Add setting to hide active language button in the status bar (#33977)

Release Notes:

- Added settings status_bar.show_active_language_button to show/hide the
language button in the status bar.

The motivation for this is visual, I have had zero issues with its
functionality.

The language switcher can still be accessed by the command palette,
menu, or a keyboard shortcut.

------

This is my first Zed and first Rust PR, so criticism is very welcome. 

I know there has been discussion around how the status bar settings are
structured and named, and I am happy to change it to whatever is best. I
was also not sure what order to put it in in the settings default.json.
Feedback welcome.

Here is a picture of it in action:


![image](https://github.com/user-attachments/assets/c50131e2-71aa-4fab-8db0-8b2aae586e71)

---------

Co-authored-by: zumbalogy <3770982+zumbalogy@users.noreply.github.com>
Co-authored-by: Kirill Bulatov <kirill@zed.dev>

assets/settings/default.json

@@ -1238,6 +1238,11 @@
     // 2. hour24
     "hour_format": "hour12"
   },
+  // Status bar-related settings.
+  "status_bar": {
+    // Whether to show the active language button in the status bar.
+    "active_language_button": true
+  },
   // Settings specific to the terminal
   "terminal": {
     // What shell to use when opening a terminal. May take 3 values:

crates/editor/src/editor_settings.rs

@@ -20,6 +20,7 @@ pub struct EditorSettings {
     pub lsp_highlight_debounce: u64,
     pub hover_popover_enabled: bool,
     pub hover_popover_delay: u64,
+    pub status_bar: StatusBar,
     pub toolbar: Toolbar,
     pub scrollbar: Scrollbar,
     pub minimap: Minimap,
@@ -125,6 +126,14 @@ pub struct JupyterContent {
     pub enabled: Option<bool>,
 }
 
+#[derive(Copy, Clone, Default, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+pub struct StatusBar {
+    /// Whether to display the active language button in the status bar.
+    ///
+    /// Default: true
+    pub active_language_button: bool,
+}
+
 #[derive(Copy, Clone, Debug, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
 pub struct Toolbar {
     pub breadcrumbs: bool,
@@ -440,6 +449,8 @@ pub struct EditorSettingsContent {
     ///
     /// Default: 300
     pub hover_popover_delay: Option<u64>,
+    /// Status bar related settings
+    pub status_bar: Option<StatusBarContent>,
     /// Toolbar related settings
     pub toolbar: Option<ToolbarContent>,
     /// Scrollbar related settings
@@ -567,6 +578,15 @@ pub struct EditorSettingsContent {
     pub lsp_document_colors: Option<DocumentColorsRenderMode>,
 }
 
+// Status bar related settings
+#[derive(Clone, Default, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
+pub struct StatusBarContent {
+    /// Whether to display the active language button in the status bar.
+    ///
+    /// Default: true
+    pub active_language_button: Option<bool>,
+}
+
 // Toolbar related settings
 #[derive(Clone, Default, Serialize, Deserialize, JsonSchema, PartialEq, Eq)]
 pub struct ToolbarContent {

crates/language_selector/src/active_buffer_language.rs

@@ -1,8 +1,9 @@
-use editor::Editor;
+use editor::{Editor, EditorSettings};
 use gpui::{
     Context, Entity, IntoElement, ParentElement, Render, Subscription, WeakEntity, Window, div,
 };
 use language::LanguageName;
+use settings::Settings as _;
 use ui::{Button, ButtonCommon, Clickable, FluentBuilder, LabelSize, Tooltip};
 use workspace::{StatusItemView, Workspace, item::ItemHandle};
 
@@ -39,6 +40,13 @@ impl ActiveBufferLanguage {
 
 impl Render for ActiveBufferLanguage {
     fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
+        if !EditorSettings::get_global(cx)
+            .status_bar
+            .active_language_button
+        {
+            return div();
+        }
+
         div().when_some(self.active_language.as_ref(), |el, active_language| {
             let active_language_text = if let Some(active_language_text) = active_language {
                 active_language_text.to_string()

docs/src/configuring-zed.md

@@ -1275,6 +1275,18 @@ Each option controls displaying of a particular toolbar element. If all elements
 
 `boolean` values
 
+## Status Bar
+
+- Description: Control various elements in the status bar. Note that some items in the status bar have their own settings set elsewhere.
+- Setting: `status_bar`
+- Default:
+
+```json
+"status_bar": {
+  "active_language_button": true,
+},
+```
+
 ## LSP
 
 - Description: Configuration for language servers.

docs/src/visual-customization.md

@@ -306,6 +306,17 @@ TBD: Centered layout related settings
   }
 ```
 
+### Status Bar
+
+```json
+  "status_bar": {
+    // Show/hide a button that displays the active buffer's language.
+    // Clicking the button brings up the language selector.
+    // Defaults to true.
+    "active_language_button": true,
+  },
+```
+
 ### Multibuffer
 
 ```json