editor: When expanding first excerpt up, scroll it into view (#41445)

Lukas Wirth created 5 days ago

Before

https://github.com/user-attachments/assets/2390e924-112a-43fa-8ab8-429a55456d12

After

https://github.com/user-attachments/assets/b47c95f0-ccd9-40a6-ab04-28295158102e

Release Notes:

- Fixed an issue where expanding the first excerpt upwards would expand
it out of view

Change summary

crates/editor/src/editor.rs | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)

Detailed changes

crates/editor/src/editor.rs

@@ -15845,7 +15845,7 @@ impl Editor {
     ) {
         let current_scroll_position = self.scroll_position(cx);
         let lines_to_expand = EditorSettings::get_global(cx).expand_excerpt_lines;
-        let mut should_scroll_up = false;
+        let mut scroll = None;
 
         if direction == ExpandExcerptDirection::Down {
             let multi_buffer = self.buffer.read(cx);
@@ -15858,17 +15858,30 @@ impl Editor {
                 let excerpt_end_row = Point::from_anchor(&excerpt_range.end, &buffer_snapshot).row;
                 let last_row = buffer_snapshot.max_point().row;
                 let lines_below = last_row.saturating_sub(excerpt_end_row);
-                should_scroll_up = lines_below >= lines_to_expand;
+                if lines_below >= lines_to_expand {
+                    scroll = Some(
+                        current_scroll_position
+                            + gpui::Point::new(0.0, lines_to_expand as ScrollOffset),
+                    );
+                }
             }
         }
+        if direction == ExpandExcerptDirection::Up
+            && self
+                .buffer
+                .read(cx)
+                .snapshot(cx)
+                .excerpt_before(excerpt)
+                .is_none()
+        {
+            scroll = Some(current_scroll_position);
+        }
 
         self.buffer.update(cx, |buffer, cx| {
             buffer.expand_excerpts([excerpt], lines_to_expand, direction, cx)
         });
 
-        if should_scroll_up {
-            let new_scroll_position =
-                current_scroll_position + gpui::Point::new(0.0, lines_to_expand as ScrollOffset);
+        if let Some(new_scroll_position) = scroll {
             self.set_scroll_position(new_scroll_position, window, cx);
         }
     }