From aa89632286487304ed2a6626e786dd42233277eb Mon Sep 17 00:00:00 2001
From: Mikayla Maki <mikayla@zed.dev>
Date: Wed, 17 May 2023 11:40:30 -0700
Subject: [PATCH] Add diff hunks to the scroll bar

---
 crates/editor/src/element.rs | 49 ++++++++++++++++++++++++++++++++++--
 1 file changed, 47 insertions(+), 2 deletions(-)

diff --git a/crates/editor/src/element.rs b/crates/editor/src/element.rs
index c1710b7337..1d4aff39de 100644
--- a/crates/editor/src/element.rs
+++ b/crates/editor/src/element.rs
@@ -1022,15 +1022,16 @@ impl EditorElement {
         let mut first_row_y_offset = 0.0;
 
         // Impose a minimum height on the scrollbar thumb
+        let row_height = height / max_row;
         let min_thumb_height =
             style.min_height_factor * cx.font_cache.line_height(self.style.text.font_size);
-        let thumb_height = (row_range.end - row_range.start) * height / max_row;
+        let thumb_height = (row_range.end - row_range.start) * row_height;
         if thumb_height < min_thumb_height {
             first_row_y_offset = (min_thumb_height - thumb_height) / 2.0;
             height -= min_thumb_height - thumb_height;
         }
 
-        let y_for_row = |row: f32| -> f32 { top + first_row_y_offset + row * height / max_row };
+        let y_for_row = |row: f32| -> f32 { top + first_row_y_offset + row * row_height };
 
         let thumb_top = y_for_row(row_range.start) - first_row_y_offset;
         let thumb_bottom = y_for_row(row_range.end) + first_row_y_offset;
@@ -1044,6 +1045,50 @@ impl EditorElement {
                 background: style.track.background_color,
                 ..Default::default()
             });
+
+            let diff_style = cx.global::<Settings>().theme.editor.diff.clone();
+            for hunk in layout
+                .position_map
+                .snapshot
+                .buffer_snapshot
+                .git_diff_hunks_in_range(0..(max_row.floor() as u32), false)
+            {
+                let start_y = y_for_row(hunk.buffer_range.start as f32);
+                let mut end_y = if hunk.buffer_range.start == hunk.buffer_range.end {
+                    y_for_row((hunk.buffer_range.end + 1) as f32)
+                } else {
+                    y_for_row((hunk.buffer_range.end) as f32)
+                };
+
+                if end_y - start_y < 1. {
+                    end_y = start_y + 1.;
+                }
+                let bounds = RectF::from_points(vec2f(left, start_y), vec2f(right, end_y));
+
+                let color = match hunk.status() {
+                    DiffHunkStatus::Added => diff_style.inserted,
+                    DiffHunkStatus::Modified => diff_style.modified,
+                    DiffHunkStatus::Removed => diff_style.deleted,
+                };
+
+                let border = Border {
+                    width: 1.,
+                    color: style.thumb.border.color,
+                    overlay: false,
+                    top: false,
+                    right: true,
+                    bottom: false,
+                    left: true,
+                };
+
+                scene.push_quad(Quad {
+                    bounds,
+                    background: Some(color),
+                    border,
+                    corner_radius: style.thumb.corner_radius,
+                })
+            }
+
             scene.push_quad(Quad {
                 bounds: thumb_bounds,
                 border: style.thumb.border,