Merge pull request #1519 from iced-rs/customizable-theme

Built-in `Theme` customization

examples/solar_system/src/main.rs

@@ -79,10 +79,14 @@ impl Application for SolarSystem {
     }
 
     fn style(&self) -> theme::Application {
-        theme::Application::Custom(|_theme| application::Appearance {
-            background_color: Color::BLACK,
-            text_color: Color::WHITE,
-        })
+        fn dark_background(_theme: &Theme) -> application::Appearance {
+            application::Appearance {
+                background_color: Color::BLACK,
+                text_color: Color::WHITE,
+            }
+        }
+
+        theme::Application::from(dark_background as fn(&Theme) -> _)
     }
 
     fn subscription(&self) -> Subscription<Message> {

native/src/overlay/menu.rs

@@ -178,7 +178,7 @@ where
             font,
             text_size,
             padding,
-            style,
+            style: style.clone(),
         }));
 
         state.tree.diff(&container as &dyn Widget<_, _>);
@@ -288,7 +288,7 @@ where
         layout: Layout<'_>,
         cursor_position: Point,
     ) {
-        let appearance = theme.appearance(self.style);
+        let appearance = theme.appearance(&self.style);
         let bounds = layout.bounds();
 
         renderer.fill_quad(
@@ -460,7 +460,7 @@ where
         _cursor_position: Point,
         viewport: &Rectangle,
     ) {
-        let appearance = theme.appearance(self.style);
+        let appearance = theme.appearance(&self.style);
         let bounds = layout.bounds();
 
         let text_size =

native/src/widget/button.rs

@@ -231,7 +231,7 @@ where
             cursor_position,
             self.on_press.is_some(),
             theme,
-            self.style,
+            &self.style,
             || tree.state.downcast_ref::<State>(),
         );
 
@@ -361,7 +361,7 @@ pub fn draw<'a, Renderer: crate::Renderer>(
     style_sheet: &dyn StyleSheet<
         Style = <Renderer::Theme as StyleSheet>::Style,
     >,
-    style: <Renderer::Theme as StyleSheet>::Style,
+    style: &<Renderer::Theme as StyleSheet>::Style,
     state: impl FnOnce() -> &'a State,
 ) -> Appearance
 where

native/src/widget/checkbox.rs

@@ -224,9 +224,9 @@ where
         let mut children = layout.children();
 
         let custom_style = if is_mouse_over {
-            theme.hovered(self.style, self.is_checked)
+            theme.hovered(&self.style, self.is_checked)
         } else {
-            theme.active(self.style, self.is_checked)
+            theme.active(&self.style, self.is_checked)
         };
 
         {

native/src/widget/container.rs

@@ -228,7 +228,7 @@ where
         cursor_position: Point,
         viewport: &Rectangle,
     ) {
-        let style = theme.appearance(self.style);
+        let style = theme.appearance(&self.style);
 
         draw_background(renderer, &style, layout.bounds());
 

native/src/widget/helpers.rs

@@ -1,4 +1,5 @@
 //! Helper functions to create pure widgets.
+use crate::overlay;
 use crate::widget;
 use crate::{Element, Length};
 
@@ -84,6 +85,7 @@ pub fn button<'a, Message, Renderer>(
 where
     Renderer: crate::Renderer,
     Renderer::Theme: widget::button::StyleSheet,
+    <Renderer::Theme as widget::button::StyleSheet>::Style: Default,
 {
     widget::Button::new(content)
 }
@@ -208,7 +210,12 @@ where
     T: ToString + Eq + 'static,
     [T]: ToOwned<Owned = Vec<T>>,
     Renderer: crate::text::Renderer,
-    Renderer::Theme: widget::pick_list::StyleSheet,
+    Renderer::Theme: widget::pick_list::StyleSheet
+        + widget::scrollable::StyleSheet
+        + overlay::menu::StyleSheet
+        + widget::container::StyleSheet,
+    <Renderer::Theme as overlay::menu::StyleSheet>::Style:
+        From<<Renderer::Theme as widget::pick_list::StyleSheet>::Style>,
 {
     widget::PickList::new(options, selected, on_selected)
 }

native/src/widget/pane_grid.rs

@@ -401,7 +401,7 @@ where
             viewport,
             self.spacing,
             self.on_resize.as_ref().map(|(leeway, _)| *leeway),
-            self.style,
+            &self.style,
             self.contents
                 .iter()
                 .zip(&tree.children)
@@ -727,7 +727,7 @@ pub fn draw<Renderer, T>(
     viewport: &Rectangle,
     spacing: u16,
     resize_leeway: Option<u16>,
-    style: <Renderer::Theme as StyleSheet>::Style,
+    style: &<Renderer::Theme as StyleSheet>::Style,
     contents: impl Iterator<Item = (Pane, T)>,
     draw_pane: impl Fn(
         T,

native/src/widget/pane_grid/content.rs

@@ -103,7 +103,7 @@ where
         let bounds = layout.bounds();
 
         {
-            let style = theme.appearance(self.style);
+            let style = theme.appearance(&self.style);
 
             container::draw_background(renderer, &style, bounds);
         }

native/src/widget/pane_grid/title_bar.rs

@@ -129,7 +129,7 @@ where
         use container::StyleSheet;
 
         let bounds = layout.bounds();
-        let style = theme.appearance(self.style);
+        let style = theme.appearance(&self.style);
         let inherited_style = renderer::Style {
             text_color: style.text_color.unwrap_or(inherited_style.text_color),
         };

native/src/widget/pick_list.rs

@@ -9,6 +9,8 @@ use crate::overlay::menu::{self, Menu};
 use crate::renderer;
 use crate::text::{self, Text};
 use crate::touch;
+use crate::widget::container;
+use crate::widget::scrollable;
 use crate::widget::tree::{self, Tree};
 use crate::{
     Clipboard, Element, Layout, Length, Padding, Point, Rectangle, Shell, Size,
@@ -42,7 +44,12 @@ where
     T: ToString + Eq,
     [T]: ToOwned<Owned = Vec<T>>,
     Renderer: text::Renderer,
-    Renderer::Theme: StyleSheet,
+    Renderer::Theme: StyleSheet
+        + scrollable::StyleSheet
+        + menu::StyleSheet
+        + container::StyleSheet,
+    <Renderer::Theme as menu::StyleSheet>::Style:
+        From<<Renderer::Theme as StyleSheet>::Style>,
 {
     /// The default padding of a [`PickList`].
     pub const DEFAULT_PADDING: Padding = Padding::new(5);
@@ -114,7 +121,12 @@ where
     [T]: ToOwned<Owned = Vec<T>>,
     Message: 'a,
     Renderer: text::Renderer + 'a,
-    Renderer::Theme: StyleSheet,
+    Renderer::Theme: StyleSheet
+        + scrollable::StyleSheet
+        + menu::StyleSheet
+        + container::StyleSheet,
+    <Renderer::Theme as menu::StyleSheet>::Style:
+        From<<Renderer::Theme as StyleSheet>::Style>,
 {
     fn tag(&self) -> tree::Tag {
         tree::Tag::of::<State<T>>()
@@ -202,7 +214,7 @@ where
             &self.font,
             self.placeholder.as_deref(),
             self.selected.as_ref(),
-            self.style,
+            &self.style,
         )
     }
 
@@ -221,7 +233,7 @@ where
             self.text_size,
             self.font.clone(),
             &self.options,
-            self.style,
+            self.style.clone(),
         )
     }
 }
@@ -233,7 +245,12 @@ where
     [T]: ToOwned<Owned = Vec<T>>,
     Message: 'a,
     Renderer: text::Renderer + 'a,
-    Renderer::Theme: StyleSheet,
+    Renderer::Theme: StyleSheet
+        + scrollable::StyleSheet
+        + menu::StyleSheet
+        + container::StyleSheet,
+    <Renderer::Theme as menu::StyleSheet>::Style:
+        From<<Renderer::Theme as StyleSheet>::Style>,
 {
     fn from(pick_list: PickList<'a, T, Message, Renderer>) -> Self {
         Self::new(pick_list)
@@ -456,7 +473,12 @@ where
     T: Clone + ToString,
     Message: 'a,
     Renderer: text::Renderer + 'a,
-    Renderer::Theme: StyleSheet,
+    Renderer::Theme: StyleSheet
+        + scrollable::StyleSheet
+        + menu::StyleSheet
+        + container::StyleSheet,
+    <Renderer::Theme as menu::StyleSheet>::Style:
+        From<<Renderer::Theme as StyleSheet>::Style>,
 {
     if state.is_open {
         let bounds = layout.bounds();
@@ -493,7 +515,7 @@ pub fn draw<T, Renderer>(
     font: &Renderer::Font,
     placeholder: Option<&str>,
     selected: Option<&T>,
-    style: <Renderer::Theme as StyleSheet>::Style,
+    style: &<Renderer::Theme as StyleSheet>::Style,
 ) where
     Renderer: text::Renderer,
     Renderer::Theme: StyleSheet,

native/src/widget/progress_bar.rs

@@ -124,7 +124,7 @@ where
                 / (range_end - range_start)
         };
 
-        let style = theme.appearance(self.style);
+        let style = theme.appearance(&self.style);
 
         renderer.fill_quad(
             renderer::Quad {

native/src/widget/radio.rs

@@ -230,9 +230,9 @@ where
         let mut children = layout.children();
 
         let custom_style = if is_mouse_over {
-            theme.hovered(self.style, self.is_selected)
+            theme.hovered(&self.style, self.is_selected)
         } else {
-            theme.active(self.style, self.is_selected)
+            theme.active(&self.style, self.is_selected)
         };
 
         {

native/src/widget/rule.rs

@@ -88,7 +88,7 @@ where
         _viewport: &Rectangle,
     ) {
         let bounds = layout.bounds();
-        let style = theme.style(self.style);
+        let style = theme.appearance(&self.style);
 
         let bounds = if self.is_horizontal {
             let line_y = (bounds.y + (bounds.height / 2.0)

native/src/widget/scrollable.rs

@@ -233,7 +233,7 @@ where
             self.scrollbar_width,
             self.scrollbar_margin,
             self.scroller_width,
-            self.style,
+            &self.style,
             |renderer, layout, cursor_position, viewport| {
                 self.content.as_widget().draw(
                     &tree.children[0],
@@ -627,7 +627,7 @@ pub fn draw<Renderer>(
     scrollbar_width: u16,
     scrollbar_margin: u16,
     scroller_width: u16,
-    style: <Renderer::Theme as StyleSheet>::Style,
+    style: &<Renderer::Theme as StyleSheet>::Style,
     draw_content: impl FnOnce(&mut Renderer, Layout<'_>, Point, &Rectangle),
 ) where
     Renderer: crate::Renderer,

native/src/widget/slider.rs

@@ -222,7 +222,7 @@ where
             self.value,
             &self.range,
             theme,
-            self.style,
+            &self.style,
         )
     }
 
@@ -353,7 +353,7 @@ pub fn draw<T, R>(
     value: T,
     range: &RangeInclusive<T>,
     style_sheet: &dyn StyleSheet<Style = <R::Theme as StyleSheet>::Style>,
-    style: <R::Theme as StyleSheet>::Style,
+    style: &<R::Theme as StyleSheet>::Style,
 ) where
     T: Into<f64> + Copy,
     R: crate::Renderer,

native/src/widget/text_input.rs

@@ -188,7 +188,7 @@ where
             self.size,
             &self.font,
             self.is_secure,
-            self.style,
+            &self.style,
         )
     }
 }
@@ -284,7 +284,7 @@ where
             self.size,
             &self.font,
             self.is_secure,
-            self.style,
+            &self.style,
         )
     }
 
@@ -746,7 +746,7 @@ pub fn draw<Renderer>(
     size: Option<u16>,
     font: &Renderer::Font,
     is_secure: bool,
-    style: <Renderer::Theme as StyleSheet>::Style,
+    style: &<Renderer::Theme as StyleSheet>::Style,
 ) where
     Renderer: text::Renderer,
     Renderer::Theme: StyleSheet,

native/src/widget/toggler.rs

@@ -260,9 +260,9 @@ where
         let is_mouse_over = bounds.contains(cursor_position);
 
         let style = if is_mouse_over {
-            theme.hovered(self.style, self.is_active)
+            theme.hovered(&self.style, self.is_active)
         } else {
-            theme.active(self.style, self.is_active)
+            theme.active(&self.style, self.is_active)
         };
 
         let border_radius = bounds.height as f32 / BORDER_RADIUS_RATIO;

native/src/widget/tooltip.rs

@@ -201,7 +201,7 @@ where
             self.gap,
             self.padding,
             self.snap_within_viewport,
-            self.style,
+            &self.style,
             |renderer, limits| {
                 Widget::<(), Renderer>::layout(tooltip, renderer, limits)
             },
@@ -275,7 +275,7 @@ pub fn draw<Renderer>(
     gap: u16,
     padding: u16,
     snap_within_viewport: bool,
-    style: <Renderer::Theme as container::StyleSheet>::Style,
+    style: &<Renderer::Theme as container::StyleSheet>::Style,
     layout_text: impl FnOnce(&Renderer, &layout::Limits) -> layout::Node,
     draw_text: impl FnOnce(
         &mut Renderer,

style/src/application.rs

@@ -1,9 +1,9 @@
 use iced_core::Color;
 
 pub trait StyleSheet {
-    type Style: Default + Copy;
+    type Style: Default;
 
-    fn appearance(&self, style: Self::Style) -> Appearance;
+    fn appearance(&self, style: &Self::Style) -> Appearance;
 }
 
 #[derive(Debug, Clone, Copy, PartialEq)]

style/src/button.rs

@@ -27,11 +27,11 @@ impl std::default::Default for Appearance {
 
 /// A set of rules that dictate the style of a button.
 pub trait StyleSheet {
-    type Style: Default + Copy;
+    type Style: Default;
 
-    fn active(&self, style: Self::Style) -> Appearance;
+    fn active(&self, style: &Self::Style) -> Appearance;
 
-    fn hovered(&self, style: Self::Style) -> Appearance {
+    fn hovered(&self, style: &Self::Style) -> Appearance {
         let active = self.active(style);
 
         Appearance {
@@ -40,14 +40,14 @@ pub trait StyleSheet {
         }
     }
 
-    fn pressed(&self, style: Self::Style) -> Appearance {
+    fn pressed(&self, style: &Self::Style) -> Appearance {
         Appearance {
             shadow_offset: Vector::default(),
             ..self.active(style)
         }
     }
 
-    fn disabled(&self, style: Self::Style) -> Appearance {
+    fn disabled(&self, style: &Self::Style) -> Appearance {
         let active = self.active(style);
 
         Appearance {

style/src/checkbox.rs

@@ -14,9 +14,9 @@ pub struct Appearance {
 
 /// A set of rules that dictate the style of a checkbox.
 pub trait StyleSheet {
-    type Style: Default + Copy;
+    type Style: Default;
 
-    fn active(&self, style: Self::Style, is_checked: bool) -> Appearance;
+    fn active(&self, style: &Self::Style, is_checked: bool) -> Appearance;
 
-    fn hovered(&self, style: Self::Style, is_checked: bool) -> Appearance;
+    fn hovered(&self, style: &Self::Style, is_checked: bool) -> Appearance;
 }

style/src/container.rs

@@ -25,8 +25,8 @@ impl std::default::Default for Appearance {
 
 /// A set of rules that dictate the [`Appearance`] of a container.
 pub trait StyleSheet {
-    type Style: Default + Copy;
+    type Style: Default;
 
     /// Produces the [`Appearance`] of a container.
-    fn appearance(&self, style: Self::Style) -> Appearance;
+    fn appearance(&self, style: &Self::Style) -> Appearance;
 }

style/src/menu.rs

@@ -13,7 +13,7 @@ pub struct Appearance {
 }
 
 pub trait StyleSheet {
-    type Style: Default + Copy;
+    type Style: Default + Clone;
 
-    fn appearance(&self, style: Self::Style) -> Appearance;
+    fn appearance(&self, style: &Self::Style) -> Appearance;
 }

style/src/pane_grid.rs

@@ -4,13 +4,13 @@ use iced_core::Color;
 
 /// A set of rules that dictate the style of a container.
 pub trait StyleSheet {
-    type Style: Default + Copy;
+    type Style: Default;
 
     /// The [`Line`] to draw when a split is picked.
-    fn picked_split(&self, style: Self::Style) -> Option<Line>;
+    fn picked_split(&self, style: &Self::Style) -> Option<Line>;
 
     /// The [`Line`] to draw when a split is hovered.
-    fn hovered_split(&self, style: Self::Style) -> Option<Line>;
+    fn hovered_split(&self, style: &Self::Style) -> Option<Line>;
 }
 
 /// A line.

style/src/pick_list.rs

@@ -1,9 +1,5 @@
 use iced_core::{Background, Color};
 
-use crate::container;
-use crate::menu;
-use crate::scrollable;
-
 /// The appearance of a pick list.
 #[derive(Debug, Clone, Copy)]
 pub struct Appearance {
@@ -17,13 +13,10 @@ pub struct Appearance {
 }
 
 /// A set of rules that dictate the style of a container.
-pub trait StyleSheet:
-    container::StyleSheet + menu::StyleSheet + scrollable::StyleSheet
-{
-    type Style: Default + Copy + Into<<Self as menu::StyleSheet>::Style>;
+pub trait StyleSheet {
+    type Style: Default + Clone;
 
-    fn active(&self, style: <Self as StyleSheet>::Style) -> Appearance;
+    fn active(&self, style: &<Self as StyleSheet>::Style) -> Appearance;
 
-    /// Produces the style of a container.
-    fn hovered(&self, style: <Self as StyleSheet>::Style) -> Appearance;
+    fn hovered(&self, style: &<Self as StyleSheet>::Style) -> Appearance;
 }

style/src/progress_bar.rs

@@ -11,7 +11,7 @@ pub struct Appearance {
 
 /// A set of rules that dictate the style of a progress bar.
 pub trait StyleSheet {
-    type Style: Default + Copy;
+    type Style: Default;
 
-    fn appearance(&self, style: Self::Style) -> Appearance;
+    fn appearance(&self, style: &Self::Style) -> Appearance;
 }

style/src/radio.rs

@@ -13,9 +13,9 @@ pub struct Appearance {
 
 /// A set of rules that dictate the style of a radio button.
 pub trait StyleSheet {
-    type Style: Default + Copy;
+    type Style: Default;
 
-    fn active(&self, style: Self::Style, is_selected: bool) -> Appearance;
+    fn active(&self, style: &Self::Style, is_selected: bool) -> Appearance;
 
-    fn hovered(&self, style: Self::Style, is_selected: bool) -> Appearance;
+    fn hovered(&self, style: &Self::Style, is_selected: bool) -> Appearance;
 }

style/src/rule.rs

@@ -16,10 +16,10 @@ pub struct Appearance {
 
 /// A set of rules that dictate the style of a rule.
 pub trait StyleSheet {
-    type Style: Default + Copy;
+    type Style: Default;
 
     /// Produces the style of a rule.
-    fn style(&self, style: Self::Style) -> Appearance;
+    fn appearance(&self, style: &Self::Style) -> Appearance;
 }
 
 /// The fill mode of a rule.

style/src/scrollable.rs

@@ -22,16 +22,16 @@ pub struct Scroller {
 
 /// A set of rules that dictate the style of a scrollable.
 pub trait StyleSheet {
-    type Style: Default + Copy;
+    type Style: Default;
 
     /// Produces the style of an active scrollbar.
-    fn active(&self, style: Self::Style) -> Scrollbar;
+    fn active(&self, style: &Self::Style) -> Scrollbar;
 
     /// Produces the style of an hovered scrollbar.
-    fn hovered(&self, style: Self::Style) -> Scrollbar;
+    fn hovered(&self, style: &Self::Style) -> Scrollbar;
 
     /// Produces the style of a scrollbar that is being dragged.
-    fn dragging(&self, style: Self::Style) -> Scrollbar {
+    fn dragging(&self, style: &Self::Style) -> Scrollbar {
         self.hovered(style)
     }
 }

style/src/slider.rs

@@ -26,14 +26,14 @@ pub enum HandleShape {
 
 /// A set of rules that dictate the style of a slider.
 pub trait StyleSheet {
-    type Style: Default + Copy;
+    type Style: Default;
 
     /// Produces the style of an active slider.
-    fn active(&self, style: Self::Style) -> Appearance;
+    fn active(&self, style: &Self::Style) -> Appearance;
 
     /// Produces the style of an hovered slider.
-    fn hovered(&self, style: Self::Style) -> Appearance;
+    fn hovered(&self, style: &Self::Style) -> Appearance;
 
     /// Produces the style of a slider that is being dragged.
-    fn dragging(&self, style: Self::Style) -> Appearance;
+    fn dragging(&self, style: &Self::Style) -> Appearance;
 }

style/src/text_input.rs

@@ -12,22 +12,22 @@ pub struct Appearance {
 
 /// A set of rules that dictate the style of a text input.
 pub trait StyleSheet {
-    type Style: Default + Copy;
+    type Style: Default;
 
     /// Produces the style of an active text input.
-    fn active(&self, style: Self::Style) -> Appearance;
+    fn active(&self, style: &Self::Style) -> Appearance;
 
     /// Produces the style of a focused text input.
-    fn focused(&self, style: Self::Style) -> Appearance;
+    fn focused(&self, style: &Self::Style) -> Appearance;
 
-    fn placeholder_color(&self, style: Self::Style) -> Color;
+    fn placeholder_color(&self, style: &Self::Style) -> Color;
 
-    fn value_color(&self, style: Self::Style) -> Color;
+    fn value_color(&self, style: &Self::Style) -> Color;
 
-    fn selection_color(&self, style: Self::Style) -> Color;
+    fn selection_color(&self, style: &Self::Style) -> Color;
 
     /// Produces the style of an hovered text input.
-    fn hovered(&self, style: Self::Style) -> Appearance {
+    fn hovered(&self, style: &Self::Style) -> Appearance {
         self.focused(style)
     }
 }

style/src/toggler.rs

@@ -12,9 +12,9 @@ pub struct Appearance {
 
 /// A set of rules that dictate the style of a toggler.
 pub trait StyleSheet {
-    type Style: Default + Copy;
+    type Style: Default;
 
-    fn active(&self, style: Self::Style, is_active: bool) -> Appearance;
+    fn active(&self, style: &Self::Style, is_active: bool) -> Appearance;
 
-    fn hovered(&self, style: Self::Style, is_active: bool) -> Appearance;
+    fn hovered(&self, style: &Self::Style, is_active: bool) -> Appearance;
 }

winit/src/application/state.rs

@@ -32,7 +32,7 @@ where
         let title = application.title();
         let scale_factor = application.scale_factor();
         let theme = application.theme();
-        let appearance = theme.appearance(application.style());
+        let appearance = theme.appearance(&application.style());
 
         let viewport = {
             let physical_size = window.inner_size();
@@ -210,6 +210,6 @@ where
 
         // Update theme and appearance
         self.theme = application.theme();
-        self.appearance = self.theme.appearance(application.style());
+        self.appearance = self.theme.appearance(&application.style());
     }
 }