Show a border when scrolled in chat

crates/collab_ui/src/chat_panel.rs

@@ -112,7 +112,7 @@ impl ChatPanel {
                 if event.visible_range.start < MESSAGE_LOADING_THRESHOLD {
                     this.load_more_messages(cx);
                 }
-                this.is_scrolled_to_bottom = event.visible_range.end == event.count;
+                this.is_scrolled_to_bottom = !event.is_scrolled;
             }));
 
             let mut this = Self {
@@ -567,7 +567,7 @@ impl Render for ChatPanel {
                     ),
                 ),
             )
-            .child(div().flex_grow().px_2().py_1().map(|this| {
+            .child(div().flex_grow().px_2().pt_1().map(|this| {
                 if self.active_chat.is_some() {
                     this.child(list(self.message_list.clone()).full())
                 } else {
@@ -597,7 +597,13 @@ impl Render for ChatPanel {
                     )
                 }
             }))
-            .child(h_stack().p_2().map(|el| {
+            .child(
+                h_stack()
+                    .when(!self.is_scrolled_to_bottom, |el| {
+                        el.border_t_1().border_color(cx.theme().colors().border)
+                    })
+                    .p_2()
+                    .map(|el| {
                         if self.active_chat.is_some() {
                             el.child(self.message_editor.clone())
                         } else {
@@ -609,7 +615,8 @@ impl Render for ChatPanel {
                                     .bg(cx.theme().colors().editor_background),
                             )
                         }
-            }))
+                    }),
+            )
             .into_any()
     }
 }

crates/gpui/src/elements/list.rs

@@ -43,6 +43,7 @@ pub enum ListAlignment {
 pub struct ListScrollEvent {
     pub visible_range: Range<usize>,
     pub count: usize,
+    pub is_scrolled: bool,
 }
 
 #[derive(Clone)]
@@ -253,6 +254,7 @@ impl StateInner {
                 &ListScrollEvent {
                     visible_range,
                     count: self.items.summary().count,
+                    is_scrolled: self.logical_scroll_top.is_some(),
                 },
                 cx,
             );