feat: Use custom character to draw editor rulers

book/src/editor.md

@@ -42,6 +42,8 @@
 | `true-color` | Set to `true` to override automatic detection of terminal truecolor support in the event of a false negative | `false` |
 | `undercurl` | Set to `true` to override automatic detection of terminal undercurl support in the event of a false negative | `false` |
 | `rulers` | List of column positions at which to display the rulers. Can be overridden by language specific `rulers` in `languages.toml` file | `[]` |
+| `ruler-style` | `bg` displays the ruler as a background color, while `char` displays the configured `ruler-char` | `bg` |
+| `ruler-char` | Specifies the character used to display the rulers when `ruler-style` is `char` | `│` |
 | `bufferline` | Renders a line at the top of the editor displaying open buffers. Can be `always`, `never` or `multiple` (only shown if more than one buffer is in use) | `never` |
 | `color-modes` | Whether to color the mode indicator with different colors depending on the mode itself | `false` |
 | `text-width` | Maximum line length. Used for the `:reflow` command and soft-wrapping if `soft-wrap.wrap-at-text-width` is set | `80` |

book/src/themes.md

@@ -307,6 +307,7 @@ These scopes are used for theming the editor interface:
 | `ui.text.inactive`                | Same as `ui.text` but when the text is inactive (e.g. suggestions)                             |
 | `ui.text.info`                    | The key: command text in `ui.popup.info` boxes                                                 |
 | `ui.virtual.ruler`                | Ruler columns (see the [`editor.rulers` config][editor-section])                               |
+| `ui.virtual.ruler.char`           | Ruler columns, ([only if `editor.ruler-char` is set][editor-section]                           |
 | `ui.virtual.whitespace`           | Visible whitespace characters                                                                  |
 | `ui.virtual.indent-guide`         | Vertical indent width guides                                                                   |
 | `ui.virtual.inlay-hint`           | Default style for inlay hints of all kinds                                                     |

helix-term/src/ui/editor.rs

@@ -24,7 +24,7 @@ use helix_core::{
 use helix_view::{
     annotations::diagnostics::DiagnosticFilter,
     document::{Mode, SavePoint, SCRATCH_BUFFER_NAME},
-    editor::{CompleteAction, CursorShapeConfig},
+    editor::{CompleteAction, CursorShapeConfig, RulerStyle},
     graphics::{Color, CursorKind, Modifier, Rect, Style},
     input::{KeyEvent, MouseButton, MouseEvent, MouseEventKind},
     keyboard::{KeyCode, KeyModifiers},
@@ -201,6 +201,9 @@ impl EditorView {
             inline_diagnostic_config,
             config.end_of_line_diagnostics,
         ));
+
+        Self::render_rulers(editor, doc, view, inner, surface, theme);
+
         render_document(
             surface,
             inner,
@@ -212,7 +215,6 @@ impl EditorView {
             theme,
             decorations,
         );
-        Self::render_rulers(editor, doc, view, inner, surface, theme);
 
         // if we're not at the edge of the screen, draw a right border
         if viewport.right() != view.area.right() {
@@ -252,8 +254,16 @@ impl EditorView {
         theme: &Theme,
     ) {
         let editor_rulers = &editor.config().rulers;
+        let ruler_style = &editor.config().ruler_style;
+        let ruler_char = editor.config().ruler_char.to_string();
+
+        let theme_key = match ruler_style {
+            RulerStyle::Bg => "ui.virtual.ruler",
+            RulerStyle::Char => "ui.virtual.ruler.char",
+        };
+
         let ruler_theme = theme
-            .try_get("ui.virtual.ruler")
+            .try_get(theme_key)
             .unwrap_or_else(|| Style::default().bg(Color::Red));
 
         let rulers = doc
@@ -270,7 +280,18 @@ impl EditorView {
             .filter_map(|ruler| ruler.checked_sub(1 + view_offset.horizontal_offset as u16))
             .filter(|ruler| ruler < &viewport.width)
             .map(|ruler| viewport.clip_left(ruler).with_width(1))
-            .for_each(|area| surface.set_style(area, ruler_theme))
+            .for_each(|area| {
+                match ruler_style {
+                    RulerStyle::Bg => {
+                        surface.set_style(area, ruler_theme);
+                    }
+                    RulerStyle::Char => {
+                        for y in area.y..area.height {
+                            surface.set_string(area.x, y, &ruler_char, ruler_theme);
+                        }
+                    }
+                }
+            })
     }
 
     fn viewport_byte_range(

helix-view/src/editor.rs

@@ -314,6 +314,10 @@ pub struct Config {
     pub terminal: Option<TerminalConfig>,
     /// Column numbers at which to draw the rulers. Defaults to `[]`, meaning no rulers.
     pub rulers: Vec<u16>,
+    /// Set to `bg` to display rulers with background color (default) or `char` to use character from `ruler-char`.
+    pub ruler_style: RulerStyle,
+    /// Character used to draw the rulers when specified
+    pub ruler_char: char,
     #[serde(default)]
     pub whitespace: WhitespaceConfig,
     /// Persistently display open buffers along the top
@@ -636,6 +640,17 @@ impl Default for CursorShapeConfig {
     }
 }
 
+/// ruler render style
+#[derive(Debug, Default, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "kebab-case")]
+pub enum RulerStyle {
+    /// Render rulers with background color
+    #[default]
+    Bg,
+    /// Render rulers with character from `ruler-char`
+    Char,
+}
+
 /// bufferline render modes
 #[derive(Debug, Default, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case")]
@@ -963,6 +978,8 @@ impl Default for Config {
             lsp: LspConfig::default(),
             terminal: get_terminal_provider(),
             rulers: Vec::new(),
+            ruler_style: RulerStyle::default(),
+            ruler_char: '│',
             whitespace: WhitespaceConfig::default(),
             bufferline: BufferLine::default(),
             indent_guides: IndentGuidesConfig::default(),