Add `Toggler` widget to `iced_web`

web/src/css.rs

@@ -14,6 +14,9 @@ pub enum Rule {
 
     /// Spacing between elements
     Spacing(u16),
+
+    /// Toggler input for a specific size
+    Toggler(u16),
 }
 
 impl Rule {
@@ -23,6 +26,7 @@ impl Rule {
             Rule::Column => String::from("c"),
             Rule::Row => String::from("r"),
             Rule::Spacing(spacing) => format!("s-{}", spacing),
+            Rule::Toggler(size) => format!("toggler-{}", size),
         }
     }
 
@@ -55,6 +59,46 @@ impl Rule {
                 class
             )
             .into_bump_str(),
+            Rule::Toggler(size) => bumpalo::format!(
+                in bump,
+                ".toggler-{} {{ display: flex; cursor: pointer; justify-content: space-between; }} \
+                 .toggler-{} input {{ display:none; }} \
+                 .toggler-{} span {{ background-color: #b1b1b1; position: relative; display: inline-flex; width:{}px; height: {}px; border-radius: {}px;}} \
+                 .toggler-{} span > span {{ background-color: #FFFFFF; width: {}px; height: {}px; border-radius: 50%; top: 1px; left: 1px;}} \
+                 .toggler-{}:hover span > span {{ background-color: #f1f1f1 !important; }} \
+                 .toggler-{} input:checked + span {{ background-color: #00FF00; }} \
+                 .toggler-{} input:checked + span > span {{ -webkit-transform: translateX({}px); -ms-transform:translateX({}px); transform: translateX({}px); }}
+                ",
+                // toggler
+                size,
+
+                // toggler input
+                size,
+
+                // toggler span
+                size,
+                size*2,
+                size,
+                size,
+
+                // toggler span > span
+                size,
+                size-2,
+                size-2,
+
+                // toggler: hover + span > span
+                size,
+
+                // toggler input:checked + span
+                size,
+
+                // toggler input:checked + span > span
+                size,
+                size,
+                size,
+                size
+            )
+            .into_bump_str(),
         }
     }
 }

web/src/widget.rs

@@ -24,6 +24,7 @@ pub mod radio;
 pub mod scrollable;
 pub mod slider;
 pub mod text_input;
+pub mod toggler;
 
 mod column;
 mod row;
@@ -40,6 +41,8 @@ pub use slider::Slider;
 pub use text::Text;
 #[doc(no_inline)]
 pub use text_input::TextInput;
+#[doc(no_inline)]
+pub use toggler::Toggler;
 
 pub use checkbox::Checkbox;
 pub use column::Column;

web/src/widget/toggler.rs

@@ -0,0 +1,168 @@
+//! Show toggle controls using togglers.
+use crate::{css, Bus, Css, Element, Length, Widget};
+
+pub use iced_style::toggler::{Style, StyleSheet};
+
+use dodrio::bumpalo;
+use std::rc::Rc;
+
+/// A toggler that can be toggled.
+/// 
+/// # Example
+/// 
+/// ```
+/// # use iced_web::Toggler;
+/// 
+/// pub enum Message {
+///     TogglerToggled(bool),
+/// }
+/// 
+/// let is_active = true;
+/// 
+/// Toggler::new(is_active, String::from("Toggle me!"), Message::TogglerToggled);
+/// ```
+/// 
+#[allow(missing_debug_implementations)]
+pub struct Toggler<Message> {
+    is_active: bool,
+    on_toggle: Rc<dyn Fn(bool) -> Message>,
+    label: Option<String>,
+    id: Option<String>,
+    width: Length,
+    style: Box<dyn StyleSheet>,
+}
+
+impl<Message> Toggler<Message> {
+    /// Creates a new [`Toggler`].
+    /// 
+    /// It expects:
+    ///   * a boolean describing whether the [`Toggler`] is active or not
+    ///   * An optional label for 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<Option<String>>, f: F) -> Self
+    where
+        F: 'static + Fn(bool) -> Message,
+    {
+        Toggler {
+            is_active,
+            on_toggle: Rc::new(f),
+            label: label.into(),
+            id: None,
+            width: Length::Shrink,
+            style: Default::default(),
+        }
+    }
+
+    /// Sets the width of the [`Toggler`].
+    /// 
+    /// [`Toggler`]: struct.Toggler.html
+    pub fn width(mut self, width: Length) -> Self {
+        self.width = width;
+        self
+    }
+
+    /// Sets the style of the [`Toggler`].
+    /// 
+    /// [`Toggler`]: struct.Toggler.html
+    pub fn style(mut self, style: impl Into<Box<dyn StyleSheet>>) -> Self {
+        self.style = style.into();
+        self
+    }
+
+    /// Sets the id of the [`Toggler`].
+    /// 
+    /// [`Toggler`]: struct.Toggler.html
+    pub fn id(mut self, id: impl Into<String>) -> Self {
+        self.id = Some(id.into());
+        self
+    }
+}
+
+impl<Message> Widget<Message> for Toggler<Message>
+where
+    Message: 'static,
+{
+    fn node<'b>(
+        &self,
+        bump: &'b bumpalo::Bump,
+        bus: &Bus<Message>,
+        style_sheet: &mut Css<'b>,
+    ) -> dodrio::Node<'b> {
+        use dodrio::builder::*;
+        use dodrio::bumpalo::collections::String;
+
+        let toggler_label = &self.label.as_ref().map(|label| {
+            String::from_str_in(&label, bump).into_bump_str()
+        });
+
+        let event_bus = bus.clone();
+        let on_toggle = self.on_toggle.clone();
+        let is_active = self.is_active;
+
+        let row_class = style_sheet.insert(bump, css::Rule::Row);
+        let toggler_class = style_sheet.insert(bump, css::Rule::Toggler(16));
+
+        let (label, input) = if let Some(id) = &self.id {
+            let id = String::from_str_in(id, bump).into_bump_str();
+
+            (label(bump).attr("for", id), input(bump).attr("id", id))
+        } else {
+            (label(bump), input(bump))
+        };
+
+        let checkbox = input
+            .attr("type", "checkbox")
+            .bool_attr("checked", self.is_active)
+            .on("click", move |_root, vdom, _event| {
+                let msg = on_toggle(!is_active);
+                event_bus.publish(msg);
+
+                vdom.schedule_render();
+            })
+            .finish();
+
+        let toggler = span(bump)
+            .children(vec![span(bump).finish()])
+            .finish();
+
+        label
+            .attr(
+                "class",
+                bumpalo::format!(in bump, "{} {}", row_class, toggler_class)
+                    .into_bump_str(),
+            )
+            .attr(
+                "style",
+                bumpalo::format!(in bump, "width: {}; align-items: center", css::length(self.width))
+                .into_bump_str()
+            )
+            .children(                
+                if let Some(label) = toggler_label {
+                    vec![
+                        text(label),
+                        checkbox,
+                        toggler,
+                    ]
+                } else {
+                    vec![
+                        checkbox,
+                        toggler,
+                    ]
+                }
+            )
+            .finish()
+    }
+}
+
+impl<'a, Message> From<Toggler<Message>> for Element<'a, Message>
+where
+    Message: 'static,
+{
+    fn from(toggler: Toggler<Message>) -> Element<'a, Message> {
+        Element::new(toggler)
+    }
+}