From 1001663f02c9728d804313d2f1b36bb3e80f6bac Mon Sep 17 00:00:00 2001
From: Danilo Leal <67129314+danilo-leal@users.noreply.github.com>
Date: Wed, 26 Mar 2025 09:45:51 -0300
Subject: [PATCH] assistant2: Improve tool card header scrolling affordance
 (#27492)

Follow up to https://github.com/zed-industries/zed/pull/27489

Added this subtle gradient to the right side of the tool card header so
users know there is more content, suggesting it can be scrolled. Also
took the opportunity to extract out commonly used custom colors in all
of these cards into their own functions to ensure consistency.

Here's the final product:


https://github.com/user-attachments/assets/e44150f9-7751-46c7-8790-149b86cc5e0f

Release Notes:

- N/A
---
 crates/assistant2/src/active_thread.rs | 46 +++++++++++++++++---------
 1 file changed, 31 insertions(+), 15 deletions(-)

diff --git a/crates/assistant2/src/active_thread.rs b/crates/assistant2/src/active_thread.rs
index b2e16db1a7..27c29e3fa8 100644
--- a/crates/assistant2/src/active_thread.rs
+++ b/crates/assistant2/src/active_thread.rs
@@ -12,9 +12,9 @@ use editor::{Editor, MultiBuffer};
 use gpui::{
     linear_color_stop, linear_gradient, list, percentage, pulsating_between, AbsoluteLength,
     Animation, AnimationExt, AnyElement, App, ClickEvent, DefiniteLength, EdgesRefinement, Empty,
-    Entity, Focusable, Length, ListAlignment, ListOffset, ListState, ScrollHandle, StyleRefinement,
-    Subscription, Task, TextStyleRefinement, Transformation, UnderlineStyle, WeakEntity,
-    WindowHandle,
+    Entity, Focusable, Hsla, Length, ListAlignment, ListOffset, ListState, ScrollHandle,
+    StyleRefinement, Subscription, Task, TextStyleRefinement, Transformation, UnderlineStyle,
+    WeakEntity, WindowHandle,
 };
 use language::{Buffer, LanguageRegistry};
 use language_model::{LanguageModelRegistry, LanguageModelToolUseId, Role};
@@ -1145,6 +1145,17 @@ impl ActiveThread {
             )
     }
 
+    fn tool_card_border_color(&self, cx: &Context<Self>) -> Hsla {
+        cx.theme().colors().border.opacity(0.5)
+    }
+
+    fn tool_card_header_bg(&self, cx: &Context<Self>) -> Hsla {
+        cx.theme()
+            .colors()
+            .element_background
+            .blend(cx.theme().colors().editor_foreground.opacity(0.025))
+    }
+
     fn render_message_thinking_segment(
         &self,
         message_id: MessageId,
@@ -1160,26 +1171,25 @@ impl ActiveThread {
             .copied()
             .unwrap_or_default();
 
-        let lighter_border = cx.theme().colors().border.opacity(0.5);
         let editor_bg = cx.theme().colors().editor_background;
 
         div().py_2().child(
             v_flex()
                 .rounded_lg()
                 .border_1()
-                .border_color(lighter_border)
+                .border_color(self.tool_card_border_color(cx))
                 .child(
                     h_flex()
                         .group("disclosure-header")
                         .justify_between()
                         .py_1()
                         .px_2()
-                        .bg(cx.theme().colors().editor_foreground.opacity(0.025))
+                        .bg(self.tool_card_header_bg(cx))
                         .map(|this| {
                             if pending || is_open {
                                 this.rounded_t_md()
                                     .border_b_1()
-                                    .border_color(lighter_border)
+                                    .border_color(self.tool_card_border_color(cx))
                             } else {
                                 this.rounded_md()
                             }
@@ -1314,22 +1324,21 @@ impl ActiveThread {
             .copied()
             .unwrap_or_default();
 
-        let lighter_border = cx.theme().colors().border.opacity(0.5);
-
         div().py_2().child(
             v_flex()
                 .rounded_lg()
                 .border_1()
-                .border_color(lighter_border)
+                .border_color(self.tool_card_border_color(cx))
                 .overflow_hidden()
                 .child(
                     h_flex()
                         .group("disclosure-header")
+                        .relative()
                         .gap_1p5()
                         .justify_between()
                         .py_1()
                         .px_2()
-                        .bg(cx.theme().colors().editor_foreground.opacity(0.025))
+                        .bg(self.tool_card_header_bg(cx))
                         .map(|element| {
                             if is_open {
                                 element.border_b_1().rounded_t_md()
@@ -1337,7 +1346,7 @@ impl ActiveThread {
                                 element.rounded_md()
                             }
                         })
-                        .border_color(lighter_border)
+                        .border_color(self.tool_card_border_color(cx))
                         .child(
                             h_flex()
                                 .id("tool-label-container")
@@ -1350,7 +1359,7 @@ impl ActiveThread {
                                         .size(IconSize::XSmall)
                                         .color(Color::Muted),
                                 )
-                                .child(h_flex().text_ui_sm(cx).children(
+                                .child(h_flex().pr_8().text_ui_sm(cx).children(
                                     self.rendered_tool_use_labels.get(&tool_use.id).cloned(),
                                 )),
                         )
@@ -1410,7 +1419,14 @@ impl ActiveThread {
                                         icon.into_any_element()
                                     }
                                 }),
-                        ),
+                        )
+                        .child(div().h_full().absolute().w_8().bottom_0().right_12().bg(
+                            linear_gradient(
+                                90.,
+                                linear_color_stop(self.tool_card_header_bg(cx), 1.),
+                                linear_color_stop(self.tool_card_header_bg(cx).opacity(0.2), 0.),
+                            ),
+                        )),
                 )
                 .map(|parent| {
                     if !is_open {
@@ -1427,7 +1443,7 @@ impl ActiveThread {
                             .child(
                                 content_container()
                                     .border_b_1()
-                                    .border_color(lighter_border)
+                                    .border_color(self.tool_card_border_color(cx))
                                     .child(
                                         Label::new("Input")
                                             .size(LabelSize::XSmall)