Add settings_ui(group) attribute to macro

Co-authored-by: Ben Kunkle <ben@zed.dev>

crates/git_hosting_providers/src/settings.rs

@@ -5,7 +5,7 @@ use git::GitHostingProviderRegistry;
 use gpui::App;
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
-use settings::{SettingsUI, Settings, SettingsStore};
+use settings::{Settings, SettingsStore, SettingsUI};
 use url::Url;
 use util::ResultExt as _;
 

crates/gpui_macros/src/derive_action.rs

@@ -16,6 +16,13 @@ pub(crate) fn derive_action(input: TokenStream) -> TokenStream {
     let mut deprecated = None;
     let mut doc_str: Option<String> = None;
 
+    /*
+    *
+    * #[action()]
+    * Struct Foo {
+    *  bar: bool // is bar considered an attribute
+    }
+    */
     for attr in &input.attrs {
         if attr.path().is_ident("action") {
             attr.parse_nested_meta(|meta| {

crates/settings/src/settings_ui.rs

@@ -11,14 +11,20 @@ pub trait SettingsUI {
 }
 
 pub struct SettingsUIItem {
-    // TODO:
-    // path: SmallVec<[&'static str; 8]>,
+    // TODO: move this back here once there isn't a None variant
+    // pub path: &'static str,
     pub item: SettingsUIItemVariant,
 }
 
 pub enum SettingsUIItemVariant {
-    Group(SettingsUIItemGroup),
-    Item(SettingsUIItemSingle),
+    Group {
+        path: &'static str,
+        group: SettingsUIItemGroup,
+    },
+    Item {
+        path: &'static str,
+        item: SettingsUIItemSingle,
+    },
     // TODO: remove
     None,
 }

crates/settings_ui_macros/src/settings_ui_macros.rs

@@ -1,6 +1,6 @@
 use proc_macro::TokenStream;
 use quote::quote;
-use syn::{DeriveInput, parse_macro_input};
+use syn::{DeriveInput, LitStr, Token, parse_macro_input};
 
 /// Derive macro for the `SettingsUI` marker trait.
 ///
@@ -15,12 +15,13 @@ use syn::{DeriveInput, parse_macro_input};
 /// use settings_ui_macros::SettingsUI;
 ///
 /// #[derive(SettingsUI)]
+/// #[settings_ui(group = "Standard")]
 /// struct MySettings {
 ///     enabled: bool,
 ///     count: usize,
 /// }
 /// ```
-#[proc_macro_derive(SettingsUI)]
+#[proc_macro_derive(SettingsUI, attributes(settings_ui))]
 pub fn derive_settings_ui(input: TokenStream) -> TokenStream {
     let input = parse_macro_input!(input as DeriveInput);
     let name = &input.ident;
@@ -28,8 +29,41 @@ pub fn derive_settings_ui(input: TokenStream) -> TokenStream {
     // Handle generic parameters if present
     let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
 
+    let mut group_name = Option::<String>::None;
+
+    for attr in &input.attrs {
+        if attr.path().is_ident("settings_ui") {
+            attr.parse_nested_meta(|meta| {
+                if meta.path.is_ident("group") {
+                    if group_name.is_some() {
+                        return Err(meta.error("Only one 'group' path can be specified"));
+                    }
+                    meta.input.parse::<Token![=]>()?;
+                    let lit: LitStr = meta.input.parse()?;
+                    group_name = Some(lit.value());
+                }
+                Ok(())
+            })
+            .unwrap_or_else(|e| panic!("in #[settings_ui] attribute: {}", e));
+        }
+    }
+
+    let ui_item_fn_body = if let Some(group_name) = group_name {
+        quote! {
+            settings::SettingsUIItem { item: settings::SettingsUIItemVariant::Group{ path: #group_name, group: settings::SettingsUIItemGroup{ items: Default::default() } } }
+        }
+    } else {
+        quote! {
+            settings::SettingsUIItem { item: settings::SettingsUIItemVariant::None }
+        }
+    };
+
     let expanded = quote! {
-        impl #impl_generics settings::SettingsUI for #name #ty_generics #where_clause {}
+        impl #impl_generics settings::SettingsUI for #name #ty_generics #where_clause {
+            fn ui_item() -> settings::SettingsUIItem {
+                #ui_item_fn_body
+            }
+        }
     };
 
     TokenStream::from(expanded)