Make tour work with iced_web again 🎉

- Implements `TextInput`, `Scrollable`, and `Container`
- Adds basic style generation

web/src/widget/text_input.rs

@@ -0,0 +1,197 @@
+//! Display fields that can be filled with text.
+//!
+//! A [`TextInput`] has some local [`State`].
+//!
+//! [`TextInput`]: struct.TextInput.html
+//! [`State`]: struct.State.html
+use crate::{bumpalo, style, Bus, Element, Length, Style, Widget};
+use std::rc::Rc;
+
+/// A field that can be filled with text.
+///
+/// # Example
+/// ```
+/// # use iced_web::{text_input, TextInput};
+/// #
+/// enum Message {
+///     TextInputChanged(String),
+/// }
+///
+/// let mut state = text_input::State::new();
+/// let value = "Some text";
+///
+/// let input = TextInput::new(
+///     &mut state,
+///     "This is the placeholder...",
+///     value,
+///     Message::TextInputChanged,
+/// );
+/// ```
+#[allow(missing_debug_implementations)]
+pub struct TextInput<'a, Message> {
+    _state: &'a mut State,
+    placeholder: String,
+    value: String,
+    width: Length,
+    max_width: Length,
+    padding: u16,
+    size: Option<u16>,
+    on_change: Rc<Box<dyn Fn(String) -> Message>>,
+    on_submit: Option<Message>,
+}
+
+impl<'a, Message> TextInput<'a, Message> {
+    /// Creates a new [`TextInput`].
+    ///
+    /// It expects:
+    /// - some [`State`]
+    /// - a placeholder
+    /// - the current value
+    /// - a function that produces a message when the [`TextInput`] changes
+    ///
+    /// [`TextInput`]: struct.TextInput.html
+    /// [`State`]: struct.State.html
+    pub fn new<F>(
+        state: &'a mut State,
+        placeholder: &str,
+        value: &str,
+        on_change: F,
+    ) -> Self
+    where
+        F: 'static + Fn(String) -> Message,
+    {
+        Self {
+            _state: state,
+            placeholder: String::from(placeholder),
+            value: String::from(value),
+            width: Length::Fill,
+            max_width: Length::Shrink,
+            padding: 0,
+            size: None,
+            on_change: Rc::new(Box::new(on_change)),
+            on_submit: None,
+        }
+    }
+
+    /// Sets the width of the [`TextInput`].
+    ///
+    /// [`TextInput`]: struct.TextInput.html
+    pub fn width(mut self, width: Length) -> Self {
+        self.width = width;
+        self
+    }
+
+    /// Sets the maximum width of the [`TextInput`].
+    ///
+    /// [`TextInput`]: struct.TextInput.html
+    pub fn max_width(mut self, max_width: Length) -> Self {
+        self.max_width = max_width;
+        self
+    }
+
+    /// Sets the padding of the [`TextInput`].
+    ///
+    /// [`TextInput`]: struct.TextInput.html
+    pub fn padding(mut self, units: u16) -> Self {
+        self.padding = units;
+        self
+    }
+
+    /// Sets the text size of the [`TextInput`].
+    ///
+    /// [`TextInput`]: struct.TextInput.html
+    pub fn size(mut self, size: u16) -> Self {
+        self.size = Some(size);
+        self
+    }
+
+    /// Sets the message that should be produced when the [`TextInput`] is
+    /// focused and the enter key is pressed.
+    ///
+    /// [`TextInput`]: struct.TextInput.html
+    pub fn on_submit(mut self, message: Message) -> Self {
+        self.on_submit = Some(message);
+        self
+    }
+}
+
+impl<'a, Message> Widget<Message> for TextInput<'a, Message>
+where
+    Message: 'static + Clone,
+{
+    fn node<'b>(
+        &self,
+        bump: &'b bumpalo::Bump,
+        bus: &Bus<Message>,
+        style_sheet: &mut style::Sheet<'b>,
+    ) -> dodrio::Node<'b> {
+        use dodrio::builder::*;
+        use wasm_bindgen::JsCast;
+
+        let padding_class =
+            style_sheet.insert(bump, Style::Padding(self.padding));
+
+        let on_change = self.on_change.clone();
+        let event_bus = bus.clone();
+
+        input(bump)
+            .attr(
+                "class",
+                bumpalo::format!(in bump, "{}", padding_class).into_bump_str(),
+            )
+            .attr(
+                "style",
+                bumpalo::format!(
+                    in bump,
+                    "font-size: {}px",
+                    self.size.unwrap_or(20)
+                )
+                .into_bump_str(),
+            )
+            .attr(
+                "placeholder",
+                bumpalo::format!(in bump, "{}", self.placeholder)
+                    .into_bump_str(),
+            )
+            .attr(
+                "value",
+                bumpalo::format!(in bump, "{}", self.value).into_bump_str(),
+            )
+            .on("input", move |root, vdom, event| {
+                let text_input = match event.target().and_then(|t| {
+                    t.dyn_into::<web_sys::HtmlInputElement>().ok()
+                }) {
+                    None => return,
+                    Some(text_input) => text_input,
+                };
+
+                event_bus.publish(on_change(text_input.value()), root);
+                vdom.schedule_render();
+            })
+            .finish()
+    }
+}
+
+impl<'a, Message> From<TextInput<'a, Message>> for Element<'a, Message>
+where
+    Message: 'static + Clone,
+{
+    fn from(text_input: TextInput<'a, Message>) -> Element<'a, Message> {
+        Element::new(text_input)
+    }
+}
+
+/// The state of a [`TextInput`].
+///
+/// [`TextInput`]: struct.TextInput.html
+#[derive(Debug, Clone, Copy, Default)]
+pub struct State;
+
+impl State {
+    /// Creates a new [`State`], representing an unfocused [`TextInput`].
+    ///
+    /// [`State`]: struct.State.html
+    pub fn new() -> Self {
+        Self::default()
+    }
+}