2 files changed, 117 insertions, 0 deletions
diff --git a/style/src/lib.rs b/style/src/lib.rs
index 8e402bb1..3d23d990 100644
--- a/style/src/lib.rs
+++ b/style/src/lib.rs
@@ -11,6 +11,7 @@ pub mod menu;
 pub mod pick_list;
 pub mod progress_bar;
 pub mod radio;
+pub mod rule;
 pub mod scrollable;
 pub mod slider;
 pub mod text_input;
diff --git a/style/src/rule.rs b/style/src/rule.rs
new file mode 100644
index 00000000..6ba54e33
--- /dev/null
+++ b/style/src/rule.rs
@@ -0,0 +1,116 @@
+//! Display a horizontal or vertical rule for dividing content.
+
+use iced_core::Color;
+
+/// The fill mode of a rule.
+#[derive(Debug, Clone, Copy)]
+pub enum FillMode {
+    /// Fill the whole length of the container.
+    Full,
+    /// Fill a percent of the length of the container. The rule
+    /// will be centered in that container.
+    ///
+    /// The range is `[0.0, 100.0]`.
+    Percent(f32),
+    /// Uniform offset from each end, length units.
+    Padded(u16),
+    /// Different offset on each end of the rule, length units.
+    /// First = top or left.
+    AsymmetricPadding(u16, u16),
+}
+
+impl FillMode {
+    /// Return the starting offset and length of the rule.
+    ///
+    /// * `space` - The space to fill.
+    ///
+    /// # Returns
+    ///
+    /// * (starting_offset, length)
+    pub fn fill(&self, space: f32) -> (f32, f32) {
+        match *self {
+            FillMode::Full => (0.0, space),
+            FillMode::Percent(percent) => {
+                if percent >= 100.0 {
+                    (0.0, space)
+                } else {
+                    let percent_width = (space * percent / 100.0).round();
+
+                    (((space - percent_width) / 2.0).round(), percent_width)
+                }
+            }
+            FillMode::Padded(padding) => {
+                if padding == 0 {
+                    (0.0, space)
+                } else {
+                    let padding = padding as f32;
+                    let mut line_width = space - (padding * 2.0);
+                    if line_width < 0.0 {
+                        line_width = 0.0;
+                    }
+
+                    (padding, line_width)
+                }
+            }
+            FillMode::AsymmetricPadding(first_pad, second_pad) => {
+                let first_pad = first_pad as f32;
+                let second_pad = second_pad as f32;
+                let mut line_width = space - first_pad - second_pad;
+                if line_width < 0.0 {
+                    line_width = 0.0;
+                }
+
+                (first_pad, line_width)
+            }
+        }
+    }
+}
+
+/// The appearance of a rule.
+#[derive(Debug, Clone, Copy)]
+pub struct Style {
+    /// The color of the rule.
+    pub color: Color,
+    /// The width (thickness) of the rule line.
+    pub width: u16,
+    /// The radius of the line corners.
+    pub radius: u16,
+    /// The [`FillMode`] of the rule.
+    ///
+    /// [`FillMode`]: enum.FillMode.html
+    pub fill_mode: FillMode,
+}
+
+/// A set of rules that dictate the style of a rule.
+pub trait StyleSheet {
+    /// Produces the style of a rule.
+    fn style(&self) -> Style;
+}
+
+struct Default;
+
+impl StyleSheet for Default {
+    fn style(&self) -> Style {
+        Style {
+            color: [0.6, 0.6, 0.6, 0.51].into(),
+            width: 1,
+            radius: 0,
+            fill_mode: FillMode::Percent(90.0),
+        }
+    }
+}
+
+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)
+    }
+}