Refactor highlight scope fallback for markdown popup

helix-editor · Feb 27, 2022 · 8169887 · 8169887
1 parent 6a6a9ab
commit 8169887
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Showing 2 changed files with 21 additions and 17 deletions.
diff --git a/helix-term/src/ui/markdown.rs b/helix-term/src/ui/markdown.rs
@@ -27,16 +27,15 @@ pub struct Markdown {
 // better yet, just use Tendril + subtendril for references
 
 impl Markdown {
-    // theme keys, including fallbacks
-    const TEXT_STYLE: [&'static str; 2] = ["ui.text", "ui"];
-    const BLOCK_STYLE: [&'static str; 3] = ["markup.raw.inline", "markup.raw", "markup"];
-    const HEADING_STYLES: [[&'static str; 3]; 6] = [
-        ["markup.heading.1", "markup.heading", "markup"],
-        ["markup.heading.2", "markup.heading", "markup"],
-        ["markup.heading.3", "markup.heading", "markup"],
-        ["markup.heading.4", "markup.heading", "markup"],
-        ["markup.heading.5", "markup.heading", "markup"],
-        ["markup.heading.6", "markup.heading", "markup"],
+    const TEXT_STYLE: &'static str = "ui.text";
+    const BLOCK_STYLE: &'static str = "markup.raw.inline";
+    const HEADING_STYLES: [&'static str; 6] = [
+        "markup.heading.1",
+        "markup.heading.2",
+        "markup.heading.3",
+        "markup.heading.4",
+        "markup.heading.5",
+        "markup.heading.6",
     ];
 
     pub fn new(contents: String, config_loader: Arc<syntax::Loader>) -> Self {
@@ -59,13 +58,8 @@ impl Markdown {
         let mut spans = Vec::new();
         let mut lines = Vec::new();
 
-        let get_theme = |keys: &[&str]| match theme {
-            Some(theme) => keys
-                .iter()
-                .find_map(|key| theme.try_get(key))
-                .unwrap_or_default(),
-            None => Default::default(),
-        };
+        let get_theme =
+            |key: &str| -> Style { theme.map(|t| t.get_with_fallback(key)).unwrap_or_default() };
         let text_style = get_theme(&Self::TEXT_STYLE);
         let code_style = get_theme(&Self::BLOCK_STYLE);
         let heading_styles: Vec<Style> = Self::HEADING_STYLES

diff --git a/helix-view/src/theme.rs b/helix-view/src/theme.rs
@@ -157,6 +157,16 @@ impl Theme {
         self.styles.get(scope).copied()
     }
 
+    /// Get the style of a scope, falling back to dot separated broader
+    /// scopes. For example if `ui.text.focus` is not defined in the theme,
+    /// `ui.text` is tried and then `ui` is tried. If none of the fallbacks
+    /// are found, the default style is returned.
+    pub fn get_with_fallback<'s>(&self, scope: &'s str) -> Style {
+        std::iter::successors(Some(scope), |s| Some(s.rsplit_once('.')?.0))
+            .find_map(|s| self.try_get(s))
+            .unwrap_or_default()
+    }
+
     #[inline]
     pub fn scopes(&self) -> &[String] {
         &self.scopes