feat: add markdown view component

crates/editor/src/lib.rs

@@ -8,6 +8,9 @@ pub mod code_view;
 #[cfg(feature = "diff_view")]
 pub mod diff_view;
 
+#[cfg(feature = "markdown_view")]
+pub mod markdown;
+
 pub mod highlight;
 
 mod utils;

crates/editor/src/utils.rs

@@ -1,9 +1,11 @@
-//! Shared helpers for the editor's views: gutter cells, role colors, change
-//! washes and diff row building.
+//! Shared helpers for the editor's views: gutter cells, role colors, code
+//! line text, language mapping, change washes and diff row building.
 
-#[cfg(feature = "diff_view")]
+#[cfg(any(feature = "diff_view", feature = "markdown_view"))]
 use std::ops::Range;
 
+#[cfg(feature = "markdown_view")]
+use gpui::StyledText;
 use gpui::{App, HighlightStyle, Hsla, IntoElement, ParentElement as _, Styled as _, div};
 use gpui_native_theme::{ActiveTheme as _, ColorTokens, Ramps};
 #[cfg(feature = "diff_view")]
@@ -14,6 +16,8 @@ use crate::diff_view::{DiffRow, DiffRowKind};
 #[cfg(feature = "diff_view")]
 use crate::highlight::HighlightedCode;
 use crate::highlight::Role;
+#[cfg(feature = "markdown_view")]
+use crate::highlight::{Language, Line};
 
 /// Maps a highlight role to the theme's semantic palette.
 pub(crate) fn role_color(role: Role, colors: ColorTokens, ramps: Ramps) -> Hsla {
@@ -136,3 +140,38 @@ pub(crate) fn wash_gutter(colors: &ColorTokens) -> Hsla {
         ..colors.muted
     }
 }
+
+/// One highlighted code line as styled text, roles resolved from the theme.
+#[cfg(feature = "markdown_view")]
+pub(crate) fn code_line(line: &Line, colors: ColorTokens, ramps: Ramps) -> StyledText {
+    let mut text = String::new();
+    let mut highlights: Vec<(Range<usize>, HighlightStyle)> = Vec::new();
+
+    for span in &line.spans {
+        let start = text.len();
+        text.push_str(&span.text);
+        if span.role != Role::Text {
+            highlights.push((
+                start..text.len(),
+                HighlightStyle {
+                    color: Some(role_color(span.role, colors, ramps)),
+                    ..Default::default()
+                },
+            ));
+        }
+    }
+
+    StyledText::new(text).with_highlights(highlights)
+}
+
+/// Maps a fence info string to a bundled grammar.
+#[cfg(feature = "markdown_view")]
+pub(crate) fn grammar_language(info: &str) -> Option<Language> {
+    match info.to_ascii_lowercase().as_str() {
+        "rust" | "rs" => Some(Language::Rust),
+        "typescript" | "ts" => Some(Language::TypeScript),
+        "javascript" | "js" => Some(Language::JavaScript),
+        "python" | "py" => Some(Language::Python),
+        _ => None,
+    }
+}