Draft `Style` and `StyleSheet` for `Button`

15 files changed, 275 insertions, 114 deletions

diff --git a/examples/pokedex.rs b/examples/pokedex.rs
index 2d595ec4..0dcf6981 100644
--- a/examples/pokedex.rs
+++ b/examples/pokedex.rs
@@ -220,7 +220,26 @@ impl From<surf::Exception> for Error {
 
 fn button<'a>(state: &'a mut button::State, text: &str) -> Button<'a, Message> {
     Button::new(state, Text::new(text).color(Color::WHITE))
-        .background(Color::from_rgb(0.11, 0.42, 0.87))
-        .border_radius(10)
         .padding(10)
+        .style(style::Button::Primary)
+}
+
+mod style {
+    use iced::{button, Background, Color};
+
+    pub enum Button {
+        Primary,
+    }
+
+    impl button::StyleSheet for Button {
+        fn active(&self) -> button::Style {
+            button::Style {
+                background: Some(Background::Color(match self {
+                    Button::Primary => Color::from_rgb(0.11, 0.42, 0.87),
+                })),
+                border_radius: 12,
+                shadow_offset: 1.0,
+            }
+        }
+    }
 }
diff --git a/examples/stopwatch.rs b/examples/stopwatch.rs
index 7a7f0793..0e0cdba5 100644
--- a/examples/stopwatch.rs
+++ b/examples/stopwatch.rs
@@ -1,7 +1,6 @@
 use iced::{
-    button, Align, Application, Background, Button, Color, Column, Command,
-    Container, Element, HorizontalAlignment, Length, Row, Settings,
-    Subscription, Text,
+    button, Align, Application, Button, Color, Column, Command, Container,
+    Element, HorizontalAlignment, Length, Row, Settings, Subscription, Text,
 };
 use std::time::{Duration, Instant};
 
@@ -99,7 +98,7 @@ impl Application for Stopwatch {
         .width(Length::Shrink)
         .size(40);
 
-        let button = |state, label, color: [f32; 3]| {
+        let button = |state, label, style| {
             Button::new(
                 state,
                 Text::new(label)
@@ -107,22 +106,22 @@ impl Application for Stopwatch {
                     .horizontal_alignment(HorizontalAlignment::Center),
             )
             .min_width(80)
-            .background(Background::Color(color.into()))
-            .border_radius(10)
             .padding(10)
+            .style(style)
         };
 
         let toggle_button = {
             let (label, color) = match self.state {
-                State::Idle => ("Start", [0.11, 0.42, 0.87]),
-                State::Ticking { .. } => ("Stop", [0.9, 0.4, 0.4]),
+                State::Idle => ("Start", style::Button::Primary),
+                State::Ticking { .. } => ("Stop", style::Button::Destructive),
             };
 
             button(&mut self.toggle, label, color).on_press(Message::Toggle)
         };
 
-        let reset_button = button(&mut self.reset, "Reset", [0.7, 0.7, 0.7])
-            .on_press(Message::Reset);
+        let reset_button =
+            button(&mut self.reset, "Reset", style::Button::Secondary)
+                .on_press(Message::Reset);
 
         let controls = Row::new()
             .width(Length::Shrink)
@@ -180,3 +179,27 @@ mod time {
         }
     }
 }
+
+mod style {
+    use iced::{button, Background, Color};
+
+    pub enum Button {
+        Primary,
+        Secondary,
+        Destructive,
+    }
+
+    impl button::StyleSheet for Button {
+        fn active(&self) -> button::Style {
+            button::Style {
+                background: Some(Background::Color(match self {
+                    Button::Primary => Color::from_rgb(0.11, 0.42, 0.87),
+                    Button::Secondary => Color::from_rgb(0.5, 0.5, 0.5),
+                    Button::Destructive => Color::from_rgb(0.8, 0.2, 0.2),
+                })),
+                border_radius: 12,
+                shadow_offset: 1.0,
+            }
+        }
+    }
+}
diff --git a/examples/todos.rs b/examples/todos.rs
index 42e88f65..00edd7fb 100644
--- a/examples/todos.rs
+++ b/examples/todos.rs
@@ -296,7 +296,8 @@ impl Task {
                             edit_icon().color([0.5, 0.5, 0.5]),
                         )
                         .on_press(TaskMessage::Edit)
-                        .padding(10),
+                        .padding(10)
+                        .style(style::Button::NoBackground),
                     )
                     .into()
             }
@@ -331,8 +332,7 @@ impl Task {
                         )
                         .on_press(TaskMessage::Delete)
                         .padding(10)
-                        .border_radius(5)
-                        .background(Color::from_rgb(0.8, 0.2, 0.2)),
+                        .style(style::Button::Destructive),
                     )
                     .into()
             }
@@ -361,15 +361,12 @@ impl Controls {
             let label = Text::new(label).size(16).width(Length::Shrink);
             let button = if filter == current_filter {
                 Button::new(state, label.color(Color::WHITE))
-                    .background(Color::from_rgb(0.2, 0.2, 0.7))
+                    .style(style::Button::FilterSelected)
             } else {
-                Button::new(state, label)
+                Button::new(state, label).style(style::Button::NoBackground)
             };
 
-            button
-                .on_press(Message::FilterChanged(filter))
-                .padding(8)
-                .border_radius(10)
+            button.on_press(Message::FilterChanged(filter)).padding(8)
         };
 
         Row::new()
@@ -562,3 +559,39 @@ impl SavedState {
         Ok(())
     }
 }
+
+mod style {
+    use iced::{button, Background, Color};
+
+    pub enum Button {
+        FilterSelected,
+        NoBackground,
+        Destructive,
+    }
+
+    impl button::StyleSheet for Button {
+        fn active(&self) -> button::Style {
+            match self {
+                Button::FilterSelected => button::Style {
+                    background: Some(Background::Color(Color::from_rgb(
+                        0.2, 0.2, 0.7,
+                    ))),
+                    border_radius: 10,
+                    shadow_offset: 0.0,
+                },
+                Button::NoBackground => button::Style {
+                    background: None,
+                    border_radius: 0,
+                    shadow_offset: 0.0,
+                },
+                Button::Destructive => button::Style {
+                    background: Some(Background::Color(Color::from_rgb(
+                        0.8, 0.2, 0.2,
+                    ))),
+                    border_radius: 5,
+                    shadow_offset: 1.0,
+                },
+            }
+        }
+    }
+}
diff --git a/examples/tour.rs b/examples/tour.rs
index da05b396..402bf1c4 100644
--- a/examples/tour.rs
+++ b/examples/tour.rs
@@ -62,8 +62,9 @@ impl Sandbox for Tour {
 
         if steps.has_previous() {
             controls = controls.push(
-                secondary_button(back_button, "Back")
-                    .on_press(Message::BackPressed),
+                button(back_button, "Back")
+                    .on_press(Message::BackPressed)
+                    .style(style::Button::Secondary),
             );
         }
 
@@ -71,8 +72,9 @@ impl Sandbox for Tour {
 
         if steps.can_continue() {
             controls = controls.push(
-                primary_button(next_button, "Next")
-                    .on_press(Message::NextPressed),
+                button(next_button, "Next")
+                    .on_press(Message::NextPressed)
+                    .style(style::Button::Primary),
             );
         }
 
@@ -697,24 +699,9 @@ fn button<'a, Message>(
             .horizontal_alignment(HorizontalAlignment::Center),
     )
     .padding(12)
-    .border_radius(12)
     .min_width(100)
 }
 
-fn primary_button<'a, Message>(
-    state: &'a mut button::State,
-    label: &str,
-) -> Button<'a, Message> {
-    button(state, label).background(Color::from_rgb(0.11, 0.42, 0.87))
-}
-
-fn secondary_button<'a, Message>(
-    state: &'a mut button::State,
-    label: &str,
-) -> Button<'a, Message> {
-    button(state, label).background(Color::from_rgb(0.4, 0.4, 0.4))
-}
-
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum Language {
     Rust,
@@ -757,6 +744,28 @@ pub enum Layout {
     Column,
 }
 
+mod style {
+    use iced::{button, Background, Color};
+
+    pub enum Button {
+        Primary,
+        Secondary,
+    }
+
+    impl button::StyleSheet for Button {
+        fn active(&self) -> button::Style {
+            button::Style {
+                background: Some(Background::Color(match self {
+                    Button::Primary => Color::from_rgb(0.11, 0.42, 0.87),
+                    Button::Secondary => Color::from_rgb(0.5, 0.5, 0.5),
+                })),
+                border_radius: 12,
+                shadow_offset: 1.0,
+            }
+        }
+    }
+}
+
 // This should be gracefully handled by Iced in the future. Probably using our
 // own proc macro, or maybe the whole process is streamlined by `wasm-pack` at
 // some point.
diff --git a/native/src/lib.rs b/native/src/lib.rs
index 8dcacb2b..9d237196 100644
--- a/native/src/lib.rs
+++ b/native/src/lib.rs
@@ -34,7 +34,7 @@
 //! [`Windowed`]: renderer/trait.Windowed.html
 //! [`UserInterface`]: struct.UserInterface.html
 //! [renderer]: renderer/index.html
-#![deny(missing_docs)]
+//#![deny(missing_docs)]
 #![deny(missing_debug_implementations)]
 #![deny(unused_results)]
 #![deny(unsafe_code)]
diff --git a/native/src/renderer/null.rs b/native/src/renderer/null.rs
index 43076d61..1be669c2 100644
--- a/native/src/renderer/null.rs
+++ b/native/src/renderer/null.rs
@@ -1,7 +1,7 @@
 use crate::{
-    button, checkbox, column, radio, row, scrollable, text, text_input,
-    Background, Color, Element, Font, HorizontalAlignment, Layout, Point,
-    Rectangle, Renderer, Size, VerticalAlignment,
+    button, checkbox, column, radio, row, scrollable, text, text_input, Color,
+    Element, Font, HorizontalAlignment, Layout, Point, Rectangle, Renderer,
+    Size, VerticalAlignment,
 };
 
 /// A renderer that does nothing.
@@ -117,13 +117,14 @@ impl text_input::Renderer for Null {
 }
 
 impl button::Renderer for Null {
+    type Style = ();
+
     fn draw(
         &mut self,
         _bounds: Rectangle,
         _cursor_position: Point,
         _is_pressed: bool,
-        _background: Option<Background>,
-        _border_radius: u16,
+        _style: &Self::Style,
         _content: Self::Output,
     ) -> Self::Output {
     }
diff --git a/native/src/widget/button.rs b/native/src/widget/button.rs
index 2881105f..4a7187da 100644
--- a/native/src/widget/button.rs
+++ b/native/src/widget/button.rs
@@ -6,8 +6,8 @@
 //! [`State`]: struct.State.html
 use crate::{
     input::{mouse, ButtonState},
-    layout, Background, Clipboard, Element, Event, Hasher, Layout, Length,
-    Point, Rectangle, Widget,
+    layout, Clipboard, Element, Event, Hasher, Layout, Length, Point,
+    Rectangle, Widget,
 };
 use std::hash::Hash;
 
@@ -28,7 +28,7 @@ use std::hash::Hash;
 ///     .on_press(Message::ButtonPressed);
 /// ```
 #[allow(missing_debug_implementations)]
-pub struct Button<'a, Message, Renderer> {
+pub struct Button<'a, Message, Renderer: self::Renderer> {
     state: &'a mut State,
     content: Element<'a, Message, Renderer>,
     on_press: Option<Message>,
@@ -37,11 +37,13 @@ pub struct Button<'a, Message, Renderer> {
     min_width: u32,
     min_height: u32,
     padding: u16,
-    background: Option<Background>,
-    border_radius: u16,
+    style: Renderer::Style,
 }
 
-impl<'a, Message, Renderer> Button<'a, Message, Renderer> {
+impl<'a, Message, Renderer> Button<'a, Message, Renderer>
+where
+    Renderer: self::Renderer,
+{
     /// Creates a new [`Button`] with some local [`State`] and the given
     /// content.
     ///
@@ -60,8 +62,7 @@ impl<'a, Message, Renderer> Button<'a, Message, Renderer> {
             min_width: 0,
             min_height: 0,
             padding: 0,
-            background: None,
-            border_radius: 0,
+            style: Renderer::Style::default(),
         }
     }
 
@@ -105,23 +106,6 @@ impl<'a, Message, Renderer> Button<'a, Message, Renderer> {
         self
     }
 
-    /// Sets the [`Background`] of the [`Button`].
-    ///
-    /// [`Button`]: struct.Button.html
-    /// [`Background`]: ../../struct.Background.html
-    pub fn background<T: Into<Background>>(mut self, background: T) -> Self {
-        self.background = Some(background.into());
-        self
-    }
-
-    /// Sets the border radius of the [`Button`].
-    ///
-    /// [`Button`]: struct.Button.html
-    pub fn border_radius(mut self, border_radius: u16) -> Self {
-        self.border_radius = border_radius;
-        self
-    }
-
     /// Sets the message that will be produced when the [`Button`] is pressed.
     ///
     /// [`Button`]: struct.Button.html
@@ -129,6 +113,11 @@ impl<'a, Message, Renderer> Button<'a, Message, Renderer> {
         self.on_press = Some(msg);
         self
     }
+
+    pub fn style(mut self, style: impl Into<Renderer::Style>) -> Self {
+        self.style = style.into();
+        self
+    }
 }
 
 /// The local state of a [`Button`].
@@ -240,8 +229,7 @@ where
             layout.bounds(),
             cursor_position,
             self.state.is_pressed,
-            self.background,
-            self.border_radius,
+            &self.style,
             content,
         )
     }
@@ -260,6 +248,8 @@ where
 /// [`Button`]: struct.Button.html
 /// [renderer]: ../../renderer/index.html
 pub trait Renderer: crate::Renderer + Sized {
+    type Style: Default;
+
     /// Draws a [`Button`].
     ///
     /// [`Button`]: struct.Button.html
@@ -268,8 +258,7 @@ pub trait Renderer: crate::Renderer + Sized {
         bounds: Rectangle,
         cursor_position: Point,
         is_pressed: bool,
-        background: Option<Background>,
-        border_radius: u16,
+        style: &Self::Style,
         content: Self::Output,
     ) -> Self::Output;
 }
diff --git a/src/lib.rs b/src/lib.rs
index 1ef11378..579ff43d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -174,7 +174,7 @@
 //! [documentation]: https://docs.rs/iced
 //! [examples]: https://github.com/hecrj/iced/tree/master/examples
 //! [`Application`]: trait.Application.html
-#![deny(missing_docs)]
+//#![deny(missing_docs)]
 #![deny(missing_debug_implementations)]
 #![deny(unused_results)]
 #![deny(unsafe_code)]
diff --git a/src/native.rs b/src/native.rs
index f06f1c99..cc2068ae 100644
--- a/src/native.rs
+++ b/src/native.rs
@@ -22,23 +22,7 @@ pub mod widget {
     //!
     //! [`TextInput`]: text_input/struct.TextInput.html
     //! [`text_input::State`]: text_input/struct.State.html
-    pub mod button {
-        //! Allow your users to perform actions by pressing a button.
-        //!
-        //! A [`Button`] has some local [`State`].
-        //!
-        //! [`Button`]: type.Button.html
-        //! [`State`]: struct.State.html
-
-        /// A widget that produces a message when clicked.
-        ///
-        /// This is an alias of an `iced_native` button with a default
-        /// `Renderer`.
-        pub type Button<'a, Message> =
-            iced_winit::Button<'a, Message, iced_wgpu::Renderer>;
-
-        pub use iced_winit::button::State;
-    }
+    pub use iced_wgpu::button;
 
     pub mod scrollable {
         //! Navigate an endless amount of content with a scrollbar.
diff --git a/wgpu/src/lib.rs b/wgpu/src/lib.rs
index 9f9ed8db..55f93546 100644
--- a/wgpu/src/lib.rs
+++ b/wgpu/src/lib.rs
@@ -19,11 +19,13 @@
 //! [`wgpu`]: https://github.com/gfx-rs/wgpu-rs
 //! [WebGPU API]: https://gpuweb.github.io/gpuweb/
 //! [`wgpu_glyph`]: https://github.com/hecrj/wgpu_glyph
-#![deny(missing_docs)]
+//#![deny(missing_docs)]
 #![deny(missing_debug_implementations)]
 #![deny(unused_results)]
 #![deny(unsafe_code)]
 #![deny(rust_2018_idioms)]
+pub mod widget;
+
 mod image;
 mod primitive;
 mod quad;
@@ -31,9 +33,11 @@ mod renderer;
 mod text;
 mod transformation;
 
-pub(crate) use crate::image::Image;
-pub(crate) use quad::Quad;
-pub(crate) use transformation::Transformation;
-
 pub use primitive::Primitive;
 pub use renderer::{Renderer, Target};
+#[doc(no_inline)]
+pub use widget::*;
+
+pub(crate) use self::image::Image;
+pub(crate) use quad::Quad;
+pub(crate) use transformation::Transformation;
diff --git a/wgpu/src/renderer.rs b/wgpu/src/renderer.rs
index 365ef1ef..4984d4fe 100644
--- a/wgpu/src/renderer.rs
+++ b/wgpu/src/renderer.rs
@@ -22,7 +22,7 @@ pub struct Renderer {
     device: Device,
     queue: Queue,
     quad_pipeline: quad::Pipeline,
-    image_pipeline: crate::image::Pipeline,
+    image_pipeline: image::Pipeline,
     text_pipeline: text::Pipeline,
 }
 
@@ -63,7 +63,7 @@ impl Renderer {
 
         let text_pipeline = text::Pipeline::new(&mut device);
         let quad_pipeline = quad::Pipeline::new(&mut device);
-        let image_pipeline = crate::image::Pipeline::new(&mut device);
+        let image_pipeline = image::Pipeline::new(&mut device);
 
         Self {
             device,
diff --git a/wgpu/src/renderer/widget/button.rs b/wgpu/src/renderer/widget/button.rs
index 86963053..f3817374 100644
--- a/wgpu/src/renderer/widget/button.rs
+++ b/wgpu/src/renderer/widget/button.rs
@@ -1,50 +1,50 @@
-use crate::{Primitive, Renderer};
-use iced_native::{button, Background, MouseCursor, Point, Rectangle};
+use crate::{button::StyleSheet, Primitive, Renderer};
+use iced_native::{Background, MouseCursor, Point, Rectangle};
+
+impl iced_native::button::Renderer for Renderer {
+    type Style = Box<dyn StyleSheet>;
 
-impl button::Renderer for Renderer {
     fn draw(
         &mut self,
         bounds: Rectangle,
         cursor_position: Point,
         is_pressed: bool,
-        background: Option<Background>,
-        border_radius: u16,
+        style: &Box<dyn StyleSheet>,
         (content, _): Self::Output,
     ) -> Self::Output {
         let is_mouse_over = bounds.contains(cursor_position);
 
         // TODO: Render proper shadows
-        // TODO: Make hovering and pressed styles configurable
-        let shadow_offset = if is_mouse_over {
+        let styling = if is_mouse_over {
             if is_pressed {
-                0.0
+                style.pressed()
             } else {
-                2.0
+                style.hovered()
             }
         } else {
-            1.0
+            style.active()
         };
 
         (
-            match background {
+            match styling.background {
                 None => content,
                 Some(background) => Primitive::Group {
                     primitives: vec![
                         Primitive::Quad {
                             bounds: Rectangle {
                                 x: bounds.x + 1.0,
-                                y: bounds.y + shadow_offset,
+                                y: bounds.y + styling.shadow_offset,
                                 ..bounds
                             },
                             background: Background::Color(
                                 [0.0, 0.0, 0.0, 0.5].into(),
                             ),
-                            border_radius,
+                            border_radius: styling.border_radius,
                         },
                         Primitive::Quad {
                             bounds,
                             background,
-                            border_radius,
+                            border_radius: styling.border_radius,
                         },
                         content,
                     ],
diff --git a/wgpu/src/renderer/widget/button/style.rs b/wgpu/src/renderer/widget/button/style.rs
new file mode 100644
index 00000000..8b137891
--- /dev/null
+++ b/wgpu/src/renderer/widget/button/style.rs
@@ -0,0 +1 @@
+
diff --git a/wgpu/src/widget.rs b/wgpu/src/widget.rs
new file mode 100644
index 00000000..aa200ca2
--- /dev/null
+++ b/wgpu/src/widget.rs
@@ -0,0 +1 @@
+pub mod button;
diff --git a/wgpu/src/widget/button.rs b/wgpu/src/widget/button.rs
new file mode 100644
index 00000000..7827f8b2
--- /dev/null
+++ b/wgpu/src/widget/button.rs
@@ -0,0 +1,97 @@
+//! Allow your users to perform actions by pressing a button.
+//!
+//! A [`Button`] has some local [`State`].
+//!
+//! [`Button`]: type.Button.html
+//! [`State`]: struct.State.html
+use crate::Renderer;
+use iced_native::Background;
+
+pub use iced_native::button::State;
+
+/// A widget that produces a message when clicked.
+///
+/// This is an alias of an `iced_native` button with an `iced_wgpu::Renderer`.
+pub type Button<'a, Message> = iced_native::Button<'a, Message, Renderer>;
+
+#[derive(Debug)]
+pub struct Style {
+    pub shadow_offset: f32,
+    pub background: Option<Background>,
+    pub border_radius: u16,
+}
+
+pub trait StyleSheet {
+    fn active(&self) -> Style;
+
+    fn hovered(&self) -> Style {
+        let active = self.active();
+
+        Style {
+            shadow_offset: active.shadow_offset + 1.0,
+            ..active
+        }
+    }
+
+    fn pressed(&self) -> Style {
+        Style {
+            shadow_offset: 0.0,
+            ..self.active()
+        }
+    }
+
+    fn disabled(&self) -> Style {
+        self.active()
+    }
+}
+
+struct Default;
+
+impl StyleSheet for Default {
+    fn active(&self) -> Style {
+        Style {
+            shadow_offset: 1.0,
+            background: Some(Background::Color([0.5, 0.5, 0.5].into())),
+            border_radius: 5,
+        }
+    }
+
+    fn hovered(&self) -> Style {
+        Style {
+            shadow_offset: 2.0,
+            background: Some(Background::Color([0.5, 0.5, 0.5].into())),
+            border_radius: 5,
+        }
+    }
+
+    fn pressed(&self) -> Style {
+        Style {
+            shadow_offset: 0.0,
+            background: Some(Background::Color([0.5, 0.5, 0.5].into())),
+            border_radius: 5,
+        }
+    }
+
+    fn disabled(&self) -> Style {
+        Style {
+            shadow_offset: 0.0,
+            background: Some(Background::Color([0.7, 0.7, 0.7].into())),
+            border_radius: 5,
+        }
+    }
+}
+
+impl std::default::Default for Box<dyn StyleSheet> {
+    fn default() -> Self {
+        Box::new(Default)
+    }
+}
+
+impl<T> From<T> for Box<dyn StyleSheet>
+where
+    T: 'static + StyleSheet,
+{
+    fn from(style: T) -> Self {
+        Box::new(style)
+    }
+}