Segmented button

- Implemented the segmented button widget

src/widget/segmented_button.rs

@@ -0,0 +1,91 @@
+use derive_setters::Setters;
+use iced::{
+    alignment::{Horizontal, Vertical},
+    theme,
+    widget::{button, container, text, Row},
+    Background, Element, Length, Renderer, Theme,
+};
+use iced_lazy::Component;
+
+#[derive(Setters)]
+pub struct SegmentedButton<'a, Message> {
+    options: Vec<&'a str>,
+    #[setters(strip_option)]
+    on_button_pressed: Option<Box<dyn Fn(usize) -> Message>>,
+}
+
+pub fn segmented_button<'a, Message>() -> SegmentedButton<'a, Message> {
+    SegmentedButton {
+        options: vec![],
+        on_button_pressed: None,
+    }
+}
+
+#[derive(Clone)]
+pub enum SegmentedButtonEvent {
+    Pressed(usize),
+}
+
+impl<'a, Message> Component<Message, Renderer> for SegmentedButton<'a, Message> {
+    type State = usize;
+
+    type Event = SegmentedButtonEvent;
+
+    fn update(&mut self, state: &mut Self::State, event: Self::Event) -> Option<Message> {
+        match event {
+            SegmentedButtonEvent::Pressed(index) => {
+                *state = index;
+                self.on_button_pressed
+                    .as_ref()
+                    .map(|on_button_pressed| (on_button_pressed)(index))
+            }
+        }
+    }
+
+    fn view(&self, state: &Self::State) -> Element<Self::Event> {
+        let buttons: Vec<Element<'a, Self::Event>> = self
+            .options
+            .iter()
+            .enumerate()
+            .map(|(index, option)| {
+                button(
+                    container(text(*option))
+                        .width(Length::Fill)
+                        .height(Length::Fill)
+                        .align_x(Horizontal::Center)
+                        .align_y(Vertical::Center),
+                )
+                .width(Length::Units(136))
+                .height(Length::Units(32))
+                .style(if *state == index {
+                    theme::Button::Secondary.into()
+                } else {
+                    theme::Button::Primary.into()
+                })
+                .on_press(SegmentedButtonEvent::Pressed(index))
+                .into()
+            })
+            .collect();
+        container(Row::with_children(buttons).spacing(5).width(Length::Shrink))
+            .padding(2)
+            .style(theme::Container::Custom(view_switcher_container_style))
+            .into()
+    }
+}
+
+pub fn view_switcher_container_style(theme: &Theme) -> iced_style::container::Appearance {
+    let accent = &theme.cosmic().accent;
+    iced_style::container::Appearance {
+        text_color: Default::default(),
+        background: Some(Background::Color(accent.base.into())),
+        border_radius: 24.0,
+        border_width: 2.0,
+        border_color: accent.base.into(),
+    }
+}
+
+impl<'a, Message: 'a> From<SegmentedButton<'a, Message>> for Element<'a, Message> {
+    fn from(segmented_button: SegmentedButton<'a, Message>) -> Self {
+        iced_lazy::component(segmented_button)
+    }
+}