        Style(f)
     }
 }
 

widget/src/pane_grid/content.rs

@@ -34,12 +34,12 @@ where
     /// Creates a new [`Content`] with the provided body.
     pub fn new(body: impl Into<Element<'a, Message, Theme, Renderer>>) -> Self
     where
-        container::Style<Theme>: Default,
+        Theme: container::DefaultStyle,
     {
         Self {
             title_bar: None,
             body: body.into(),
-            style: container::Style::default(),
+            style: Theme::default_style(),
         }
     }
 
@@ -114,7 +114,7 @@ where
                     container::Status::Idle
                 };
 
-                self.style.resolve(theme, status)
+                (self.style)(theme, status)
             };
 
             container::draw_background(renderer, &style, bounds);
@@ -403,8 +403,8 @@ impl<'a, T, Message, Theme, Renderer> From<T>
     for Content<'a, Message, Theme, Renderer>
 where
     T: Into<Element<'a, Message, Theme, Renderer>>,
+    Theme: container::DefaultStyle,
     Renderer: crate::core::Renderer,
-    container::Style<Theme>: Default,
 {
     fn from(element: T) -> Self {
         Self::new(element)

widget/src/pane_grid/title_bar.rs

@@ -37,14 +37,14 @@ where
         content: impl Into<Element<'a, Message, Theme, Renderer>>,
     ) -> Self
     where
-        container::Style<Theme>: Default,
+        Theme: container::DefaultStyle,
     {
         Self {
             content: content.into(),
             controls: None,
             padding: Padding::ZERO,
             always_show_controls: false,
-            style: container::Style::default(),
+            style: Theme::default_style(),
         }
     }
 
@@ -138,7 +138,7 @@ where
                 container::Status::Idle
             };
 
-            self.style.resolve(theme, status)
+            (self.style)(theme, status)
         };
 
         let inherited_style = renderer::Style {

widget/src/pick_list.rs

@@ -69,7 +69,7 @@ where
         on_select: impl Fn(T) -> Message + 'a,
     ) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
     {
         Self {
             on_select: Box::new(on_select),
@@ -85,7 +85,7 @@ where
             text_shaping: text::Shaping::Basic,
             font: None,
             handle: Handle::default(),
-            style: Style::default(),
+            style: Theme::default_style(),
         }
     }
 
@@ -266,7 +266,7 @@ where
             Status::Active
         };
 
-        let appearance = (self.style.pick_list)(theme, status);
+        let appearance = (self.style.field)(theme, status);
 
         renderer.fill_quad(
             renderer::Quad {
@@ -737,16 +737,24 @@ pub struct Appearance {
     pub border: Border,
 }
 
-/// The different styles of a [`PickList`].
+/// The styles of the different parts of a [`PickList`].
 #[derive(Debug, PartialEq, Eq)]
 pub struct Style<Theme> {
     /// The style of the [`PickList`] itself.
-    pub pick_list: fn(&Theme, Status) -> Appearance,
+    pub field: fn(&Theme, Status) -> Appearance,
 
     /// The style of the [`Menu`] of the pick list.
     pub menu: menu::Style<Theme>,
 }
 
+impl Style<Theme> {
+    /// The default style of a [`PickList`] with the built-in [`Theme`].
+    pub const DEFAULT: Self = Self {
+        field: default,
+        menu: menu::Style::<Theme>::DEFAULT,
+    };
+}
+
 impl<Theme> Clone for Style<Theme> {
     fn clone(&self) -> Self {
         *self
@@ -755,16 +763,19 @@ impl<Theme> Clone for Style<Theme> {
 
 impl<Theme> Copy for Style<Theme> {}
 
-impl Default for Style<Theme> {
+/// The default style of a [`PickList`].
-    fn default() -> Self {
+pub trait DefaultStyle: Sized {
-        Self {
+    /// Returns the default style of a [`PickList`].
-            pick_list: default,
+    fn default_style() -> Style<Self>;
-            menu: menu::Style::default(),
+}
-        }
+
+impl DefaultStyle for Theme {
+    fn default_style() -> Style<Self> {
+        Style::<Self>::DEFAULT
     }
 }
 
-/// The default style of a [`PickList`].
+/// The default style of the field of a [`PickList`].
 pub fn default(theme: &Theme, status: Status) -> Appearance {
     let palette = theme.extended_palette();
 

widget/src/progress_bar.rs

@@ -41,14 +41,14 @@ impl<Theme> ProgressBar<Theme> {
     ///   * the current value of the [`ProgressBar`]
     pub fn new(range: RangeInclusive<f32>, value: f32) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
     {
         ProgressBar {
             value: value.clamp(*range.start(), *range.end()),
             range,
             width: Length::Fill,
             height: None,
-            style: Style::default(),
+            style: Theme::default_style(),
         }
     }
 
@@ -116,7 +116,7 @@ where
                 / (range_end - range_start)
         };
 
-        let appearance = (self.style.0)(theme);
+        let appearance = (self.style)(theme);
 
         renderer.fill_quad(
             renderer::Quad {
@@ -169,26 +169,23 @@ pub struct Appearance {
 }
 
 /// The style of a [`ProgressBar`].
-#[derive(Debug, PartialEq, Eq)]
+pub type Style<Theme> = fn(&Theme) -> Appearance;
-pub struct Style<Theme>(fn(&Theme) -> Appearance);
 
-impl<Theme> Clone for Style<Theme> {
+/// The default style of a [`ProgressBar`].
-    fn clone(&self) -> Self {
+pub trait DefaultStyle {
-        *self
+    /// Returns the default style of a [`ProgressBar`].
+    fn default_style() -> Style<Self>;
+}
+
+impl DefaultStyle for Theme {
+    fn default_style() -> Style<Self> {
+        primary
     }
 }
 
-impl<Theme> Copy for Style<Theme> {}
+impl DefaultStyle for Appearance {
-
+    fn default_style() -> Style<Self> {
-impl Default for Style<Theme> {
+        |appearance| *appearance
-    fn default() -> Self {
-        Style(primary)
-    }
-}
-
-impl<Theme> From<fn(&Theme) -> Appearance> for Style<Theme> {
-    fn from(f: fn(&Theme) -> Appearance) -> Self {
-        Style(f)
     }
 }
 

widget/src/qr_code.rs

@@ -30,12 +30,12 @@ impl<'a, Theme> QRCode<'a, Theme> {
     /// Creates a new [`QRCode`] with the provided [`Data`].
     pub fn new(data: &'a Data) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
     {
         Self {
             data,
             cell_size: DEFAULT_CELL_SIZE,
-            style: Style::default(),
+            style: Theme::default_style(),
         }
     }
 
@@ -97,7 +97,7 @@ impl<'a, Message, Theme> Widget<Message, Theme, Renderer>
         let bounds = layout.bounds();
         let side_length = self.data.width + 2 * QUIET_ZONE;
 
-        let appearance = (self.style.0)(theme);
+        let appearance = (self.style)(theme);
         let mut last_appearance = state.last_appearance.borrow_mut();
 
         if Some(appearance) != *last_appearance {
@@ -336,26 +336,23 @@ pub struct Appearance {
 }
 
 /// The style of a [`QRCode`].
-#[derive(Debug, PartialEq, Eq)]
+pub type Style<Theme> = fn(&Theme) -> Appearance;
-pub struct Style<Theme>(fn(&Theme) -> Appearance);
 
-impl<Theme> Clone for Style<Theme> {
+/// The default style of a [`QRCode`].
-    fn clone(&self) -> Self {
+pub trait DefaultStyle {
-        *self
+    /// Returns the default style of a [`QRCode`].
+    fn default_style() -> Style<Self>;
+}
+
+impl DefaultStyle for Theme {
+    fn default_style() -> Style<Self> {
+        default
     }
 }
 
-impl<Theme> Copy for Style<Theme> {}
+impl DefaultStyle for Appearance {
-
+    fn default_style() -> Style<Self> {
-impl Default for Style<Theme> {
+        |appearance| *appearance
-    fn default() -> Self {
-        Style(default)
-    }
-}
-
-impl<Theme> From<fn(&Theme) -> Appearance> for Style<Theme> {
-    fn from(f: fn(&Theme) -> Appearance) -> Self {
-        Style(f)
     }
 }
 

widget/src/radio.rs

@@ -110,7 +110,7 @@ where
         f: F,
     ) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
         V: Eq + Copy,
         F: FnOnce(V) -> Message,
     {
@@ -125,7 +125,7 @@ where
             text_line_height: text::LineHeight::default(),
             text_shaping: text::Shaping::Basic,
             font: None,
-            style: Style::default(),
+            style: Theme::default_style(),
         }
     }
 
@@ -176,7 +176,7 @@ where
 
     /// Sets the style of the [`Radio`] button.
     pub fn style(mut self, style: fn(&Theme, Status) -> Appearance) -> Self {
-        self.style = Style(style);
+        self.style = style;
         self
     }
 }
@@ -297,7 +297,7 @@ where
             Status::Active { is_selected }
         };
 
-        let appearance = (self.style.0)(theme, status);
+        let appearance = (self.style)(theme, status);
 
         {
             let layout = children.next().unwrap();
@@ -398,26 +398,23 @@ pub struct Appearance {
 }
 
 /// The style of a [`Radio`] button.
-#[derive(Debug, PartialEq, Eq)]
+pub type Style<Theme> = fn(&Theme, Status) -> Appearance;
-pub struct Style<Theme>(fn(&Theme, Status) -> Appearance);
 
-impl<Theme> Clone for Style<Theme> {
+/// The default style of a [`Radio`] button.
-    fn clone(&self) -> Self {
+pub trait DefaultStyle {
-        *self
+    /// Returns the default style of a [`Radio`] button.
+    fn default_style() -> Style<Self>;
+}
+
+impl DefaultStyle for Theme {
+    fn default_style() -> Style<Self> {
+        default
     }
 }
 
-impl<Theme> Copy for Style<Theme> {}
+impl DefaultStyle for Appearance {
-
+    fn default_style() -> Style<Self> {
-impl Default for Style<Theme> {
+        |appearance, _status| *appearance
-    fn default() -> Self {
-        Style(default)
-    }
-}
-
-impl<Theme> From<fn(&Theme, Status) -> Appearance> for Style<Theme> {
-    fn from(f: fn(&Theme, Status) -> Appearance) -> Self {
-        Style(f)
     }
 }
 

widget/src/rule.rs

@@ -21,32 +21,32 @@ impl<Theme> Rule<Theme> {
     /// Creates a horizontal [`Rule`] with the given height.
     pub fn horizontal(height: impl Into<Pixels>) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
     {
         Rule {
             width: Length::Fill,
             height: Length::Fixed(height.into().0),
             is_horizontal: true,
-            style: Style::default(),
+            style: Theme::default_style(),
         }
     }
 
     /// Creates a vertical [`Rule`] with the given width.
     pub fn vertical(width: impl Into<Pixels>) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
     {
         Rule {
             width: Length::Fixed(width.into().0),
             height: Length::Fill,
             is_horizontal: false,
-            style: Style::default(),
+            style: Theme::default_style(),
         }
     }
 
     /// Sets the style of the [`Rule`].
     pub fn style(mut self, style: fn(&Theme) -> Appearance) -> Self {
-        self.style = Style(style);
+        self.style = style;
         self
     }
 }
@@ -82,7 +82,7 @@ where
         _viewport: &Rectangle,
     ) {
         let bounds = layout.bounds();
-        let appearance = (self.style.0)(theme);
+        let appearance = (self.style)(theme);
 
         let bounds = if self.is_horizontal {
             let line_y = (bounds.y + (bounds.height / 2.0)
@@ -216,26 +216,23 @@ impl FillMode {
 }
 
 /// The style of a [`Rule`].
-#[derive(Debug, PartialEq, Eq)]
+pub type Style<Theme> = fn(&Theme) -> Appearance;
-pub struct Style<Theme>(fn(&Theme) -> Appearance);
 
-impl<Theme> Clone for Style<Theme> {
+/// The default style of a [`Rule`].
-    fn clone(&self) -> Self {
+pub trait DefaultStyle {
-        *self
+    /// Returns the default style of a [`Rule`].
+    fn default_style() -> Style<Self>;
+}
+
+impl DefaultStyle for Theme {
+    fn default_style() -> Style<Self> {
+        default
     }
 }
 
-impl<Theme> Copy for Style<Theme> {}
+impl DefaultStyle for Appearance {
-
+    fn default_style() -> Style<Self> {
-impl Default for Style<Theme> {
+        |appearance| *appearance
-    fn default() -> Self {
-        Style(default)
-    }
-}
-
-impl<Theme> From<fn(&Theme) -> Appearance> for Style<Theme> {
-    fn from(f: fn(&Theme) -> Appearance) -> Self {
-        Style(f)
     }
 }
 

widget/src/scrollable.rs

@@ -48,7 +48,7 @@ where
         content: impl Into<Element<'a, Message, Theme, Renderer>>,
     ) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
     {
         Self::with_direction(content, Direction::default())
     }
@@ -59,9 +59,13 @@ where
         direction: Direction,
     ) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
     {
-        Self::with_direction_and_style(content, direction, Style::default().0)
+        Self::with_direction_and_style(
+            content,
+            direction,
+            Theme::default_style(),
+        )
     }
 
     /// Creates a new [`Scrollable`] with the given [`Direction`] and style.
@@ -407,7 +411,7 @@ where
             Status::Active
         };
 
-        let appearance = (self.style.0)(theme, status);
+        let appearance = (self.style)(theme, status);
 
         container::draw_background(
             renderer,
@@ -1662,26 +1666,23 @@ pub struct Scroller {
 }
 
 /// The style of a [`Scrollable`].
-#[derive(Debug, PartialEq, Eq)]
+pub type Style<Theme> = fn(&Theme, Status) -> Appearance;
-pub struct Style<Theme>(fn(&Theme, Status) -> Appearance);
 
-impl<Theme> Clone for Style<Theme> {
+/// The default style of a [`Scrollable`].
-    fn clone(&self) -> Self {
+pub trait DefaultStyle {
-        *self
+    /// Returns the default style of a [`Scrollable`].
+    fn default_style() -> Style<Self>;
+}
+
+impl DefaultStyle for Theme {
+    fn default_style() -> Style<Self> {
+        default
     }
 }
 
-impl<Theme> Copy for Style<Theme> {}
+impl DefaultStyle for Appearance {
-
+    fn default_style() -> Style<Self> {
-impl Default for Style<Theme> {
+        |appearance, _status| *appearance
-    fn default() -> Self {
-        Style(default)
-    }
-}
-
-impl<Theme> From<fn(&Theme, Status) -> Appearance> for Style<Theme> {
-    fn from(f: fn(&Theme, Status) -> Appearance) -> Self {
-        Style(f)
     }
 }
 

widget/src/slider.rs

@@ -70,7 +70,7 @@ where
     ///   `Message`.
     pub fn new<F>(range: RangeInclusive<T>, value: T, on_change: F) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
         F: 'a + Fn(T) -> Message,
     {
         let value = if value >= *range.start() {
@@ -95,7 +95,7 @@ where
             on_release: None,
             width: Length::Fill,
             height: Self::DEFAULT_HEIGHT,
-            style: Style::default(),
+            style: Theme::default_style(),
         }
     }
 
@@ -346,7 +346,7 @@ where
         let bounds = layout.bounds();
         let is_mouse_over = cursor.is_over(bounds);
 
-        let style = (self.style.0)(
+        let style = (self.style)(
             theme,
             if state.is_dragging {
                 Status::Dragged
@@ -547,26 +547,23 @@ pub enum HandleShape {
 }
 
 /// The style of a [`Slider`].
-#[derive(Debug, PartialEq, Eq)]
+pub type Style<Theme> = fn(&Theme, Status) -> Appearance;
-pub struct Style<Theme>(pub(crate) fn(&Theme, Status) -> Appearance);
 
-impl<Theme> Clone for Style<Theme> {
+/// The default style of a [`Slider`].
-    fn clone(&self) -> Self {
+pub trait DefaultStyle {
-        *self
+    /// Returns the default style of a [`Slider`].
+    fn default_style() -> Style<Self>;
+}
+
+impl DefaultStyle for Theme {
+    fn default_style() -> Style<Self> {
+        default
     }
 }
 
-impl<Theme> Copy for Style<Theme> {}
+impl DefaultStyle for Appearance {
-
+    fn default_style() -> Style<Self> {
-impl Default for Style<Theme> {
+        |appearance, _status| *appearance
-    fn default() -> Self {
-        Style(default)
-    }
-}
-
-impl<Theme> From<fn(&Theme, Status) -> Appearance> for Style<Theme> {
-    fn from(f: fn(&Theme, Status) -> Appearance) -> Self {
-        Style(f)
     }
 }
 

widget/src/svg.rs

@@ -32,14 +32,14 @@ impl<Theme> Svg<Theme> {
     /// Creates a new [`Svg`] from the given [`Handle`].
     pub fn new(handle: impl Into<Handle>) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
     {
         Svg {
             handle: handle.into(),
             width: Length::Fill,
             height: Length::Shrink,
             content_fit: ContentFit::Contain,
-            style: Style::default(),
+            style: Theme::default_style(),
         }
     }
 
@@ -48,7 +48,7 @@ impl<Theme> Svg<Theme> {
     #[must_use]
     pub fn from_path(path: impl Into<PathBuf>) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
     {
         Self::new(Handle::from_path(path))
     }
@@ -81,7 +81,7 @@ impl<Theme> Svg<Theme> {
     /// Sets the style variant of this [`Svg`].
     #[must_use]
     pub fn style(mut self, style: fn(&Theme, Status) -> Appearance) -> Self {
-        self.style = Style(style);
+        self.style = style;
         self
     }
 }
@@ -163,7 +163,7 @@ where
                 Status::Idle
             };
 
-            let appearance = (self.style.0)(theme, status);
+            let appearance = (self.style)(theme, status);
 
             renderer.draw(
                 self.handle.clone(),
@@ -214,25 +214,22 @@ pub struct Appearance {
 }
 
 /// The style of an [`Svg`].
-#[derive(Debug, PartialEq, Eq)]
+pub type Style<Theme> = fn(&Theme, Status) -> Appearance;
-pub struct Style<Theme>(fn(&Theme, Status) -> Appearance);
 
-impl<Theme> Clone for Style<Theme> {
+/// The default style of an [`Svg`].
-    fn clone(&self) -> Self {
+pub trait DefaultStyle {
-        *self
+    /// Returns the default style of an [`Svg`].
+    fn default_style() -> Style<Self>;
+}
+
+impl DefaultStyle for Theme {
+    fn default_style() -> Style<Self> {
+        |_theme, _status| Appearance::default()
     }
 }
 
-impl<Theme> Copy for Style<Theme> {}
+impl DefaultStyle for Appearance {
-
+    fn default_style() -> Style<Self> {
-impl Default for Style<Theme> {
+        |appearance, _status| *appearance
-    fn default() -> Self {
-        Style(|_, _| Appearance::default())
-    }
-}
-
-impl<Theme> From<fn(&Theme, Status) -> Appearance> for Style<Theme> {
-    fn from(f: fn(&Theme, Status) -> Appearance) -> Self {
-        Style(f)
     }
 }

widget/src/text_editor.rs

@@ -58,7 +58,7 @@ where
     /// Creates new [`TextEditor`] with the given [`Content`].
     pub fn new(content: &'a Content<Renderer>) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
     {
         Self {
             content,
@@ -68,7 +68,7 @@ where
             width: Length::Fill,
             height: Length::Shrink,
             padding: Padding::new(5.0),
-            style: Style::default(),
+            style: Theme::default_style(),
             on_edit: None,
             highlighter_settings: (),
             highlighter_format: |_highlight, _theme| {
@@ -505,7 +505,7 @@ where
             Status::Active
         };
 
-        let appearance = (self.style.0)(theme, status);
+        let appearance = (self.style)(theme, status);
 
         renderer.fill_quad(
             renderer::Quad {
@@ -809,26 +809,23 @@ pub struct Appearance {
 }
 
 /// The style of a [`TextEditor`].
-#[derive(Debug, PartialEq, Eq)]
+pub type Style<Theme> = fn(&Theme, Status) -> Appearance;
-pub struct Style<Theme>(fn(&Theme, Status) -> Appearance);
 
-impl<Theme> Clone for Style<Theme> {
+/// The default style of a [`TextEditor`].
-    fn clone(&self) -> Self {
+pub trait DefaultStyle {
-        *self
+    /// Returns the default style of a [`TextEditor`].
+    fn default_style() -> Style<Self>;
+}
+
+impl DefaultStyle for Theme {
+    fn default_style() -> Style<Self> {
+        default
     }
 }
 
-impl<Theme> Copy for Style<Theme> {}
+impl DefaultStyle for Appearance {
-
+    fn default_style() -> Style<Self> {
-impl Default for Style<Theme> {
+        |appearance, _status| *appearance
-    fn default() -> Self {
-        Style(default)
-    }
-}
-
-impl<Theme> From<fn(&Theme, Status) -> Appearance> for Style<Theme> {
-    fn from(f: fn(&Theme, Status) -> Appearance) -> Self {
-        Style(f)
     }
 }
 

widget/src/text_input.rs

@@ -90,9 +90,9 @@ where
     /// its current value.
     pub fn new(placeholder: &str, value: &str) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
     {
-        Self::with_style(placeholder, value, Style::default().0)
+        Self::with_style(placeholder, value, Theme::default_style())
     }
 
     /// Creates a new [`TextInput`] with the given placeholder,
@@ -342,7 +342,7 @@ where
             Status::Active
         };
 
-        let appearance = (self.style.0)(theme, status);
+        let appearance = (self.style)(theme, status);
 
         renderer.fill_quad(
             renderer::Quad {
@@ -1412,26 +1412,23 @@ pub struct Appearance {
 }
 
 /// The style of a [`TextInput`].
-#[derive(Debug, PartialEq, Eq)]
+pub type Style<Theme> = fn(&Theme, Status) -> Appearance;
-pub struct Style<Theme>(fn(&Theme, Status) -> Appearance);
 
-impl<Theme> Clone for Style<Theme> {
+/// The default style of a [`TextInput`].
-    fn clone(&self) -> Self {
+pub trait DefaultStyle {
-        *self
+    /// Returns the default style of a [`TextInput`].
+    fn default_style() -> Style<Self>;
+}
+
+impl DefaultStyle for Theme {
+    fn default_style() -> Style<Self> {
+        default
     }
 }
 
-impl<Theme> Copy for Style<Theme> {}
+impl DefaultStyle for Appearance {
-
+    fn default_style() -> Style<Self> {
-impl Default for Style<Theme> {
+        |appearance, _status| *appearance
-    fn default() -> Self {
-        Style(default)
-    }
-}
-
-impl<Theme> From<fn(&Theme, Status) -> Appearance> for Style<Theme> {
-    fn from(f: fn(&Theme, Status) -> Appearance) -> Self {
-        Style(f)
     }
 }
 

widget/src/toggler.rs

@@ -72,7 +72,7 @@ where
         f: F,
     ) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
         F: 'a + Fn(bool) -> Message,
     {
         Toggler {
@@ -87,7 +87,7 @@ where
             text_shaping: text::Shaping::Basic,
             spacing: Self::DEFAULT_SIZE / 2.0,
             font: None,
-            style: Style::default(),
+            style: Theme::default_style(),
         }
     }
 
@@ -299,7 +299,7 @@ where
             }
         };
 
-        let appearance = (self.style.0)(theme, status);
+        let appearance = (self.style)(theme, status);
 
         let border_radius = bounds.height / BORDER_RADIUS_RATIO;
         let space = SPACE_RATIO * bounds.height;
@@ -398,26 +398,23 @@ pub struct Appearance {
 }
 
 /// The style of a [`Toggler`].
-#[derive(Debug, PartialEq, Eq)]
+pub type Style<Theme> = fn(&Theme, Status) -> Appearance;
-pub struct Style<Theme>(fn(&Theme, Status) -> Appearance);
 
-impl<Theme> Clone for Style<Theme> {
+/// The default style of a [`Toggler`].
-    fn clone(&self) -> Self {
+pub trait DefaultStyle {
-        *self
+    /// Returns the default style of a [`Toggler`].
+    fn default_style() -> Style<Self>;
+}
+
+impl DefaultStyle for Theme {
+    fn default_style() -> Style<Self> {
+        default
     }
 }
 
-impl<Theme> Copy for Style<Theme> {}
+impl DefaultStyle for Appearance {
-
+    fn default_style() -> Style<Self> {
-impl Default for Style<Theme> {
+        |appearance, _status| *appearance
-    fn default() -> Self {
-        Style(default)
-    }
-}
-
-impl<Theme> From<fn(&Theme, Status) -> Appearance> for Style<Theme> {
-    fn from(f: fn(&Theme, Status) -> Appearance) -> Self {
-        Style(f)
     }
 }
 

widget/src/tooltip.rs

@@ -47,7 +47,7 @@ where
         position: Position,
     ) -> Self
     where
-        container::Style<Theme>: Default,
+        Theme: container::DefaultStyle,
     {
         Tooltip {
             content: content.into(),
@@ -56,7 +56,7 @@ where
             gap: 0.0,
             padding: Self::DEFAULT_PADDING,
             snap_within_viewport: true,
-            style: container::Style::default(),
+            style: Theme::default_style(),
         }
     }
 
@@ -424,7 +424,7 @@ where
         layout: Layout<'_>,
         cursor_position: mouse::Cursor,
     ) {
-        let style = self.style.resolve(theme, container::Status::Idle);
+        let style = (self.style)(theme, container::Status::Idle);
 
         container::draw_background(renderer, &style, layout.bounds());
 

widget/src/vertical_slider.rs

@@ -2,7 +2,7 @@
 use std::ops::RangeInclusive;
 
 pub use crate::slider::{
-    default, Appearance, Handle, HandleShape, Status, Style,
+    default, Appearance, DefaultStyle, Handle, HandleShape, Status, Style,
 };
 
 use crate::core;
@@ -72,7 +72,7 @@ where
     ///   `Message`.
     pub fn new<F>(range: RangeInclusive<T>, value: T, on_change: F) -> Self
     where
-        Style<Theme>: Default,
+        Theme: DefaultStyle,
         F: 'a + Fn(T) -> Message,
     {
         let value = if value >= *range.start() {
@@ -97,7 +97,7 @@ where
             on_release: None,
             width: Self::DEFAULT_WIDTH,
             height: Length::Fill,
-            style: Style::default(),
+            style: Theme::default_style(),
         }
     }
 
@@ -351,7 +351,7 @@ where
         let bounds = layout.bounds();
         let is_mouse_over = cursor.is_over(bounds);
 
-        let style = (self.style.0)(
+        let style = (self.style)(
             theme,
             if state.is_dragging {
                 Status::Dragged

winit/src/application.rs

@@ -38,7 +38,7 @@ use std::sync::Arc;
 /// can be toggled by pressing `F12`.
 pub trait Application: Program
 where
-    Style<Self::Theme>: Default,
+    Self::Theme: DefaultStyle,
 {
     /// The data needed to initialize your [`Application`].
     type Flags;
@@ -64,7 +64,7 @@ where
 
     /// Returns the `Style` variation of the `Theme`.
     fn style(&self, theme: &Self::Theme) -> Appearance {
-        Style::default().resolve(theme)
+        theme.default_style()
     }
 
     /// Returns the event `Subscription` for the current state of the
@@ -104,39 +104,19 @@ pub struct Appearance {
     pub text_color: Color,
 }
 
-/// The style of an [`Application`].
-#[derive(Debug, PartialEq, Eq)]
-pub struct Style<Theme>(pub fn(&Theme) -> Appearance);
-
-impl<Theme> Style<Theme> {
-    /// Resolves the [`Style`] with the given `Theme` to produce
-    /// an [`Appearance`].
-    pub fn resolve(self, theme: &Theme) -> Appearance {
-        (self.0)(theme)
-    }
-}
-
-impl<Theme> Clone for Style<Theme> {
-    fn clone(&self) -> Self {
-        *self
-    }
-}
-
-impl<Theme> Copy for Style<Theme> {}
-
-impl<Theme> From<fn(&Theme) -> Appearance> for Style<Theme> {
-    fn from(f: fn(&Theme) -> Appearance) -> Self {
-        Style(f)
-    }
-}
-
-impl Default for Style<Theme> {
-    fn default() -> Self {
-        Style(default)
-    }
-}
-
 /// The default style of an [`Application`].
+pub trait DefaultStyle {
+    /// Returns the default style of an [`Application`].
+    fn default_style(&self) -> Appearance;
+}
+
+impl DefaultStyle for Theme {
+    fn default_style(&self) -> Appearance {
+        default(self)
+    }
+}
+
+/// The default [`Appearance`] of an [`Application`] with the built-in [`Theme`].
 pub fn default(theme: &Theme) -> Appearance {
     let palette = theme.extended_palette();
 
@@ -156,7 +136,7 @@ where
     A: Application + 'static,
     E: Executor + 'static,
     C: Compositor<Renderer = A::Renderer> + 'static,
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     use futures::task;
     use futures::Future;
@@ -340,7 +320,7 @@ async fn run_instance<A, E, C>(
     A: Application + 'static,
     E: Executor + 'static,
     C: Compositor<Renderer = A::Renderer> + 'static,
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     use futures::stream::StreamExt;
     use winit::event;
@@ -663,7 +643,7 @@ pub fn build_user_interface<'a, A: Application>(
     debug: &mut Debug,
 ) -> UserInterface<'a, A::Message, A::Theme, A::Renderer>
 where
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     debug.view_started();
     let view = application.view();
@@ -694,7 +674,7 @@ pub fn update<A: Application, C, E: Executor>(
     window: &winit::window::Window,
 ) where
     C: Compositor<Renderer = A::Renderer> + 'static,
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     for message in messages.drain(..) {
         debug.log_message(&message);
@@ -745,7 +725,7 @@ pub fn run_command<A, C, E>(
     A: Application,
     E: Executor,
     C: Compositor<Renderer = A::Renderer> + 'static,
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     use crate::runtime::command;
     use crate::runtime::system;

winit/src/application/state.rs

@@ -14,7 +14,7 @@ use winit::window::Window;
 #[allow(missing_debug_implementations)]
 pub struct State<A: Application>
 where
-    application::Style<A::Theme>: Default,
+    A::Theme: application::DefaultStyle,
 {
     title: String,
     scale_factor: f64,
@@ -29,7 +29,7 @@ where
 
 impl<A: Application> State<A>
 where
-    application::Style<A::Theme>: Default,
+    A::Theme: application::DefaultStyle,
 {
     /// Creates a new [`State`] for the provided [`Application`] and window.
     pub fn new(application: &A, window: &Window) -> Self {

winit/src/multi_window.rs

@@ -22,7 +22,7 @@ use crate::runtime::user_interface::{self, UserInterface};
 use crate::runtime::Debug;
 use crate::{Clipboard, Error, Proxy, Settings};
 
-pub use crate::application::{default, Appearance, Style};
+pub use crate::application::{default, Appearance, DefaultStyle};
 
 use std::collections::HashMap;
 use std::mem::ManuallyDrop;
@@ -42,7 +42,7 @@ use std::time::Instant;
 /// can be toggled by pressing `F12`.
 pub trait Application: Program
 where
-    Style<Self::Theme>: Default,
+    Self::Theme: DefaultStyle,
 {
     /// The data needed to initialize your [`Application`].
     type Flags;
@@ -68,7 +68,7 @@ where
 
     /// Returns the `Style` variation of the `Theme`.
     fn style(&self, theme: &Self::Theme) -> Appearance {
-        Style::default().resolve(theme)
+        theme.default_style()
     }
 
     /// Returns the event `Subscription` for the current state of the
@@ -109,7 +109,7 @@ where
     A: Application + 'static,
     E: Executor + 'static,
     C: Compositor<Renderer = A::Renderer> + 'static,
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     use winit::event_loop::EventLoopBuilder;
 
@@ -350,7 +350,7 @@ async fn run_instance<A, E, C>(
     A: Application + 'static,
     E: Executor + 'static,
     C: Compositor<Renderer = A::Renderer> + 'static,
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     use winit::event;
     use winit::event_loop::ControlFlow;
@@ -820,7 +820,7 @@ fn build_user_interface<'a, A: Application>(
     id: window::Id,
 ) -> UserInterface<'a, A::Message, A::Theme, A::Renderer>
 where
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     debug.view_started();
     let view = application.view(id);
@@ -848,7 +848,7 @@ fn update<A: Application, C, E: Executor>(
     ui_caches: &mut HashMap<window::Id, user_interface::Cache>,
 ) where
     C: Compositor<Renderer = A::Renderer> + 'static,
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     for message in messages.drain(..) {
         debug.log_message(&message);
@@ -891,7 +891,7 @@ fn run_command<A, C, E>(
     A: Application,
     E: Executor,
     C: Compositor<Renderer = A::Renderer> + 'static,
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     use crate::runtime::clipboard;
     use crate::runtime::system;
@@ -1218,7 +1218,7 @@ pub fn build_user_interfaces<'a, A: Application, C: Compositor>(
 ) -> HashMap<window::Id, UserInterface<'a, A::Message, A::Theme, A::Renderer>>
 where
     C: Compositor<Renderer = A::Renderer>,
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     cached_user_interfaces
         .drain()

winit/src/multi_window/state.rs

@@ -11,7 +11,7 @@ use winit::window::Window;
 /// The state of a multi-windowed [`Application`].
 pub struct State<A: Application>
 where
-    multi_window::Style<A::Theme>: Default,
+    A::Theme: multi_window::DefaultStyle,
 {
     title: String,
     scale_factor: f64,
@@ -25,7 +25,7 @@ where
 
 impl<A: Application> Debug for State<A>
 where
-    multi_window::Style<A::Theme>: Default,
+    A::Theme: multi_window::DefaultStyle,
 {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("multi_window::State")
@@ -41,7 +41,7 @@ where
 
 impl<A: Application> State<A>
 where
-    multi_window::Style<A::Theme>: Default,
+    A::Theme: multi_window::DefaultStyle,
 {
     /// Creates a new [`State`] for the provided [`Application`]'s `window`.
     pub fn new(

winit/src/multi_window/window_manager.rs

@@ -2,7 +2,7 @@ use crate::core::mouse;
 use crate::core::window::Id;
 use crate::core::{Point, Size};
 use crate::graphics::Compositor;
-use crate::multi_window::{Application, State, Style};
+use crate::multi_window::{Application, DefaultStyle, State};
 
 use std::collections::BTreeMap;
 use std::sync::Arc;
@@ -12,7 +12,7 @@ use winit::monitor::MonitorHandle;
 pub struct WindowManager<A: Application, C: Compositor>
 where
     C: Compositor<Renderer = A::Renderer>,
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     aliases: BTreeMap<winit::window::WindowId, Id>,
     entries: BTreeMap<Id, Window<A, C>>,
@@ -22,7 +22,7 @@ impl<A, C> WindowManager<A, C>
 where
     A: Application,
     C: Compositor<Renderer = A::Renderer>,
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     pub fn new() -> Self {
         Self {
@@ -108,7 +108,7 @@ impl<A, C> Default for WindowManager<A, C>
 where
     A: Application,
     C: Compositor<Renderer = A::Renderer>,
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     fn default() -> Self {
         Self::new()
@@ -120,7 +120,7 @@ pub struct Window<A, C>
 where
     A: Application,
     C: Compositor<Renderer = A::Renderer>,
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     pub raw: Arc<winit::window::Window>,
     pub state: State<A>,
@@ -135,7 +135,7 @@ impl<A, C> Window<A, C>
 where
     A: Application,
     C: Compositor<Renderer = A::Renderer>,
-    Style<A::Theme>: Default,
+    A::Theme: DefaultStyle,
 {
     pub fn position(&self) -> Option<Point> {
         self.raw