Add Toggler widget to iced_web

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)
+    }
+}