From 92ae31925f9e8d24e518f1cb99052052c0c62dfe Mon Sep 17 00:00:00 2001
From: David Vogt <david.vogt@adfinis.com>
Date: Tue, 26 Sep 2023 15:17:45 +0200
Subject: [PATCH] feat: tree sitter path

This adds a "tree-sitter-path" element to the possible status lines, which
is useful for large code bases where you cannot see the beginning of the current
function/class/type etc.

Suggested config:

```
[editor.statusline]
center = ["tree-sitter-path"]
```
---
 helix-term/src/ui/statusline.rs | 50 +++++++++++++++++++++++++++++++++
 helix-view/src/editor.rs        |  3 ++
 2 files changed, 53 insertions(+)

diff --git a/helix-term/src/ui/statusline.rs b/helix-term/src/ui/statusline.rs
index 7437cbd07..6dd2b0433 100644
--- a/helix-term/src/ui/statusline.rs
+++ b/helix-term/src/ui/statusline.rs
@@ -158,6 +158,7 @@ where
         }
         helix_view::editor::StatusLineElement::Position => render_position,
         helix_view::editor::StatusLineElement::PositionPercentage => render_position_percentage,
+        helix_view::editor::StatusLineElement::TreeSitterPath => render_tree_sitter_path,
         helix_view::editor::StatusLineElement::TotalLineNumbers => render_total_line_numbers,
         helix_view::editor::StatusLineElement::Separator => render_separator,
         helix_view::editor::StatusLineElement::Spacer => render_spacer,
@@ -381,6 +382,55 @@ where
     }
 }
 
+fn render_tree_sitter_path<F>(context: &mut RenderContext, write: F)
+where
+    F: Fn(&mut RenderContext, String, Option<Style>) + Copy,
+{
+    if let Some(syntax) = context.doc.syntax() {
+        let text = context.doc.text().slice(..);
+
+        let pos = text.char_to_byte(
+            context
+                .doc
+                .selection(context.view.id)
+                .primary()
+                .cursor(text),
+        );
+        let mut node = match syntax
+            .tree()
+            .root_node()
+            .descendant_for_byte_range(pos, pos)
+        {
+            Some(node) => node,
+            None => return,
+        };
+
+        let mut scopes = Vec::new();
+
+        loop {
+            match node.child_by_field_name("name") {
+                Some(child) => {
+                    let child_id = text.byte_slice(child.byte_range());
+                    scopes.push(format!("\u{203A}{}", child_id));
+                }
+                None => {}
+            }
+
+            match node.parent() {
+                Some(parent) => {
+                    node = parent;
+                }
+                None => {
+                    break;
+                }
+            }
+        }
+
+        scopes.reverse();
+        write(context, scopes.join(""), None);
+    }
+}
+
 fn render_file_line_ending<F>(context: &mut RenderContext, write: F)
 where
     F: Fn(&mut RenderContext, String, Option<Style>) + Copy,
diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index ef4918539..9806c8fa3 100644
--- a/helix-view/src/editor.rs
+++ b/helix-view/src/editor.rs
@@ -557,6 +557,9 @@ pub enum StatusLineElement {
     /// The cursor position as a percent of the total file
     PositionPercentage,
 
+    // Path of tree sitter elements
+    TreeSitterPath,
+
     /// The total line numbers of the current file
     TotalLineNumbers,