Implement `ProgressBar` widget in `iced_web`

2 files changed, 127 insertions, 0 deletions

diff --git a/web/src/widget.rs b/web/src/widget.rs
index e5481243..025cf22f 100644
--- a/web/src/widget.rs
+++ b/web/src/widget.rs
@@ -21,6 +21,7 @@ pub mod button;
 pub mod checkbox;
 pub mod container;
 pub mod image;
+pub mod progress_bar;
 pub mod radio;
 pub mod scrollable;
 pub mod slider;
@@ -46,6 +47,7 @@ pub use checkbox::Checkbox;
 pub use column::Column;
 pub use container::Container;
 pub use image::Image;
+pub use progress_bar::ProgressBar;
 pub use radio::Radio;
 pub use row::Row;
 pub use space::Space;
diff --git a/web/src/widget/progress_bar.rs b/web/src/widget/progress_bar.rs
new file mode 100644
index 00000000..b1fcb4d8
--- /dev/null
+++ b/web/src/widget/progress_bar.rs
@@ -0,0 +1,125 @@
+//! Provide progress feedback to your users.
+use crate::{bumpalo, css, Bus, Css, Element, Length, Widget};
+
+pub use iced_style::progress_bar::{Style, StyleSheet};
+
+use std::ops::RangeInclusive;
+
+/// A bar that displays progress.
+///
+/// # Example
+/// ```
+/// # use iced_native::renderer::Null;
+/// #
+/// # pub type ProgressBar = iced_native::ProgressBar<Null>;
+/// let value = 50.0;
+///
+/// ProgressBar::new(0.0..=100.0, value);
+/// ```
+///
+/// ![Progress bar drawn with `iced_wgpu`](https://user-images.githubusercontent.com/18618951/71662391-a316c200-2d51-11ea-9cef-52758cab85e3.png)
+#[allow(missing_debug_implementations)]
+pub struct ProgressBar {
+    range: RangeInclusive<f32>,
+    value: f32,
+    width: Length,
+    height: Option<Length>,
+    style: Box<dyn StyleSheet>,
+}
+
+impl ProgressBar {
+    /// Creates a new [`ProgressBar`].
+    ///
+    /// It expects:
+    ///   * an inclusive range of possible values
+    ///   * the current value of the [`ProgressBar`]
+    ///
+    /// [`ProgressBar`]: struct.ProgressBar.html
+    pub fn new(range: RangeInclusive<f32>, value: f32) -> Self {
+        ProgressBar {
+            value: value.max(*range.start()).min(*range.end()),
+            range,
+            width: Length::Fill,
+            height: None,
+            style: Default::default(),
+        }
+    }
+
+    /// Sets the width of the [`ProgressBar`].
+    ///
+    /// [`ProgressBar`]: struct.ProgressBar.html
+    pub fn width(mut self, width: Length) -> Self {
+        self.width = width;
+        self
+    }
+
+    /// Sets the height of the [`ProgressBar`].
+    ///
+    /// [`ProgressBar`]: struct.ProgressBar.html
+    pub fn height(mut self, height: Length) -> Self {
+        self.height = Some(height);
+        self
+    }
+
+    /// Sets the style of the [`ProgressBar`].
+    ///
+    /// [`ProgressBar`]: struct.ProgressBar.html
+    pub fn style(mut self, style: impl Into<Box<dyn StyleSheet>>) -> Self {
+        self.style = style.into();
+        self
+    }
+}
+
+impl<Message> Widget<Message> for ProgressBar {
+    fn node<'b>(
+        &self,
+        bump: &'b bumpalo::Bump,
+        _bus: &Bus<Message>,
+        _style_sheet: &mut Css<'b>,
+    ) -> dodrio::Node<'b> {
+        use dodrio::builder::*;
+
+        let (range_start, range_end) = self.range.clone().into_inner();
+        let amount_filled =
+            (self.value - range_start) / (range_end - range_start).max(1.0);
+
+        let style = self.style.style();
+
+        let bar = div(bump)
+            .attr(
+                "style",
+                bumpalo::format!(
+                    in bump,
+                    "width: {}%; height: 100%; background: {}",
+                    amount_filled * 100.0,
+                    css::background(style.bar)
+                )
+                .into_bump_str(),
+            )
+            .finish();
+
+        let node = div(bump).attr(
+            "style",
+            bumpalo::format!(
+                in bump,
+                "width: {}; height: {}; background: {}; border-radius: {}px; overflow: hidden;",
+                css::length(self.width),
+                css::length(self.height.unwrap_or(Length::Units(30))),
+                css::background(style.background),
+                style.border_radius
+            )
+            .into_bump_str(),
+        ).children(vec![bar]);
+
+        node.finish()
+    }
+}
+
+impl<'a, Message> From<ProgressBar> for Element<'a, Message>
+where
+    Message: 'static,
+{
+    fn from(container: ProgressBar) -> Element<'a, Message> {
+        Element::new(container)
+    }
+}