From 119ef17316ad906db6bca6ae8d0070e70e5e62e0 Mon Sep 17 00:00:00 2001
From: Aaron Ang <awz.ang@gmail.com>
Date: Wed, 20 May 2026 15:42:50 -0700
Subject: [PATCH] Make Thumb use full-height track hitbox, remove OverlayTrack
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Thumb-only hitboxes (covering just the thumb rectangle) always let
clicks on the track area fall through to content underneath. There is no
use case for this — the scrollbar strip should always intercept its own
clicks. Fold OverlayTrack's behavior directly into Thumb by including it
in needs_scroll_track(), then remove the now-redundant OverlayTrack
variant and with_overlay_track_along() method.

All vertical_scrollbar_for call sites get the correct behavior
automatically. Settings and project panel callers are cleaned up:
the settings main list reverts to vertical_scrollbar_for, and the
now-redundant with_overlay_track_along calls are removed.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 crates/project_panel/src/project_panel.rs | 14 ++++----------
 crates/settings_ui/src/settings_ui.rs     |  9 +--------
 crates/ui/src/components/scrollbar.rs     |  8 +-------
 3 files changed, 6 insertions(+), 25 deletions(-)

diff --git a/crates/project_panel/src/project_panel.rs b/crates/project_panel/src/project_panel.rs
index ce3a9863bb0..aef907ed9f1 100644
--- a/crates/project_panel/src/project_panel.rs
+++ b/crates/project_panel/src/project_panel.rs
@@ -62,7 +62,7 @@ use theme_settings::ThemeSettings;
 use ui::{
     Color, ContextMenu, ContextMenuEntry, DecoratedIcon, Icon, IconDecoration, IconDecorationKind,
     IndentGuideColors, IndentGuideLayout, Indicator, KeyBinding, Label, LabelSize, ListItem,
-    ListItemSpacing, ProjectEmptyState, ScrollAxes, ScrollableHandle, Scrollbars, StickyCandidate,
+    ListItemSpacing, ProjectEmptyState, ScrollableHandle, Scrollbars, StickyCandidate,
     Tooltip, WithScrollbar, prelude::*, v_flex,
 };
 use util::{
@@ -7087,15 +7087,9 @@ impl Render for ProjectPanel {
                 )
                 .custom_scrollbars(
                     {
-                        let mut scrollbars =
-                            Scrollbars::for_settings::<ProjectPanelScrollbarProxy>()
-                                .tracked_scroll_handle(&self.scroll_handle)
-                                .with_overlay_track_along(ScrollAxes::Vertical);
-                        if horizontal_scroll {
-                            scrollbars =
-                                scrollbars.with_overlay_track_along(ScrollAxes::Horizontal);
-                        }
-                        scrollbars.notify_content()
+                        Scrollbars::for_settings::<ProjectPanelScrollbarProxy>()
+                            .tracked_scroll_handle(&self.scroll_handle)
+                            .notify_content()
                     },
                     window,
                     cx,
diff --git a/crates/settings_ui/src/settings_ui.rs b/crates/settings_ui/src/settings_ui.rs
index e4e7f4ad4bf..02bbacdfa30 100644
--- a/crates/settings_ui/src/settings_ui.rs
+++ b/crates/settings_ui/src/settings_ui.rs
@@ -3477,19 +3477,12 @@ impl SettingsWindow {
                 window.focus_prev(cx);
             }))
             .when(current_sub_page.is_none(), |this| {
-                this.custom_scrollbars(
-                    Scrollbars::new(ui::ScrollAxes::Vertical)
-                        .tracked_scroll_handle(&self.list_state)
-                        .with_overlay_track_along(ui::ScrollAxes::Vertical),
-                    window,
-                    cx,
-                )
+                this.vertical_scrollbar_for(&self.list_state, window, cx)
             })
             .when_some(current_sub_page, |this, current_sub_page| {
                 this.custom_scrollbars(
                     Scrollbars::new(ui::ScrollAxes::Vertical)
                         .tracked_scroll_handle(&current_sub_page.scroll_handle)
-                        .with_overlay_track_along(ui::ScrollAxes::Vertical)
                         .id((current_sub_page.link.title.clone(), 42)),
                     window,
                     cx,
diff --git a/crates/ui/src/components/scrollbar.rs b/crates/ui/src/components/scrollbar.rs
index af29605f8e9..22bb47c6fd8 100644
--- a/crates/ui/src/components/scrollbar.rs
+++ b/crates/ui/src/components/scrollbar.rs
@@ -321,7 +321,6 @@ enum ReservedSpace {
     None,
     Thumb,
     Track,
-    OverlayTrack,
     StableTrack,
 }
 
@@ -331,7 +330,7 @@ impl ReservedSpace {
     }
 
     fn needs_scroll_track(&self) -> bool {
-        matches!(self, Self::Track | Self::OverlayTrack | Self::StableTrack)
+        matches!(self, Self::Thumb | Self::Track | Self::StableTrack)
     }
 
     fn needs_space_reserved(&self, max_offset: Pixels) -> bool {
@@ -474,11 +473,6 @@ impl<ScrollHandle: ScrollableHandle> Scrollbars<ScrollHandle> {
         self
     }
 
-    pub fn with_overlay_track_along(mut self, along: ScrollAxes) -> Self {
-        self.visibility = along.apply_to(self.visibility, ReservedSpace::OverlayTrack);
-        self
-    }
-
     pub fn with_stable_track_along(mut self, along: ScrollAxes, background_color: Hsla) -> Self {
         self.visibility = along.apply_to(self.visibility, ReservedSpace::StableTrack);
         self.track_color = Some(background_color);