Fix shared element state across component instances

crates/editor/src/code_view.rs

@@ -13,7 +13,7 @@ use gpui::{
 use gpui_native_core::scrollbar::{Scrollbar, ScrollbarHandle, ScrollbarVisibility};
 use gpui_native_theme::{ActiveTheme as _, ColorTokens, Ramps};
 
-use crate::highlight::{HighlightedCode, Language, Role, highlight_with_tree};
+use crate::highlight::{HighlightedCode, Language, Role, highlight};
 use crate::utils::{gutter_cell, run_style};
 
 actions!(code_view, [Copy]);
@@ -53,8 +53,6 @@ pub struct CodeViewState {
     source: SharedString,
     language: Language,
     code: HighlightedCode,
-    /// The parse tree of `source`, so updates reparse incrementally instead of from scratch.
-    tree: Option<tree_sitter::Tree>,
     handle: UniformListScrollHandle,
     /// The hovered line, driving the active-line wash and number emphasis.
     active_line: Option<usize>,
@@ -74,14 +72,13 @@ impl CodeViewState {
         S: Into<SharedString>,
     {
         let source = source.into();
-        let (code, tree) = highlight_with_tree(&source, language, None);
+        let code = highlight(&source, language);
 
         Self {
             id: id.into(),
             source,
             language,
             code,
-            tree,
             handle: UniformListScrollHandle::new(),
             active_line: None,
             selection: None,
@@ -98,18 +95,9 @@ impl CodeViewState {
     {
         let source = source.into();
 
-        // The old tree is only reusable when the grammar stays the same.
-        let old_tree = if language == self.language {
-            self.tree.as_ref()
-        } else {
-            None
-        };
-
-        let (code, tree) = highlight_with_tree(&source, language, old_tree);
+        self.code = highlight(&source, language);
         self.source = source;
         self.language = language;
-        self.code = code;
-        self.tree = tree;
         self.selection = None;
         self.handle.scroll_to_item(0, ScrollStrategy::Top);
 
@@ -134,9 +122,7 @@ impl CodeViewState {
         lines.splice(line_ix..line_ix + 1, replacement);
         self.source = (lines.join("\n") + if trailing_newline { "\n" } else { "" }).into();
 
-        let (code, tree) = highlight_with_tree(&self.source, self.language, self.tree.as_ref());
-        self.code = code;
-        self.tree = tree;
+        self.code = highlight(&self.source, self.language);
         self.selection = None;
         cx.notify();
     }
@@ -348,7 +334,7 @@ impl Render for CodeViewState {
                         code.position_at(
                             *bounds,
                             event.position,
-                            Pixels::ZERO,
+                            ScrollbarHandle::offset(&code.handle).y,
                             line_height,
                             char_width,
                             text_x,
@@ -453,7 +439,8 @@ impl Render for CodeViewState {
             )
             .child(rows)
             .child(
-                Scrollbar::vertical(self.handle.clone()).visibility(ScrollbarVisibility::Platform),
+                Scrollbar::vertical((self.id.clone(), "v-scrollbar"), self.handle.clone())
+                    .visibility(ScrollbarVisibility::Platform),
             )
             .when_some(self.a11y_label.clone(), |view, label| {
                 view.aria_label(label)

crates/editor/src/diff_view.rs

@@ -363,13 +363,11 @@ impl Render for DiffViewState {
             })
             .child(rows)
             .child(
-                Scrollbar::vertical(self.handle.clone())
-                    .key("v-scrollbar")
+                Scrollbar::vertical((self.id.clone(), "v-scrollbar"), self.handle.clone())
                     .visibility(ScrollbarVisibility::Platform),
             )
             .child(
-                Scrollbar::horizontal(self.handle.clone())
-                    .key("h-scrollbar")
+                Scrollbar::horizontal((self.id.clone(), "h-scrollbar"), self.handle.clone())
                     .visibility(ScrollbarVisibility::Platform),
             )
     }

crates/editor/src/highlight.rs

@@ -67,17 +67,8 @@ pub struct HighlightedCode {
 
 /// Highlights `source` with `language`'s tree-sitter grammar.
 pub fn highlight(source: &str, language: Language) -> HighlightedCode {
-    highlight_with_tree(source, language, None).0
-}
-
-/// Highlights `source`, reusing `old_tree` so only the changed region is re-lexed.
-pub fn highlight_with_tree(
-    source: &str,
-    language: Language,
-    old_tree: Option<&tree_sitter::Tree>,
-) -> (HighlightedCode, Option<tree_sitter::Tree>) {
     let Some((grammar, query_source)) = grammar_for(language) else {
-        return (plain(source), None);
+        return plain(source);
     };
 
     HIGHLIGHTERS.with(|cache| {
@@ -104,11 +95,11 @@ pub fn highlight_with_tree(
             .as_mut();
 
         let Some(highlighter) = highlighter else {
-            return (plain(source), None);
+            return plain(source);
         };
 
-        let Some(tree) = highlighter.parser.parse(source, old_tree) else {
-            return (plain(source), None);
+        let Some(tree) = highlighter.parser.parse(source, None) else {
+            return plain(source);
         };
 
         // One role per byte; matches arrive in query order
@@ -134,7 +125,7 @@ pub fn highlight_with_tree(
             }
         }
 
-        (build_lines(source, &role_at), Some(tree))
+        build_lines(source, &role_at)
     })
 }
 

crates/editor/src/markdown.rs

@@ -18,7 +18,7 @@ use pulldown_cmark::{CodeBlockKind, Event, HeadingLevel, Options, Parser, Tag, T
 
 use std::ops::Range;
 
-use crate::highlight::{HighlightedCode, highlight_with_tree, plain};
+use crate::highlight::{HighlightedCode, highlight, plain};
 use crate::utils::{code_line, grammar_language};
 
 /// Heading scale steps relative to the root font size, H1 first.
@@ -277,7 +277,8 @@ impl Render for MarkdownViewState {
             .size_full()
             .child(blocks)
             .child(
-                Scrollbar::vertical(self.handle.clone()).visibility(ScrollbarVisibility::Platform),
+                Scrollbar::vertical((self.id.clone(), "v-scrollbar"), self.handle.clone())
+                    .visibility(ScrollbarVisibility::Platform),
             )
             .when_some(self.a11y_label.clone(), |view, label| {
                 view.aria_label(label)
@@ -588,7 +589,7 @@ fn parse(source: &str, highlight_code: bool) -> Vec<MarkdownBlock> {
                         .then(|| language.as_deref().and_then(grammar_language))
                         .flatten()
                     {
-                        Some(grammar) => highlight_with_tree(text, grammar, None).0,
+                        Some(grammar) => highlight(text, grammar),
                         None => plain(text),
                     };
                     blocks.push(MarkdownBlock::Code {