feat: render bufferline separator

Closes #11372

helix-term/src/ui/editor.rs

@@ -615,7 +615,7 @@ pub fn render_bufferline(editor: &Editor, viewport: Rect, surface: &mut Surface)
         let mut x = viewport.x;
         let current_doc = view!(editor).doc;
 
-        for doc in editor.documents() {
+        for (idx, doc) in editor.documents().enumerate() {
             let fname = doc
                 .path()
                 .unwrap_or(&scratch)
@@ -630,6 +630,16 @@ pub fn render_bufferline(editor: &Editor, viewport: Rect, surface: &mut Surface)
                 bufferline_inactive
             };
 
+            // Render the separator before the text if the current document is not first.
+            if idx > 0 {
+                let used_width = viewport.x.saturating_sub(x);
+                let rem_width = surface.area.width.saturating_sub(used_width);
+                let sep = &editor.config().bufferline.separator;
+                x = surface
+                    .set_stringn(x, viewport.y, sep, rem_width as usize, bufferline_inactive)
+                    .0;
+            }
+
             let text = format!(" {}{} ", fname, if doc.is_modified() { "[+]" } else { "" });
             let used_width = viewport.x.saturating_sub(x);
             let rem_width = surface.area.width.saturating_sub(used_width);
@@ -1479,10 +1489,10 @@ fn render(&mut self, area: Rect, surface: &mut Surface, cx: &mut Context) {
         let config = cx.editor.config();
 
         // check if bufferline should be rendered
-        use helix_view::editor::BufferLine;
+        use helix_view::editor::BufferLineRenderMode;
-        let use_bufferline = match config.bufferline {
+        let use_bufferline = match config.bufferline.render_mode {
-            BufferLine::Always => true,
+            BufferLineRenderMode::Always => true,
-            BufferLine::Multiple if cx.editor.documents.len() > 1 => true,
+            BufferLineRenderMode::Multiple if cx.editor.documents.len() > 1 => true,
             _ => false,
         };
 

helix-view/src/editor.rs

@@ -299,6 +299,8 @@ pub struct Config {
     /// Whether to display infoboxes. Defaults to true.
     pub auto_info: bool,
     pub file_picker: FilePickerConfig,
+    /// Configuration of the bufferline
+    pub bufferline: BufferLineConfig,
     /// Configuration of the statusline elements
     pub statusline: StatusLineConfig,
     /// Shape for cursor in each mode
@@ -316,8 +318,6 @@ pub struct Config {
     pub rulers: Vec<u16>,
     #[serde(default)]
     pub whitespace: WhitespaceConfig,
-    /// Persistently display open buffers along the top
-    pub bufferline: BufferLine,
     /// Vertical indent width guides.
     pub indent_guides: IndentGuidesConfig,
     /// Whether to color modes with different colors. Defaults to `false`.
@@ -458,6 +458,35 @@ pub struct SearchConfig {
     pub wrap_around: bool,
 }
 
+/// bufferline render modes
+#[derive(Debug, Default, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "kebab-case")]
+pub enum BufferLineRenderMode {
+    /// Don't render bufferline
+    #[default]
+    Never,
+    /// Always render
+    Always,
+    /// Only if multiple buffers are open
+    Multiple,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "kebab-case", default, deny_unknown_fields)]
+pub struct BufferLineConfig {
+    pub render_mode: BufferLineRenderMode,
+    pub separator: String,
+}
+
+impl Default for BufferLineConfig {
+    fn default() -> Self {
+        Self {
+            render_mode: BufferLineRenderMode::default(),
+            separator: String::from("│"),
+        }
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case", default, deny_unknown_fields)]
 pub struct StatusLineConfig {
@@ -633,19 +662,6 @@ fn default() -> Self {
     }
 }
 
-/// bufferline render modes
-#[derive(Debug, Default, Clone, PartialEq, Eq, Serialize, Deserialize)]
-#[serde(rename_all = "kebab-case")]
-pub enum BufferLine {
-    /// Don't render bufferline
-    #[default]
-    Never,
-    /// Always render
-    Always,
-    /// Only if multiple buffers are open
-    Multiple,
-}
-
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case")]
 pub enum LineNumber {
@@ -952,6 +968,7 @@ fn default() -> Self {
             completion_trigger_len: 2,
             auto_info: true,
             file_picker: FilePickerConfig::default(),
+            bufferline: BufferLineConfig::default(),
             statusline: StatusLineConfig::default(),
             cursor_shape: CursorShapeConfig::default(),
             true_color: false,
@@ -961,7 +978,6 @@ fn default() -> Self {
             terminal: get_terminal_provider(),
             rulers: Vec::new(),
             whitespace: WhitespaceConfig::default(),
-            bufferline: BufferLine::default(),
             indent_guides: IndentGuidesConfig::default(),
             color_modes: false,
             soft_wrap: SoftWrap {