Show annotations more like the inline assistant (#11530)

* compute gutter width
* show the AI icon
* borders, background, and text color for annotations

<img width="1840" alt="image"
src="https://github.com/zed-industries/zed/assets/836375/93f2e9b8-d7f7-4c25-b3e2-cf77a0c4ca36">

Release Notes:

- N/A

crates/assistant2/src/tools/annotate_code.rs

@@ -14,51 +14,51 @@ use ui::prelude::*;
 use util::ResultExt;
 use workspace::Workspace;
 
-pub struct OpenBufferTool {
+pub struct AnnotationTool {
     workspace: WeakView<Workspace>,
     project: Model<Project>,
 }
 
-impl OpenBufferTool {
+impl AnnotationTool {
     pub fn new(workspace: WeakView<Workspace>, project: Model<Project>) -> Self {
         Self { workspace, project }
     }
 }
 
 #[derive(Debug, Deserialize, JsonSchema, Clone)]
-pub struct ExplainInput {
-    /// Name for this set of excerpts
+pub struct AnnotationInput {
+    /// Name for this set of annotations
     title: String,
-    excerpts: Vec<ExplainedExcerpt>,
+    annotations: Vec<Annotation>,
 }
 
 #[derive(Debug, Deserialize, JsonSchema, Clone)]
-struct ExplainedExcerpt {
+struct Annotation {
     /// Path to the file
     path: String,
-    /// Name of a symbol in the buffer to show
+    /// Name of a symbol in the code
     symbol_name: String,
     /// Text to display near the symbol definition
-    comment: String,
+    text: String,
 }
 
-impl LanguageModelTool for OpenBufferTool {
-    type Input = ExplainInput;
+impl LanguageModelTool for AnnotationTool {
+    type Input = AnnotationInput;
     type Output = String;
-    type View = OpenBufferView;
+    type View = AnnotationResultView;
 
     fn name(&self) -> String {
-        "explain_code".to_string()
+        "annotate_code".to_string()
     }
 
     fn description(&self) -> String {
-        "Show and explain one or more code snippets from files in the current project. Code snippets are identified using a file path and the name of a symbol defined in that file.".to_string()
+        "Dynamically annotate symbols in the current codebase. Opens a buffer in a panel in their editor, to the side of the conversation. The annotations are shown in the editor as a block decoration.".to_string()
     }
 
     fn execute(&self, input: &Self::Input, cx: &mut WindowContext) -> Task<Result<Self::Output>> {
         let workspace = self.workspace.clone();
         let project = self.project.clone();
-        let excerpts = input.excerpts.clone();
+        let excerpts = input.annotations.clone();
         let title = input.title.clone();
 
         let worktree_id = project.update(cx, |project, cx| {
@@ -115,11 +115,11 @@ impl LanguageModelTool for OpenBufferTool {
                                     cx,
                                 )
                             });
-                            let explanation = SharedString::from(excerpt.comment.clone());
+                            let explanation = SharedString::from(excerpt.text.clone());
                             editor.insert_blocks(
                                 [BlockProperties {
                                     position: ranges[0].start,
-                                    height: 1,
+                                    height: 2,
                                     style: BlockStyle::Fixed,
                                     render: Box::new(move |cx| {
                                         Self::render_note_block(&explanation, cx)
@@ -149,21 +149,41 @@ impl LanguageModelTool for OpenBufferTool {
         output: Result<Self::Output>,
         cx: &mut WindowContext,
     ) -> View<Self::View> {
-        cx.new_view(|_cx| OpenBufferView { output })
+        cx.new_view(|_cx| AnnotationResultView { output })
     }
 }
 
-impl OpenBufferTool {
-    fn render_note_block(explanation: &SharedString, _cx: &mut BlockContext) -> AnyElement {
-        div().child(explanation.clone()).into_any_element()
+impl AnnotationTool {
+    fn render_note_block(explanation: &SharedString, cx: &mut BlockContext) -> AnyElement {
+        let anchor_x = cx.anchor_x;
+        let gutter_width = cx.gutter_dimensions.width;
+
+        h_flex()
+            .w_full()
+            .py_2()
+            .border_y_1()
+            .border_color(cx.theme().colors().border)
+            .child(
+                h_flex()
+                    .justify_center()
+                    .w(gutter_width)
+                    .child(Icon::new(IconName::Ai).color(Color::Hint)),
+            )
+            .child(
+                h_flex()
+                    .w_full()
+                    .ml(anchor_x - gutter_width)
+                    .child(explanation.clone()),
+            )
+            .into_any_element()
     }
 }
 
-pub struct OpenBufferView {
+pub struct AnnotationResultView {
     output: Result<String>,
 }
 
-impl Render for OpenBufferView {
+impl Render for AnnotationResultView {
     fn render(&mut self, _cx: &mut ViewContext<Self>) -> impl IntoElement {
         match &self.output {
             Ok(output) => div().child(output.clone().into_any_element()),
@@ -172,7 +192,7 @@ impl Render for OpenBufferView {
     }
 }
 
-impl ToolOutput for OpenBufferView {
+impl ToolOutput for AnnotationResultView {
     fn generate(&self, _: &mut ProjectContext, _: &mut WindowContext) -> String {
         match &self.output {
             Ok(output) => output.clone(),