wire up app shell with dock, sidebar, and dialogs

crates/signed_app/src/views/placeholder.rs

@@ -0,0 +1,30 @@
+use gpui::{
+    App, Context, IntoElement, ParentElement as _, Render, SharedString, Styled as _, Window, div,
+};
+use gpui_native_kit::empty_state::EmptyState;
+use gpui_native_kit::layout::dock::Panel;
+
+/// A tab that stands in for a screen that is not ported yet.
+pub struct PlaceholderView {
+    title: SharedString,
+}
+
+impl PlaceholderView {
+    pub fn new(title: impl Into<SharedString>) -> Self {
+        Self {
+            title: title.into(),
+        }
+    }
+}
+
+impl Panel for PlaceholderView {
+    fn title(&self, _cx: &App) -> Option<SharedString> {
+        Some(self.title.clone())
+    }
+}
+
+impl Render for PlaceholderView {
+    fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
+        div().size_full().child(EmptyState::new(self.title.clone()))
+    }
+}