From 2924427702da918a524fd0c480c9e74a57812ec9 Mon Sep 17 00:00:00 2001
From: Jakob Schikowski <jakob.schikowski@gmx.de>
Date: Tue, 7 Feb 2023 00:20:56 +0100
Subject: [PATCH] Show code point in statusline

---
 book/src/configuration.md       |  1 +
 helix-term/src/ui/statusline.rs | 39 +++++++++++++++++++++++++++++++++
 helix-view/src/editor.rs        |  3 +++
 3 files changed, 43 insertions(+)

diff --git a/book/src/configuration.md b/book/src/configuration.md
index 7514a3d0fcc3..7db1d210cacf 100644
--- a/book/src/configuration.md
+++ b/book/src/configuration.md
@@ -108,6 +108,7 @@ The following statusline elements can be configured:
 | `primary-selection-length` | The number of characters currently in primary selection |
 | `position` | The cursor position |
 | `position-percentage` | The cursor position as a percentage of the total number of lines |
+| `code-point` | The code point under the cursor |
 | `separator` | The string defined in `editor.statusline.separator` (defaults to `"│"`) |
 | `spacer` | Inserts a space between elements (multiple/contiguous spacers may be specified) |
 
diff --git a/helix-term/src/ui/statusline.rs b/helix-term/src/ui/statusline.rs
index a25b4540d1f9..a619cb9ffbe2 100644
--- a/helix-term/src/ui/statusline.rs
+++ b/helix-term/src/ui/statusline.rs
@@ -153,6 +153,7 @@ where
         helix_view::editor::StatusLineElement::Position => render_position,
         helix_view::editor::StatusLineElement::PositionPercentage => render_position_percentage,
         helix_view::editor::StatusLineElement::TotalLineNumbers => render_total_line_numbers,
+        helix_view::editor::StatusLineElement::CodePoint => render_code_point,
         helix_view::editor::StatusLineElement::Separator => render_separator,
         helix_view::editor::StatusLineElement::Spacer => render_spacer,
     }
@@ -447,6 +448,22 @@ where
     write(context, title, None);
 }
 
+fn render_code_point<F>(context: &mut RenderContext, write: F)
+where
+    F: Fn(&mut RenderContext, String, Option<Style>) + Copy,
+{
+    let text = context.doc.text();
+    let cursor = context
+        .doc
+        .selection(context.view.id)
+        .primary()
+        .cursor(text.slice(..));
+
+    if let Some(c) = text.get_char(cursor) {
+        write(context, char_to_code_point(c), None)
+    }
+}
+
 fn render_separator<F>(context: &mut RenderContext, write: F)
 where
     F: Fn(&mut RenderContext, String, Option<Style>) + Copy,
@@ -466,3 +483,25 @@ where
 {
     write(context, String::from(" "), None);
 }
+
+fn char_to_code_point(c: char) -> String {
+    // Uses "U+" notation as described here:
+    // https://en.wikipedia.org/wiki/Unicode#Architecture_and_terminology
+    format!("U+{:04X}", c as u32)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::char_to_code_point;
+
+    #[test]
+    fn char_to_code_point_examples() {
+        assert_eq!("U+0000", &char_to_code_point('\u{0}'));
+        assert_eq!("U+000F", &char_to_code_point('\u{F}'));
+        assert_eq!("U+00FF", &char_to_code_point('\u{FF}'));
+        assert_eq!("U+0FFF", &char_to_code_point('\u{FFF}'));
+        assert_eq!("U+FFFF", &char_to_code_point('\u{FFFF}'));
+        assert_eq!("U+FFFFF", &char_to_code_point('\u{FFFFF}'));
+        assert_eq!("U+10FFFF", &char_to_code_point('\u{10FFFF}'));
+    }
+}
diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index 042f5bdb4269..ddfa130006b6 100644
--- a/helix-view/src/editor.rs
+++ b/helix-view/src/editor.rs
@@ -489,6 +489,9 @@ pub enum StatusLineElement {
     /// The total line numbers of the current file
     TotalLineNumbers,
 
+    /// The code point under the cursor
+    CodePoint,
+
     /// A single space
     Spacer,
 }