From 6ebb9418a09ba09ed0f20878224a77946fb75499 Mon Sep 17 00:00:00 2001
From: Jason Lee <huacnlee@gmail.com>
Date: Fri, 24 Oct 2025 20:18:30 +0800
Subject: [PATCH] editor: Use `measure_indent_width` for indent guides width.
 (#1428)

Continue #1426, this changes I was forgotten to push before #1426
merged.
---
 crates/story/examples/editor.rs |  8 ++++---
 crates/ui/src/input/element.rs  |  5 ++--
 crates/ui/src/input/indent.rs   | 41 +++++++++++++++++++++++++++------
 3 files changed, 42 insertions(+), 12 deletions(-)

diff --git a/crates/story/examples/editor.rs b/crates/story/examples/editor.rs
index 37af4d59..bb7cc1d9 100644
--- a/crates/story/examples/editor.rs
+++ b/crates/story/examples/editor.rs
@@ -9,7 +9,7 @@ use std::{
 use anyhow::Ok;
 use gpui::{prelude::FluentBuilder, *};
 use gpui_component::{
-    ActiveTheme, ContextModal, IconName, IndexPath, Selectable, Sizable,
+    ActiveTheme, ContextModal, IconName, IndexPath, Sizable,
     button::{Button, ButtonVariants as _},
     dropdown::{Dropdown, DropdownEvent, DropdownState},
     h_flex,
@@ -998,16 +998,18 @@ impl Render for Example {
                                         Button::new("soft-wrap")
                                             .ghost()
                                             .xsmall()
+                                            .when(self.soft_wrap, |this| this.icon(IconName::Check))
                                             .label("Soft Wrap")
-                                            .selected(self.soft_wrap)
                                             .on_click(cx.listener(Self::toggle_soft_wrap))
                                     })
                                     .child({
                                         Button::new("indent-guides")
                                             .ghost()
                                             .xsmall()
+                                            .when(self.indent_guides, |this| {
+                                                this.icon(IconName::Check)
+                                            })
                                             .label("Indent Guides")
-                                            .selected(self.indent_guides)
                                             .on_click(cx.listener(Self::toggle_indent_guides))
                                     }),
                             )
diff --git a/crates/ui/src/input/element.rs b/crates/ui/src/input/element.rs
index b7c5e880..703d9889 100644
--- a/crates/ui/src/input/element.rs
+++ b/crates/ui/src/input/element.rs
@@ -1084,7 +1084,8 @@ impl Element for TextElement {
         };
 
         let hover_definition_hitbox = self.layout_hover_definition_hitbox(state, window, cx);
-        let indent_guides_path = self.layout_indent_guides(state, &last_layout);
+        let indent_guides_path =
+            self.layout_indent_guides(state, &last_layout, &text_style, window);
 
         PrepaintState {
             bounds,
@@ -1194,7 +1195,7 @@ impl Element for TextElement {
 
         // Paint indent guides
         if let Some(path) = prepaint.indent_guides_path.take() {
-            window.paint_path(path, cx.theme().secondary);
+            window.paint_path(path, cx.theme().border.opacity(0.85));
         }
 
         // Paint selections
diff --git a/crates/ui/src/input/indent.rs b/crates/ui/src/input/indent.rs
index 8183f176..ba0519e3 100644
--- a/crates/ui/src/input/indent.rs
+++ b/crates/ui/src/input/indent.rs
@@ -1,5 +1,6 @@
 use gpui::{
-    point, px, Context, EntityInputHandler as _, Path, PathBuilder, Pixels, SharedString, Window,
+    point, px, Context, EntityInputHandler as _, Hsla, Path, PathBuilder, Pixels, SharedString,
+    TextRun, TextStyle, Window,
 };
 use ropey::RopeSlice;
 
@@ -80,21 +81,46 @@ impl InputMode {
 }
 
 impl TextElement {
+    /// Measure the indent width in pixels for given column count.
+    fn measure_indent_width(&self, style: &TextStyle, column: usize, window: &Window) -> Pixels {
+        let font_size = style.font_size.to_pixels(window.rem_size());
+        let layout = window.text_system().shape_line(
+            SharedString::from(" ".repeat(column)),
+            font_size,
+            &[TextRun {
+                len: column,
+                font: style.font(),
+                color: Hsla::default(),
+                background_color: None,
+                strikethrough: None,
+                underline: None,
+            }],
+            None,
+        );
+
+        layout.width
+    }
+
     pub(super) fn layout_indent_guides(
         &self,
         state: &InputState,
         last_layout: &LastLayout,
+        text_style: &TextStyle,
+        window: &mut Window,
     ) -> Option<Path<Pixels>> {
         if !state.mode.has_indent_guides() {
             return None;
         }
 
+        let indent_width =
+            self.measure_indent_width(text_style, state.mode.tab_size().tab_size, window);
+
         let tab_size = state.mode.tab_size();
         let line_height = last_layout.line_height;
         let visible_range = last_layout.visible_range.clone();
         let mut builder = PathBuilder::stroke(px(1.));
         let mut offset_y =
-            last_layout.visible_top + state.scroll_handle.offset().y + (line_height * 2 - px(3.));
+            last_layout.visible_top + state.scroll_handle.offset().y + (line_height * 2 - px(3.5));
         let mut last_indents = vec![];
         for ix in visible_range {
             let line = state.text.slice_line(ix);
@@ -103,12 +129,13 @@ impl TextElement {
             if line.len() > 0 {
                 let indent_count = tab_size.indent_count(&line);
                 for offset in (0..indent_count).step_by(tab_size.tab_size) {
-                    let mut pos = line_layout
-                        .position_for_index(offset, line_height)
-                        .unwrap_or(point(px(0.), px(0.)));
+                    let x = if indent_count > 0 {
+                        indent_width * offset as f32 / tab_size.tab_size as f32
+                    } else {
+                        px(0.)
+                    };
 
-                    pos.x += last_layout.line_number_width;
-                    pos.y += offset_y;
+                    let pos = point(x + last_layout.line_number_width, offset_y);
 
                     builder.move_to(pos);
                     builder.line_to(point(pos.x, pos.y + line_height));