Use closures for Checkbox::style

examples/checkbox/src/main.rs

@@ -63,17 +63,16 @@ impl Application for Example {
         let default_checkbox = checkbox("Default", self.default)
             .on_toggle(Message::DefaultToggled);
 
-        let styled_checkbox = |label, style| {
+        let styled_checkbox = |label| {
             checkbox(label, self.styled)
                 .on_toggle_maybe(self.default.then_some(Message::StyledToggled))
-                .style(style)
         };
 
         let checkboxes = row![
-            styled_checkbox("Primary", checkbox::primary),
-            styled_checkbox("Secondary", checkbox::secondary),
-            styled_checkbox("Success", checkbox::success),
-            styled_checkbox("Danger", checkbox::danger),
+            styled_checkbox("Primary").style(checkbox::primary),
+            styled_checkbox("Secondary").style(checkbox::secondary),
+            styled_checkbox("Success").style(checkbox::success),
+            styled_checkbox("Danger").style(checkbox::danger),
         ]
         .spacing(20);
 

widget/src/checkbox.rs

@@ -51,7 +51,7 @@ pub struct Checkbox<
     text_shaping: text::Shaping,
     font: Option<Renderer::Font>,
     icon: Icon<Renderer::Font>,
-    style: Style<Theme>,
+    style: Style<'a, Theme>,
 }
 
 impl<'a, Message, Theme, Renderer> Checkbox<'a, Message, Theme, Renderer>
@@ -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
-        Theme: DefaultStyle,
+        Theme: DefaultStyle + 'a,
     {
         Checkbox {
             is_checked,
@@ -91,7 +91,7 @@ where
                 line_height: text::LineHeight::default(),
                 shaping: text::Shaping::Basic,
             },
-            style: Theme::default_style(),
+            style: Box::new(Theme::default_style),
         }
     }
 
@@ -174,8 +174,11 @@ where
     }
 
     /// Sets the style of the [`Checkbox`].
-    pub fn style(mut self, style: fn(&Theme, Status) -> Appearance) -> Self {
-        self.style = style;
+    pub fn style(
+        mut self,
+        style: impl Fn(&Theme, Status) -> Appearance + 'a,
+    ) -> Self {
+        self.style = Box::new(style);
         self
     }
 }
@@ -424,23 +427,23 @@ pub struct Appearance {
 }
 
 /// The style of a [`Checkbox`].
-pub type Style<Theme> = fn(&Theme, Status) -> Appearance;
+pub type Style<'a, Theme> = Box<dyn Fn(&Theme, Status) -> Appearance + 'a>;
 
 /// The default style of a [`Checkbox`].
 pub trait DefaultStyle {
     /// Returns the default style of a [`Checkbox`].
-    fn default_style() -> Style<Self>;
+    fn default_style(&self, status: Status) -> Appearance;
 }
 
 impl DefaultStyle for Theme {
-    fn default_style() -> Style<Self> {
-        primary
+    fn default_style(&self, status: Status) -> Appearance {
+        primary(self, status)
     }
 }
 
 impl DefaultStyle for Appearance {
-    fn default_style() -> Style<Self> {
-        |appearance, _status| *appearance
+    fn default_style(&self, _status: Status) -> Appearance {
+        *self
     }
 }
 

widget/src/helpers.rs

@@ -161,7 +161,7 @@ pub fn checkbox<'a, Message, Theme, Renderer>(
     is_checked: bool,
 ) -> Checkbox<'a, Message, Theme, Renderer>
 where
-    Theme: checkbox::DefaultStyle,
+    Theme: checkbox::DefaultStyle + 'a,
     Renderer: core::text::Renderer,
 {
     Checkbox::new(label, is_checked)