Allow disabling editor scrollbars programmatically (#22333)

Disable them in the diff editors

Closes https://github.com/zed-industries/zed/issues/22271

Release Notes:

- N/A

crates/assistant/src/assistant_panel.rs

@@ -1556,6 +1556,7 @@ impl ContextEditor {
             let mut editor = Editor::for_buffer(context.read(cx).buffer().clone(), None, cx);
             editor.set_soft_wrap_mode(SoftWrap::EditorWidth, cx);
             editor.set_show_line_numbers(false, cx);
+            editor.set_show_scrollbars(false, cx);
             editor.set_show_git_diff_gutter(false, cx);
             editor.set_show_code_actions(false, cx);
             editor.set_show_runnables(false, cx);

crates/editor/src/editor.rs

@@ -606,6 +606,7 @@ pub struct Editor {
     mode: EditorMode,
     show_breadcrumbs: bool,
     show_gutter: bool,
+    show_scrollbars: bool,
     show_line_numbers: Option<bool>,
     use_relative_line_numbers: Option<bool>,
     show_git_diff_gutter: Option<bool>,
@@ -1235,6 +1236,7 @@ impl Editor {
             project,
             blink_manager: blink_manager.clone(),
             show_local_selections: true,
+            show_scrollbars: true,
             mode,
             show_breadcrumbs: EditorSettings::get_global(cx).toolbar.breadcrumbs,
             show_gutter: mode == EditorMode::Full,
@@ -11260,6 +11262,11 @@ impl Editor {
         cx.notify();
     }
 
+    pub fn set_show_scrollbars(&mut self, show_scrollbars: bool, cx: &mut ViewContext<Self>) {
+        self.show_scrollbars = show_scrollbars;
+        cx.notify();
+    }
+
     pub fn set_show_line_numbers(&mut self, show_line_numbers: bool, cx: &mut ViewContext<Self>) {
         self.show_line_numbers = Some(show_line_numbers);
         cx.notify();

crates/editor/src/element.rs

@@ -1192,7 +1192,8 @@ impl EditorElement {
         );
 
         let scrollbar_settings = EditorSettings::get_global(cx).scrollbar;
-        let show_scrollbars = match scrollbar_settings.show {
+        let show_scrollbars = self.editor.read(cx).show_scrollbars
+            && match scrollbar_settings.show {
                 ShowScrollbar::Auto => {
                     let editor = self.editor.read(cx);
                     let is_singleton = editor.is_singleton(cx);

crates/editor/src/hunk_diff.rs

@@ -1155,6 +1155,11 @@ fn editor_with_deleted_text(
         editor.set_soft_wrap_mode(language::language_settings::SoftWrap::None, cx);
         editor.set_show_wrap_guides(false, cx);
         editor.set_show_gutter(false, cx);
+        editor.set_show_line_numbers(false, cx);
+        editor.set_show_scrollbars(false, cx);
+        editor.set_show_runnables(false, cx);
+        editor.set_show_git_diff_gutter(false, cx);
+        editor.set_show_code_actions(false, cx);
         editor.scroll_manager.set_forbid_vertical_scroll(true);
         editor.set_read_only(true);
         editor.set_show_inline_completions(Some(false), cx);
@@ -1166,7 +1171,7 @@ fn editor_with_deleted_text(
             false,
             cx,
         );
-        editor.set_current_line_highlight(Some(CurrentLineHighlight::None)); //
+        editor.set_current_line_highlight(Some(CurrentLineHighlight::None));
         editor
             ._subscriptions
             .extend([cx.on_blur(&editor.focus_handle, |editor, cx| {

crates/zeta/src/rate_completion_modal.rs

@@ -269,6 +269,7 @@ impl RateCompletionModal {
                 let mut editor = Editor::multi_line(cx);
                 editor.set_soft_wrap_mode(language_settings::SoftWrap::EditorWidth, cx);
                 editor.set_show_line_numbers(false, cx);
+                editor.set_show_scrollbars(false, cx);
                 editor.set_show_git_diff_gutter(false, cx);
                 editor.set_show_code_actions(false, cx);
                 editor.set_show_runnables(false, cx);