From 211d6205b904247cbf10e58b93f924767a3cec58 Mon Sep 17 00:00:00 2001
From: Danilo Leal <67129314+danilo-leal@users.noreply.github.com>
Date: Tue, 8 Jul 2025 01:18:52 -0300
Subject: [PATCH] project panel: Add a shadow in the last sticky item (#34042)
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Follow-up to https://github.com/zed-industries/zed/pull/33994. This PR
adds a subtle shadow—built from an absolute-positioned div, due to
layering of items—to the last sticky item in the project panel when that
setting is turned on. This helps understand the block of items that is
currently sticky.

<img
src="https://github.com/user-attachments/assets/0e030e93-9bc6-42ff-8d0d-3e46f1986152"
width="300"/>

Would love to add indent guides to the items that are sticky as a next
step.

Release Notes:

- project panel: When `sticky_scroll` is true, the last item will now
have a subtle shadow to help visualizing the block of items that are
currently sticky.
---
 crates/project_panel/src/project_panel.rs | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/crates/project_panel/src/project_panel.rs b/crates/project_panel/src/project_panel.rs
index ca791869d9db9a70090583f21b06b8099e9d74f1..a5861250a41fba178c6959726548d9283d900cad 100644
--- a/crates/project_panel/src/project_panel.rs
+++ b/crates/project_panel/src/project_panel.rs
@@ -23,7 +23,8 @@ use gpui::{
     ListSizingBehavior, Modifiers, ModifiersChangedEvent, MouseButton, MouseDownEvent,
     ParentElement, Pixels, Point, PromptLevel, Render, ScrollStrategy, Stateful, Styled,
     Subscription, Task, UniformListScrollHandle, WeakEntity, Window, actions, anchored, deferred,
-    div, point, px, size, transparent_white, uniform_list,
+    div, hsla, linear_color_stop, linear_gradient, point, px, size, transparent_white,
+    uniform_list,
 };
 use indexmap::IndexMap;
 use language::DiagnosticSeverity;
@@ -185,6 +186,7 @@ struct EntryDetails {
 #[derive(Debug, PartialEq, Eq, Clone)]
 struct StickyDetails {
     sticky_index: usize,
+    is_last: bool,
 }
 
 /// Permanently deletes the selected file or directory.
@@ -3928,8 +3930,24 @@ impl ProjectPanel {
             }
         };
 
+        let last_sticky_item = details.sticky.as_ref().map_or(false, |item| item.is_last);
+        let shadow_color_top = hsla(0.0, 0.0, 0.0, 0.15);
+        let shadow_color_bottom = hsla(0.0, 0.0, 0.0, 0.);
+        let sticky_shadow = div()
+            .absolute()
+            .left_0()
+            .bottom_neg_1p5()
+            .h_1p5()
+            .w_full()
+            .bg(linear_gradient(
+                0.,
+                linear_color_stop(shadow_color_top, 1.),
+                linear_color_stop(shadow_color_bottom, 0.),
+            ));
+
         div()
             .id(entry_id.to_proto() as usize)
+            .relative()
             .group(GROUP_NAME)
             .cursor_pointer()
             .rounded_none()
@@ -3938,6 +3956,7 @@ impl ProjectPanel {
             .border_r_2()
             .border_color(border_color)
             .hover(|style| style.bg(bg_hover_color).border_color(border_hover_color))
+            .when(is_sticky && last_sticky_item, |this| this.child(sticky_shadow))
             .when(!is_sticky, |this| {
                 this
                 .when(is_highlighted && folded_directory_drag_target.is_none(), |this| this.border_color(transparent_white()).bg(item_colors.drag_over))
@@ -4931,6 +4950,7 @@ impl ProjectPanel {
                     .unwrap_or_default();
                 let sticky_details = Some(StickyDetails {
                     sticky_index: index,
+                    is_last: index == sticky_parents.len() - 1,
                 });
                 let details = self.details_for_entry(
                     entry,