Add language icons to the language selector (#21298)

Closes https://github.com/zed-industries/zed/issues/21290

This is a first attempt to show the language icons to the selector.
Ideally, I wouldn't like to have yet another place mapping extensions to
icons, as we already have the `file_types.json` file doing that, but I'm
not so sure how to pull from it yet. Maybe in a future pass we'll
improve this and make it more solid.

<img width="700" alt="Screenshot 2024-11-28 at 16 10 27"
src="https://github.com/user-attachments/assets/683c3bef-5389-470f-a41e-3d510b927b61">

Release Notes:

- N/A

---------

Co-authored-by: Kirill Bulatov <kirill@zed.dev>
Co-authored-by: Piotr Osiewicz <24362066+osiewicz@users.noreply.github.com>

crates/language/src/language.rs

@@ -129,6 +129,10 @@ pub static PLAIN_TEXT: LazyLock<Arc<Language>> = LazyLock::new(|| {
         LanguageConfig {
             name: "Plain Text".into(),
             soft_wrap: Some(SoftWrap::EditorWidth),
+            matcher: LanguageMatcher {
+                path_suffixes: vec!["txt".to_owned()],
+                first_line_pattern: None,
+            },
             ..Default::default()
         },
         None,
@@ -1418,6 +1422,10 @@ impl Language {
     pub fn prettier_parser_name(&self) -> Option<&str> {
         self.config.prettier_parser_name.as_deref()
     }
+
+    pub fn config(&self) -> &LanguageConfig {
+        &self.config
+    }
 }
 
 impl LanguageScope {

crates/language/src/language_registry.rs

@@ -130,6 +130,7 @@ pub struct AvailableLanguage {
     name: LanguageName,
     grammar: Option<Arc<str>>,
     matcher: LanguageMatcher,
+    hidden: bool,
     load: Arc<dyn Fn() -> Result<LoadedLanguage> + 'static + Send + Sync>,
     loaded: bool,
 }
@@ -142,6 +143,9 @@ impl AvailableLanguage {
     pub fn matcher(&self) -> &LanguageMatcher {
         &self.matcher
     }
+    pub fn hidden(&self) -> bool {
+        self.hidden
+    }
 }
 
 enum AvailableGrammar {
@@ -288,6 +292,7 @@ impl LanguageRegistry {
             config.name.clone(),
             config.grammar.clone(),
             config.matcher.clone(),
+            config.hidden,
             Arc::new(move || {
                 Ok(LoadedLanguage {
                     config: config.clone(),
@@ -436,6 +441,7 @@ impl LanguageRegistry {
         name: LanguageName,
         grammar_name: Option<Arc<str>>,
         matcher: LanguageMatcher,
+        hidden: bool,
         load: Arc<dyn Fn() -> Result<LoadedLanguage> + 'static + Send + Sync>,
     ) {
         let state = &mut *self.state.write();
@@ -455,6 +461,7 @@ impl LanguageRegistry {
             grammar: grammar_name,
             matcher,
             load,
+            hidden,
             loaded: false,
         });
         state.version += 1;
@@ -522,6 +529,7 @@ impl LanguageRegistry {
             name: language.name(),
             grammar: language.config.grammar.clone(),
             matcher: language.config.matcher.clone(),
+            hidden: language.config.hidden,
             load: Arc::new(|| Err(anyhow!("already loaded"))),
             loaded: true,
         });
@@ -590,15 +598,12 @@ impl LanguageRegistry {
         async move { rx.await? }
     }
 
-    pub fn available_language_for_name(
-        self: &Arc<Self>,
-        name: &LanguageName,
-    ) -> Option<AvailableLanguage> {
+    pub fn available_language_for_name(self: &Arc<Self>, name: &str) -> Option<AvailableLanguage> {
         let state = self.state.read();
         state
             .available_languages
             .iter()
-            .find(|l| &l.name == name)
+            .find(|l| l.name.0.as_ref() == name)
             .cloned()
     }