Make BufferSearch less wide (#10459)

This also adds some "responsiveness" so that UI elements are hidden
before everything has to be occluded

Release Notes:

- Improved search UI. It now works in narrower panes, and avoids
scrolling the editor on open.

<img width="899" alt="Screenshot 2024-04-11 at 21 33 17"
src="https://github.com/zed-industries/zed/assets/94272/44b95d4f-08d6-4c40-a175-0e594402ca01">
<img width="508" alt="Screenshot 2024-04-11 at 21 33 45"
src="https://github.com/zed-industries/zed/assets/94272/baf4638d-427b-43e6-ad67-13d43f0f18a2">
<img width="361" alt="Screenshot 2024-04-11 at 21 34 00"
src="https://github.com/zed-industries/zed/assets/94272/ff60b561-2f77-49c0-9df7-e26227fe9225">
<img width="348" alt="Screenshot 2024-04-11 at 21 37 03"
src="https://github.com/zed-industries/zed/assets/94272/a2a700a2-ce99-41bd-bf47-9b14d7082b0e">

crates/editor/src/editor.rs

@@ -471,6 +471,8 @@ pub struct Editor {
                 + Fn(&mut Self, DisplayPoint, &mut ViewContext<Self>) -> Option<View<ui::ContextMenu>>,
         >,
     >,
+    last_bounds: Option<Bounds<Pixels>>,
+    expect_bounds_change: Option<Bounds<Pixels>>,
 }
 
 #[derive(Clone)]
@@ -1485,6 +1487,8 @@ impl Editor {
             inlay_hint_cache: InlayHintCache::new(inlay_hint_settings),
             gutter_hovered: false,
             pixel_position_of_newest_cursor: None,
+            last_bounds: None,
+            expect_bounds_change: None,
             gutter_width: Default::default(),
             style: None,
             show_cursor_names: false,

crates/editor/src/element.rs

@@ -3371,6 +3371,7 @@ impl Element for EditorElement {
                 let overscroll = size(em_width, px(0.));
 
                 snapshot = self.editor.update(cx, |editor, cx| {
+                    editor.last_bounds = Some(bounds);
                     editor.gutter_width = gutter_dimensions.width;
                     editor.set_visible_line_count(bounds.size.height / line_height, cx);
 
@@ -3419,7 +3420,7 @@ impl Element for EditorElement {
 
                 let autoscroll_horizontally = self.editor.update(cx, |editor, cx| {
                     let autoscroll_horizontally =
-                        editor.autoscroll_vertically(bounds.size.height, line_height, cx);
+                        editor.autoscroll_vertically(bounds, line_height, cx);
                     snapshot = editor.snapshot(cx);
                     autoscroll_horizontally
                 });

crates/editor/src/items.rs

@@ -1167,6 +1167,10 @@ impl SearchableItem for Editor {
             &self.buffer().read(cx).snapshot(cx),
         )
     }
+
+    fn search_bar_visibility_changed(&mut self, _visible: bool, _cx: &mut ViewContext<Self>) {
+        self.expect_bounds_change = self.last_bounds;
+    }
 }
 
 pub fn active_match_index(

crates/editor/src/scroll/autoscroll.rs

@@ -1,6 +1,6 @@
 use std::{cmp, f32};
 
-use gpui::{px, Pixels, ViewContext};
+use gpui::{px, Bounds, Pixels, ViewContext};
 use language::Point;
 
 use crate::{display_map::ToDisplayPoint, Editor, EditorMode, LineWithInvisibles};
@@ -63,13 +63,23 @@ impl AutoscrollStrategy {
 impl Editor {
     pub fn autoscroll_vertically(
         &mut self,
-        viewport_height: Pixels,
+        bounds: Bounds<Pixels>,
         line_height: Pixels,
         cx: &mut ViewContext<Editor>,
     ) -> bool {
+        let viewport_height = bounds.size.height;
         let visible_lines = viewport_height / line_height;
         let display_map = self.display_map.update(cx, |map, cx| map.snapshot(cx));
         let mut scroll_position = self.scroll_manager.scroll_position(&display_map);
+        let original_y = scroll_position.y;
+        if let Some(last_bounds) = self.expect_bounds_change.take() {
+            if scroll_position.y != 0. {
+                scroll_position.y += (bounds.top() - last_bounds.top()) / line_height;
+                if scroll_position.y < 0. {
+                    scroll_position.y = 0.;
+                }
+            }
+        }
         let max_scroll_top = if matches!(self.mode, EditorMode::AutoHeight { .. }) {
             (display_map.max_point().row() as f32 - visible_lines + 1.).max(0.)
         } else {
@@ -77,6 +87,9 @@ impl Editor {
         };
         if scroll_position.y > max_scroll_top {
             scroll_position.y = max_scroll_top;
+        }
+
+        if original_y != scroll_position.y {
             self.set_scroll_position(scroll_position, cx);
         }