Don't scroll the editor on select all matches (#28435)

Part of https://github.com/zed-industries/zed/issues/9309

Release Notes:

- Improved scroll behavior of `editor: select all matches`

---------

Co-authored-by: Kirill Bulatov <kirill@zed.dev>

crates/editor/src/editor.rs

@@ -11573,7 +11573,7 @@ impl Editor {
             window: &mut Window,
             cx: &mut Context<Editor>,
         ) {
-            this.unfold_ranges(&[range.clone()], false, true, cx);
+            this.unfold_ranges(&[range.clone()], false, auto_scroll.is_some(), cx);
             this.change_selections(auto_scroll, window, cx, |s| {
                 if replace_newest {
                     s.delete(s.newest_anchor().id);
@@ -11748,16 +11748,21 @@ impl Editor {
             return Ok(());
         }
 
-        let mut new_selections = self.selections.all::<usize>(cx);
+        let mut new_selections = Vec::new();
 
+        let reversed = self.selections.oldest::<usize>(cx).reversed;
         let buffer = &display_map.buffer_snapshot;
         let query_matches = select_next_state
             .query
             .stream_find_iter(buffer.bytes_in_range(0..buffer.len()));
 
-        for query_match in query_matches {
-            let query_match = query_match.unwrap(); // can only fail due to I/O
-            let offset_range = query_match.start()..query_match.end();
+        for query_match in query_matches.into_iter() {
+            let query_match = query_match.context("query match for select all action")?; // can only fail due to I/O
+            let offset_range = if reversed {
+                query_match.end()..query_match.start()
+            } else {
+                query_match.start()..query_match.end()
+            };
             let display_range = offset_range.start.to_display_point(&display_map)
                 ..offset_range.end.to_display_point(&display_map);
 
@@ -11765,52 +11770,14 @@ impl Editor {
                 || (!movement::is_inside_word(&display_map, display_range.start)
                     && !movement::is_inside_word(&display_map, display_range.end))
             {
-                self.selections.change_with(cx, |selections| {
-                    new_selections.push(Selection {
-                        id: selections.new_selection_id(),
-                        start: offset_range.start,
-                        end: offset_range.end,
-                        reversed: false,
-                        goal: SelectionGoal::None,
-                    });
-                });
+                new_selections.push(offset_range.start..offset_range.end);
             }
         }
 
-        new_selections.sort_by_key(|selection| selection.start);
-        let mut ix = 0;
-        while ix + 1 < new_selections.len() {
-            let current_selection = &new_selections[ix];
-            let next_selection = &new_selections[ix + 1];
-            if current_selection.range().overlaps(&next_selection.range()) {
-                if current_selection.id < next_selection.id {
-                    new_selections.remove(ix + 1);
-                } else {
-                    new_selections.remove(ix);
-                }
-            } else {
-                ix += 1;
-            }
-        }
-
-        let reversed = self.selections.oldest::<usize>(cx).reversed;
-
-        for selection in new_selections.iter_mut() {
-            selection.reversed = reversed;
-        }
-
         select_next_state.done = true;
-        self.unfold_ranges(
-            &new_selections
-                .iter()
-                .map(|selection| selection.range())
-                .collect::<Vec<_>>(),
-            false,
-            false,
-            cx,
-        );
-        self.change_selections(Some(Autoscroll::fit()), window, cx, |selections| {
-            selections.select(new_selections)
+        self.unfold_ranges(&new_selections.clone(), false, false, cx);
+        self.change_selections(None, window, cx, |selections| {
+            selections.select_ranges(new_selections)
         });
 
         Ok(())

crates/editor/src/editor_tests.rs

@@ -5842,6 +5842,37 @@ async fn test_select_all_matches(cx: &mut TestAppContext) {
     cx.assert_editor_state("abc\n«  ˇ»abc\nabc");
 }
 
+#[gpui::test]
+async fn test_select_all_matches_does_not_scroll(cx: &mut TestAppContext) {
+    init_test(cx, |_| {});
+
+    let mut cx = EditorTestContext::new(cx).await;
+
+    let large_body_1 = "\nd".repeat(200);
+    let large_body_2 = "\ne".repeat(200);
+
+    cx.set_state(&format!(
+        "abc\nabc{large_body_1} «ˇa»bc{large_body_2}\nefabc\nabc"
+    ));
+    let initial_scroll_position = cx.update_editor(|editor, _, cx| {
+        let scroll_position = editor.scroll_position(cx);
+        assert!(scroll_position.y > 0.0, "Initial selection is between two large bodies and should have the editor scrolled to it");
+        scroll_position
+    });
+
+    cx.update_editor(|e, window, cx| e.select_all_matches(&SelectAllMatches, window, cx))
+        .unwrap();
+    cx.assert_editor_state(&format!(
+        "«ˇa»bc\n«ˇa»bc{large_body_1} «ˇa»bc{large_body_2}\nef«ˇa»bc\n«ˇa»bc"
+    ));
+    let scroll_position_after_selection =
+        cx.update_editor(|editor, _, cx| editor.scroll_position(cx));
+    assert_eq!(
+        initial_scroll_position, scroll_position_after_selection,
+        "Scroll position should not change after selecting all matches"
+    );
+}
+
 #[gpui::test]
 async fn test_select_next_with_multiple_carets(cx: &mut TestAppContext) {
     init_test(cx, |_| {});