agent: Keep horizontal scrollbar in edit file tool cards (#31510)

Previously disabled both scrollbars, but horizontal scrolling is still
needed when
lines exceed the viewport width. Now editors can disable a single scroll
axis, not just both.

Release Notes:

- N/A

crates/assistant_tools/src/edit_file_tool.rs

@@ -9,7 +9,7 @@ use assistant_tool::{
     ToolUseStatus,
 };
 use buffer_diff::{BufferDiff, BufferDiffSnapshot};
-use editor::{Editor, EditorMode, MultiBuffer, PathKey};
+use editor::{Editor, EditorMode, MinimapVisibility, MultiBuffer, PathKey};
 use futures::StreamExt;
 use gpui::{
     Animation, AnimationExt, AnyWindowHandle, App, AppContext, AsyncApp, Entity, EntityId, Task,
@@ -428,7 +428,9 @@ impl EditFileToolCard {
             editor.set_show_gutter(false, cx);
             editor.disable_inline_diagnostics();
             editor.disable_expand_excerpt_buttons(cx);
-            editor.disable_scrollbars_and_minimap(window, cx);
+            // Keep horizontal scrollbar so user can scroll horizontally if needed
+            editor.set_show_vertical_scrollbar(false, cx);
+            editor.set_minimap_visibility(MinimapVisibility::Disabled, window, cx);
             editor.set_soft_wrap_mode(SoftWrap::None, cx);
             editor.scroll_manager.set_forbid_vertical_scroll(true);
             editor.set_show_indent_guides(false, cx);

crates/editor/src/editor.rs

@@ -63,8 +63,8 @@ use dap::TelemetrySpawnLocation;
 use display_map::*;
 pub use display_map::{ChunkRenderer, ChunkRendererContext, DisplayPoint, FoldPlaceholder};
 pub use editor_settings::{
-    CurrentLineHighlight, EditorSettings, HideMouseMode, ScrollBeyondLastLine, SearchSettings,
-    ShowScrollbar,
+    CurrentLineHighlight, EditorSettings, HideMouseMode, ScrollBeyondLastLine, ScrollbarAxes,
+    SearchSettings, ShowScrollbar,
 };
 use editor_settings::{GoToDefinitionFallback, Minimap as MinimapSettings};
 pub use editor_settings_controls::*;
@@ -961,7 +961,7 @@ pub struct Editor {
     mode: EditorMode,
     show_breadcrumbs: bool,
     show_gutter: bool,
-    show_scrollbars: bool,
+    show_scrollbars: ScrollbarAxes,
     minimap_visibility: MinimapVisibility,
     offset_content: bool,
     disable_expand_excerpt_buttons: bool,
@@ -1801,7 +1801,10 @@ impl Editor {
             project,
             blink_manager: blink_manager.clone(),
             show_local_selections: true,
-            show_scrollbars: full_mode,
+            show_scrollbars: ScrollbarAxes {
+                horizontal: full_mode,
+                vertical: full_mode,
+            },
             minimap_visibility: MinimapVisibility::for_mode(&mode, cx),
             offset_content: !matches!(mode, EditorMode::SingleLine { .. }),
             show_breadcrumbs: EditorSettings::get_global(cx).toolbar.breadcrumbs,
@@ -16999,8 +17002,21 @@ impl Editor {
         cx.notify();
     }
 
-    pub fn set_show_scrollbars(&mut self, show_scrollbars: bool, cx: &mut Context<Self>) {
-        self.show_scrollbars = show_scrollbars;
+    pub fn set_show_scrollbars(&mut self, show: bool, cx: &mut Context<Self>) {
+        self.show_scrollbars = ScrollbarAxes {
+            horizontal: show,
+            vertical: show,
+        };
+        cx.notify();
+    }
+
+    pub fn set_show_vertical_scrollbar(&mut self, show: bool, cx: &mut Context<Self>) {
+        self.show_scrollbars.vertical = show;
+        cx.notify();
+    }
+
+    pub fn set_show_horizontal_scrollbar(&mut self, show: bool, cx: &mut Context<Self>) {
+        self.show_scrollbars.horizontal = show;
         cx.notify();
     }
 

crates/editor/src/element.rs

@@ -1465,7 +1465,10 @@ impl EditorElement {
         window: &mut Window,
         cx: &mut App,
     ) -> Option<EditorScrollbars> {
-        if !self.editor.read(cx).show_scrollbars || self.style.scrollbar_width.is_zero() {
+        let show_scrollbars = self.editor.read(cx).show_scrollbars;
+        if (!show_scrollbars.horizontal && !show_scrollbars.vertical)
+            || self.style.scrollbar_width.is_zero()
+        {
             return None;
         }
 
@@ -1510,7 +1513,12 @@ impl EditorElement {
         };
 
         Some(EditorScrollbars::from_scrollbar_axes(
-            scrollbar_settings.axes,
+            ScrollbarAxes {
+                horizontal: scrollbar_settings.axes.horizontal
+                    && self.editor.read(cx).show_scrollbars.horizontal,
+                vertical: scrollbar_settings.axes.vertical
+                    && self.editor.read(cx).show_scrollbars.vertical,
+            },
             scrollbar_layout_information,
             content_offset,
             scroll_position,
@@ -7558,7 +7566,7 @@ impl Element for EditorElement {
                     let scrollbars_shown = settings.scrollbar.show != ShowScrollbar::Never;
                     let vertical_scrollbar_width = (scrollbars_shown
                         && settings.scrollbar.axes.vertical
-                        && self.editor.read(cx).show_scrollbars)
+                        && self.editor.read(cx).show_scrollbars.vertical)
                         .then_some(style.scrollbar_width)
                         .unwrap_or_default();
                     let minimap_width = self