Implement `Toggler` widget for iced_native

10 files changed, 452 insertions, 4 deletions

diff --git a/graphics/src/widget.rs b/graphics/src/widget.rs
index 190ea9c0..e34d267f 100644
--- a/graphics/src/widget.rs
+++ b/graphics/src/widget.rs
@@ -20,6 +20,7 @@ pub mod scrollable;
 pub mod slider;
 pub mod svg;
 pub mod text_input;
+pub mod toggler;
 pub mod tooltip;
 
 mod column;
@@ -50,6 +51,8 @@ pub use slider::Slider;
 #[doc(no_inline)]
 pub use text_input::TextInput;
 #[doc(no_inline)]
+pub use toggler::Toggler;
+#[doc(no_inline)]
 pub use tooltip::Tooltip;
 
 pub use column::Column;
diff --git a/graphics/src/widget/toggler.rs b/graphics/src/widget/toggler.rs
new file mode 100644
index 00000000..a258443e
--- /dev/null
+++ b/graphics/src/widget/toggler.rs
@@ -0,0 +1,94 @@
+//! Show toggle controls using togglers.
+use crate::backend::{self, Backend};
+use crate::{Primitive, Renderer};
+use iced_native::mouse;
+use iced_native::toggler;
+use iced_native::Rectangle;
+
+pub use iced_style::toggler::{Style, StyleSheet};
+
+/// Makes sure that the border radius of the toggler looks good at every size.
+const BORDER_RADIUS_RATIO: f32 = 32.0 / 13.0;
+
+/// The space ratio between the background Quad and the Toggler bounds, and
+/// between the background Quad and foreground Quad.
+const SPACE_RATIO: f32 = 0.05;
+
+/// A toggler that can be toggled.
+///
+/// This is an alias of an `iced_native` toggler with an `iced_wgpu::Renderer`.
+pub type Toggler<Message, Backend> =
+    iced_native::Toggler<Message, Renderer<Backend>>;
+
+impl<B> toggler::Renderer for Renderer<B>
+where
+    B: Backend + backend::Text,
+{
+    type Style = Box<dyn StyleSheet>;
+
+    const DEFAULT_SIZE: u16 = 20;
+
+    fn draw(
+        &mut self,
+        bounds: Rectangle,
+        is_active: bool,
+        is_mouse_over: bool,
+        (label, _): Self::Output,
+        style_sheet: &Self::Style,
+    ) -> Self::Output {
+        let style = if is_mouse_over {
+            style_sheet.hovered(is_active)
+        } else {
+            style_sheet.active(is_active)
+        };
+
+        let border_radius = bounds.height as f32 / BORDER_RADIUS_RATIO;
+        let space = SPACE_RATIO * bounds.height as f32;
+
+        let toggler_background_bounds = Rectangle {
+            x: bounds.x + space,
+            y: bounds.y + space,
+            width: bounds.width - (2.0 * space),
+            height: bounds.height - (2.0 * space),
+        };
+
+        let toggler_background = Primitive::Quad {
+            bounds: toggler_background_bounds,
+            background: style.background.into(),
+            border_radius,
+            border_width: 1.0,
+            border_color: style.background_border.unwrap_or(style.background),
+        };
+
+        let toggler_foreground_bounds = Rectangle {
+            x: bounds.x
+                + if is_active {
+                    bounds.width - 2.0 * space - (bounds.height - (4.0 * space))
+                } else {
+                    2.0 * space
+                },
+            y: bounds.y + (2.0 * space),
+            width: bounds.height - (4.0 * space),
+            height: bounds.height - (4.0 * space),
+        };
+
+        let toggler_foreground = Primitive::Quad {
+            bounds: toggler_foreground_bounds,
+            background: style.foreground.into(),
+            border_radius,
+            border_width: 1.0,
+            border_color: style.foreground_border.unwrap_or(style.foreground),
+        };
+
+        (
+            Primitive::Group {
+                primitives: vec![label, toggler_background, toggler_foreground],
+            },
+            if is_mouse_over {
+                mouse::Interaction::Pointer
+            } else {
+                mouse::Interaction::default()
+            },
+        )
+    }
+}
diff --git a/native/src/renderer/null.rs b/native/src/renderer/null.rs
index 28746585..89bb9433 100644
--- a/native/src/renderer/null.rs
+++ b/native/src/renderer/null.rs
@@ -1,6 +1,6 @@
 use crate::{
     button, checkbox, column, container, pane_grid, progress_bar, radio, row,
-    scrollable, slider, text, text_input, Color, Element, Font,
+    scrollable, slider, text, text_input, toggler, Color, Element, Font,
     HorizontalAlignment, Layout, Padding, Point, Rectangle, Renderer, Size,
     VerticalAlignment,
 };
@@ -288,3 +288,19 @@ impl pane_grid::Renderer for Null {
     ) {
     }
 }
+
+impl toggler::Renderer for Null {
+    type Style = ();
+
+    const DEFAULT_SIZE: u16 = 20;
+
+    fn draw(
+        &mut self,
+        _bounds: Rectangle,
+        _is_checked: bool,
+        _is_mouse_over: bool,
+        _label: Self::Output,
+        _style: &Self::Style,
+    ) {
+    }
+}
diff --git a/native/src/widget.rs b/native/src/widget.rs
index 791c53a3..759fe71a 100644
--- a/native/src/widget.rs
+++ b/native/src/widget.rs
@@ -36,6 +36,7 @@ pub mod space;
 pub mod svg;
 pub mod text;
 pub mod text_input;
+pub mod toggler;
 pub mod tooltip;
 
 #[doc(no_inline)]
@@ -73,6 +74,8 @@ pub use text::Text;
 #[doc(no_inline)]
 pub use text_input::TextInput;
 #[doc(no_inline)]
+pub use toggler::Toggler;
+#[doc(no_inline)]
 pub use tooltip::Tooltip;
 
 use crate::event::{self, Event};
diff --git a/native/src/widget/toggler.rs b/native/src/widget/toggler.rs
new file mode 100644
index 00000000..250abac4
--- /dev/null
+++ b/native/src/widget/toggler.rs
@@ -0,0 +1,262 @@
+//! Show toggle controls using togglers.
+use std::hash::Hash;
+
+use crate::{
+    event, layout, mouse, row, text, Align, Clipboard, Element, Event, Hasher,
+    HorizontalAlignment, Layout, Length, Point, Rectangle, Row, Text,
+    VerticalAlignment, Widget,
+};
+
+/// A toggler widget
+///
+/// # Example
+///
+/// ```
+/// # type Toggler<Message> = iced_native::Toggler<Message, iced_native::renderer::Null>;
+/// #
+/// pub enum Message {
+///     TogglerToggled(bool),
+/// }
+///
+/// let is_active = true;
+///
+/// Toggler::new(is_active, "Toggle me!", |b| Message::TogglerToggled(b))
+/// ```
+///
+#[allow(missing_debug_implementations)]
+pub struct Toggler<Message, Renderer: self::Renderer + text::Renderer> {
+    is_active: bool,
+    on_toggle: Box<dyn Fn(bool) -> Message>,
+    label: String,
+    width: Length,
+    size: u16,
+    text_size: Option<u16>,
+    font: Renderer::Font,
+    style: Renderer::Style,
+}
+
+impl<Message, Renderer: self::Renderer + text::Renderer>
+    Toggler<Message, Renderer>
+{
+    /// Creates a new [`Toggler`].
+    ///
+    /// It expects:
+    ///   * a boolean describing whether the [`Toggler`] is checked or not
+    ///   * the label of the [`Toggler`]
+    ///   * a function that will be called when the [`Toggler`] is toggled. It
+    ///     will receive the new state of the [`Toggler`] and must produce a
+    ///     `Message`.
+    ///
+    /// [`Toggler`]: struct.Toggler.html
+    pub fn new<F>(is_active: bool, label: impl Into<String>, f: F) -> Self
+    where
+        F: 'static + Fn(bool) -> Message,
+    {
+        Toggler {
+            is_active,
+            on_toggle: Box::new(f),
+            label: label.into(),
+            width: Length::Fill,
+            size: <Renderer as self::Renderer>::DEFAULT_SIZE,
+            text_size: None,
+            font: Renderer::Font::default(),
+            style: Renderer::Style::default(),
+        }
+    }
+
+    /// Sets the size of the [`Toggler`].
+    ///
+    /// [`Toggler`]: struct.Toggler.html
+    pub fn size(mut self, size: u16) -> Self {
+        self.size = size;
+        self
+    }
+
+    /// Sets the width of the [`Toggler`].
+    ///
+    /// [`Toggler`]: struct.Toggler.html
+    pub fn width(mut self, width: Length) -> Self {
+        self.width = width;
+        self
+    }
+
+    /// Sets the text size o the [`Toggler`].
+    ///
+    /// [`Toggler`]: struct.Toggler.html
+    pub fn text_size(mut self, text_size: u16) -> Self {
+        self.text_size = Some(text_size);
+        self
+    }
+
+    /// Sets the [`Font`] of the text of the [`Toggler`]
+    ///
+    /// [`Toggler`]: struct.Toggler.html
+    /// [`Font`]: ../../struct.Font.html
+    pub fn font(mut self, font: Renderer::Font) -> Self {
+        self.font = font;
+        self
+    }
+
+    /// Sets the style of the [`Toggler`].
+    ///
+    /// [`Toggler`]: struct.Toggler.html
+    pub fn style(mut self, style: impl Into<Renderer::Style>) -> Self {
+        self.style = style.into();
+        self
+    }
+}
+
+impl<Message, Renderer> Widget<Message, Renderer> for Toggler<Message, Renderer>
+where
+    Renderer: self::Renderer + text::Renderer + row::Renderer,
+{
+    fn width(&self) -> Length {
+        self.width
+    }
+
+    fn height(&self) -> Length {
+        Length::Shrink
+    }
+
+    fn layout(
+        &self,
+        renderer: &Renderer,
+        limits: &layout::Limits,
+    ) -> layout::Node {
+        Row::<(), Renderer>::new()
+            .width(self.width)
+            .align_items(Align::Center)
+            .push(
+                Text::new(&self.label)
+                    .font(self.font)
+                    .width(self.width)
+                    .size(self.text_size.unwrap_or(renderer.default_size())),
+            )
+            .push(
+                Row::new()
+                    .width(Length::Units(2 * self.size))
+                    .height(Length::Units(self.size)),
+            )
+            .layout(renderer, limits)
+    }
+
+    fn on_event(
+        &mut self,
+        event: Event,
+        layout: Layout<'_>,
+        cursor_position: Point,
+        _renderer: &Renderer,
+        _clipboard: &mut dyn Clipboard,
+        messages: &mut Vec<Message>,
+    ) -> event::Status {
+        match event {
+            Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left)) => {
+                let mouse_over = layout.bounds().contains(cursor_position);
+
+                if mouse_over {
+                    messages.push((self.on_toggle)(!self.is_active));
+
+                    event::Status::Captured
+                } else {
+                    event::Status::Ignored
+                }
+            }
+            _ => event::Status::Ignored,
+        }
+    }
+
+    fn draw(
+        &self,
+        renderer: &mut Renderer,
+        defaults: &Renderer::Defaults,
+        layout: Layout<'_>,
+        cursor_position: Point,
+        _viewport: &Rectangle,
+    ) -> Renderer::Output {
+        let bounds = layout.bounds();
+        let mut children = layout.children();
+
+        let label_layout = children.next().unwrap();
+        let toggler_layout = children.next().unwrap();
+        let toggler_bounds = toggler_layout.bounds();
+
+        let label = text::Renderer::draw(
+            renderer,
+            defaults,
+            label_layout.bounds(),
+            &self.label,
+            self.text_size.unwrap_or(renderer.default_size()),
+            self.font,
+            None,
+            HorizontalAlignment::Left,
+            VerticalAlignment::Center,
+        );
+
+        let is_mouse_over = bounds.contains(cursor_position);
+
+        self::Renderer::draw(
+            renderer,
+            toggler_bounds,
+            self.is_active,
+            is_mouse_over,
+            label,
+            &self.style,
+        )
+    }
+
+    fn hash_layout(&self, state: &mut Hasher) {
+        struct Marker;
+        std::any::TypeId::of::<Marker>().hash(state);
+
+        self.label.hash(state)
+    }
+}
+
+/// The renderer of a [`Toggler`].
+///
+/// Your [renderer] will need to implement this trait before being
+/// able to use a [`Toggler`] in your user interface.
+///
+/// [`Toggler`]: struct.Toggler.html
+/// [renderer]: ../../renderer/index.html
+pub trait Renderer: crate::Renderer {
+    /// The style supported by this renderer.
+    type Style: Default;
+
+    /// The default size of a [`Toggler`].
+    ///
+    /// [`Toggler`]: struct.Toggler.html
+    const DEFAULT_SIZE: u16;
+
+    /// Draws a [`Toggler`].
+    ///
+    /// It receives:
+    ///   * the bounds of the [`Toggler`]
+    ///   * whether the [`Toggler`] is activated or not
+    ///   * whether the mouse is over the [`Toggler`] or not
+    ///   * the drawn label of the [`Toggler`]
+    ///   * the style of the [`Toggler`]
+    ///
+    /// [`Toggler`]: struct.Toggler.html
+    fn draw(
+        &mut self,
+        bounds: Rectangle,
+        is_active: bool,
+        is_mouse_over: bool,
+        label: Self::Output,
+        style: &Self::Style,
+    ) -> Self::Output;
+}
+
+impl<'a, Message, Renderer> From<Toggler<Message, Renderer>>
+    for Element<'a, Message, Renderer>
+where
+    Renderer: 'a + self::Renderer + text::Renderer + row::Renderer,
+    Message: 'a,
+{
+    fn from(
+        toggler: Toggler<Message, Renderer>,
+    ) -> Element<'a, Message, Renderer> {
+        Element::new(toggler)
+    }
+}
diff --git a/src/widget.rs b/src/widget.rs
index eac50d57..db052106 100644
--- a/src/widget.rs
+++ b/src/widget.rs
@@ -17,8 +17,8 @@
 mod platform {
     pub use crate::renderer::widget::{
         button, checkbox, container, pane_grid, pick_list, progress_bar, radio,
-        rule, scrollable, slider, text_input, tooltip, Column, Row, Space,
-        Text,
+        rule, scrollable, slider, text_input, toggler, tooltip, Column, Row,
+        Space, Text,
     };
 
     #[cfg(any(feature = "canvas", feature = "glow_canvas"))]
@@ -53,7 +53,7 @@ mod platform {
         button::Button, checkbox::Checkbox, container::Container, image::Image,
         pane_grid::PaneGrid, pick_list::PickList, progress_bar::ProgressBar,
         radio::Radio, rule::Rule, scrollable::Scrollable, slider::Slider,
-        svg::Svg, text_input::TextInput, tooltip::Tooltip,
+        svg::Svg, text_input::TextInput, toggler::Toggler, tooltip::Tooltip,
     };
 
     #[cfg(any(feature = "canvas", feature = "glow_canvas"))]
diff --git a/style/src/lib.rs b/style/src/lib.rs
index f09b5f9d..08d9f044 100644
--- a/style/src/lib.rs
+++ b/style/src/lib.rs
@@ -18,3 +18,4 @@ pub mod rule;
 pub mod scrollable;
 pub mod slider;
 pub mod text_input;
+pub mod toggler;
diff --git a/style/src/toggler.rs b/style/src/toggler.rs
new file mode 100644
index 00000000..5a155123
--- /dev/null
+++ b/style/src/toggler.rs
@@ -0,0 +1,57 @@
+//! Show toggle controls using togglers.
+use iced_core::Color;
+
+/// The appearance of a toggler.
+#[derive(Debug)]
+pub struct Style {
+    pub background: Color,
+    pub background_border: Option<Color>,
+    pub foreground: Color,
+    pub foreground_border: Option<Color>,
+}
+
+/// A set of rules that dictate the style of a toggler.
+pub trait StyleSheet {
+    fn active(&self, is_active: bool) -> Style;
+
+    fn hovered(&self, is_active: bool) -> Style;
+}
+
+struct Default;
+
+impl StyleSheet for Default {
+    fn active(&self, is_active: bool) -> Style {
+        Style {
+            background: if is_active {
+                Color::from_rgb(0.0, 1.0, 0.0)
+            } else {
+                Color::from_rgb(0.7, 0.7, 0.7)
+            },
+            background_border: None,
+            foreground: Color::WHITE,
+            foreground_border: None,
+        }
+    }
+
+    fn hovered(&self, is_active: bool) -> Style {
+        Style {
+            foreground: Color::from_rgb(0.95, 0.95, 0.95),
+            ..self.active(is_active)
+        }
+    }
+}
+
+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)
+    }
+}
diff --git a/wgpu/src/widget.rs b/wgpu/src/widget.rs
index 304bb726..a575d036 100644
--- a/wgpu/src/widget.rs
+++ b/wgpu/src/widget.rs
@@ -20,6 +20,7 @@ pub mod rule;
 pub mod scrollable;
 pub mod slider;
 pub mod text_input;
+pub mod toggler;
 pub mod tooltip;
 
 #[doc(no_inline)]
@@ -45,6 +46,8 @@ pub use slider::Slider;
 #[doc(no_inline)]
 pub use text_input::TextInput;
 #[doc(no_inline)]
+pub use toggler::Toggler;
+#[doc(no_inline)]
 pub use tooltip::Tooltip;
 
 #[cfg(feature = "canvas")]
diff --git a/wgpu/src/widget/toggler.rs b/wgpu/src/widget/toggler.rs
new file mode 100644
index 00000000..dfcf759b
--- /dev/null
+++ b/wgpu/src/widget/toggler.rs
@@ -0,0 +1,9 @@
+//! Show toggle controls using togglers.
+use crate::Renderer;
+
+pub use iced_graphics::toggler::{Style, StyleSheet};
+
+/// A toggler that can be toggled
+///
+/// This is an alias of an `iced_native` toggler with an `iced_wgpu::Renderer`.
+pub type Toggler<Message> = iced_native::Toggler<Message, Renderer>;