From f0ce62ead884a33b65868efa6702102d2481e158 Mon Sep 17 00:00:00 2001
From: JonasKaplan <94881921+JonasKaplan@users.noreply.github.com>
Date: Mon, 9 Jun 2025 16:48:49 -0400
Subject: [PATCH] editor: Add trailing whitespace rendering (#32329)

Closes #5237

- Adds "trailing" option for "show_whitespaces" in settings.json
- Supports importing this setting from vscode

The option in question will render only whitespace characters that
appear after every non-whitespace character in a given line.

Release Notes:

- Added trailing whitespace rendering
---
 crates/editor/src/element.rs             | 11 +++++++++++
 crates/language/src/language_settings.rs |  5 ++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/crates/editor/src/element.rs b/crates/editor/src/element.rs
index e5a0eb616e..52101f35fd 100644
--- a/crates/editor/src/element.rs
+++ b/crates/editor/src/element.rs
@@ -7329,6 +7329,17 @@ impl LineWithInvisibles {
                 paint(window, cx);
             }),
 
+            ShowWhitespaceSetting::Trailing => {
+                let mut previous_start = self.len;
+                for ([start, end], paint) in invisible_iter.rev() {
+                    if previous_start != end {
+                        break;
+                    }
+                    previous_start = start;
+                    paint(window, cx);
+                }
+            }
+
             // For a whitespace to be on a boundary, any of the following conditions need to be met:
             // - It is a tab
             // - It is adjacent to an edge (start or end)
diff --git a/crates/language/src/language_settings.rs b/crates/language/src/language_settings.rs
index daaf4ef35d..6793329b61 100644
--- a/crates/language/src/language_settings.rs
+++ b/crates/language/src/language_settings.rs
@@ -765,6 +765,8 @@ pub enum ShowWhitespaceSetting {
     /// - It is adjacent to an edge (start or end)
     /// - It is adjacent to a whitespace (left or right)
     Boundary,
+    /// Draw whitespaces only after non-whitespace characters.
+    Trailing,
 }
 
 /// Controls which formatter should be used when formatting code.
@@ -1452,7 +1454,8 @@ impl settings::Settings for AllLanguageSettings {
         vscode.bool_setting("editor.inlineSuggest.enabled", &mut d.show_edit_predictions);
         vscode.enum_setting("editor.renderWhitespace", &mut d.show_whitespaces, |s| {
             Some(match s {
-                "boundary" | "trailing" => ShowWhitespaceSetting::Boundary,
+                "boundary" => ShowWhitespaceSetting::Boundary,
+                "trailing" => ShowWhitespaceSetting::Trailing,
                 "selection" => ShowWhitespaceSetting::Selection,
                 "all" => ShowWhitespaceSetting::All,
                 _ => ShowWhitespaceSetting::None,