improv: use current design for nav bar toggle button

src/widget/nav_bar_toggle.rs

@@ -0,0 +1,54 @@
+// Copyright 2022 System76 <info@system76.com>
+// SPDX-License-Identifier: MPL-2.0
+
+use crate::{theme, Element};
+use apply::Apply;
+use derive_setters::Setters;
+use iced::Length;
+
+use super::IconSource;
+
+#[derive(Setters)]
+pub struct NavBarToggle<Message> {
+    nav_bar_active: bool,
+    #[setters(strip_option)]
+    on_nav_bar_toggled: Option<Message>,
+}
+
+#[must_use]
+pub fn nav_bar_toggle<Message>() -> NavBarToggle<Message> {
+    NavBarToggle {
+        nav_bar_active: false,
+        on_nav_bar_toggled: None,
+    }
+}
+
+impl<Message: 'static + Clone> From<NavBarToggle<Message>> for Element<'static, Message> {
+    fn from(nav_bar_toggle: NavBarToggle<Message>) -> Self {
+        let mut widget = super::icon(
+            if nav_bar_toggle.nav_bar_active {
+                IconSource::EmbeddedSvg(iced::widget::svg::Handle::from_memory(
+                    &include_bytes!("../../res/sidebar-active.svg")[..],
+                ))
+            } else {
+                IconSource::Name("open-menu-symbolic".into())
+            },
+            16,
+        )
+        .style(theme::Svg::SymbolicActive)
+        .apply(iced::widget::container)
+        .apply(iced::widget::button)
+        .padding([8, 16, 8, 16])
+        .style(theme::Button::Text);
+
+        if let Some(message) = nav_bar_toggle.on_nav_bar_toggled {
+            widget = widget.on_press(message);
+        }
+
+        widget
+            .apply(iced::widget::container)
+            .center_y()
+            .height(Length::Fill)
+            .into()
+    }
+}