initial implementation of bufferline

book/src/configuration.md

@@ -46,6 +46,7 @@ hidden = false
 | `auto-info` | Whether to display infoboxes | `true` |
 | `true-color` | Set to `true` to override automatic detection of terminal truecolor 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. | `[]` |
+| `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) | `multiple` |
 | `color-modes` | Whether to color the mode indicator with different colors depending on the mode itself | `false` |
 
 ### `[editor.lsp]` Section

helix-term/src/ui/editor.rs

@@ -24,7 +24,7 @@ use helix_view::{
     keyboard::{KeyCode, KeyModifiers},
     Document, Editor, Theme, View,
 };
-use std::borrow::Cow;
+use std::{borrow::Cow, path::PathBuf};
 
 use crossterm::event::{Event, MouseButton, MouseEvent, MouseEventKind};
 use tui::buffer::Buffer as Surface;
@@ -136,7 +136,7 @@ impl EditorView {
             highlights,
             &editor.config(),
         );
-        Self::render_gutter(editor, doc, view, view.area, surface, theme, is_focused);
+        Self::render_gutter(editor, doc, view, area, surface, theme, is_focused);
         Self::render_rulers(editor, doc, view, inner, surface, theme);
 
         if is_focused {
@@ -582,6 +582,57 @@ impl EditorView {
         }
     }
 
+    /// Render bufferline at the top
+    pub fn render_bufferline(editor: &Editor, viewport: Rect, surface: &mut Surface) {
+        let scratch = PathBuf::from(SCRATCH_BUFFER_NAME); // default filename to use for scratch buffer
+        surface.clear_with(
+            viewport,
+            editor
+                .theme
+                .try_get("ui.bufferline.background")
+                .unwrap_or_else(|| editor.theme.get("ui.statusline")),
+        );
+        let mut len = 0usize;
+        for doc in editor.documents() {
+            let fname = doc
+                .path()
+                .unwrap_or(&scratch)
+                .file_name()
+                .unwrap_or_default()
+                .to_str()
+                .unwrap_or_default();
+
+            let style = if view!(editor).doc == doc.id() {
+                editor
+                    .theme
+                    .try_get("ui.bufferline.active")
+                    .unwrap_or_else(|| editor.theme.get("ui.background"))
+            } else {
+                editor
+                    .theme
+                    .try_get("ui.bufferline")
+                    .unwrap_or_else(|| editor.theme.get("ui.statusline"))
+            };
+
+            let text = format!(" {}{} ", fname, if doc.is_modified() { "[+]" } else { "" });
+            let offset = text.len();
+
+            surface.set_stringn(
+                1 + viewport.x + len as u16,
+                viewport.y,
+                text,
+                surface.area.width as usize,
+                style,
+            );
+
+            len += offset;
+
+            if len > surface.area.width as usize {
+                break;
+            }
+        }
+    }
+
     pub fn render_gutter(
         editor: &Editor,
         doc: &Document,
@@ -1371,8 +1422,27 @@ impl Component for EditorView {
         // clear with background color
         surface.set_style(area, cx.editor.theme.get("ui.background"));
         let config = cx.editor.config();
+
+        // check if bufferline should be rendered
+        use helix_view::editor::BufferLine;
+        let use_bufferline = match config.bufferline {
+            BufferLine::Always => true,
+            BufferLine::Multiple if cx.editor.documents.len() > 1 => true,
+            _ => false,
+        };
+
+        // -1 for commandline and -1 for bufferline
+        let mut editor_area = area.clip_bottom(1);
+        if use_bufferline {
+            editor_area = editor_area.clip_top(1);
+        }
+
         // if the terminal size suddenly changed, we need to trigger a resize
-        cx.editor.resize(area.clip_bottom(1)); // -1 from bottom for commandline
+        cx.editor.resize(editor_area);
+
+        if use_bufferline {
+            Self::render_bufferline(cx.editor, area.with_height(1), surface);
+        }
 
         for (view, is_focused) in cx.editor.tree.views() {
             let doc = cx.editor.document(view.doc).unwrap();

helix-view/src/editor.rs

@@ -159,6 +159,8 @@ 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`.
@@ -234,6 +236,24 @@ impl Default for CursorShapeConfig {
     }
 }
 
+/// bufferline render modes
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "kebab-case")]
+pub enum BufferLine {
+    /// Don't render bufferline
+    Never,
+    /// Always render
+    Always,
+    /// Only if multiple buffers are open
+    Multiple,
+}
+
+impl Default for BufferLine {
+    fn default() -> Self {
+        BufferLine::Never
+    }
+}
+
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case")]
 pub enum LineNumber {
@@ -415,6 +435,7 @@ impl Default for Config {
             lsp: LspConfig::default(),
             rulers: Vec::new(),
             whitespace: WhitespaceConfig::default(),
+            bufferline: BufferLine::default(),
             indent_guides: IndentGuidesConfig::default(),
             color_modes: false,
         }