feat: relative numbers

helix-term/src/ui/editor.rs

@@ -17,6 +17,7 @@ use helix_core::{
 };
 use helix_view::{
     document::Mode,
+    editor::LineNumber,
     graphics::{CursorKind, Modifier, Rect, Style},
     info::Info,
     input::KeyEvent,
@@ -71,6 +72,7 @@ impl EditorView {
         theme: &Theme,
         is_focused: bool,
         loader: &syntax::Loader,
+        config: &helix_view::editor::Config,
     ) {
         let area = Rect::new(
             view.area.x + GUTTER_OFFSET,
@@ -79,7 +81,7 @@ impl EditorView {
             view.area.height.saturating_sub(1),
         ); // - 1 for statusline
 
-        self.render_buffer(doc, view, area, surface, theme, is_focused, loader);
+        self.render_buffer(doc, view, area, surface, theme, is_focused, loader, config);
 
         // if we're not at the edge of the screen, draw a right border
         if viewport.right() != view.area.right() {
@@ -115,6 +117,7 @@ impl EditorView {
         theme: &Theme,
         is_focused: bool,
         loader: &syntax::Loader,
+        config: &helix_view::editor::Config,
     ) {
         let text = doc.text().slice(..);
 
@@ -358,7 +361,16 @@ impl EditorView {
             let line_number_text = if line == last_line && !draw_last {
                 "    ~".into()
             } else {
-                format!("{:>5}", line + 1)
+                match config.line_number {
+                    LineNumber::Absolute => format!("{:>5}", line + 1),
+                    LineNumber::Relative => {
+                        // TODO: Put char_to_line out of the loop
+                        let current_line = doc.text().char_to_line(selections.primary().anchor);
+                        let relative_line =
+                            ((current_line as isize) - (line as isize)).abs() as usize;
+                        format!("{:>5}", relative_line)
+                    }
+                }
             };
             surface.set_stringn(
                 viewport.x + 1 - GUTTER_OFFSET,
@@ -925,6 +937,7 @@ impl Component for EditorView {
                 &cx.editor.theme,
                 is_focused,
                 loader,
+                &cx.editor.config,
             );
         }
 

helix-view/src/editor.rs

@@ -29,6 +29,18 @@ pub struct Config {
     pub scroll_lines: isize,
     /// Mouse support. Defaults to true.
     pub mouse: bool,
+    /// Line number mode.
+    pub line_number: LineNumber,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+#[serde(rename_all = "kebab-case")]
+pub enum LineNumber {
+    /// Show absolute line number
+    Absolute,
+
+    /// Show relative line number to the primary cursor
+    Relative,
 }
 
 impl Default for Config {
@@ -37,6 +49,7 @@ impl Default for Config {
             scrolloff: 5,
             scroll_lines: 3,
             mouse: true,
+            line_number: LineNumber::Absolute,
         }
     }
 }