feat: redesign the sidebar and workspace (#53)

Reviewed-on: reya/coop#53

crates/workspace/src/sidebar/utils.rs

@@ -0,0 +1,58 @@
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use gpui::prelude::FluentBuilder as _;
+use gpui::{AnyElement, App, ImageSource, IntoElement, ParentElement, SharedString, Styled, px};
+use settings::AppSettings;
+use theme::ActiveTheme;
+use ui::avatar::{Avatar, PixelAvatar};
+use ui::{Icon, IconName, Sizable, h_flex};
+
+pub(crate) fn nav_avatar(
+    seed: Option<impl Into<SharedString>>,
+    picture: Option<impl Into<ImageSource>>,
+    cx: &App,
+) -> Option<AnyElement> {
+    if AppSettings::get_hide_avatar(cx) {
+        return None;
+    }
+
+    match (seed.map(Into::into), picture.map(Into::into)) {
+        (None, None) => None,
+        (seed, Some(picture)) => Some(
+            Avatar::from_source(picture)
+                .when_some(seed, |avatar, seed| avatar.seed(seed))
+                .small()
+                .flex_shrink_0()
+                .into_any_element(),
+        ),
+        (Some(seed), None) => Some(
+            PixelAvatar::new(seed)
+                .small()
+                .flex_shrink_0()
+                .into_any_element(),
+        ),
+    }
+}
+
+pub(crate) fn nav_icon(icon: IconName, cx: &App) -> AnyElement {
+    h_flex()
+        .flex_shrink_0()
+        .w(px(20.))
+        .justify_center()
+        .text_color(cx.theme().icon_muted)
+        .child(Icon::new(icon).small())
+        .into_any_element()
+}
+
+/// Brand backgrounds shown behind the signed-out screen; one is picked at random.
+const SIGNED_OUT_BANNERS: [&str; 2] = ["brand/bg1.jpg", "brand/bg2.jpg"];
+
+/// Pick one of the signed-out backgrounds at random.
+pub(crate) fn pick_banner() -> SharedString {
+    let nanos = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map(|elapsed| elapsed.subsec_nanos())
+        .unwrap_or_default();
+    let index = nanos as usize % SIGNED_OUT_BANNERS.len();
+    SIGNED_OUT_BANNERS[index].into()
+}