git: Add hunk_style setting (#26038)

This PR adds the `git.hunk_style` setting, allowing setting an alternate
style for hunks – specifically the rendering of unstaged hunks.

It has 2 options:

- `transparent` (unstaged hunks are more transparent/less opaque than
staged hunks)
- `pattern (unstaged hunks are indicated by a visual pattern)

We'll possibly explore a VSCode-style "don't show staged hunks", but the
complexity it adds is a bit out of scope for now.

Transparent:

![CleanShot 2025-03-04 at 09 07
09@2x](https://github.com/user-attachments/assets/a74c4286-8264-48a2-bd58-0c582efb4e22)

Pattern:

![CleanShot 2025-03-04 at 09 10
12@2x](https://github.com/user-attachments/assets/4dd3040e-fb36-4670-9279-fcc7a4f12ced)

Release Notes:

- Git Beta: Added `git.hunk_style` setting to allow toggling between git
hunk visual styles.

assets/settings/default.json

@@ -837,7 +837,15 @@
       //
       // The minimum column number to show the inline blame information at
       // "min_column": 0
-    }
+    },
+    // How git hunks are displayed visually in the editor.
+    // This setting can take two values:
+    //
+    // 1. Show unstaged hunks with a transparent background (default):
+    //    "hunk_style": "transparent"
+    // 2. Show unstaged hunks with a pattern background:
+    //    "hunk_style": "pattern"
+    "hunk_style": "transparent"
   },
   // Configuration for how direnv configuration should be loaded. May take 2 values:
   // 1. Load direnv configuration using `direnv export json` directly.
@@ -851,15 +859,7 @@
     // Any addition to this list will be merged with the default list.
     // Globs are matched relative to the worktree root,
     // except when starting with a slash (/) or equivalent in Windows.
-    "disabled_globs": [
+    "disabled_globs": ["**/.env*", "**/*.pem", "**/*.key", "**/*.cert", "**/*.crt", "**/.dev.vars", "**/secrets.yml"],
-      "**/.env*",
-      "**/*.pem",
-      "**/*.key",
-      "**/*.cert",
-      "**/*.crt",
-      "**/.dev.vars",
-      "**/secrets.yml"
-    ],
     // When to show edit predictions previews in buffer.
     // This setting takes two possible values:
     // 1. Display predictions inline when there are no language server completions available.

crates/editor/src/element.rs

@@ -32,14 +32,15 @@ use collections::{BTreeMap, HashMap, HashSet};
 use file_icons::FileIcons;
 use git::{blame::BlameEntry, status::FileStatus, Oid};
 use gpui::{
-    anchored, deferred, div, fill, linear_color_stop, linear_gradient, outline, point, px, quad,
+    anchored, deferred, div, fill, linear_color_stop, linear_gradient, outline, pattern_slash,
-    relative, size, svg, transparent_black, Action, AnyElement, App, AvailableSpace, Axis, Bounds,
+    point, px, quad, relative, size, solid_background, svg, transparent_black, Action, AnyElement,
-    ClickEvent, ClipboardItem, ContentMask, Context, Corner, Corners, CursorStyle, DispatchPhase,
+    App, AvailableSpace, Axis, Bounds, ClickEvent, ClipboardItem, ContentMask, Context, Corner,
-    Edges, Element, ElementInputHandler, Entity, Focusable as _, FontId, GlobalElementId, Hitbox,
+    Corners, CursorStyle, DispatchPhase, Edges, Element, ElementInputHandler, Entity,
-    Hsla, InteractiveElement, IntoElement, Keystroke, Length, ModifiersChangedEvent, MouseButton,
+    Focusable as _, FontId, GlobalElementId, Hitbox, Hsla, InteractiveElement, IntoElement,
-    MouseDownEvent, MouseMoveEvent, MouseUpEvent, PaintQuad, ParentElement, Pixels, ScrollDelta,
+    Keystroke, Length, ModifiersChangedEvent, MouseButton, MouseDownEvent, MouseMoveEvent,
-    ScrollWheelEvent, ShapedLine, SharedString, Size, StatefulInteractiveElement, Style, Styled,
+    MouseUpEvent, PaintQuad, ParentElement, Pixels, ScrollDelta, ScrollWheelEvent, ShapedLine,
-    Subscription, TextRun, TextStyleRefinement, Window,
+    SharedString, Size, StatefulInteractiveElement, Style, Styled, Subscription, TextRun,
+    TextStyleRefinement, Window,
 };
 use itertools::Itertools;
 use language::{
@@ -54,7 +55,7 @@ use multi_buffer::{
     Anchor, ExcerptId, ExcerptInfo, ExpandExcerptDirection, MultiBufferPoint, MultiBufferRow,
     RowInfo,
 };
-use project::project_settings::{self, GitGutterSetting, ProjectSettings};
+use project::project_settings::{self, GitGutterSetting, GitHunkStyleSetting, ProjectSettings};
 use settings::Settings;
 use smallvec::{smallvec, SmallVec};
 use std::{
@@ -4346,7 +4347,7 @@ impl EditorElement {
         }
     }
 
-    fn paint_diff_hunks(layout: &mut EditorLayout, window: &mut Window, cx: &mut App) {
+    fn paint_gutter_diff_hunks(layout: &mut EditorLayout, window: &mut Window, cx: &mut App) {
         let is_light = cx.theme().appearance().is_light();
 
         if layout.display_hunks.is_empty() {
@@ -4416,10 +4417,19 @@ impl EditorElement {
                         background_color =
                             background_color.opacity(if is_light { 0.2 } else { 0.32 });
                     }
+
+                    // Flatten the background color with the editor color to prevent
+                    // elements below transparent hunks from showing through
+                    let flattened_background_color = cx
+                        .theme()
+                        .colors()
+                        .editor_background
+                        .blend(background_color);
+
                     window.paint_quad(quad(
                         hunk_bounds,
                         corner_radii,
-                        background_color,
+                        flattened_background_color,
                         Edges::default(),
                         transparent_black(),
                     ));
@@ -4547,7 +4557,7 @@ impl EditorElement {
                 )
             });
         if show_git_gutter {
-            Self::paint_diff_hunks(layout, window, cx)
+            Self::paint_gutter_diff_hunks(layout, window, cx)
         }
 
         let highlight_width = 0.275 * layout.position_map.line_height;
@@ -6711,15 +6721,16 @@ impl Element for EditorElement {
                         .update(cx, |editor, cx| editor.highlighted_display_rows(window, cx));
 
                     let is_light = cx.theme().appearance().is_light();
+                    let use_pattern = ProjectSettings::get_global(cx)
+                        .git
+                        .hunk_style
+                        .map_or(false, |style| matches!(style, GitHunkStyleSetting::Pattern));
 
                     for (ix, row_info) in row_infos.iter().enumerate() {
                         let Some(diff_status) = row_info.diff_status else {
                             continue;
                         };
 
-                        let staged_opacity = if is_light { 0.14 } else { 0.10 };
-                        let unstaged_opacity = 0.04;
-
                         let background_color = match diff_status.kind {
                             DiffHunkStatusKind::Added => cx.theme().colors().version_control_added,
                             DiffHunkStatusKind::Deleted => {
@@ -6730,15 +6741,34 @@ impl Element for EditorElement {
                                 continue;
                             }
                         };
-                        let background_color = if diff_status.has_secondary_hunk() {
+
-                            background_color.opacity(unstaged_opacity)
+                        let unstaged = diff_status.has_secondary_hunk();
+                        let hunk_opacity = if is_light { 0.16 } else { 0.12 };
+
+                        let staged_background =
+                            solid_background(background_color.opacity(hunk_opacity));
+                        let unstaged_background = if use_pattern {
+                            pattern_slash(
+                                background_color.opacity(hunk_opacity),
+                                window.rem_size().0 * 1.125, // ~18 by default
+                            )
                         } else {
-                            background_color.opacity(staged_opacity)
+                            solid_background(background_color.opacity(if is_light {
+                                0.08
+                            } else {
+                                0.04
+                            }))
+                        };
+
+                        let background = if unstaged {
+                            unstaged_background
+                        } else {
+                            staged_background
                         };
 
                         highlighted_rows
                             .entry(start_row + DisplayRow(ix as u32))
-                            .or_insert(background_color.into());
+                            .or_insert(background);
                     }
 
                     let highlighted_ranges = self.editor.read(cx).background_highlights_in_range(

crates/gpui/src/color.rs

@@ -670,6 +670,14 @@ pub fn pattern_slash(color: Hsla, thickness: f32) -> Background {
     }
 }
 
+/// Creates a solid background color.
+pub fn solid_background(color: impl Into<Hsla>) -> Background {
+    Background {
+        solid: color.into(),
+        ..Default::default()
+    }
+}
+
 /// Creates a LinearGradient background color.
 ///
 /// The gradient line's angle of direction. A value of `0.` is equivalent to to top; increasing values rotate clockwise from there.

crates/project/src/project_settings.rs

@@ -168,6 +168,10 @@ pub struct GitSettings {
     ///
     /// Default: on
     pub inline_blame: Option<InlineBlameSettings>,
+    /// How hunks are displayed visually in the editor.
+    ///
+    /// Default: transparent
+    pub hunk_style: Option<GitHunkStyleSetting>,
 }
 
 impl GitSettings {
@@ -200,6 +204,16 @@ impl GitSettings {
     }
 }
 
+#[derive(Clone, Copy, Debug, Default, Serialize, Deserialize, JsonSchema)]
+#[serde(rename_all = "snake_case")]
+pub enum GitHunkStyleSetting {
+    /// Show unstaged hunks with a transparent background
+    #[default]
+    Transparent,
+    /// Show unstaged hunks with a pattern background
+    Pattern,
+}
+
 #[derive(Clone, Copy, Debug, Default, Serialize, Deserialize, JsonSchema)]
 #[serde(rename_all = "snake_case")]
 pub enum GitGutterSetting {