add empty state

crates/core/src/empty_state.rs

@@ -0,0 +1,109 @@
+use gpui::prelude::FluentBuilder as _;
+use gpui::{
+    App, IntoElement, ParentElement as _, RenderOnce, SharedString, StyleRefinement, Styled as _,
+    Window, div, relative,
+};
+use gpui_native_icons::{IconRole, icon};
+use gpui_native_theme::{ActiveTheme as _, Size};
+
+use crate::common::{StyledExt, v_flex};
+
+/// The centered "nothing here yet" panel for lists, tables, and searches.
+#[derive(IntoElement)]
+pub struct EmptyState {
+    icon: Option<IconRole>,
+    headline: SharedString,
+    hint: Option<SharedString>,
+    action: Option<gpui::AnyElement>,
+    style: StyleRefinement,
+}
+
+impl EmptyState {
+    /// Creates an empty state whose headline is the primary statement.
+    pub fn new<L>(headline: L) -> Self
+    where
+        L: Into<SharedString>,
+    {
+        Self {
+            icon: None,
+            headline: headline.into(),
+            hint: None,
+            action: None,
+            style: StyleRefinement::default(),
+        }
+    }
+
+    /// Sets a large muted icon above the headline.
+    pub fn icon(mut self, role: IconRole) -> Self {
+        self.icon = Some(role);
+        self
+    }
+
+    /// Sets a secondary line under the headline.
+    pub fn hint<L>(mut self, hint: L) -> Self
+    where
+        L: Into<SharedString>,
+    {
+        self.hint = Some(hint.into());
+        self
+    }
+
+    /// Sets an action element — usually a button — under the hint.
+    pub fn action<E>(mut self, action: E) -> Self
+    where
+        E: IntoElement,
+    {
+        self.action = Some(action.into_any_element());
+        self
+    }
+}
+
+impl gpui::Styled for EmptyState {
+    fn style(&mut self) -> &mut StyleRefinement {
+        &mut self.style
+    }
+}
+
+impl RenderOnce for EmptyState {
+    fn render(self, _window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let theme = cx.theme();
+        let metrics = theme.sizes.resolve(Size::Medium);
+        let muted_foreground = theme.colors.muted_foreground;
+        let foreground = theme.colors.foreground;
+        let illustration = metrics.icon_size * 2.0;
+
+        v_flex()
+            .w_full()
+            .items_center()
+            .justify_center()
+            .text_center()
+            .p_4()
+            .when_some(self.icon, |state, role| {
+                state.child(
+                    div()
+                        .mb_2()
+                        .child(icon(role).size(illustration).color(muted_foreground)),
+                )
+            })
+            .child(
+                div()
+                    .text_size(metrics.text_size)
+                    .font_weight(gpui::FontWeight::MEDIUM)
+                    .text_color(foreground)
+                    .line_height(relative(1.3))
+                    .child(self.headline),
+            )
+            .when_some(self.hint, |state, hint| {
+                state.child(
+                    div()
+                        .text_size(metrics.caption_size)
+                        .text_color(muted_foreground)
+                        .child(hint),
+                )
+            })
+            .when_some(self.action, |state, action| {
+                state.child(div().mt_3().child(action))
+            })
+            .refine_style(&self.style)
+    }
+}

crates/core/src/lib.rs

@@ -48,6 +48,9 @@ pub mod input;
 #[cfg(feature = "dialog")]
 pub mod dialog;
 
+#[cfg(feature = "empty_state")]
+pub mod empty_state;
+
 #[cfg(feature = "menu")]
 pub mod menu;