feat: focusable segmented items in segmented button

src/widget/segmented_button/item.rs

@@ -0,0 +1,57 @@
+// Copyright 2022 System76 <info@system76.com>
+// SPDX-License-Identifier: MPL-2.0
+
+//! Defines the model that's used by each button in the widget.
+
+use crate::widget::IconSource;
+use derive_setters::Setters;
+use std::borrow::Cow;
+
+/// Describes a button in a segmented button
+#[must_use]
+pub fn item() -> SegmentedItem {
+    SegmentedItem::default()
+}
+
+/// Information about a specific button in a segmented button
+#[derive(Setters)]
+pub struct SegmentedItem {
+    #[setters(into, strip_option)]
+    /// The label to display in this button.
+    pub text: Option<Cow<'static, str>>,
+
+    #[setters(into, strip_option)]
+    /// An optionally-displayed icon beside the label.
+    pub icon: Option<IconSource<'static>>,
+
+    /// Whether the button is clickable or not.
+    pub enabled: bool,
+}
+
+impl Default for SegmentedItem {
+    fn default() -> Self {
+        Self {
+            text: None,
+            icon: None,
+            enabled: true,
+        }
+    }
+}
+
+impl From<String> for SegmentedItem {
+    fn from(text: String) -> Self {
+        Self::from(Cow::Owned(text))
+    }
+}
+
+impl From<&'static str> for SegmentedItem {
+    fn from(text: &'static str) -> Self {
+        Self::from(Cow::Borrowed(text))
+    }
+}
+
+impl From<Cow<'static, str>> for SegmentedItem {
+    fn from(text: Cow<'static, str>) -> Self {
+        SegmentedItem::default().text(text)
+    }
+}